maf flow lb per min vs hp

[bob450]

hi a quick question on my 11 gt my maf is showing 41.61 lb per min at 6500 rpm it give 416 hp at the crank do i miss something in the equation i have a airraid cai w-out insert is there a calibration in the tune to correct ecu.. i also have a cat off..thank

 

[slagburn]

Lb per min gives a rough estimation of HP, until the pid pegs at 86 lb/min

 

[Healthforhazard]

How accurate is this really? Im tuned on e85 with off road pipe and i pull 41.7 lbs at 7k

 

[Blazer707@TBR]

Ive heard its just how the maf is scaled in the tune.

 

[CPRsm]

How accurate is this really? Im tuned on e85 with off road pipe and i pull 41.7 lbs at 7k

It can be pretty damn accurate. But really depends on the tune. Just having a maf curve or injector data off a little can skew the lbs/min reading

 

[Doug1227]

It's pretty accurate at 10 hp per lb. I have (3) boost settings on my car and a datalog from the track for each and it's really close to what I dyno'd until it gets to the cap of 86 as mentioned above.

 

[bob450]

thank for info guys
is there a solution to improve.. cam ajust.. timming..maybe a vacuum leak..a clog air filter.. i still na..

 

[Blazer707@TBR]

Yea a good tune.

 

[Black02GT]

It's pretty accurate at 10 hp per lb. I have (3) boost settings on my car and a datalog from the track for each and it's really close to what I dyno'd until it gets to the cap of 86 as mentioned above.

I can see that working turbo or N/A but would be a little less accurate with a blower. You figure as you start upping the boost your giving more of the HP back to the blower. But for these purposes a stockish vehicle should be damn close.

 

[Doug1227]

I went back and looked at some logs that I did back when I had the KB on my car, but unfortunatelly, I didn't log that PID back then. :|

 

[Healthforhazard]

Does this equation work the same for e85 over gasoline?

 

[zinc03svt]

Cool. Just checked my log on a 93 base tune and was seeing 47 plus in a lower non 1:1 gear.

 

[nate-roth]

It can be pretty damn accurate. But really depends on the tune. Just having a maf curve or injector data off a little can skew the lbs/min reading

This is true, you can really see it when you are dialing in the MAF, if the MAF is off a little the load is off and the maf lbs/min will be skewed. When I was data logging my car, dialing in a Magnuson blower my lb/min were intially 78 and by the time the car was dialed in, load calculations and short term fueling were correct the lb/min was 68 lbs/min which is probably about spot on for the power the car is making. Basically the car is ingesting enough air to produce in the neighborhood of 680 flywheel horse power.