running a DP+cutout on a stock exhaust?
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Joined: Apr 2006
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From: MA
running a DP+cutout on a stock exhaust?
i want to do a full exhaust for obvious power reasons, however, cops have not been friendly to some people i hang around with and have gone as far and looking under the car, under the hood and then scraping the inspection sticker off because they said their exhaust was too loud and that made the car illegal. this was on an 05 STi and he wasn't doing anything. i live in MA, we have serious emissions tests too. so, i found a DP that has a cutout built into it so i could just put an electric cutout on it and have the best of both worlds. the question i have is, how much will this effect my tune? i'll it be to the point where i'd have to swap tunes if i opened it? thanks to all who can help.
oh yea, its for an 06 MR
oh yea, its for an 06 MR
You must tune for a cutout, however if you have a high flow TBE tune that will suffice. I am in the middle of doing the same thing. And only tune for it open, you should only be getting on it with the cutout open anyway.
You don't HAVE to tune for the cutout. It's just like a bigger exhaust. I don't think it'll really affect the A/F tables much. You can probably run more timing after tuning for the cutout, but again, you don't HAVE to tune for it. You just won't be optimized for power.
From what I understand a cutout does affect your AFR's making it about 1 point leaner. You will probably want to get a tune with it open and then when you run with it closed it will just be a little rich, which should be ok.
Last edited by onefast4dr; Jun 13, 2007 at 06:42 PM.
Thread Starter
Newbie
Joined: Apr 2006
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From: MA
ok, thats what i was hoping for. i have a new wideband sitting here that will go in too so i can watch it. and its not tuned yet, i'm not even getting it till next week, i just want to have everything planned so i don't have to do stuff two or three times. thanks for the help guys
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From: mount vernon, wash.
just get it tuned with the cut out open when you are running with the stock exhaust you will be a little rich yes but that wont matter unless you are taking well into boost if you are just driving normal it will be cool open it up and rail the P!$$ out of it.
i dont know if that made any sence but there you have it and install your wide band at the cut out.
i dont know if that made any sence but there you have it and install your wide band at the cut out.