Pegging 90mm LMAF, anyone recommend replacement?

supercatxr7

Registered User
I'm hitting 5 volts on and off starting from around 4300 rpm on up with a 90mm Lightning F150 MAF, and that's on a hot day. Can someone recommend a replacement MAF that's up to my power?
 
Call Evenoff for the Pro-M 87. I had to replace my Lightning MAF with it because of the same reason. .. Now there's plenty of room.

Good Luck,
Anthony
 
supercatxr7 said:
I'm hitting 5 volts on and off starting from around 4300 rpm on up with a 90mm Lightning F150 MAF, and that's on a hot day. Can someone recommend a replacement MAF that's up to my power?

You have another problem.

Your 12mhz EEC-IV can only calculate MAF upto 1,400 kg/hr. Anything after that it does not factor into the engine load calculations.

The max value that the 12mhz EEC will acknowledge after the lbm/tic has been converted to decimal (coloum K or M) is 5498 (or 2.56E-06 lbm/tic). If math is not your thing trust me this came from Jerry W.

You can put a higher number but the EEC will not use any value higher that it's preset range. To actually use a higher KG/hr number you will have to divied the KG/HR, injector sizes, and engine displacement by a % say .65. This will keep the values in balance and allow for high KG/hr numbers.
 
That's a lot of figuring out above. I tried, but couldn't do it. ..

Brian Herron recently tuned my car to over 400rwhp with the Pro-M. He said that he's been doing the lightnings & those guys have to replace their MAFS once they get close to that mark because it pegs the meter.

Although Rich is much better at the calculations & I'm sure he maybe right. I just know what Brian told me about his tuning the 90's.

Anthony
 
The lightings have faster processors so they have a higher range for MAF kg/hr. The 12mhz processor (89-93 auto/5-speed and 94-95 5-speed) is good for upto 1400 kg/hr while the 15mhz processor (94-95 auto) is good for up to 1700 kg/hr. The engine will continue to make HP above 1400 kg/hr but it will not recalculate additional engine load. So if you hit 1400 kg/hr whatever the Spark and fuel tables ended with is all the EEC will adjust for. If your MAF goes to 1700 kg/hr the air flow that is above 1400 is not reconized in the load calculations. As long as your final spark and fuel ratio is sufficient you will be OK. For example your MAF curve hits 1400 kg/hr at 4.5 volts and your WOT voltage is 4.7 . Your EEC will never be able to readjust the load after hitting WOT voltage of 4.7. (Open Loop vs Closed Loop) Unless you are getting a check engine light upgrading your MAF to a higher kg/hr unit may not be worth the $$.
 
can you verify that some of the super coupes are 12MHZ?

you can always scale down displacement to adjust for the higher flowing MAF sensors. Even the newer cars have a limit of 63.9lb/hr, and the lightning MAF sensor actually exceeds that. If you look at the tuning files for an 03-04 cobra, they have scaled down some things to compensate in just the same way.

Brian
 
Back
Top