Need Help With Turbo Tune (Tune and Log Inside)

[mikeyayell]

I understand you guys say I need a wideband. It was just tuned on a dyno with 11.5 AFR across the board by a reputable shop. It is a SD tune, I have 60lb injectors. The car also cuts out in neutral or if you are steady at 3500-4000rpms. It sounds like it has a 2 step. It does not do it if you hit it at idle or less than 3k and stay in it. Any ideas?

Thanks

[Stealth97]

Read this thread on why a MAF is better than a Speed Density tune. I just read it.

http://forum.efilive.com/showthread.php?t=1811

Cliff Notes: Speed Density is great for precise weather conditions. Change temperature, humidity, etc. etc. and the tune goes wacky lean or rich or both depending on how far out of wack constants and other values are.

It may have been "tuned to 11.5 on a dyno with an SD tune", but was it thoroughly road checked and tuned for different atmospheric conditions? You already know the answer or else you wouldn't be here.

Simply put, your tune still needs a lot of work. I'd take the suggestions of fixing your IFR rate to match 60 lb. injectors and retune the VE table. Having IFR wrong caues a lot of problems, I've been down this road before.

Do you own EFI live? Get the wideband and do some AutoVE tuning with it.

You might be able to do STFT tuning using Jesse/Wait4me's tuning trick with the narrowband O2 sensors but I have not checked out how well it works. I'm just testing it out this week. I'm waiting on my LC1 and sLC1 TAQuickness cable.

One thing that is cool, if you had the car running okay before, you can get it back there and make it stay there, it just takes work. Good news is the spark timing table should have been tuned on the dyno for good power and you should just need to get fuel in line and she should MOVE OUT.

I'd play with 3 tables. IFR, VE and MAF.

Eric

[SS2win]

Any ideas?

Thanks

Yeah. get a wideband, hook up your tuner and start figuring it out. No one on here can tell you what to do without accurate data. Saying it was tuned by a reputable shop is as good as saying my Aunt Effie tuned it via the Internet using a trojan backdoor program in my pcm.

[LS1Nova]

How did you ever make out with your tune??
I'm just throwing this out there, but don't you need a 2 bar map sensor for boosted applications less then 15psi? I would imagine the ve table is setup for the way the turbo built boost on the dyno, but on the street it will build boost differen, hitting different cells that you may not have tuned from the dyno session.