What are your Maf Readings ?

[84GNGary]

I am trying to get some kinks worked out and am going in the right direction but the maf is throwing me a curve and effecting the fueling. On Direct Scan at wot I am only getting 170 g/sec @ 4650 rpm while accelerating. Now I tried another 87 good maf and there was no difference. I still have the stock down pipe and exhaust with a gutted cat and a K&N cone filter. Next I am going to loosen up the bolts before the cat and see if the readings increase any. Then after that a LS1 and a Translator. I did check all the grounds and the voltages to the maf, all were good

So I am curious if 255 g/sec is realistic with my setup.

 

[Jerryl]

What are the boost, LV and inlet temp at the 170 reading?

 

[84GNGary]

I can have 15 lbs of boost and 255 on LV8 and the maf is 170-180 at wot. I do not have a MAT sensor or a cold air intake so the intake is whatever is under the hood.

 

[Jerryl]

Sounds like there may not be any problems.
Just reviewed some of my logs.

@ Boost 15
MAF 189
LV 255
RPM 3523

@ Boost 19 (90 Deg Outside)
MAF 255
LV 255
RPM 4475

Interesting review/comparison.
I know for a fact that in 40-50 deg weather, the MAF will max out around 14 psi.

 

[84GNGary]

Thanks Jerryl, I just wanted to make sure. Eric from TT thinks they are normal too and the HA's won't hit 255 g/sec like the IC's do. My readings were low before and I found the K&N stock filter replacement with the bottom open could not flow enough. I borrowed a semi dirty cone filter and the readings went up by 10-15 g/sec. With no filter at all I had 220 g/sec.

 

[Jerryl]

.......... With no filter at all I had 220 g/sec.

That is a BIG difference.
Sounds like the filter is restrictive, all else being equal.

 

[timevacuum]

I am trying to get some kinks worked out and am going in the right direction but the maf is throwing me a curve and effecting the fueling. On Direct Scan at wot I am only getting 170 g/sec @ 4650 rpm while accelerating. Now I tried another 87 good maf and there was no difference. I still have the stock down pipe and exhaust with a gutted cat and a K&N cone filter. Next I am going to loosen up the bolts before the cat and see if the readings increase any. Then after that a LS1 and a Translator. I did check all the grounds and the voltages to the maf, all were good

So I am curious if 255 g/sec is realistic with my setup.

Gary,

My PowerLogger and Scan master both indicate 255 at WOT with my setup. Before the mods with the stock MAF it would be about 220, and I saw 238 a few times.
I'm running a 3" Delco MAF with translator,(set to the default settings), custom 3 1/2 air intake pipe and cone filter, and the 3" DP w/ free flowing exhaust. I think I posted PICs of it here or TBs a while back.

EDIT: I'm running a Turbotweak alcohol chip, the boost is at 22lb, and I'm spraying methanol.

HTH,

Bill

 

[84GNGary]

I did wash the K&N filter I borrowed and it was pretty dirty, just haven't had a chance to drive it again. If all is okay K&N makes a 5"round filter that is 10" long that I will make work with the top of the stock filter box, or I may just get a 3"cone.

The problem I have is this.
I still have the stock street tires on the car so I can't bring up the rpm's from a stop. So all I can do is mash the pedal to the floor and that still causes the a$$ end to go sideways. Doing this was leaning it out and at 17 mph I was getting knock. Eric did not like the maf #'s and thats when I found the air filter problem. Now with no air filter or the cone I get no knock but I still get a brief lean peroid up to about 7 mph when the O2's drop and flat line into the 100's. What I need to check is my fuel pressure when I nail it. I think the regulator may not be reacting fast enough and causing the lean peroid now and not the maf. It did get better when I put the fp to 44 psi, maybe I will try 45 psi. Eric said he could change the chip to add more fuel then but if it's not available the change won't help.

I don't know if it is normal to see this leaning out. Let me know what your fp & O2's do in the same situation. Hopefully I get a chance this weekend to do some further investigating and testing.

I know it's not really a good idea just to mash the gas down but it's all I can do now. I know it is not false knock either because I can hear it and see it on Direct Scan. If I can get this solved then I can start on the boost, timing and fueling adjustments:biggrin:
Then I will work on my next problem TRACTION

If you want to see my DS files pm me your e mail.

 

[timevacuum]

Gary,
FYI, I had to set my 1/2 fueling in the TT chip to 130 to quell the slight knock that I had when launching hard.
Bill

 

[boostmaster]

Maf readings

Took the T out for a drive today with data from my translater gen II with a LS 2 maf. At about 8-10 psi 175-185 gps, @ 12-14 psi 248 gps, anymore boost than that and I will peg the maf. 90* temps today.