Fell into race class, want street class. I have a restictive cat/muff Tune question
04-19-2010, 02:27 AM
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Fell into race class, want street class. I have a restictive cat/muff Tune question I'm on the fence on what to do with the exhaust on my car, and since I'm back to the drawing board and welding up the flanges on the manifolds for the new twins this week I've got some options. I heard some tough news about which class my car lands in yesterday and need to make it look and sound as conservative/stock as possible (F/I 347 old 911).
Run dual 3" and reuse my 3" magnaflow three chamber muffs OR run 3" cutouts directly off exhaust housings (still duals) then into dual 2.25" magnaflow cats and dual 2.25" dynomax super turbo muffs? No X or H in either setup (it's a pain in the *** on my car and not worth it). I realize this is apples and oranges but here is my Q.
Will my tune be affected going from dual 3" cutouts to dual 2.25" cats/mufflers? I guess what I'm asking is, is it possible for my competent tuner to iron out this issue? Say, keep my A/F safe in both scenarios without compromising the other too much?
The reason I'm going so small and restrictive is that I spoke to the director at miller motorsports park about which class my car would fall into yesterday and he said race...I don't have sponsors and the budget to be competitive in the race class. This is a rich guy sport. I'm 26 and I still work hourly...not so rich. All my cash goes into the car/rent...I'll eat after race season.
So my plan is to present my car as a sleeper with limited info (he hasn't seen it) no wing (intercooler snugly fits into C2 decklid auto spoiler in the UP position, really stock looking) and try to enter and excel in the street class. I do have the interior gutted w/sparco buckets and harness no radio/heat/ac, so this is gonna be tough to get in. I might need to add some thin marine carpet to add to the illusion
If this is a stupid idea, I'll just reuse my 3" N/A magna mufflers and not run cutouts and attempt to make it work with a smaller Z06/>215 cam.
Russ
Run dual 3" and reuse my 3" magnaflow three chamber muffs OR run 3" cutouts directly off exhaust housings (still duals) then into dual 2.25" magnaflow cats and dual 2.25" dynomax super turbo muffs? No X or H in either setup (it's a pain in the *** on my car and not worth it). I realize this is apples and oranges but here is my Q.
Will my tune be affected going from dual 3" cutouts to dual 2.25" cats/mufflers? I guess what I'm asking is, is it possible for my competent tuner to iron out this issue? Say, keep my A/F safe in both scenarios without compromising the other too much?
The reason I'm going so small and restrictive is that I spoke to the director at miller motorsports park about which class my car would fall into yesterday and he said race...I don't have sponsors and the budget to be competitive in the race class. This is a rich guy sport. I'm 26 and I still work hourly...not so rich. All my cash goes into the car/rent...I'll eat after race season.
So my plan is to present my car as a sleeper with limited info (he hasn't seen it) no wing (intercooler snugly fits into C2 decklid auto spoiler in the UP position, really stock looking) and try to enter and excel in the street class. I do have the interior gutted w/sparco buckets and harness no radio/heat/ac, so this is gonna be tough to get in. I might need to add some thin marine carpet to add to the illusion
If this is a stupid idea, I'll just reuse my 3" N/A magna mufflers and not run cutouts and attempt to make it work with a smaller Z06/>215 cam.
Russ
Last edited by lazylongboarder; 04-19-2010 at 02:02 PM.
04-19-2010, 04:46 PM
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I believe this should be easy to tune around. It just would have been better if you had known in advance - it may have affected your turbo choice, cam choice and/or system layout, eh?
Sounds like a sweet project - I love sleepers and 911's, so a sleeper 911 rings all my bells!
Jim
Sounds like a sweet project - I love sleepers and 911's, so a sleeper 911 rings all my bells!
Jim
04-19-2010, 08:38 PM
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I believe this should be easy to tune around. It just would have been better if you had known in advance - it may have affected your turbo choice, cam choice and/or system layout, eh?
Sounds like a sweet project - I love sleepers and 911's, so a sleeper 911 rings all my bells!
Jim
Sounds like a sweet project - I love sleepers and 911's, so a sleeper 911 rings all my bells!
Jim
I'm hoping this issue CAN be tuned around.
Your car is a true sleeper. Bad *** man. I love it.
This has been worse than a gambling addiction.
Anybody run stock cats/exhaust with cutouts on +12 lbs boost?
Russ
