SRT Chat Sessions

From 2008 to 2011, I attended all of the SRT Engineers' Chat Sessions on various MOPAR forums and have recorded them. I found the comments of the engineers to be very informative. For those of you who didn't attend these sessions, this condensed thread should be invaluable to you in understanding the engineering of your Challengers.

Here are some of their responses that might interest you. from the 9/21/11 SRT Chat Session (1 of 2):

Why can’t the Challengers come with a convenience spare tire in the car? The mini compressor is useless.
Why can’t the after market make tuners for the 392?Challengers?

1) The mini-spare does not clear the front brake caliper. Looking at the frequency of needing a spare tire these days and the fact that everyone has a cellphone to call for a tow, it is not worth carrying the extra weight. Feel free to install the mini-spare and jack out of the regular Challenger. If you get a flat on the front, put the minispare on the rear, and put your good rear tire on the front.
2) They haven't broken the code, yet. It is a rolling code, like your garage door opener!

On some of the forums they are saying that the new 392 intake manifold has a built in oil separator/ catch can. I believe they are mistaking the PCV system for a factory catch can. Can you please clear this up. I am not talking about if a catch can is good or not but is there a built in catch can in the intake manifold. Thanks for your time. My wife loves the new challenger and is buying me a 2012. How could a guy be more lucky.

You’re correct, it’s the PCV oil/air separator and not a catch can. The flow path is from the passenger cylinder head into the separator and then back into the intake. Through the separator, you'll find a series of baffles that work with gravity to separate the oil from the air.

Where does the oil go? Is the waste oil still burned through the combustion chamber?

The oil separators pull the vast majority of the oil in the crank vapor out where it drains into the heads and then back into the crankcase through the head drain backs.

Another suggestion is to offer a Chrome or Chrome Clad Wheel option for the SRT8 Challenger.

Chrome clad wheels and performance wheels don't mix.

Have you ever considered building a "bare bones" SRT model no fancy hood ,leather, brembos, hid lights? Jjust a lighter less expensive go fast street car.

All the time.

How soon will Chrysler's Hemi-powered SRT vehicles have a Viper 6-speed transmission? Is there such a plan in the works?

The Challenger SRT8 has had the TR-6060 transmission (which is also in the Viper) since it launched in the 2008 model year.

I own a 2010 300C and was wondering is it possible to install the Brembo brakes from the SRT8 300? Will the stock 300C master cylinder and proportioning valve work with the Brembos? What other changes will be required?

Upgrading to a SRT brake components is a quagmire. The calipers won't even bolt up to the knuckles, which are SRT unique. On top of that, the ESC calibration is TOTALLY different, and your base ESC controller will ramp in way too much pressure to control the car. Same with ABS because the SRT brakes are significantly more effective. You really need a wrecked SRT to take the whole ABS system and front and rear knuckles off of. There is no prop valve on cars anymore. That is handled electronically via EBD.

Can you offer some insight as to why the exterior colors change so often and why some of the most popular colors are not offered any more in the Challenger SRT8 or is this a marketing question- hemi-orange, torred, detonator yellow, b5 blue, plum crazy, etc.

It's more of a marketing question, but we will give you an answer anyway. The colors you specified were brought out in limited production as a throw back to the colors of our muscle cars in the 60s and 70s. SRT vehicles are exclusive to begin with, but with special, limited run colors, you get a little more collectability and exclusivity.

Will a 6.4 production crankshaft fit in a 5.7 6.1 2003-2008 hemi?
I know the crankshaft toner ring has been changed since 2009.
Will the toner rings from earlier hemi bolt on a production 6.4 crankshaft?

The crank will physically fit..yes...however you'll crash valves without a reduction in valve lift. The Tone Rings have been changed...yes they are interchangeable...make sure you change your crank sensor too if you do that.

I love my new 2011 Challenger SRT8-392! But I am having one problem which after reading these boards, seems to be prevalent. My power steering sometimes loses power in low-speed parking maneuvers.
Had it to dealer a few times, but since it is a sporadic issue, & it can't be duplicated at the dealership (of course), nothing can be done! Why is this a common issue, & What should I do?

It seems that you have a power steering pump issue. Take the vehicle back to the dealer and have them replace the power steering pump AND flush the system.

I have a stock 2006 300 SRT8, and a 2010 challenger SRT8....if you had $500-1000 to spend, what would be the first mods you would do to increase horsepower/torque?

Nitrous. Don't run more than a 125 shot with plenty of fuel or you will knock the ring lands off the pistons. Make sure you get a bottle heater. But that's just my advice. I've had a 60 shot of nitrous on my Neon for 7 years.

HEMI 6.4L engine related questions:
1- What are the intake & exhaust ports sizes?

I: 54mm, E: 42mm

2- Why did you space the throttle body away from the intake manifold, when the 5.7L and 6.1L have their throttle body right next to the intake manifold?

Mostly packaging to give us the plenum entry we desired. With the triangle at the top of the front cover being so close, this was our only option. At SRT, we care about airflow.

3- Will the GC SRT suspensions and brakes fit into the Durango R/T?

Yes, if you by everything...springs, shocks, knuckles, controls arms, brakes, and ABS controller...

Why did you go one step colder on the 6.1L plugs? I have an 06 C SRT. Would a colder plug be any advantage for me?

Only if your doing power adders will they help you.

On aggressive cornering maneuvers the car exhibits post-apex steering effort increase (almost like lack of power assist) while unwinding steering angle/wheel. Increased effort is also accompanied by a type of grunt/low freq. short duration hum/sound. normal steering effort returns just before steering wheel & wheels are straight again. no understeer/oversteer present - (i.e. @ corner-speeds below threshold of tire adhesion). I've heard there may be some type of check valve that is closing in the rack.. does such a device exist in this design? Any ideas what may be causing this condition?

I would replace the pump. Sounds like it is weak and not handling the extra load.

Which of the "new and improved" suspension components would fit my '06 and make a noticeable difference? Will the 2011 SRT steering wheel fit earlier models?

See response for question number 2 for suspension components. 2011 steering wheel will mount onto prior models but wheel electronics will not function.

 

(2 of 2)

The 2011 Challenger ATX has some ridiculously fast shift times...200ms range. The trans has never been asked to shift so fast and also handle the torque of the 392 HEMI...so in order to keep the trans happy shifting that fast, we have to pull a considerable amount of torque.

Two suggestions:
1. for the Challenger, allow the rear seat headrests to fold down out of the way to improve visibility. Many of us never have back seat passengers and this would be a great feature. This would also allow the front seats to be moved back further when the rear seats backs are folded down when hauling something larger in the trunk.
2. Charger SRT8 - offer all-wheel-drive (AWD) like Porsche does on the 911 but don't raise the ride height like you do on the Charger R/T.

