speed density vs MAF sytems

[vettetruck89]

Hi , I was talking to jesse bubb from wait4meperformance( he did my harness and reprogram) to talk about the setup he sold me. My LS6 uses a 5 pin MAF but because I switched to a F-body throttle body I had to use the F-body harness and computer. well the harness is for a three pin MAF. I called to ask if I needed to get the computer reprogramed for the the 5 pin and he said his tunes dont use the MAF and are basically Speed density. Can someone tell me if this makes any sense. I talked to allen and he said that its real tough to do a mail order speed density tune. Are any of you using speed density and if so how is it running.

[chrisj6]

Speed density tunes are almost impossible to do unless you have logs to work with. Tuning the VE will vary from vehicle to vehicle, so its really hard to get it dialed in over mail order. Allen tuned mine for my Z06 cam using the MAF mainly and got all the trims from +1/-1 (good guessing game allen&#33 So if your not using a truck MAF did you install the IAT sensor anywhere in the intake tubing?

Chris

[vettetruck89]

nope that was going to be my next question...whether or not i needed to use the iat sensor. im thinking since i bought the 5pin pigtail from S&P that I would put in the maf but leave the three pins for the maf unterminated. then i could still use the IAT thats built into the MAF

[chrisj6]

yeah you wanna be able to use the IAT, or else your speed density tune is going to be way off. That IAT has a big part in SD mode and also comes into play pulling or adding timing in the IAT adder table.

Chris

[vettetruck89]

thanks for the info. I think im going to end up getting nelson to do a retune. It just seems to me that I should be using the MAF

[farmtruc]

IF you're using the fbody harness, you have a separate maf and iat. You can easily use the truck 5 pin maf.
Instead of the iat and maf being separate, they'll just reside in the same housing.
All you need to do is connect the fbody maf wires to the first three pins on the 5 pin connector. Then the last two wires are for the iat, I believe they are the purple and black or tan wire, but it's the last two in that combination, call me and I'll be glad to provide you with the 5pin maf connector and info on wire colors.
You definitely need the iat, if it's disconnected, the pcm will read -32 degs and think you're at the north pole and run very rich.
For you LS6 swap, I'd use a 2002 fbody pcm setup for the maf table, that'll get your engine running strong.

thanks and I'll talk to you soon,

allen