kirky ok guys i got my vec dyno'd last night and got a shock.the cars engine is standard apart from a cat back s/s exhaust and a k n panal filter it produced 139.4 bhp at the flywheel and 114 at the wheels.the mechanic told me the exhaust was costing me about 8 bhp.its a custom made exhaust.what ive notest that eversince i got the exhaust put on ive had rough idle :? has eny1 experienced this?
Jamee I cant see anything wrong with that set up mate, so i wouldnt have thought it would be the exhaust, have you removed the pre cat yet?
TimSri I can't see how you can lose 8 bhp through the exhaust, and it deffinetly wont cause rough idle.
vocky as above, have you removed the precat notsure.gif it won't be lack of back pressure, most likely a sticking egr valve dunno..
kirky vocky theres no pre cat and ive blanked the egr valve air to fuel ratio is fine as is the fuel pressure and vac.the ignition timing is also spot on
Matt Erm, how about a different Dyno? They are all subject to a lot of external factors, so I'd only be worries if it was consistantly low on other dyno's
kirky cheers m8 its a brand new 75 grand dyno it was on,hes done other cars on it then taken them to other dynos.its pretty accurate and the boys are well trained
baldie87 if u still have your oem exhaust put that back on and get it done again and see what the outcome is