We built one AWD 300C SRT8 mule and it was slower than the RWD car due to the extra weight and interia. The traction advantage couldn't make it back up. Some of us rwd guys at SRT joke with the awd guys at SRT that awd is just an expensive solution to having the wrong tire on your car.

With the above frustration in mind, will the super charger that Chrysler/Dodge eventually puts on the 392, be stuck with a canned tune or will it be open to the aftermarket for custom tuning? Will there ever be a 426 SRT?

We haven't announced a supercharger for the 392, and we can't talk about potential future product, but thanks for asking, we appreciate the interest. For the other part of your post, we keep the information proprietary due to issues with warranty fraud.

What HP will the 392 fuel system support over stock? How much more fuel capacity is there between the previous model year's fuel system?

Fuel capacity is equal from previous years.

Can you specify, from experience, what the best conditions are to run any of the 2012 LX SRT cars at the drag strip? I'm interested to know things like optimal outside temperature, tire pressure, where to rev the engine to before leaving the tree, etc. And, in a Challenger with the 6 speed, should you just go from a dead stop? Or bring the revs to a certain range and dump the clutch? ESP on, off, or full off? What has given you the best results?

It really depends on conditions and traction. You need to experiment. Sometimes a brief brake torque to 1200 then go works well if there is enough grip. Don't brake torque it harder and stall the torque converter or the controller will reduce torque to not go over the trans torque limit. Otherwise, experiment with flat punching or squeezing depending on grip. On manuals, I prefer riding the clutch quite heavily from 3000-4000 rpm depending on grip. That is pretty hard on the clutch, though.

How big of a shot would you chance running in a new 392 running on race fuel?

125 shot. Risky, but you wanted to know what power adder I would put on for less than $1000. If I blew it up, I would just pull it and rebuild it.

Can I get SRT with beats system?

The 2012 SRT models have their own performance sound system. Here are the stats from our press kit:

An available 900-watt, 19-speaker premium SRT performance audio surround-sound system from Harman Kardon®. The system offers world premier innovation, featuring a 32-volt TPS (Tracking Power Supply) 12-channel Class D amplifier that delivers outstanding acoustics and brings multi-dimensional, quality sound for all interior occupants.

The new system uses GreenEdge® speaker and amplifier technology to offer superior sound quality and high Sound Pressure Level outputs with minimum energy consumption. GreenEdge amplifiers alone outperform traditional amplifier efficiency by up to 55 percent, representing a net efficiency of more than 90 percent in some cases. The speakers are tuned for maximum efficiency and perfectly matched to the amplifier output.
The system’s 19 GreenEdge high-efficiency speakers include:

Seven 3.5-inch Unity Coaxial mid-range speakers with seven integrated tweeters located in the front dash, rear doors and rear deck
Two 6 x 9-inch subwoofers located in the front doors
Two 6 x 9-inch subwoofers in the rear deck
One 10-inch subwoofer in the rear deck
Can you specify, from experience, what the best conditions are to run any of the 2012 LX SRT cars at the drag strip? I'm interested to know things like optimal outside temperature, tire pressure, where to rev the engine to before leaving the tree, etc.
And, in a Challenger with the 6 speed, should you just go from a dead stop? Or bring the revs to a certain range and dump the clutch? ESP on, off, or full off? What has given you the best results?

Partial off and full off are fine for the drag strip. Full on will cut torque and grab the rear brakes, slowing you down.

Any difference in the Nag1 between the 2010 SRT8 vs. 2012 srt8's?

The torque converter is brazed and the drive plate is shot peened to give them a bit more strength. Other than that they are functionally the same.

Heard the clutches are a larger diameter as well?

That's a negative.

Without discussing future product, is it possible that a turbocharger instead of a supercharger is up for consideration? Seems to me that using a supercharger would only be following suit with Chevy and Ford (something that Chrysler has not made a habit of doing). Why not follow the likes of AMG, M Power, and Porsche who have seen tremendous performance gains by use of smaller displacement and turbochargers? Is the cost simply too great? Just seems to me that aiming at the German competitors would be more advantageous.

As you noted, we can't talk about what we may or may not do in the future, but turbocharging and supercharging are always up for consideration. That's the best we can do on the future product front.

I have an 06 Magnum SRT and at 7,100 miles had to have the pads replaced by the dealer.... a few hundred miles later a HUGE break squeal. Taking it back to the dealer they told me my rotors were SHOT ~ I don't even drive mine hard; ONLY a few WOT take offs. Anyhow they put new "slotted" rotors and new pads again at 8,000 miles. My question: I currently have just turned 11,000 miles... should I be wary of having MORE brake problems?Secondly, my car had a HUGE lag at WOT take offs and between each gear. After having it checked out; was told my computer program was written on 4/20/05... Does this sound plausible to you all? Would you suggest having something rewritten?

If your brakes gave you problems without the slots, the problem is you are driving it too easy. The brakes are performance components and are designed to be used. Drive an SRT like and old lady, and she won't like it. There are a few calibration upgrades available for your car. Have the dealer flash them in. For brake squeal, make sure the copper paste from Brembo is being used between the pads and pistons.

You must be talking about 1/4 mile times, because the 2010 Jeep SRT8 would beat the Challenger, 300, and Charger SRT8's in that year. At the SRT Track Experience in the 1/8 mile runs a couple of years ago the Jeep beat all the other SRT8's consistently!

Not past 75mph. The Jeep was developed from the get go with the AWD system, and it has better grip because of the wider tires.

Are the new Charger SRT8/300SRT8/GCSRT8 being used at the SRT Experience track days yet?

We don't believe the SRT Track Experience folks have taken delivery of their 2012 vehicles yet, you can check their website or give them a call.

I love the performance EVIC (I think that is what it is called). It would be nice in addition to what you already have on there to offer 0 to 30, 0 to 40, and 0 to 50 timers. That way we can easily test some performance changes and launches.

Glad you like it, we will keep your suggestions in mind.

I've taken my 09 Challenger SRT8 6 speed to the track a few times. I've heard axles are the weak link in these cars so I'm basically rolling it out and powering it up{stock F1's}. I'm averaging 13.2's and 13.3's with the shaker hood and hopnot being the only perf. modifications. I have dumped the clutch around 3200 rpm and got it down to 12.9 once. But it was a cold day at Atco. My questions are am I being to careful? Will this drivetrain handle harder launches? And are these times about right for this car?

You are looking pretty good here, time wise. Push her! 12.9 real good here. We test them at the track just for this!

With all that you have learned over the years with the 6.1 and had a chance to go back in time..... What would be some of the changes you would make to it?

