Hey all. This winter I decided to do a cam swap (and some more). I have been reading on other forums that swapping the stock cam from a SRT 6.4L is a great power adder. Many have claimed it adds @60 horsepower. So I decided I would do that swap and see the results myself. My car is a 2010 R/T Classic 6 speed..5.7L with stock claims of 376bhp/400 lb ft I have been running a Diablosport T-1000 InTune tuner with a canned 93 octane (CAI) tune. Here's is what I purchased: -a Mopar Parts 6.4L stock non-MDS cam -PSI Performance LS1511 "Max Life" (that's Chevrolet LS6) valve springs -Comp Cams spring retainers -Manley spring cups -.020 (intake) and .030 (exhaust) spring shims from Arrington -a Modern Muscle 87mm throttle body -JBA 'shorty' headers Overall the swap was pretty simple. The only exception is the headers. They are a pain in the butt to install. If I ever do headers again, I will pull the heads. Stock the car put down a 318.4 rwhp number with 387 lb ft of torque. That is pretty normal for these cars. If you figure in a 18% driveline loss, that is right on the money to stock claims. Multiplying the 318.4 x 1.18, you get 375.712bhp With the Diablosport tune and CAI, she put down a nice 340.62 rwhp and 398 lb ft. Using the above math, 340.62 x 1.18 = 401.931bhp Both of those runs were on a Mustang dynomometer The forum-ites have claimed that this cam will produce a 60hp gain. But each person who has made this claim have gone from bone stock to cam and tune. Since I know the tune adds about 23-28hp (and my results were 26.219), I was expecting to see a slightly lesser gain of around 40 hp, which is actually more realistic for a cam swap. Results: After finishing the install in mid-March, she started up perfectly and ran very well. I drove her sparingly thru April, and even did a cruise with some fellow LXers. I took the car to Tim Barth at Modular Powerhouse (formerly Mr. Norm's) in Rockford, IL for tuning on Wednesday, May 14. He uses a DynoJet dynomometer. He did a first 'baseline' run and put down a very nice 393.71 rwhp with 371 lb ft. So a 53hp gain without adjusting the tune at all. That is already showing what has been claimed, and above what I was hoping. I know that torque will usually suffer a little with a cam and headers. So the torque numbers were reflecting that. After Tim did a few adjustments, the hp increased to 394.46 and torque came back up to a nicer 389 lb ft. Next adjustment brought it up again to 397.63hp / 392 lb ft. Next adjustment 401.42hp / 396 lb ft Final adjustment produced an impressive 404.25 rwhp / and 400.07 lb ft. Those are 392 (6.4L) numbers folks. Unbelievable!!! That is a huge 64hp increase and 2 lb ft. ....404.25 x 1.18 = 477.015bhp I have my redline set at 6500rpm. Tim only ran the car up to 5800rpm. The hp was still increasing at 5800, but starting to level off. My guess is, if we pushed redline, there is another 5-10 hp there. MPG: My MPG was normally 19-20mpg city and 25-ish highway. Now I am 16-17mpg city and 26+ highway. So that means my stop and go mileage dropped a small amount (that is to be expected) and my highway went up a small amount (that is not expected). Driving: Driving around town feels similar....until you get above 3500. Stock I have noticed (and have seen on the dyno) that power starts to level off at around 3500. I have also noticed a drop around 5200 (about 5-10 hp). Now she keeps pulling all the way thru the curve. definitely much stronger in the upper rpm range. Looking at the hp curve, she has a nice climbing hp curve all the way up to redline. There is a very small (about 1-2hp) dip at 5200 still but nowhere near as pronounced as stock. I haven't pushed her much yet, but I can say that 60-100 is beastly. Much MUCH harder than stock.
Excellent write-up Jonmandude. Your final results are most encouraging. I am planning on adding the same cam and hoping for a similar 400 rwhp. Currently I have a 85 mm BBK TB, JBA shorties, Solo high flow cats and a custom diablo 93 CAI tune putting out 371 rwhp.
