cat-back exhaust w/ new mufflers

stoon aucoin · 06-01-2006

OK- does anybody have actual dyno results, at the rear wheel, showing hp/tq gains with an upgraded cat back and muffler system?
I have an 06 Gt std. and so for i have added a cai, tuner and 4.10s. What next? I have searched the board for ACTUAL DYNO results after upgrading the stock exhaust, from cat back to mufflers, and I can't seem to find a straight answer. Some people are claiming a 20 hp gain at the rear tire, while others claim only 3-5 hp gain. Most of the threads talk about how they sound, but I am ONLY interested in performance numbers. I know somebody out there has the info that I'm looking for, so PLEASE help a brother out. THANKS!

**stlwagon** · 06-02-2006

20 HP--no... Maybe 5-7 RWHP gain with just the catback. You're not going to see 20+ HP gains until you let it breathe by adding long tube headers and a new mid-pipe to the equation. Even if you did high-flow cats (or deleted them), an offroad H or X and the cat back, you're probably still not going to see a 20 HP gain until you replace the stock manifolds. As to your original question, I haven't seen any exhaust-only dyno results. Maybe someone else on here has. And... don't believe the manufacturer HP gain claims.

kj_cinci · 06-02-2006

Yes I have seen tests and no I don't have numbers... The gains were so small it could have been dyno/run glitches!! No peak gain and under 5 RWHP gain all across, lowend TQ was better, 5-10 lbs idle to about 2,000 RPM....

If you can afford it get long tube headers for 20-25 RWHP, 5-7 less for a high flow catted system... Highly recomended!

Otherwise you have Under Drive Pulleys and Charge Motion Delete Plates....

stoon aucoin · 06-05-2006

KJ- so you are saying with long tube headers, i'll see 20-25 hp at the rear tire, or long tubes, new x pipe, no cats and mufflers? Thanks!

kj_cinci · 06-05-2006

Yes, Kooks LTs OR midpipes and X to stock (or whatever muffs) will give +20 to the wheels! Same for JBA (H-pipe) who will be a bit under at peak but ahead the whole way up to 4,500 or so RPM. I think they're all pretty close... I'd go Kooks on fit and material... especially at the price; http://www.modulardepot.com/product_...roducts_id=229

Donnie Darko · 06-08-2006

What about a bassani setup? Long tubes on back.

kj_cinci · 06-09-2006

Bassani is good... don't know any numbers... other than that they're pricey...lol...

Donnie Darko · 06-09-2006

Quote:

Originally Posted by kj_cinci

Bassani is good... don't know any numbers... other than that they're pricey...lol...

Yeah, I'm not going to say price doesn't matter, but if Bassani can make good numbers I'll save a little bit longer and get that.