There seems to be a lot of differing opinions on what constitutes a pegged MAF here and on NLOC. So, I've got a couple of questions to hopefully get a definitive answer.
I put my 03 L on a dynojet and @ 5300 rpm my MAF V read 4.92. My dyno chart showed the A/F going rich at that rpm which means it was doing its job.

#1-- Should I be concerned with that voltage since it was on the dyno and not the street (load factors)? It was 64 degrees.

#2-- What MAF voltage range is SAFE to run the stock 90mm?

I have a ported eaton, 6# lower, cai, extrude honed upper, stock manifolds, bassani mids w/ high flow cats, and bassani catback.

 

A voltage of 4.92 volts is very close to pegging. Since it was done on a dyno, it may hit 5 volts on the street. But, at 5300 rpms, you probably won't see anything bad from that, considering the truck shifts just a tad higher than that rpm. Still, I'd look into an SCT 2400 or MAFia extender.

There is another factor as well. The factory tune has a max MAF value set to 4.78 volts. If this has not been changed to 4.99 volts in your tune, then that could be an issue as well. I have always done that correction, and I think nowadays, most other vendors are doing it as well.

Hope this helps.

 

A good indication of Maf max is a spike in a/f just after 5k rpm. If you are still within the stock capabilities of the stock fuel system, that is a good indication of what's going on if you know your are running somewhat heavy mods (6lb lower and ported blower like me). This is not always the case, If you are richening up your maf might not be there.

My truck was tuned for a 4lb lower and ported blower, but Jim set it so it should be ready to go with a 6lb. I put the 6lb on and right at about 4800 rpm the a/f on my wideband started climbing and I went through the traps well over 12, and called it a day. I don't know 100 percent but i bought an sct2400 for precaution, hopefully that solves it. If not, I also got a set of twin 255 pumps.

 

My MAF is working properly as you can see on the chart but I was wondering what the tuners thought about me getting on the street and what the "safe" voltage range was. I'm gonna have to see what it is doing on the street.

 

they seem to be on the low side no doubt. Anyone else agree?

 

That's funny you should say that. I posted my disappointment in these numbers over on NLOC:
http://nloc.net/forum/showthread.php?s=&threadid=117957
I'm posting the MAF question over here because people couldn't get off that subject over there and it didn't have to do with my dyno numbers but it's an important subject nonetheless. My less than desirable numbers are a whole different subject. It's a JLP tune and he can post up his comments he had for me if he likes. I'd appreciate him posting his thoughts himself because I don't want to start a vendor flame war. The tune is real solid but the numbers are nowhere close to desirable. He's sent me a hotter tune but I won't be able to get to the dyno for a while. The track is my next stop.

 

Just before the MAF pegs/5volts it trys to comand as much fuel as it(it=meter) can before the A/F will start to go lean. causing a rich spot at the end (5300rpm+)

 

Rob, you coming to Rockingham on Saturday March 18th?

 

I have been worrying about this as well. With my #6 lower, I fear that I am close.

 

has anyone else run an sct 2400 maf with stock injectors?

Has anyone had any issues?

 

I ran the SCT 2400 maf with stock injectors for a few month. No problems. Worked great I have since dropped in a set of 60s

 

who did your tune on it?

 

Was this done on a mustang dyno? The numbers do seem low.

 

Our local tuner (PSI Motorsports) told me that the 2400 is not the easiest thing in the world to tune, and usually leads to some (usually minor) driveability problems. That being said, lots of people use them.

By the way, I'd datalog and look at MAF counts, not just voltage.

 

Everyones numbers are low to you