Looking back is not very constructive. We focus on looking forward.

If you were looking at a 'off-road use only' situation.. is there any low hanging fruit as far as weight reduction goes... sure would like to drop a few hundred pounds? Also.. any chance of getting manual locks and crank windows on the aforementioned lightweight stripper srt8?

Have considered Jenny Craig? Seriously though, the first thing to go would be the interior, especially the rear view mirror. "What's behind you doesn't matter".

 

7/21/10 Session:

The following is the complete questions and answers from the July 21, 2010 SRT Engineers' Chat Session:

What is the limiting factor for the 6,100 rpm redline on the 6.1? Valve springs? pistons? heads??

The valve train is the limit on the engine but the A/T trans shift speed limit is right there too.

Have you had a lot of issues with fan motors, I am on my third set and the car is only 3 years old ?

We haven't seen any issues.

Hypothetically, if you guys had a LX and wanted a stock cat back exhaust what would you do to modify it, if anything to support say 650-700hp? I know what Paul's answer is, but I wondered if there were any other opinions on increasing the flow or if it is even needed.

Sorry, I'm going to give you the same answer that Paul gave you. Your stock exhaust basically is a straight through and will support 650-700hp.

I have a old GSM kit to shut off the ESP 100%..so I thought... in listening to what you said if the esp button is not pressed is the computer still seeing delta's and compensating ? I know the predator will do the same but its just easier having the control at the touch of a switch...

Not sure how the ESP system would react with the GSM Kit. If the stock calibration is there, and still full on, it will be sending out messages to control the vehicle.

A lot of folks on the forum have had a problem with engine stalling. For me on three separate occasions the car (2009 Challenger SRT8) has stalled when slowing down and preparing to make a turn. It happened twice with my 6.1L engine and once with the 426. Given it has happened with the stock and stroker engines I don't think it is the engine. Is it a potential problem with how the fuel system/tank is designed ?
There is a software fix coming to correct this issue. Stay tuned.

Can you shed any light on the theory that line locks may be causing Getrag clucth pack failures, and why?
Still digging into that on. We've got a plan to get one of the axles back to take a look at it. I see some long smokey burnouts in my future. Darn.

What recommendations do you have to improve the life of the ball joints in the upper control arms up front?

Best thing to do is keep the stock ride height and alignment settings


Why is the TCM programming still such a mystery to aftermarket companies. Seems like the PCM tuning has either been released or at least decoded allowing us to reap some good performance gains. Why not release the TCM tuning codes to allow us to keep up with the competition (which is getting very stiff). Lots of these cars with aftermarket parts are making power past 6400 rpm and my buddy with an '06 300 SRT8 (without the TCM flash) is able to paddle hold the shift at times to 7000 rpm without a problem. Some of us here are big boys and are willing risk popping a motor (on our dime).

Sorry, for right now there are no plans to open up the cals for modification. Although we know many of you are capable ofmaking the right kinds of mods remember the trans is not rated for anything above the production performance output


Noisy bushings, struts and bracket- I only drive this car about 4000 miles a year so I feel that this should not be happening. The regional service rep said that this "noise" is a characteristic of the SRT vehicles from 2006-2007. I have driven in other SRT vehicles and did not notice this noise at all. Obviously they thought there was a problem with my car or they would not have switched out all of those parts. I even went so far as to look into the Lemon Law but unfortunately I was passed the alloted time. I don’t think this is fair and need advice.

For 2008, there was a check valve change to the shocks which helps this noise. They are returned for better ride as well, so we suggest replacing all 4 if you want to go this route. The source of the remaining noise is the front upper strut mount in rebound events. We are working on a design change to help the issue, but it will be some time before we will have something out. Thanks to these web chats, we are able to convince management we need to keep working on it.


Is there a replacement strut mount available yet? If so, is there a way to differentiate the new design vs. old to make sure I am getting the new one?I was just wanting a time line that I could possibly get the redesigned dampers..The dealership has replaced both struts and several other parts, but when showing them the chat answer from before they are also waiting the redesigned part
Best way to check the parts is the part numbers.
2008FrontFront RT04854577AC Front LT 04854576ACRearRear LT05039344ADRear RT05039344AD
The new upper strut mounts are now tooled and should be available soon.

It continues to be bandied about that the 6.1 (and to a lesser degree the 5.7) has an excessive PCV oil vapor ingestion issue that is the root-cause for pulling timing (by-way of the knock sensors - supposedly reacting to octane level degradation because of significant oil consumption/oxidation under normal operating conditions. The cure recommended by the vendors for this ailment is purchasing/installing a catch can.
Both the 5.7L and 6.1L engines meet all corporate requirements for PCV performance. However, as we have mentioned in previous chats, installing a catch can shouldn't harm anything.

During (factory) engine assembly, are the knock sensors raw voltage O/P tested, or even monitored from engine-to-engine? It appears the amount of timing being pulled due to knock sensor activation (real or perceived) varies from platform to platform. Is this normal (it's understood that fuel quality, engine load, atmospheric conditions, etc play a part)?
During end of line testing, output from the knock sensor is verified to be present. Comparing the amount of knock retard between vehicles can be deceiving. As you mentioned there are many factors that affect knock limit. Unless the conditions of your test subjects are identical (highly unlikely), the amount of knock retard can vary.

Given the popularity of the Drag Pack cars, Why is there not a way to order a factory racer like the ARC Neons ? That are street legal and would make a nice weekend racer for someone. Off a SRT that got all the fun go fast bits, but none of the extra weight ?

Nothing like that right now but there is a Challenger BIW coming very shortly. That with all the bits and pieces out there might make a great road racing project .....


Is there a recommended mileage for changing plugs in our vehicles for day to day, spirited driving?
Your SRT8 spark plugs are Platinum tipped and are good to well past 100K miles. If you are driving "spirited" they should be cleaning themselves continuously. For injectors (and valves for that matter) using good quality premium fuel will give you the detergents and additives necessary to keep those components clean. Your recommended maintenance schedule for combustion cleaning and as well as fuel injectors with again day to day spirited driving habits.

Does the TC lockup in all gears except 1st? I get a bog under light throttle in 2 and 3rd gears and I'm assuming its the TC locking up. Is there something else I may be missing that is causing this bog? Under WOT, it pulls as it should.

Yes the torque converter locks up in multiple gears. Hard to diagnose a bog over this keyboard, but that could be part of it. More likely it's in a higher gear and leaning into the throttle a bit further forces a kick down and the resulting grin on your face. You could try using the autostick feature to stay higher in the rpm band. That way the grins are readily more available when you get the urge.

