I have a new pulley that I'm itching to put in the S. It will add 1 psi to my current setup for an approximate max of 9.5 psi (I was getting 8.5 before prior to valve adjustment).

I know I'll need a new tune for optimal usage but in the meantime am I okay to put this in now? Since I've adjusted the valves the car has been running richer than before so I wouldn't think it would be too lean post install. I also have the NGKs one down from stock available for install.

What do you think? Am I playing with fire?

 

AS long as you dont beat on it i don't see anything bad happening in the time after install and before retuning. 1psi pulley change isn't going to make that much of a difference in the low rpm range.

 

the car will run more lean...thats for sure... because your forcing more air through whatever tune you had before. the computer depending on what you have might be able to slightly adjust to it. but don't go crazy or past like 4-5k rpms. cuz it could potentially cause an issue.

 

Thanks guys. Much appreciated.

 

Just keep an eye on your A/F gauge if you have one to be safe. If your saying it's been running a bit richer, you may be able to get away with it.

 

Assuming you have a wide band, I'd carefully open it up and see where your afr's rest throughout the power band, you might actually find you don

 

short answer, yes, need new tune. you will hit load points earlier on your map then previously. so even if your tuner scaled the map up for fuel and timing, they will still need to be tweaked. the other side of that is if they didnt scale up , then there could be a sharp change in your tune from one load point to another.

for instance on my tune, mase scaled it up to get fatter in fuel and slightly more timing pulled in spots i should not hit. then when i bumped up the pulley, i saw i needed to trim some fuel out. i now need some dyno time to dial in the timing. i dont beleive max timing can be achieved on the street IMHO. u could add a degree of timing and think everything is fine, but on the dyno, you gained jack shit in power, so why keep that extra timing there?


hope that makes sense.

 

[QUOTE=camuman,Sep 17 2009, 11:47 AM] short answer, yes, need new tune.

 

soo, when you buy a stock vortech or comptech kit they dont pull any timing from your map? i thought that black box that the VT came with was a timing manipulator?

i understand that the boost comes in slower/more progressive, but if at 8000rpm at 8.5 psi your at X degrees of timing, what says its the same timing number at 9.5psi? turbo, roots, centrifugal, its 8.5psi at 8000 rpm. also, when you put in smaller pullies, you hit boost sooner in the rev range, due to the nature of how it works.

i know i dont have first hand experience wiht this blower, but i just dont get how different loads, more air coming in wont require tweaked/decreased timing.

 

Thanks again, this is all great info. Unfortunately I don't have a gauge, but I could turn on data logging...not beat it but drive it a little and see where I'm at. If things don't look good I can put the old pulley back in. It's pretty easy to do with the SoS SCs.

The tuner I use has a disabled dyno and I'm having to wait until their 100% before I can tune. I have to admit the more days that go by with the pulley in my garage, the more tempted I am to put it in.

I'm in Indy, IN...I wish there were more tuners around here but there don't seem to be and Automotion has done a good job for me but I have to wait. *sigh*