3" or 2 1/2" exhaust system..?? advice please
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3" or 2 1/2" exhaust system..?? advice please
Ive got an my93wrx fitted with a remapped ecu to 300bhp, produces 1.5bar boost max, and holds 1.1bar.
Ive currently got a 3" straight through decatted system.
A mate of mine, is looking to get to 400bhp, and wants a 3"system, his is a 2 1/2" system.
If as a good mate i were to do a swap with him, what would you predict would happen to mine..??
what would be the effect of dropping down..??
Any guidance please?
thanks
Frank
Ive currently got a 3" straight through decatted system.
A mate of mine, is looking to get to 400bhp, and wants a 3"system, his is a 2 1/2" system.
If as a good mate i were to do a swap with him, what would you predict would happen to mine..??
what would be the effect of dropping down..??
Any guidance please?
thanks
Frank
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Thanks for the replies so far..
About the ecu ...... i was running that standard one, and thenbought a Z4, put that in my car,and it wouldnt run.
I took it to a local motorsport garage, they checked it, and said i'd been sold a knackered ecu. They offered me to try one of theirs that they use in their rally car. I did, and it peaked at 1.5 bar boost, with 1.1 held no probs....more importantly, its mapped for UK fuel.
The only mods are the full 3 "exhaust. ...... the ecu is doing all the work.
The ecu wasnt mapped to the car, when i bought it, and runs sound.... But, a mate of mine, is looking to buy a full 3" system, because his mods are going to take him up to the 400bhp zone.
Im not to bothered, ive been thru the new engine and gearbox syndrome, so now, im having to be a bit more careful.
I have heard that the smaller downpipe may give better spool up, but .... thats not my issue. I wouldnt want to lose big mpg, as ive got it were im happy at the moment.
Any comments, or ideas on the net effect of downsizing to a full decat 2 1/2" system....notably the downpipe.
thanks again
Frank
About the ecu ...... i was running that standard one, and thenbought a Z4, put that in my car,and it wouldnt run.
I took it to a local motorsport garage, they checked it, and said i'd been sold a knackered ecu. They offered me to try one of theirs that they use in their rally car. I did, and it peaked at 1.5 bar boost, with 1.1 held no probs....more importantly, its mapped for UK fuel.
The only mods are the full 3 "exhaust. ...... the ecu is doing all the work.
The ecu wasnt mapped to the car, when i bought it, and runs sound.... But, a mate of mine, is looking to buy a full 3" system, because his mods are going to take him up to the 400bhp zone.
Im not to bothered, ive been thru the new engine and gearbox syndrome, so now, im having to be a bit more careful.
I have heard that the smaller downpipe may give better spool up, but .... thats not my issue. I wouldnt want to lose big mpg, as ive got it were im happy at the moment.
Any comments, or ideas on the net effect of downsizing to a full decat 2 1/2" system....notably the downpipe.
thanks again
Frank
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Since you and your mate can swap exhausts, why don't you do a back to back test to compare?
How about doing a few timed 30-80mph 3rd gear runs on a particular road, get an average time then swap systems and redo the timed runs on the same day. Then decide whether to keep the exhaust on based on your results
How about doing a few timed 30-80mph 3rd gear runs on a particular road, get an average time then swap systems and redo the timed runs on the same day. Then decide whether to keep the exhaust on based on your results
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