When the professionals took us around the track they turned the ESP off what are the gains from having it off? 2009 srt8 6.1 challenger

The owners manual has a good explanation of each of the different modes, but in a nut shell...
On : All systems on
Partial Off: Engine Torque Management Off, Brake Traction Control Off, Stability Control On.
Full Off: same as above with Stability Control Off...


Is there any way to totally turn off the traction control? I only drag race this car with limited cruising lots of car shows also. Thanks in advance for your time!!I have a SRT8 Challenger 2010? Also what is the HP rating of the axles on the 2010 SRT8 Challenger?

Check your owners manual. Press and hold the ECP Off button for 5-10 seconds and the ESP full off will come on.

The 6 speed cars can get a 3.73 or a 3.91 ratio in the diff. On the auto cars there is no option for a 'performance gear'. The magic ratio to gain a little bit of an edge with the auto cars is the 3.23, I'd love to see the Getrag available with this gear set.

Actually, the SRT only has 1 ratio for each transmission. That would be the performance ratio


Please forgive the reference to a non-SRT part in this comparison; it has been suggested that the new 2009 composite intake manifold is very similar to the 6.1 aluminum intake in rate-of-flow, runner length, and therefore power band. Flow results have the 2009 composite unit within a few CFM of the existing SRT intake manifold. Can you kindly confirm or deny please they are pretty close in actual configuration. The idea being the composite version offers less mass and a lot less heat soak..

OK, you must be talking about the Eagle composite intake manifold as a comparison to the 6.1L manifold. There are several Eagle intakes (for different applications) with different features. Generally we would not recommend swapping the intakes. If you were really intent on improving the intake flow on the 6.1L a port and polish of the aluminum runners on the 6.1L would be a better way to go.

 

The following were the responses given by the SRT engineers during the Feb. 3, 2010 SRT Engineers Chat Session (1 of 2):

Air Filter Elements: My car is a daily driver. On the way to work I drive past a rock quarry. At least twice a week the road I drive on is pretty "dusty" for about 1,000 feet. My question is: Will a high performance air filter, such as a K&N drop in filter, provide me with enough filtration?

We recommend using a cold air intake system from Mopar. It will provide the necessary filtration for your daily driver. It will also allow you to wash and reuse it when it becomes dirty.

If I replace the mufflers with glasspacks will I lose power? 07 charger srt8. I plan on keeping the resonators.

Actually, Hemis like a little back pressure. You'd be better off going to a Mopar catback instead.
I have a 2009 Charger SRT8 which is used for a daily driver. I live in Calgary, and the car does stay out in winter. When it gets cold, when first starting up in the morning, I get quite a whine at engine start. It is for the first couple of seconds then it subsides and the car warms up with no issues, do you guys know what this would be? Is this something to take in and warranty or is it just the hemi engine when first starting after being cold?

More than likely it’s the power steering pump, as the fluid warms up and thins out the whine goes away.

Are there any drag racing components (lightweight engine cradle, etc.) on the drag pack challengers that would retrofit into a standard LX and if so are they available for purchase separate from the car?

Most of the unique drag pack components are available from your local Mopar parts dealer. Check the latest Mopar catalog or call the Mopar Tech line at (888) 528-HEMI for specific questions about your application.

Synthetic oil is installed at the factory for SRTs. Some have stated that because synthetic oil is so slippery, the rings and cylinders will glaze and not seal properly. This could result in excessive oil consumption. Any truth to this?

There are lots of rumors that have cropped up regarding synthetic oils. The very first synthetics (like butane in winter fuels and the first alcohols) did have some impact to gaskets and seals (swelling) but that was a long time ago and all modern materials work well with synthetic oil today. Glazing is caused by oil actually burning or Carbonizing in the hone pattern. Synthetic oil does not burn-in, carbonize or cause glazing. The lower friction may delay the break in slightly as it does reduce (slightly again) the wear of the rings and bore but in all our testing the break in does occur within our normal guidelines. If you have excessive oil consumption there is another reason.

Hi, my question is about the 2009-2010 Challenger SRT’s with a 6-speed transmission. There has been a lot of talk on the forums lately about the wheel-hop problem with these cars. In the last SRT chat session on the Jeep forum the question was posted to you guys asking if you were working on a fix for the problem, but your response was more of a “how to drive the car without spinning the tires” instead of answering the question. I would like to ask it again, and I would appreciate a direct answer to these 2 questions: Are you guys working on a fix for the wheel hop problem on the 6-speed Challengers? If you are, will it be something that people who have already bought these cars will be able to take to their dealer and have repaired at no cost? Thank you!

 

(2 of 2)- Feb. 3, 2010

Per last months WebChat...."Powerhop is, unfortunately, an unavoidable hazard in making big power with a manual transmission. From a design stand point, lowering the clamp load on the clutch would smooth that out, but the trade off is smoking the clutch after just a few launches. My recommendation is to keep working on your driving technique. It sounds like you have the handle of it in 1st. Remember, if you are power hopping the rear end you are not getting the best launch you can. And you're beating the crap out of the rear end. Could have something to do with the whine you are starting to hear. I would not worry about the axle gear wearing out, but if the pattern moved even slightly from the initial position set in the factory it will get noisy. If it's really driving you nuts you might consider taking it in, but if it's only there for a small speed range it's not an indication of wear-out or pending doom like a constant growl noise would be."

If you see a data log of any 5.7 (maybe 6.1s also) 6-speed car, you always get some short-term knock retard during the shifts. It has nothing to do with gas quality or octane (happens with 100+ octane race gas), and only happens during the shifts, so there's a lot of speculation that it's simply engine or trans noise being picked up by the knock sensors. Most folks just say 'that's normal', but since it costs a couple of degrees of timing, it would be good to get rid of it. Any thoughts?

Unfortunately, there is not a solid to do this. Your friends are right, its due to the noise that is put through the power train during the shifts. Given our knock sensor location and the algorithms used, this is what we have to deal with. I know its not the answer you want, but its the truth.

Is it possible to run E-85 in a '07 6.1 Charger? E-85 has 100 a octane rating and it seems that it would be an economical alternative to super unleaded. What are the limiting parts / factors to making it flex-fuel friendly? What would happen if we used E-85 in the car? (Yes I realize fuel efficiency goes down, but I already paid the gas guzzler tax) Why did you choose not to make it compatible right off the bat?

Due to the lower energy density of E85, the fuel injectors cannot deliver enough fuel to sustain combustion at high loads (the typical SRT owner driving style). Lean burn conditions and meltdown are potential issues. Also, the fuel delivery system (seals, lines, and tank) was not designed with the corrosive properties of E85 in mind. There is a high potential for component issues with E85.

