cavy exhaust/intake info. read before moding

[perna00]

this is just some info that i found out the hard way and was stuck with. i had a 96' cav 2.4 and added alot of mods to the engine. if you drastically change the intake and exhaust you need to get the fuel/air system tuned in. because of the increased air flow you will throw off the mixture and not gain much at all. for example, if you get an injen intake, you will notice (not exact) about a 5-7 horsepower increase but if you tune in the fuel air after mixing it, it will get about 7-9 horsepower increase. if you get a cat-back system you don't have to worry about much cause the difference will be minor. *if you get a header/free flow cat, your gain will be very minimal if not hinder it because of how far off the computer will set the mixture. your engine will actually tap and knock until the computer compensates enough to prevent it which even then is far off. i put much $ and time into all these items and more and found that after all my $ and time, i was only a little quicker than a 2.2. i've totalled my cav and no longer have any desire to find out what items are available for adjusting fuel/air mixture (don't even think about the jet power control module- absolute garbage!). i know that for my eclipse now there is a "g reddy e-manage" that lets you adjust the actual mixture directly at difference rpm settings. i will not be replying to any questions about this thread from the cavy section since i no longer have the car, but you are more than welcome to pm me with questions/comments if needed/wanted. just trying to help you out from one person's mistake so it's not repeated. -jake

[KustmAce]

Why cant you reply here even if you dont have the car?

[perna00]

i guess i can, it's just that last time assholes decided that since i didn't have thier car i didn't belong here

[ohio420jb]

i thought after mods, if ya reset the computer, itll re callobrate everything for the correct fuel, etc...

[KustmAce]

Originally Posted by perna00

i guess i can, it's just that last time assholes decided that since i didn't have thier car i didn't belong here

I can take care of that. You can post wherever you want, there is no rule saying if you dont own the car you cant post. I hope youll visit here often, you seem to have some good Cavy experience.

Anyway, I have a CAI and an exhaust, and my car runs fine. The computer compensates, but it will only compensate so much. I figure if I go any farther performance wise, it would be wise to increase my fuel flow.

[perna00]

ohio, the computer does compensate after you reset it, but only to a certain extent. there are preset value the the sensors and computer works with but if you modify it beyond a resonable limit from factory specs, the computer can not use the predefined values to properly calibrate it. there is also the problem with the stock parts only allowing so much variation (example: the amount of fuel the injectors can release in there opening time)