dont i want STFT and LTFT to equal zero when added?

[Boosted97GS-T]

I read somewhere that to set my lo throttle settings on my afc, i need to watch the ltft and stft and then say like my ltft is 12, and my stft is -3, then i want to add fuel until they equal 0?

 

[L2RTSiAWD]

Yes that is true you want them to equal zero when tuning low settings.

Later,

 

[NJGSX96]

You need to watch your STFT at 1K, 2K, 3K, 4K at idle and adjust them to reach zero. Now go for a ride and cruise and 2K, 3K, 4K and keep an eye on your STFT, adjusting as necessary to attain 0. Once set, your LTFT will follow suit. You can be around 0, you don't have to be at 0. I think +-5 is acceptable.

Basically your LTFT (long term fuel trim) is a direct reflection of your STFT (short term fuel trim).

 

[Boosted97GS-T]

ok thanks for the help. anyone know why i would be still running rich with my mods and 17psi, i'm getting .96 o2's and running 1480 degrees at the end of 3rd. keep in mind that i have stock injectors

 

[NJGSX96]

Rewired fuel pump could be overrunning the regulator? Alco, how is 4th? Car could be tuned more for a 4th gear pull. Check your EGTs and O2 in a nice long 4th gear pull.

 

[Boosted97GS-T]

i havent logged 4th gear yet, but i did notice the other night while i was racing a cobra that at around 120mph, i was getting on the edge of 1600 degrees

 

[NJGSX96]

Sounds like you got some good tuning. Every car is different. Your runs better with a little more fuel. You can lean it out some, but you will get to 1600 deg on the EGT quicker is all.

 

[Boosted97GS-T]

Well whats wierd is that i havent did any kind of adjustment on HI-throttle, its all at zero. and i'm getting 19 degrees of timing at the end of 3rd gear at 17psi. so do you think that i would benefit from putting some bigger injectors, because they way i'm looking at it is that i'm getting decent timing at a pretty high boost level and also i have room to lean it out some.

what do you think? should i get some 550s or i'm good with the stock ones?

 

[NJGSX96]

Well that is at only 17psi. What if you were to up it to 19, 20 or beyond? You got that BigT28 turbo. Almost a shame to limit it to 17psi. See what happens when you up the boost. PLus, more fuel is never a bad thing. You can always lean it out to tune it perfectly. 550s would be fine for your application.