What causes the Hemi “ticking” sound that is heard in idle and just off idle? I have read that it is caused by a lack of cushioning of the intake/exhaust valves and fuel injectors, and wearing off of the moly piston skirt coatings.

You will not hear the valve seating at or near idle conditions unless you have seriously aerated the oil system and hence the lifters. You will also not hear the moly wearing off the piston skirts. A piston that is too small in a bore too big will result in a cold slap that can be heard at cold (I mean cold like -20 deg F) idle. We do a lot of testing and guage pistons and bores very carefully to make sure you as our customer cannot detect the piston movement in the bores - hot or cold. I expect what you hear is the injectors which do make a clicking noise that can be heard and gets slightly noisier as the injector temp is elevated. The noise is caused by the injector pintel as it opens and closes and while we have not been able to eliminate the noise due to the required operation (you need the fuel) we have done some work with minimizing the noise with isolation -see some of our new stuff - oh wait I cannot talk about future product.

There is a lot of welding bead inside the port of the SRT’s clam shell headers. Would grinding them smooth produce a better air flow and any more horsepower?

The tube in shell does have welded edges that may show slightly more flow if they were "touched" or "blended" but to do so may cause that area to crack therefore ruining your manifold. I would not recommend it they are expensive to replace.

What would be the first Mod you would do with $500.00 on a 2010 Charger SRT?

Probably Cold Air. Lots of good stuff in the catalog:

http://www.mo-pod.com/pdf/09_Perform...log-120908.pdf

Some of the opinions on our wheel hop on the 6-speed Challenger's is the rear sub frame movement. What would the negatives be if the subframe was bolted tight against the car frame?

There would an increase in the amount of driveline vibration transferred though the rear cradle into the body.

I own a 2009 SRT8 Challenger 6-speed. I know the car comes from the factory with ATF+4 fluid. What is the proper fluid amount? I was told there was a change last summer?

3210ml

I'm planning on building a Challenger road racer. I assume (maybe incorrectly) that starting w/ a Challenger SE would be more cost effective than using an R/T or SRT. Do SRT brakes, suspension parts, and drive line directly bolt in to an SE body? Are the brake master cylinders different on the SE and the SRT? If only Mopar would sell me a body in white......

SRT's do not have unique body in white, so all of the suspension joints to the body are in the same the base platform vehicles. And don't give up hope. Before you embark on this project call 888-528-HEMI for the latest on the BIW program.

I see the Challenger has a rubber bushing material on both ends of the driveshaft. How strong is this material on the 6-speed cars? Consider I would be using drag radials and have 400 horse/torque to the tires.

If you have an SRT you should have 425/420 horse/torque. We have done a lot of testing to ensure those couplings live. Believe it or not the hardest part was keeping the bolts from bending. Notice the pretty pink bolts, don't use anything else, they will bend and lose clamp load. That said we have been very happy with the strength of this joint. We did do some testing with drag radials, and saw no issues.

Will the composite intake manifold from the 5.7 Hemi fit on the 6.1 Hemi without any major modification? With minor modification?

I believe it would fit but why would you do it? It will save weight but the runner system is not properly sized to deliver the air you need to go FAST. I only assume you want to go fast because we do. Some of the new dual runner adaptive intakes (2009 5.7L truck) could extend the torque band and allow a different feel but that option requires actuator electronics to make completely effective (or some cable controls and an extra person to move the controls when you yell).

I really need to know if 6.25 quarts (putting my level at full) puts my car at the proper amount of oil, or am I driving my car every day three-fourths of a quart low?

We certainly call our 6.1L oil system a 7 qt system. Discussion here in the room requires that we (read I will have to) go back and retrace some of our test data/results and get back to you at the next session. Sorry.

My engine was dyno tuned those number are to the tires. the base line was 360 hp to the tires.

Is this the same coupling you have been using in the charger platform? No difference between auto or 6-speed?

We went to a larger (thicker coupling) for 2009 to handle the manual trans loads and the auto changed along with it. The trans end is different, but the axle end is same for both auto and manual.

Thanks for adding the Getrag LSD. I retrofitted one in my car and it has been taking a lot of beating including 1.48 60' times. I've heard some have had problems with the clutches going bad and others (including me) hear a whine at part throttle at certain speeds. Are you guys happy with this rearend? Also I hear there are no rebuild kits available right now, what gives? Also, some folks have been making 1/4 mile runs without the serpentine belt. Basically start burnout with coolant temp below 120*, stage, run and shut down when temps are 180* or a little higher. Obviously there is some danger here to the motor. What do you think is the most likely thing to break first when the water pump and alternator aren't running at the drag strip?

We are very happy with the Getrag LSD. Unfortunately, production tolerances can often lead to slight whines at any given load condition (full throttle, part throttle, accel/decel). It is important to monitor this whine to see if it changes with age and wear. What is most likely to break when you run without the water pump? THE ENGINE!!!

Any response on how to make the car act more like a muscle car as opposed to a lethargic giant awaking from hibernation. Another posted on throttle response and the adaptive programming and how it is lacking to really adapt to our liking! Driving around in the suburbs with your foot in the throttle tends to catch attention of local police, scare small children and furry pets. But when the opportunity exists for some spirited driving, we want a SRT branded car to step up to the plate!

 

Jan. 13, 2010 SRT Chat Session (1 of 2):

Question: what kind of HP will be the 6.4L 2011 Challenger.

Unfortunately, we can't talk about future product details like that.


Originally Posted by Cuda340
1. Is the MOPAR CAI good for 5 rear wheel hp and 7 ft/lbs. of torque on the Challenger
SRT?
2. Is there any advantage to removing the factory radiator airflow diverter from the
lower air box to allow more air to reach the CAI?

While we don't have any numbers specific to your application, the high flow Mopar intake is designed to minimize the intake restriction and increase horsepower. Just follow the installation instructions and enjoy.


Originally Posted by Cuda340
Thanks for answering my first question about the MOPAR CAI in my Challenger SRT, but you guys did not answer my second question, namely:

Is there any advantage to removing the factory radiator airflow diverter from the
lower air box to allow more air to reach the CAI?
Sure we did. Just follow the instructions and enjoy.

Quote:
Originally Posted by Cuda340
Two weeks ago, I had the "driveability" reflash done to my 2009 Challenger SRT (auto). What improvements can I expect?
This reflash was to address some low speed driveability concerns. You should expect smoother transitions at lower speeds when you are on and off the pedal (i.e. fuel on -to- fuel shutoff transitions).


Originally Posted by srKEY
Do you guys have any tricks to keep the brakes from squeeling on a 07 GCSRT8 with 23K miles? I've heard the rotors glaze and there may be some braking techniques to get the glaze off. Any ideas?

