ok I have a www.dsmchips.com stage 2 chip set for the stock 450 injectors, since then I have put in 650's and now even under partial throttle and around 8-10 psi it knocks like a mother. I read somewhere that using my SAFC to trick my computer that much in order to compensate for the bigger injectors actually advanced timing too much. Is this my case and if so will having another chip burned for the 650's fix this problem? If it's something else for the love of God please let me know.

Have you used the SAFC to adjust your fuel curve at all? Just throwing in 650's on a chip for 450's means you'll have to pull out ~30% fuel across the curve to get back to stock levels. You must be running pig rich.

Originally posted by HybriDSM
Have you used the SAFC to adjust your fuel curve at all? Just throwing in 650's on a chip for 450's means you'll have to pull out ~30% fuel across the curve to get back to stock levels. You must be running pig rich.

use a logger and tune it. if it still knocks or is impossible to tune, then use a stock ecu and try again. If that STILL doesn't work, send your injectors to www.cruzinperformance.com to make sure they're all up to spec. <---do that step absolutely last!!!

just ordering a "reflashed ecu" without giving them your personal specs won't do much but give you a very basic baseline to begin tuning from. All cars are different, especially at diff climates, temps, elevations, boost levels, air flow levels, turbos, etc. so there really isn't a cookie cutter chip that can help you. I Have to re-tune my car here in MO from my summer settings I had in MD.

good luck!

either have someone burn a new chip for the 650's or lean it out with S-AFC. You are knocking from too much fuel.

Wow......

Ok I won't get mad it's my fault I should have told everything to begin with. I'm not a complete moron yes I have tuned for the 650's, I didn't just slap them in there and call it good. There seems to be a very fine line between sputtering because of running pig rich, and running too lean with my car here. Now the problem is that I don't seem to be able to get on that line, if I lean it out just a hair it knocks because of lack of fuel, but if I richen it up it sputters and boggs. Mods are apexi N1 turbo back(2.5 to 3 in piping), SAFC I, 255 lb/hr walbro, 650cc injectors, stage 2 chip, K&N with hacked can, MBC set to about 12.5~13psi. Ok now proceed with any further advice, please.

While I'm at it, could I get an estimate of what kind of a quarter mile time I SHOULD be capeable of with this setup? I'm not trying to be a bench racer, I would just like to know what I'm aming for with what I have, and yes I know my stock smic is super heat soaked, a fmic is next on my list, and while I'm at it would the SBR street core be enough to run in the high 11's fairly concistently? I'm sure I sound like a n-o-o-b but how else will I learn, right?

Whats your fuel pressure at? Do you have a regulator? How are you logging? Pocketlogger? Go take a few pulls and post up the results.
Also, I'd most DEFINETELY have a chip burned for your injectors. Why take the long road which will be plagued with problems?

I'm logging on a palm with mmcd. I got a new computer and apparently I lost the software for the palm. I'll try looking for it all again and post some runs for you.

What turbo are you on? I don't see that in any or your posts. Also as eclipzgst said do you have an AFPR, with a 255 and 650's you are overruning the stick FPR bad and you will never have consistent fuel pressure under boost.

Ok sorry, I'm on the stock 14b and the stock FPR, but I was told that the stock FPR would be OK. If not does anybody have a 190 they want to sell?

EDIT: again, sorry for my stupidity, but if the 255 were to overrun the stock fpr wouldn't it also do it at idle since the injectors wouldn't be using as much fuel and the fpr would have to send all the excess fuel back to the tank?

when i tuned using my safc, it almost the same fuel added across the board. many people try adding/subtracting fuel at different rpm ranges and seem to have problems with the ecu going back to stock fuel map settings (i call it "limp" mode). I have 680's, safc, 255hp, no FPR and never had a problem with it. Most of the dsm's I have tuned seem to keep the same fuel adjustments from 1k to 7k. The only true way to get it correct is a pocketlogger. good luck -Scott