69LT1Bird

iTrader: (1)

I am hoping someone can take a quick look at this log, the car runs good but the MAF seems to move a lot at WOT, just wondering if this is normal or not.

I just put in 2 more degrees of timing at WOT last night and it seems to like it. Now at 29*.

Engine info in Sig

RedHardSupra

iTrader: (1)

what kind of MAF is it? is it descreened?

Frost

iTrader: (45)

It must be an 85mm unit. He is seeing reporting up to 11.875kHz on his setup at WOT. That is one cell away from the table's MAX.

69LT1Bird

iTrader: (1)

yes, its an 85mm truck MAF that is descreened.

My intake tract is pretty simple. From the TB is a smooth 4" 90* elbow to a
4" aluminum tube. At the end of the tube is the MAF, at the end of the MAF in the wheel well, closed off from the hot engine compartment, is a 4 x 9 K & N cone on the end of the MAF.

RedHardSupra

iTrader: (1)

put the screen back on and the fluctuations will go away.

also, you want MAF at the end of a long run of a smooth pipe, not at the beginning of it

69LT1Bird

iTrader: (1)

Thanks for the feedback, I will give that a try. I put it out at the end to get the cold air reading for the IAT sensor.

I just got my DR's tonight, hope to try this setup on the strip and a chassis dyno soon to see what it makes. It pulls like a train so its a lot of fun to drive, the DR's should make it even more fun.

RedHardSupra

iTrader: (1)

no, you want to measure the most accurate temps, not the coldest temps.

MAF works only in smooth flows, long straight piping is awesome for it. if you find some C5R pics you'll see long piping going from each bank to a corner with a huge airbox at the end. this way you have a 'cache' of air so it doesnt run out at high rpm, and a smooth flow for precise airmass estimation.

69LT1Bird

iTrader: (1)

I changed the MAF location like you suggested. I put in another MAF with a screen as well. The MAF is now in the elbow just before the TB. I logged some data because I figured I should retune the MAF. The fluctuation is gone but I am now maxing out my MAF table. This is definitely proof that the screen should stay in.

I started retuning in SD mode, then turned the MAF back on but left everything else setup for SD. I changed my VE tables some but not too bad. I then turned the MAF back on by changing the frequency back to 13500 from 0 and logged more data. I am almost done, a little rich in the middle, but wanted to throw this at you for your opinion.

Frost

iTrader: (45)

That's what I don't like about the 85mm MAFs, they max out way too early. If I were in your shoes I would toss it all together and run SD.

RedHardSupra

iTrader: (1)

seems to run ok, i dont see anything wrong with it, the timing is a bit high if this is putting down good power (and airmass says it is). now you just need some dyno time and figure out what afr/timing does it want.

69LT1Bird

iTrader: (1)

Thanks guys, I just upped the timing to 29* at WOT the other day and it seems to like it, I have been running 27*. No spark knock at 29* and it runs strong. Can't wait to run some poor unsuspecting soul with the old car. That and my new rear wheels will be here Tuesday so I can get my DR's on it.

One more thing, I do have a LS3 MAF, the small card style, would that work in my 4" intake tube or am I still limited by my OS?