In the next couple weeks I'll be ordering up some tubing for my SRT6 so that I can fab up a custom exhaust. I was just wondering what size all of you are running.

 

The optimum tube size is the stock set up, your not gonna gain anything, but if you want to modify the exhaust I suggest you remove the cats for a smooth pipe. This should get you about 2-5 hp more. Remember the exhaust is designed by AMG who has more experience than you will ever have.

 

Nope, I disagree.

Optimal exhaust setup would be.

2.5" to 3" piping, 100 cell SS high flow cat (offered by evosport), resonator removal, and a eisenmann race exhaust (or borla).

 

Yeah right, maybe for a 350 Chevy. If you go that large, you will loose a lot of torque on the low end. Which is the best part of the cars power. yeah 2.5" is overkill, for stock, unless you have a full pulley kit ecu tune, and big cams, and your putting down 400 hp then yes 2.5" is about right. you are talking duel exhaust?

3" exhaust is just stupid on a v6. Trust me that factory AMG exhaust is plenty for the srt6 up to 350-400 hp. we are talking about street cars, not race cars.

 

stock on a c320 is 2.5" on a c32 amg piping is 2.75" if your interested.

100 cell high flow cats are better than "removing it" like you said, its a street car not a race car.

 

Here is a link to the best answer to your question: http://www.burnsstainless.com/. You will find a worksheet on the website that can be filled-out with all of your engine specs. and the engineers will design the most efficient system for your car:
http://www.burnsstainless.com/Xdesig...spec__form.htm.

Leave the engineering to the engineers and enjoy the HP.

 

I just had my cats removed and used stock sizing... I think I made a mistake for some reason... is it possible to loose performance by using stock size instead of the rear cats or am I just loosing my mind..? I used stainless steal pipe by the way...

 

No, but it is probable / possible to lose performance by removing your cats without altering the signal sent to the ECU by your second bank 02 sensors... If you are feeling less power after removing your cats, it could be that the secondary 02 sensors are sniffing more unburnt fuel than oxygen and trimming your fuel back and retarding your timing...

I'm testing a GIZMO this weekend that Woody built that in theory, should trick the sensors into thinking that there is more oxygen than fuel and richen the fuel mixture and advance the timing... I'll have results posted by Sunday night...

 

I always thought that the cats that I removed... the two rear cats have no sensors...?

 

Oh, Sorry... I thought you meant all the cats... Forget what I said...

 

yup looks like I am losing my mind... or that the butt dyno has become very ineffective...

 

so is the srt6 amg exhaust only for the srt6 or will it fit the limited ? if so is there a gain...?? i really do enjoy the smooth sound of the stock exhaust i want it louder but not that from what i have seen on the borla... sounds like a mustang unless i heard the sound clips wrong... any advice?

 

I went with the 2.5 inch and eliminated the muffler. Sounds nice now. Pics in my gallery too.

Check out the 1/4 mile clip here:

http://www.youtube.com/watch?v=K32PlesuAd4

- Mike

 

What did you run? And did you go 2.5 single and no muffler and stock tips?

 

I ran 15's. It was my first time ever running a car at the track...it was fun but i need some practice.

I did not use the factory tips. I wanted to keep my cat back from factory original just in case I had to take the car in for some warranty work. Any excuse the dealer can use to say "NO" they will...we all know that.

The tips were brand new stainless steel and I found them on ebay. I think they were listed for a vette. It was last year. My friend manages a muffler shop and he loves to work on cars. He bent the new exhaust and welded it all together, then he welded the new tips on. The exhaust bolts right up. I like it, but its loud when your on the throttle.