I have a 99 lightning with a 80mm maf. I bought a anderson power pipe with a intake mount to a 90mm maf (off a buddys 01). My question is I have seen where guys convert their 80mm maf to a 90mm but with a re tune. I dont have a tuner, would it be safe to use a 90mm maf housing with my stock maf? Thanks guys.

 

no because you are changing the airflow characteristics across the MAF

 

The transfer function of the respective MAFs are different. You need a tune to get the appropriate parameters changed. In looking at the transfer functions for two given voltage references for the 80mm and 90mm, the air flow calculations will be will be off 5% at ~2 v and 3.4% at ~4 v. That's enough difference to change a commanded 12.5:1 a/f ratio to 13.1:1 at the lower voltage and 12.9:1 at the higher voltage. I wouldn't do it without a tune.

 

Thanks thats helps, but that sound pretty rich @ 12.5:1. That sound like pretty safe numbers, I have read a lot of articles where 12:9:1 is max power.

 

If you are supercharged, you do not EVEN want to take a chance on it running lean. That's how you blow holes in pistons.

 

Thanks I just read, an ideal af rat for forced induction is 11:8 1

 

So - I think no matter what MAF you use, you need a custom dyno tune.................

 

Yes, if you change the MAF, especially on a FI vehicle, you must change the MAF curve in the tune to accommodate the change.

Thanks