With temperatures as cold as they are you want get your brakes hot to minimize brake noise... The harder you brake the less noise you will get.





Originally Posted by icemanthrilla
do u recomend using a catch can on the csrt??? some of us who have had them installed say they catch a fair amount of blow by while others say its very lil.
Vehicle and engine durability is done with NO catch can. There is no problem with using one provided it is properly installed in the PCV system. Depending on your drive cycle you will find varying levels of oil in the catch can. There will be no measureable performance improvement with the catch can.

Whatever is caught in the catch can SHOULD NOT be poured back into the engine, regardless of what videos may have been posted on the forums.

Originally Posted by Knuckles
Just wondering how this whole adaptives thing works?
Your vehicle adaptives are constantly learning...some more than others. By that I mean as you accumulate miles on your car, some adaptives will "re-learn" more quickly than others if you change your driving style. If you put any tune in your vehicle, your info is correct and you should start with a fresh adaptive learn to maximize the potential of the tune. Again they are correct and drive the car around like you normally do, perform a few WOT pulls when its warmed up and you should be good to go. I've never heard of the brake press after a battery pull to drain the adaptives...normally you can pull the batt negative connector and turn the key like your starting the car for a few seconds and that will drain the capacitors in the module and give you a fresh adaptive start. Hope this helps.

Originally Posted by lhcfh
I like many others with manual 6 speeds in the Challenger have experienced severe wheel hop after a few miles have been put on the car that did not exist when it was new. I fully realize why the wheel hop is happening on take off in first and I can manage it by feathering the clutch/acceleration but it is still quite a challenge to do so. My bigger concern is the amount of hop I get from 1st to 2nd. Is there anything that can be done to solve this issue in regards to aftermarket or other Mopar products? Second question, like others I have started noticing a whine from the rear end after getting wheel hop that is noticeable when decelerating from 50-60 mph. I have heard that some dealerships are getting responses from Chrysler that this is normal and not a concern.
Power-hop is, unfortunately, an unavoidable hazard in making big power with a manual transmission. From a design stand point, lowering the clamp load on the clutch would smooth that out, but the trade off is smoking the clutch after just a few launches. My recommendation is to keep working on your driving technique. It sounds like you have the handle of it in 1st. Remember, if you are power hopping the rear end you are not getting the best launch you can. And you're beating the crap out of the rear end. Could have something to do with the whine you are starting to hear. I would not worry about the axle gear wearing out, but if the pattern moved even slightly from the initial position set in the factory it will get noisy. If it's really driving you nuts you might consider taking it in, but if it's only there for a small speed range it's not an indication of wear out or pending doom like a constant growl noise would be.

 

Jan. 13, 2010 SRT Chat Session (2 of 2):

Originally Posted by 1233user
I own a 2009 6-speed Challenger SRT, which like most of the 6-speed cars suffers from severe wheel-hop. I know this issue has been talked about in your other chat sessions, where the SRT engineers gave several different responses. What I would like to know is if you guys are working on a fix for this problem that will be available for all the people who already own these cars and are very unhappy about the wheel hop?
I think you will find power-hop is not only a complaint on the 6 speed Challenger, but any of its competitors in the class. In fact the Challenger is considerably better than its rivals on this. My best recommendation is to practice smooth launches modulating both the clutch and gas pedals. No, It's not easy. Yes, it takes practice. But that's half the fun of a manual transmission in my opinion. Most of all keep in mind that power hopping is not the fastest way to launch the car. Ease off and you will go faster.

Originally Posted by SRT09
Would a larger throttle body help my car? 09 SRT8 6 spd Challenger with a Vortech
Generally speaking, increases in throttle body diameter yield modest gains. An a supercharged application like you describe, I would expect any power increases to be minimal to none at all.

Originally Posted by bfreeman
Vehicle: 2008 jeep gc srt8 (8000 mi). Mods: bwoody CAI, sway bar links, ss brake lines, predator tuner, R1 drilled/slotted rotors, Hawk ceramo-metallic pads.
Problem: Terrible bake squeal, especially near the end of the stop. Have tried deglazing, reburnishing,even wheel weights on the R rear caliper. Nothing works.
A lot of time and effort goes into developing brake pad and rotor combinations that balance outright performance with minimal customer issues. Unfortunate side effects of high performance components are noise and brake dust. Your BooYah rotors and pads most likely do not have the noise countermeasures of the SRT components. If you are really committed to your aftermarket components, you could always try to chamfer the leading edge of the pads or add an aftermarket silencer shim between the pad and the caliper.

Originally Posted by SRT09
Would replacing the cats with a high flo replacments add much HP? How much?
It is possible that lower restriction cats could increase power but I have no way to estimate how much. Bear in mind that the HEMI engine actually responds better to a bit of backpressure than most people think. Very low backpressure exhaust systems regularly make LESS power on opposed-valve HEMI engines, particularly the SRT's.

Originally Posted by 2007srt8
Is Rod knock common issue with the 6.1? I have knock during cold starts and my dealer said it was the rods.

the knock goes away when it warms up...should I replace the short block?
I am not aware of any issues with rod knock in the 6.1. Your dealer should be able to diagnose this issue, or possibly they could place a call to the Chrysler Star Center to help you with the problem. I hope this helps!

Originally Posted by shorestyle031
should the power steering fluid be changed after a road course track day
If you are only going once in a great while, you shouldn't need to change the fluid. If you're going on a regular basis, you should change change the fluid... be sure to use MS10838.

Quote:
Originally Posted by Joe Las Vegas
You can pull fuse # 11 for 30 secs on the 5.7 Hemi to reset the PCM, is there any fuse that can be pulled on the 6.1 to accomplish the same? (GC SRT8)
Same for the 6.1L - same vehicle.

Originally Posted by demonbydesign
My question is in regards to the SRT8 automatic...will swapping out the 3:06 for a 3.92 (for example) potentially hurt anything? I realize you may have used the 3:06 to strike a balance between gas mileage/performance. But I'm not knowledgeable enough to know what it may or may not hurt and/or improve as far as performance especially in a straight line drag race type situation. And will doing a swap of 3:06 for 3:92 potentially introduce the wheel hop issues of the 6-speed into the Automactic/NAG1? With the SRT challenger automatic and straight line drag race, in your experience can you suggest an optimal RPM range you might suggest I launch from to achieve the best 1/4 mile time? And what stock numbers have you experienced guys seen running the SRT Automatic Challengers through the 1/4 and 0-60?
Wheel hop won't likely be an issue with the change in axle ratio since the torque converter smoothes out the torque apply, but you do have a few hurtles to overcome. First, the trans needs to know what the axle ratio is to shift properly. I may have heard about some aftermarket products that allow you to program this, but I of course cannot recommend such actions. Going to 3.91 is a big step, and getting it to hook-up with all that ratio could be difficult and then you end up pedaling the launch and giving away all that you've gained. I'd look at the 3.73 or lower. Another option would be to go with the 175k torque converter offered by Mopar. This will give you a bunch more torque multiplication on launch and not require trans settings adjustments or effect your highway cruise rpm.

