RPM=4474, MAF Volts=4.956...... Time for a new MAF??

[BlueOvalStangGT]

I just did a couple datalogs and at 4474 RPMs my MAF volts is 4.956. Also at that RPM my A/F ratio spikes to 21. Im guessing that means im pegging my meter. Before that my A/F is a constant 12.1-12.4. I have a Pro M 75 mm, is it time to upgrade? My friend is selling me his Pro-M 77mm and 42# injectors for $200, is the 77 gonna be enough for me? Anyone wanna take a look at my datalog and my tune, give me your email address and tell me what you think.

 

[final5-0]

It sure sounds like you are running out of room on that maf.

IIRC, you are now running 36's but I don't recall the cal on your maf.
What is the cal on that 75mm maf?

Your friends maf is caled for 42's ... right Keven?

That is a great deal on the maf & 42's btw.

Grady

 

[Don 95Vert]

If you currently don't have a chip or if you have a chip and the tuner didn't extend the max MAF value than the MAF will peg at about 4.7 Volts. A chip or tune with a TwEECer can extend this to 5.0 volts, but you are there already. You are playing with fire by letting this happen.

In theory, a MAF cal'ed for 42's should have enough range to not peg for you, but we've seen some with poor calibrations peg way too early. And if you are untuned a 'calibrated' style MAF will skew load values and screw with timing. IMHO, depending on your power level a 90mm LMAF or an SCT BA MAF would cure the problems and give good driveability, but you'd need a tune.

Don

 

[WhiteDevil]

Yeah he has the MAF range extended with the tweecer and he has the all the MAF and injector info also put in the his tweecer.

 

[final5-0]

My main thought was about if his maf was caled for 36's.

If it is caled for 24's or 30's, then it will peg sooner.

Grady

 

[WhiteDevil]

My main thought was about if his maf was caled for 36's.

If it is caled for 24's or 30's, then it will peg sooner.

Grady

Yeah he checked it last night and the flow sheet said 36s i believe

 

[final5-0]

Yeah he checked it last night and the flow sheet said 36s i believe

Seems to me that fact can only mean one thing!

Keven is makin good Horse Power

Grady

 

[69clark]

Time for a new MAF!