Speed Density Enhanced vrs stock MAF

[KDS]

I've been working the tune on my moderately modified 1999 camaro for 1/4 mile performance and have it pretty close to the performance expectations for the engine configuration but i'm at a point now where I can't seem to get the variations in AFR any closer than what is commanded. It's a six speed manual car and with some throttle modulation at launch and quick shifting through first and second gears, the AFR wanders around a fair amount. it becomes more stable in third and almost spot on in fourth as the time increases between shifts and the throttle is on the floor. It's a MAF tune. My question is, if I were to go to the enhanced speed density OS would it provide any more stability in the AFR under the same conditions. Also, will the enhanced speed density OS allow me to maintain MAF functionality for daily street driving and provide enhanced speed density when I fail the MAF for track runs?

[5FDP]

The MAF still works on the SD OS upgrade. It removes the secondary VE table to make speed density VE tuning easier.

[aaronc7]

Yeah, I've kinda gone back and forth between SD and MAF. Using the custom OS is nice because I don't have to worry about making sure I copy the high octane to the low octane table etc.

My car actually runs better/smoother on SD, so that's what I have been using for now. I would say just try it out and see what works for you, there's no right or wrong answers between MAF or SD. My setup is nothing crazy, 5.7L 226/230 cam, ported 243 heads etc. But I find SD is smoother/better in low load, low speed scenarios. MAF is a little easier than VE/SD, but not that big of a deal either.

[KDS]

OK, SD enhanced OS is in, I'll give it a go and see how it compares. I'll update when I've had a few days to sort through it.

[KDS]

I went back through the VE values using the LTFT's and made some minor adjustments and it ran as well to slightly better than the MAF tune. I then used the wideband in open loop to check the VE values (fuel trims all off) and found the VE values off substantially. After wide band tuning and running in open loop this tune is far better, smoother and more powerful than my previous MAF. I'm running long tube headers with a moderate duration cam, so I didn't trust the closed loop function at low rpm low load, but it looks to me that closed loop fueling has been an issue for most of my fueling variation problems over the entire range. It seemed to hunt for stoik and oscillate when in closed loop so I'm guessing the changed sensor locations and resulting exhaust heat and flow changes due to the headers really cause tuning problems. So its open loop SD enhanced for me now, fueling is close to spot on and drivability is great.

[JoshuaGrooms83]

Ive been wondering how people are going about between MAF and SD.
Im on 2 bar operating system on my 98 TA, and tuning the VE has been pretty easy. As i get closer to finishing my tune, im also wondering if i should hook up my MAF and tune it as well, but i dont want it to mess up the tune either once i nail down the VE. With my car boosted as well, and ill be introducing some methanol after the IAT sensor and MAF, im wondering if i can even use the MAF at this point when it goes into boost unless it switches to SD at a given KPA maybe?