PDA

View Full Version : Speed Density tune


96LT1SS
04-12-2009, 07:14 PM
I will be going back to my tuner for a re-tune once the cam is in and i am wanting to know if there is any significant gain in going with a SD tune over the full wideband. My setup is full bolt-ons, cammed, stalled and geared. along with full rear suspension and bigs and skinnies.
MEAN LT1
04-12-2009, 10:53 PM
IMO...Unless your car is a full all out race car or runing an extreme amount of boost I would stay with the maf. Theres nothing wrong with keeping the maf on the car.
Fire67
04-14-2009, 04:04 PM
Usually, the people that go SD with a stock PCM are doing so for the sole reason of the pcm being able to 'see' boost. With an NA car, there really is no gain to doing this.
BLOWNDFIZ
04-15-2009, 08:29 AM
^^^^I'm with Fire67....

Also, I think you might be a little confused on your teminology. Typically you either have a SD or MAF system your car runs in. 93 Z's are SD, 94 up are MAF (a MAF car can have the MAF tuned out and run in SD). Either way you tune them you can tune with and need to tune with a wideband. Once tuned either way your car will still operate and get feedback off of the narrow band O2 sensors and at part throttle try to demand a 14.7:1 A/F ratio. A MAF tune will provide better overall driveability and mileage.
96LT1SS
04-15-2009, 08:19 PM
thanks guys for the info, so i really wouldnt pick up anything power wise
BLOWNDFIZ
04-16-2009, 10:19 AM
thanks guys for the info, so i really wouldnt pick up anything power wise

Someone else correct me if I'm wrong (I'm used to tuning my DFI) but I'm pretty sure in either mode (MAF, or SD) once you go WOT the PCM commands come from the PE tables so all things being equal the power at WOT would be equal, however driveability will most certainly be better operating with a MAF tune.
Fire67
05-08-2009, 12:55 PM
I may be wrong, but I think that the MAF cars will still use the MAF readings at WOT, but not rely on them as much as it does the PE tables. The way I was told it works (and Im with BLOWNDFIZ in that I really have only tuned stand alone setups), is that the pcm rely's more heavily on the MAF at lower loads and rpms than it does at higher load and rpm levels.