Originally Posted by icemanthrilla
Here’s some threads with pics of whats caught int he catch can...do the appearance of any of these fluids trouble u?
Moisture and oil do not mix well. The catch can collects the oil and any water vapor it was mixed with. When they settle out, you get the nasty sludge in the pictures.

I have a 2009 Challenger SRT8 6-speed. When I accelerate out of a corner I feel a shudder and it feels as though the power is down. As soon as I straighten the wheel out it goes away and you can feel the power pick back up. This happens in all three modes of the ESP (on, partial off, and disabled). It can be repeated in a parking lot by doing a circle, not too slow, and then pulling straight out of it. The dealer says that it is the computer retarding the power to protect parts. I wouldn't think think the ESP would do anything with it being disabled. Is this something I need to be worried about?
The ESP was my first guess, but you said it sill happens when disabled. So after that, I'd guess the tires are slipping. Can you have someone watch from outside the car when you do it.

How many miles are the stock spark plugs good for, realistically? I mean, at what mileage would you change them if it were your 6.1? What gap?
On any stock SRT Hemi, I would look for a plugs at about 100k per the service interval. As modifications increase, plug life can be expected to decrease somewhat. For bolt-on improvements, I would gap at .040 - .045". It's a little tougher on supercharged engines but start with a plug one heat range colder and gap about .035 -.040". As for change intervals with modifications, I can't really say.

Originally Posted by blown454nova
anything for post 123, or the other people who posted about the brake squeal, or are we just going to have to settle for another person telling us its "normal" for our cars to sound like a freight train.
Performance brake systems are more likely to have brake noise due to the aggressive content of the brake pads and the stiffer construction of the calipers. When it is cold or very humidity brake noise is more likely to occur. Another factor is amount of brake pressure you apply, the harder you brake, the hotter the brakes are, the less noise you will get.

 

The following were the Dec. 3, 2009 responses of the SRT Engineers to the questions raised during an LXforum SRT Chat session (1 of 2):

Please give us as much info as possible on the new 6.4 L motors.

All we can say is it exists!

When converting from the stock air intake to a aftermarket CAI, how long does it take for difference between the two to take effect?

Any performance increase from reduced intake system pressure loss will be immediate. There are some adaptives that will require a short drive under the right conditions to update.

why not have the "ram air" ducting go to airbox instead of over exhaust? I see slight benefit to current design but would like to know why y'all went that route instead of traditional to intake route?

It would have been a big tear up to the induction system which is rather expensive to tool. Also and probably the bigger reason is there is so little room to route between the hood scoop, throttle and where a airbox would have to be place the higher restriction would overcome any gains in ram air.

Do 6.1L Hemis have a small vacuum tap anywhere? I need a vacuum source to operate my headlight doors.

Yes, you can t-splice off the brake booster, purge harness, or map sensor.

I heard that they made a change in the Tremec 6060 trans for 2010, shouldn't that be a warranty problem and they should fix the 09's.

The changes that we made to the transmission were improvements for customers. They were not warranty issues...the 09 cars are not broken!!

I want to install a Dual Shift Light on 2009 Challenger SRT8 6 speed.

The only shift lights Mopar offers are included with Mopar branded tachometers. We are still investigating fresh air options for the T/A hood but are not ready to release any details at this point.

In our efforts to improve upon what are already two great powerplants (5.7 & 6.1), folks are putting the 6.1 intake manifold on 5.7's.

The plastic intake on the 09 5.7L cars was derived after the 6.1L, by the same person in fact....so yes, they are pretty similar in design and function. They do however have some differences since the 09 5.7L has Variable Cam Timing and the 6.1L doesn't, so there were additional tweaks done to the 09 5.7L Plastic Intake for optimization with the cam. I'm not 100% sure, but the intake tracks should be similar to the old 5.7L vs. 6.1L. As far as performance goes, the plastic will certainly have less heat soaking issues, but again the systems are different. So, play at your own risk when it comes to spark knock due to airflow mixture motion. Let me know what you guys find.....I'd expect performance to be similar.

If you had to build a Challenger roadcourse racecar which is still used as some kind of daily driver which parts would bring the biggest efficiency regarding space savings?

Obviously an aluminum block engine would save almost 100 lbs. The rest of the weight comes from unnecessary options (radio, sunroof, seats, etc...) and the body structure. When you start hacking out body structure, you are taking street risk and should substitute with cage structure which is very dangerous on the street without harnesses and a lid. The front and rear cradles are steel and heavy, too, but we have yet to see someone do one out of AL.

1) does the bore size of a CAI make a difference?

[mopar offered cai is not the largest, nor the smallest]

2) is there a measureable difference in using a CAI vs not using one?

The bore size of the CAI kit does affect the intake system tuning. In our development vehicles CAI kits have shown improved performance under most conditions.

The only shift lights Mopar offers are included with Mopar branded tachometers. We are still investigating fresh air options for the T/A hood but are not ready to release any details at this point.

As an addition to the previous answer, there will be a Mopar branded stand alone shift light available in the first quarter of 2010.

how far into an engines life can we see some oil consumption due to piston ring set-in?

It all depends on the duty cycle your car see's....I can seat (break-in) a set of rings really fast if you'd like me top In all honesty, the first 500-1000 is the most critical at getting enough heat cycles through the engine. After 2000 miles, your rings should certainly be fully seated. With that said, depending on how hard you drive your car and where you drive it in the rpm range (you do have a 6spd), you could still consume a small amount of oil. 1/4qt over 1000 miles doesn't really concern me, but keep an eye on it and let us know at next month’s chat.

Do you have any numbers of how much downforce the front and rear spoilers on the SRT Challenger generate?

The SRT8 at 130 mph generates about 60 lbs of downforce at the rear and about 150 lbs of lift at the front. That is MUCH better than most manufacturers in the industry who make much more lift. The R/T is less aggressive on both ends. The SRT airdam is better than the R/T one. You want aero understeer in the car to compensate for the natural instability as speed increases. This is why racecars have more wing in the back than splitter in the front. More down always feels better, but we have to balance aero downforce with drag.

The fastest I have gotten the '09 Challenger SRT8 up to is 181 mph (rev limiter in 5th, manual trans) with a tailwind on our test oval. Our full scale wind tunnel goes up to 140 mph. There is not much reynolds effect on the Challenger, so the aero numbers stay proportional with speed.

