Going with slightly smaller pulley - need new chip burned?
I'm gonna post this here and the general tech area. I have the D1-SC and the motor is the stock cobra except for pro-m mass air meter, 42lb injectors, offroad exhuast, ati adjustable fmu and shorty headers. I have a mail order jms chip set-up for my current boost level. I'm running a 3.55" pulley and seeing 10lbs of boost. I'm going with a 3.35" pulley. I'm running a fairly safe tune. Do I need a new chip? Can I give it more fuel with the fmu and maybe retard the timing to avoid detonation? Thanks guys.
Brian
Re: Going with slightly smaller pulley - need new chip burned?
Quote:
Originally posted by Z's Cobra
I'm gonna post this here and the general tech area. I have the D1-SC and the motor is the stock cobra except for pro-m mass air meter, 42lb injectors, offroad exhuast, ati adjustable fmu and shorty headers. I have a mail order jms chip set-up for my current boost level. I'm running a 3.55" pulley and seeing 10lbs of boost. I'm going with a 3.35" pulley. I'm running a fairly safe tune. Do I need a new chip? Can I give it more fuel with the fmu and maybe retard the timing to avoid detonation? Thanks guys.
Brian
Brian,
Are you positive your current blower pulley is a 3.55"? Reason I am saying this is because I was running a 3.80 on my D1SC and I saw 10#'s with this pulley and I have heads/cam. I installed a 3.55" pulley and am now seeing 13#'s by 6000rpm.
The car ran fine on 10#'s and was tuned on a dyno for this, however I upped the boost and blew a head gasket.
I am sure the JMS chip already has a total timing set into it, as well as fuel curves. I would call Chris Johnson and ask him what he thinks as he is the one who burned the chip for you.
If he says its ok to turn the fp up a little and back the timing off some, then so be it, however I wouldn't do anything until I talked to my tuner.
DAN