The 5.7s Plastic Intake Manifold Bolts Loosen Over Time

Oh, sadface. It is a feature that really offers a lot of tuning fun.
You can cam the engine for high RPM, then add really long runners to rescue the bottom end of the RPM range, then switch over to the higher-RPM ultra-short runners, and tune those to basically be super-short trumpets that point right down at the intake valve backs. There is so much potential when you are dealing with two completely discrete (note: this is not discreet) intake paths.
I would be tempted to go with about 2 foot long runners for low RPM and just a token bell mouth on the beginnings of the intake ports for the high RPM runners, and see just how wide we can make that torque curve while still not causing a midrange slump.

In fact, the PCM's out today could be programmed to do something like that I think. It is a lot less complicated than having telescoping intake stacks like Mazda did for the 787b and the modern F1 teams also have.

It reminds me of having actual old-school Roots blower. You don't need much length at all in the intake ports/runners due to the low-RPM emphasis of the supercharger, but you really want that short port at higher RPM, so you can take advantage of all that low-RPM grunt to design your package for high RPM only.

It's the opposite with a centrifugal supercharger. You can cam it for rock-bottom, knowing the centrifugal boost will keep building with RPM to rescue the top end from too much intake restriction. I'd still want the fat ports, though. If a cam, lots of valve lift (not duration so much) and a centrifugal blower can't rescue the bottom end, I would not care too much as I surfed the tidal wave of relatively effortless power at higher RPM, where the only limit is my valve springs.

With a properly-set up system, a Roots can have almost the same power curve as a centrifugal blower on the same long block, as Richard Holdener shows in this video:


The Roots was run with a manifold with absolutely minimal "intake runners" on it that basically had just holes emptying out of a plenum, and the centrifugal blower was run through a dual-plane manifold to further aid its low-RPM capabilities.

Amazingly, this worked, as the same engine with the two different intake setups on it produced almost identical results. Obviously, the carburetion helped cool the intake charge via evaporation, something you don't see as much of on MPFI.

 

Would you please explain what any of that has to do with the actual purpose of this thread? Please condense into less than a small paperback book.

 

I am beginning to see why many other Challenger owners avoid this forum.

 

I like the paper back book

 

Well the intake manifold bolts are not a problem anymore for my 5.7.

 

My Magi recirculates the pcv oil back to the pan through the filler tube. Did you add the catch can?

 

Yes I did, my Maggie is an older model and it ports directly back into the air horn, the catch can keeps that area before the flapper door free of oil residue.

 

I haven't taken the car to the drag strip but it dyno's at 480 to the wheels (550 at the crank) with long tubes and Corsa. Wondering if you've been with yours?

 

I haven't dyno'd it, or taken it to the track, just finished installing it about 3 weeks ago, still learning the difference from naturally aspirated, it is flipping awesome! Instant power at any rpm range, is truly amazing difference, will be data logging and getting Hemifever to fine tune the written tune. I am not really concerned about the actual HP numbers, but there is no doubt it is way more than it was!

Really did not do it for drag racing just wanted it to be more than it was, and that goal is accomplished! Ryan