What kinda gains do you get from headers, 3" cats, and Corsa catback?

[Vic]

What kinda gains do you get from headers, 3\" cats, and Corsa catback?

Yes, even at this late stage in the game, I'm just getting around to headers and cats. I've already got the Corsa catback, and all else is stock. Thinking of the Belangers, with RT metal substrate 3" cats.

Anyone know what that yields?

I tried searching, but much of the info was for different combinations, ie, heads+cam+headers, etc.

 

[Dave T (BADVENM)]

Re: What kinda gains do you get from headers, 3

I had Woodhouse install Belangers, high flow cats, air filters, Corsa and a dyno tune and gained 36 rwhp and 37 rwtq on my '01 sapphire/silver stripe beauty. Unfortunately the '01s breath pretty well so the mods compared to earlier years arent as good. the exhaust note is much better...partially due to the headers from what I was told.

 

[Topawam]

Re: What kinda gains do you get from headers, 3

...Unfortunately the '01s breath pretty well so the mods compared to earlier years arent as good...

Do you think a 96 with just K&N could gain more? I was thinking at a very similar setup, perhaps with additionnal rocker.

 

[BlueGTS]

Re: What kinda gains do you get from headers, 3

The 96 will pick up more because it has cast manifolds from the factory which are more restrictive. Another benifit is weight, as I saved 26lbs going to 2001 tubular manifolds versus my stock cast manifolds.

 

[Fast Freddy]

Re: What kinda gains do you get from headers, 3

i dyno'd 421 rwhp and 452 rwtq bone stock with no mods and approximately 2,000 miles on the odometer. the dyno was a dynojet. after installing bellanger headers, 3 inch random tech cats and 3 inch corsa cat back i went back to the same dyno with very similar weather conditions and 3,000 miles on the odometer. i dyno'd 452 rwhp and 495 rwtq. bellanger made a straight pipe for me with flanges and 3 bolt holes that can be bolted in place of my random tech cats. all you have to do is sim the rear 02 sensors.

i will be taking my car to west coast vipers in february to get their 650R package (550+ N/A rwhp) done to my motor so at that time i am gonna take my cats out. Vic i will sell you my random tech cats that are custom made by bellanger to fit a system such as ours when i take them out. i will sell them to you for half of what they cost new so PM if you are interested in buying them. the cats only have 5,000 miles on them as my car only has 7,000 miles total on it. i see that you live in california i will be at west coast vipers in temecula, california on monday february 6th.

 

[Vic]

Re: What kinda gains do you get from headers, 3

Thanks guys...

Freddy, pm sent.

 

[Fast Freddy]

Re: What kinda gains do you get from headers, 3

Vic - i found my dyno sheet that compares my pre exhaust mods (bone stock) and my after exhaust mods. as you can see the gains run through the entire RPM rev range

 

[Vic]

Re: What kinda gains do you get from headers, 3

Not too shabby! Thanks a bunch, thats exactly what I needed.

 

[Topawam]

Re: What kinda gains do you get from headers, 3

Perfect, nice gain, what about the sound? Not too loud?
Thanks for the info.

 

[Fast Freddy]

Re: What kinda gains do you get from headers, 3

in my opinion its not to much louder than stock from inside the car until you really get on the throttle then the difference in noise compared to stock becomes more pronounced. now from outside the car it is much louder from idle to full throttle and that is the way you want it. this way you can really blast your competition as you pass by them. the best thing is that this system has absolutely no drone whatsoever so you can drive across the USA and not get a headache. the tone of the sound is much better than stock. it sounds deeper and throatier (more muscular sound). the only reason i want to take the cats out of the system is because i will be road racing my car and they will get way to hot. plus i can pick up an extra 8 hp or so by getting rid of the cats. unfortunately when you take the cats out, the system gets louder. fortunately the tone or the pitch of the sound does not change though.

 

[GTS Bruce]

Re: What kinda gains do you get from headers, 3

I disagree with Fast Freddy.I have headers/no cats/corsa.No drone and loud outside.HOWEVER after driving back from VOI 7 in one shot our ears were buzzing when we got home.I suspect there IS a drone below the normal level of human hearing.Couldn't hear it in the car.Couldn't feel it.But it must be there either higher or lower than what we normaly hear and very loud.Possibly RPM related since we left by ourselfs and wern't part of a high speed convoy.No problem on the way there at higher speeds and RPM. GTS Bruce

 

[Ron]

Re: What kinda gains do you get from headers, 3

1996 / 97 cast exhaust manifolds flow the same as later stock tubular stainless manifolds. I dynoed 0.5 HP less with no other changes but the SS manifolds. Only benefit is the before mentioned weight savings.

Your HP increase isn't less than a early GENII because your engine breaths better vs. them stock, but rather because the cam was hotter in the earlier years and they gain more relative to later year GENII's with the same mods because the cam.