draztik

well just in case, whats the cause of detonation? advanced timing and not enough fuel or what? sorry i get this and knocking mixed up a lot

turbo z24 guy

detonation can be caused by a million things... timing too far advanced...too lean... temps too high... just make sure youve got pleanty of fuel and an intercooler and you should be fine. detonation is where the a/f mixture ignites before the pistion is at tdc causing the piston to be forced down as its still on its way up... not a good thing at all...

draztik

also i thought detonation will only happen on acceleration? it never did anything but go up to 4k smoothly.. it only happened when i let off the gas

turbo z24 guy

im sure its a backfire. thats when msot backfire - when letting off gas. mostlikely because everything becomes so rich for a second.

hotrex

wheres my u bend

draztik

well is it possible to happen ONLY when you let off the throttle? i held it at 4k for a bit then let go, sat at 4k like normal without boost..

turbo z24 guy

no... its can happen at anytime. its wayyy more likely to happen under heavy acceleration though. but still its can happen at any time. hows the engine run now? any new noises coming from it? im sure you didnt detonate. if the engine still runs fine and no odd sounds, then stop worrying about it. like i said, im sure it was just a backfire. backfires are very common with turbo cars, esp when letting off the throttle suddenly.

draztik

well i did that while trying to figure out my little oil leak.. i found it now so hopefully tomorrow the leak will be fixed and i'll set my V-AFC to more rich just to be on the safe side.. and set my timing back a tad more. we'll see how it goes later on, it ran fine after that... i even reved it up to 4k again to hear it and it happened again.. never happened at 3 or 3.5k...

JD

Have you actually driven the car?? Try driving it and see what happens. Just drive nice

draztik

what should i do when i actually drive it? i have not driven it yet... how would i tune by my (yes i know not good) o2 sensor non-wideband but how should i do it first drive around while hitting no boost then slowly get into boost.. and by tuning should i floor it only to a certain rpm and watch my a/f gauge and adjust my V-AFC accordingly? sorry for the noob questions.. first car I've ever turboed and did all the work to.. first and only car so far. give the 17 year old kid a break!!!! thanks a lot to all who respond in the answer of my questions.. (that doesn't mean you hotrex)