Top 10 SRT-8 performance upgrade tips

[JMatt]

1) Mopar is coming out with a cone filter for the 6.1
2) Remove the exhaust resonators to open up the exhaust. They do almost nothing on the SRT-8. They cured a harmonics problem in the MDS 5.7.
3) The transmission should handle 700 ft/lbs
4) The pistons and rods won't
5) The bottom-end should
6) The rear diff probably won't
7) The intake casting is a bit rougher than it could be
8) Higher performance heads will be available.
9) Stiffer suspension from the Charger is a direct fit on the 300C SRT-8.
10) The Cat's are fairly restrictive, but the mufflers flow straight through.
11 & 12) There's at least two more I'd tell you, but they'll shoot me.

[ramtough15]

Any talk of a super charger being built.

[marlinspike]

Is there any place where I can find a comprehensive list of everything mopar has to offer for this car (not just performance stuff but everything mopar)? And, I wonder if the computer will register a code if the cats are replaced with straight tubes.

[vvv90]

Originally Posted by JMatt

2) Remove the exhaust resonators to open up the exhaust. They do almost nothing on the SRT-8. They cured a harmonics problem in the MDS 5.7.

How do we know that? I dont' see how the resonator hurts performance. It is a true dual inlet/outlet with very minimal backpressure.

3) The transmission should handle 700 ft/lbs

That would be nice....Any technical document on it? After all the tranny threads I'm surprised there's not more on the net.

4) The pistons and rods won't

hmm....rods and bolts maybe not, but pistons should. They're cast hyper pistons I believe and various stock and aftermarket ones can take this power depending on how it's delivered.....Though I would agree it's pretty high and running on the edge.

5) The bottom-end should

4340 forged right?

6) The rear diff probably won't

This would be a traction issue. 10" ET tires will make the rear go boom with stock power I'll bet

7) The intake casting is a bit rougher than it could be

WHat do you mean? burrs and ridges in the runners? Have you looked?

8) Higher performance heads will be available.

I can't wait to see what the aftermarket puts out.

9) Stiffer suspension from the Charger is a direct fit on the 300C SRT-8.

Does it need to be stiffer? I thought it was considerably stiffer than the 300C already.

10) The Cat's are fairly restrictive, but the mufflers flow straight through.

I would do high flow bullet cats (if offered) before I touch the resonator....Of course, this depends if you pass emissions.

11 & 12) There's at least two more I'd tell you, but they'll shoot me.

I'll shoot you if you don't....Worry about what I'm gonna do.

[vvv90]

Originally Posted by ramtough15

Any talk of a super charger being built.

I'm pretty sure since the only exterior difference with the 5.7 and 6.1 I can think of off hand is the manifold, I would think GSM's blower kit will work with a difference pulley and fuel trim.

[glhs837]

VV, remember Matt posting those cool pics of his car with the SRT teams SRT-8 that ran One Lap, driven by Erich Heuschele? Remember he mentioned then that Erich had shared some knowledge.

So, as I see it.

Resonators = You can be sure they tested this config before running the One Lap car this way. And if it didn't make power, they wouldn't have.

Trans = I'd imagine Erich is about the only person we'll meet who has access to the test data on this trans.

Intake = They mentioned cleaning them up, so it must be so.

Heads = Google Topend Performance, they do three different stages of SRT-4 CNC heads, fantastic stuff.

The only potential issue I see with a blower is that the compression ratio is such that some way of lowering the compression willl be needed, unless low boost is used. Dished pistons, larger CCs, destroking. But then you run into needing either a hacked PCM or standalones for fuel and such. .

[JMatt]

Cylinder heads: From Mopar direct (which I don't consider aftermarket)
Rods & Pistons: Rods are too long and connect too high up on the piston for much more power because piston tops are too thin. Recommendation is to use a shorter, forged rod, connecting lower onto a forged piston. Current set-up not good for supercharging without rod and piston change.

Haven't seen the intake personally.

[JMatt]

Originally Posted by glhs837

VV, remember Matt posting those cool pics of his car with the SRT teams SRT-8 that ran One Lap, driven by Erich Heuschele? Remember he mentioned then that Erich had shared some knowledge.

So, as I see it.

Resonators = You can be sure they tested this config before running the One Lap car this way. And if it didn't make power, they wouldn't have.

Trans = I'd imagine Erich is about the only person we'll meet who has access to the test data on this trans.

Intake = They mentioned cleaning them up, so it must be so.

Heads = Google Topend Performance, they do three different stages of SRT-4 CNC heads, fantastic stuff.

The only potential issue I see with a blower is that the compression ratio is such that some way of lowering the compression willl be needed, unless low boost is used. Dished pistons, larger CCs, destroking. But then you run into needing either a hacked PCM or standalones for fuel and such. .

Actually, item 11 & 12 came from Erich. The rest came from elsewhere in Mopar, but are confirmed by paying attention to what was done to Erich's car. My source did sponser at least one other car in the One Lap of America race, and has ties to Mopar. It's amazing who you can meet in the automotive performance world if you live in Indianapolis.

[glhs837]

Parking issues, anyone?

[vvv90]

Originally Posted by glhs837

VV, remember Matt posting those cool pics of his car with the SRT teams SRT-8 that ran One Lap, driven by Erich Heuschele? Remember he mentioned then that Erich had shared some knowledge.

So, as I see it.

Resonators = You can be sure they tested this config before running the One Lap car this way. And if it didn't make power, they wouldn't have.

Good point. Don't get me wrong. I'm all about performance, and if they don't control any real resonance, they're gone IMO just from a weight standpoint alone.

Trans = I'd imagine Erich is about the only person we'll meet who has access to the test data on this trans.

Yeah, there's been actual engineers who state these transmissions are very stout. I wish there was more readily available technical documentation based on strenths/weaknesses/efficiencies etc...

Intake = They mentioned cleaning them up, so it must be so.

I certainly wouldn't be surprised. I'm sure this will be one of the first aftermarket compoenents (5.7 included) to be made after chip, CAI, headers, Cat back systems.

The only potential issue I see with a blower is that the compression ratio is such that some way of lowering the compression willl be needed, unless low boost is used. Dished pistons, larger CCs, destroking. But then you run into needing either a hacked PCM or standalones for fuel and such. .

Well, based on what Matt says about the pistons being too thin alone I guess I could see supercharging as being detrimental to strength. The compression alone though is fine for a well tuned properly intercooled 8psi. 6psi to be safe.