Got in race class, want street class. Restrictive cat/muff tune question with cutouts
04-19-2010, 03:12 AM
#1
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2006
Posts: 397
Likes: 0
Received 0 Likes
on
0 Posts
Got in race class, want street class. Restrictive cat/muff tune question with cutouts 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 in 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 02:13 PM.
04-20-2010, 09:04 PM
#2
TECH Apprentice
Thread Starter
iTrader: (2)
Join Date: Aug 2006
Posts: 397
Likes: 0
Received 0 Likes
on
0 Posts
Bumpers.
Still curious and need an educated answer without bugging one of our sponsors. I've already got the 2.25 cats and muffs, I try to make it a policy to not call unless I buy something from them. They're plenty busy this time of year.
Still curious and need an educated answer without bugging one of our sponsors. I've already got the 2.25 cats and muffs, I try to make it a policy to not call unless I buy something from them. They're plenty busy this time of year.
04-20-2010, 09:17 PM
#3
TECH Fanatic
iTrader: (4)
Join Date: Jun 2009
Location: Maine
Posts: 1,256
Likes: 0
Received 0 Likes
on
0 Posts
A competent tuner could set you up with both setups...run 2 different PCMs and have them tuned for each. Label them and swap according to your exhaust setup, could be that they aren't too far off from each other and you may not need a double tune. Best of both worlds to run both setups!
Just an idea, by no means am I a pro or anything close. Just thinking outside the box for you.
Just an idea, by no means am I a pro or anything close. Just thinking outside the box for you.
04-21-2010, 06:54 PM
#4
TECH Fanatic
Join Date: Jul 2007
Posts: 1,516
Likes: 0
Received 0 Likes
on
0 Posts
can a maf only tune be used in this instance? The tuner we use at work did a maf only tune where the maf is reading throughout the rpm range on a GTM we built with a LS7 that has 3 different sets of exhaust (cat and muffler, cat only, and wide open). The A/F ratio stays pretty consistent through all the different exhausts.
FWIW, im no tuning expert. I am just relaying information that has been told to me from our tuner. We have been very pleased with the results he has given us in our LS motor cars. 605 rwhp out of a cammed ls7 in a GTM, 405rwhp bone stock LS2 in a GTM, and a few others. All his tuning is done on a loaded Mustang Dyno.
FWIW, im no tuning expert. I am just relaying information that has been told to me from our tuner. We have been very pleased with the results he has given us in our LS motor cars. 605 rwhp out of a cammed ls7 in a GTM, 405rwhp bone stock LS2 in a GTM, and a few others. All his tuning is done on a loaded Mustang Dyno.