cat-back will i lose power what work's ?

I have a banks on a 5.7 and didnt notice a drop. It runs well and takes grades better than stock. They might be refering to the power loss under ~1500rpm, which is expected with larger tubes.

If its any consolation, Buy a Flowmaster and use your present pipes.

Cheers

BTW dont worry about loosing back pressure. Its the velocity youll loose at the low rpms.

i was thinking of using a 2 1/4 inch duel exhuast, with a h pipe. to get specific about the setup's my freinds have had problems with, one freind has a 3" cat back mandrel bent with a 40 series flowmaster on his 4.3 reg/cab s/b. i went for a ride in it before and after he had his exhaust done, and there was a noticeable loss of power through out the rpm band lost botom and top end...... another freind 5.3 reg/cab s/b, just replaced muffler with flowmaster also complained of lost power. and a couple other guy's i've asked at the local 1/4 mile track have said the same. just dont make sense to me any help would be appreciated. thanks again.

I would call the guys at Banks, They'll know what your particular engine suffers from. Adding a Catback without intake modifications may cause problems. My 5.7 had poor flow on the intake, and the stringer intake from banks had a noticable improvement by itself. But tthis may not be the case with the 5.3.

usually, when you reduce back pressure, you lose low rpm "grunt" which most folks think of as "power" and gain power at the higher rpm range... i'd say that if you lose both low end AND high end, that the exhaust is definitely not matched to the engine... i know that with the newer dodge trucks, dropping back pressure seems to decrease performance... maybe the big 3 have finally started putting efficient stock exhaust systems on? nah...

hay guys im just trying to figure out what works before i spend a lot of $$$ on a system that dont work. so if any one has had any experience with a late model chevy, please let me know what combo, and what were the results. thanks again.

"david cruz" sez:

I got around 10% performance & mileage increase with a Gibson stainless header/cat-back system on my '97 Suburban w/5.7 engine. See

... VLJ

I put a flowmaster 3 chamber 2.5" cat back on my 2000 Silverado w/

5.3. When I took it in, the truck would "bark" the tires (285/75/R16) off the line on dry pavement. After I had the flowmaster with 2.5" pipe from the cat back, I can now roast the tires from a dead stop. Only other mod is a K&N FIPK. I didn't notice an increase in gas mileage with either, but it's definitely louder and it "sounds" like it's going faster.

Derek

hay derek you said you have 285/75/16's tires, those are pretty tall. i have 255/70/16's with a 3.73 gear peg-leg, and i might get it to spin for 4-5 feet, but i definetley can't lite'em up. do you have a posi in it ?..... im not looking for a good exhuast just for the sound ( thats just a plus to me ) i realy would like to increase the power and mileage. thanks for the replies guys, any additional help would be appreciated.

sorry about that last post, forgot to remove my signature.

David,

Yes, I have the Eaton G80 "locker" with the 3.73 (I believe) gears also. Mine will spin hard enough to engage the posi and then will continue about 15 feet or so. I try not to do this since all I hear are how weak these posi units are. Plus the tires are $$$. As for fuel economy, I didn't really notice a big difference. May .5mpg or so. It does have more power, so I got more power with the same MPG, I am happy.

Derek

thanks dereck.

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