Does a z06 catback flow same as aftermarket

[mach350z]

Hi, Ive got a 2000 automatic c5 with ls6 cam , ls6 intake blackwing cold air and holowed cats. I just had it dyno tuned and it only made 319rwhp! From the post ive read I should be at 345RWHP.

The only thing I might have neglected is the cat back. Ive also herd that the stock cat back on vettes are very good and aftermarkets hardly pick up anyRWHP and would it mees up my dyno tune if I did?

My question is how much RWHP do you think after market cat back on c5 really gain and would a Z06 cat back be just as good.

Thanks, any comments would be greatly appreciated.


BTW I cant run headers due to extended warranty.

[SeVeReDiStOrTiOn]

What kind of dyno was it on? Dynos can vary greatly (stang dyno simulates a load so you'll get "lower" numbers while a dynojet doesn't). Also which year LS6 cam do you have, because there is a difference....though nothing huge.

2001 LS6 cam
207/217 int/exh @ 0.05" duration
0.525" / 0.525" int/exh lift
116 LSA

2002+ LS6 cam
204/218 int/exh @ 0.05" duration
0.551" / 0.547" int/exh lift
117 LSA

You'll see some gain with aftermarket mufflers...go with a straight-through muffler like magnaflow. I'm not sure about the Z06 catback...hopefully someone else will chime in.

[Wesman]

Your engine is probably having trouble breathing through the stock manifolds and stock exhaust. You increased airflow on the intake side with the LS6 manifold, and you increased the amount of air the engine can inhale/exhale with the LS6 cam, but you neglected to let the motor breathe on the other end

Add some longtube headers with a full exhaust. On a stock LS1, LT's and a tune can be good for almost 40WHP. So with your LS6 manifold and your LS6 cam, you could eaily jump up by 50WHP+, since you have a big restriction on the exhaust side of the motor.

An LS1 with an intake, LS6 cam, LT headers, full TD exhaust, and LS6 manifold should put down somewhere around 370WHP.

EDIT: Just saw the part about the extended warranty, why would LT's void the warranty?? Its only a bolt on anyway, of something majorly bad happened to the engine (unlikely anyway) you could always swap back to stockmanifolds. You already have a cam, why are you worried about the warranty?? If that doesn't void it than nothing will lol.

[SeVeReDiStOrTiOn]

LS6 cam has a stock idle...there's no way the dealer can tell it's in there. Long tubes on the other hand...

[Wesman]

LS6 cam has a stock idle...there's no way the dealer can tell it's in there. Long tubes on the other hand...

This is true, but in the event of serious warranty work (internal motor problem, although unlikely) they would pull apart the engine and the warranty would be null and void.