Before production started, I had read that the stick-shift Challengers would get stiffer motor mounts. Do they have stiffer motor mounts and if so is it a different design or just stiffer rubber?

The stick shift Challengers have totally different mounts than the autos. The autos have hydro mounts and the manuals have constrained rubber mounts. The reason for the change is to keep them alive with the larger spike loads that come with a stick shift. The SRT manuals are slightly different that the R/T. They have less travel before they snub to the housing for lower less enigne movement.

We haven't used the 75W-140 gear oil in the Getrag diff. The higher viscosity certainly couldn't hurt with gear noise, but I wouldn't expect much of a change. The risks are seal life and clutch chatter. No way to tell without testing it. The clutch pack will still need friction modifier added to it. Good luck if you want to try, but I can't say I'd recommend it.

notice MOPAR is making an aluminum block available now. Was cost the only consideration in making the 5.7 and 6.1 blocks out of iron?

This may have been addressed before but it has been noticed that some factory x-pipes are closed off and only appear to cross gases from each pipe.

Cost is the major issue behind the iron vs. alum.

The X-pipe closed vs. open was actually done for sound quality. We wanted a more aggressive exhaust note on the Charger vs. the 300C so the Chargers got the closed x-pipe.

Is a 2009 ChargerSRT8 suspension different, how do we Challenger owners "dial in" a better handling ride and what can be done about numb steering feel?

All the L series SRT's have the same steering systems, with unique suspension tunes to give them unique personalities. The 2009's do have a caster change and a slight retune to the suspension.

Are there any plans to offer offer Mopar lowering or higher performance springs for the Challenger SRT8?

2) Are there any plans to offer Mopar supercharger kits for the 5.7 or 6.1 Hemi?

3) The 6.1 L Hemi has been built to be considerably stronger, with forged crank and strengthened block, etc. Can you tell us what "limit testing" has been done to see how much horsepower this configuration will support without the use of more forged internals?

 

(2 of 2)- Dec. 3, 2009:

1)PN P5155436 lowering springs are available at your dealer today.

2) Well, we never say never but soon.

3) As engineers we work hard to optimize all of the components. So the answer to your question would be there's risk inherent in any increase in boost for your engine. How much your willing to except would be up to you.

I am trying to stagger the wheel/tire diameter difference between front and rear.

What is the largest percent difference I can achieve before the ABS or other electronic control device will be affected.

Can these controls be modified or eliminated?

5% diameter difference.

They can't be modified. If you eliminate it, you eliminate ABS. Unless you built tonewheels with more teeth on the front than rear...

Have a 2010 Challenger SRT8 6spd and I despise the skip shift. I know you can`t recommend disabling the skip shift, but there is a kit out there that emulates the resistance of the solenoid to avoid tripping the MIL due to that, but can you confirm the `10 models will trip the MIL because the ecm knows the transmission is not in 4th?


The functionality of skipshift is the same in '09 and '10.

We build a lot of supercharged SRT-8's and they all seem have the same issue. When you apply part throttle, as soon as MAP goes to 0, the throttle fully opens.

Good to hear you're a serious enthusiast but we didn't engineer the car with forced induction. It's really hard to say what the engine and sensors are doing. Kinda like telling a mechanic "it goes clacker clacker when I turn left".

Why did the Superbee get axed from production ?

It was intended to be a short production run vehicle.

Is there a way to reset the ECU / PCM to the original factory settings, pre April 2006? It appears that the many times that Chrysler has flashed the ECU on the SRT8 the software has dumbed down the performance, taken away the slap-stick functionality and removed the slippage quotient of the rear end and added an adapttive mode.

The ECU/PCM updates you speak of are typically regulatory in nature, so it is a one-way update. As far as the "dumbing down" of performance, etc... sometimes that is a temporary thing until the engine adaptives are relearned.

Did you come up with any options for the rear supension for drag raceing to help the cars launch like on the 60's cars where u had the pinion snuber and the ss springs with the extra leaves on the front half of the springs and maby som more room in the fender wells for som bigger slicks also the ability to use 15 inch wheels so we can use the big slicks.

Currently some rear axle options are being investigated, both for street and strip. At the moment, nothing to announce, but stay tuned in early 2010.

What made you choose the 3.06 gear opposed to a 3.73 or 3.92 for the automatic?

Testing showed this to be the sweet spot between fuel economy and performance. The rear tires still spin at launch so you've still got more torque than the traction available.

I live in an area of the country where summer time temps hit 110 to 120 on a daily basis. I've noticed my EVIC temp hit as high as 230 during normal driving. Is this acceptable?

I see you must be using the engineering pages. 230 degrees is not a problem.

A caster change and a slight retune to the suspension for softer/more body roll or firmer? Could my dealer change that, would they know what I am talking about?

The '09 front shocks are just incrementally firmer. I doubt anyone but a vehicle dynamicist could notice. The caster change was made by changing the front upper control arm to relocate the upper ball joint. It is not adjustable by the dealer. Moving the cradle around won't do very much. You could put '08 or earlier upper control arms on. Then you'll have to put on '08 or earlier SRT knuckles to correct the bump steer to match.

Can we inprove the wheel hop situation using the MP coilovers to further tune the suspension. Any additional recommendations?

Stiffer motor mounts might get you a small improvement.
I have 2 sets of wheels/tires (winter/summer) for my '08 Charger SRT, all the wheels are OEM, stamped "SRT" and "ALCOA FORGED". I bought 4 additional TPM sensors from a dealer, (68001698AB for '08) and they seem to communicate with the receivers, except that at any given time, I will typically see 2, 3 or often all 4 tires showing the same pressure. This happens with both the summer and winter set. The actual pressures do vary a bit by a manual gauge, so apparently 1 sensor is displaying on all 4 fields of the readout. The dealer service people want to put their scanner on it for $100 each spring and fall, when I change wheels, but it strikes me as a warranty issue. I've asked friends at Brampton Assembly about it, all they can say is, "it shouldn't do that"

Any thoughts? Thanks.


The sensors transmit a unique ID number along with the pressure information. Once the module learns the new set of sensors (you need to drive it over 20mph to make sure it transmits) and the location it will update only the one location. The module won't accept the same ID number for two locations.

The sensors are +/- 1.0 psi 1.5 psi at extreme temps and the guage in your hand is +/- 1 psi at best so it is very possible that all the sensors will read the same while the guage says they are slightly different.

Was the skip shift implemented for gas mileage reasons? Is it okay to eliminate the skip shift with the aftermarket CAGS Solenoid eliminator?

Yes, fuel economy. Can't recommend eliminating the skip shift - the EPA/CARB will come after us.