samseed101

I kept my OEM MAF until just recently. But I then I pretty much had to switch because of my blow through setup.

Bigger isn't always better and can sometimes actually hurt, depending on what is bigger. Lets say you're pushing about 290rwhp on your 24# injectors (naturally aspirated.) You see someone selling a Pro-M MAF on eBay, but it's calibrated for 83# injectors. While it is true that you can get a chip burned and use it, you may run into problems. Take a look at the flowsheet. You'll find that at the 5v mark, it will be flowing at about 4,860 kg/h. So even if you manage to pull in 1,300 or so kg/h, your MAF is only reading about 3.2v. So just based on that alone, you have the potential of wasting 10 out of your 30 points on your MAF transfer.

As a personal rule of thumb... I try to make it so that when at WOT and close to redline, my MAS will read right around / just below 4.5v.

FullAuto

I've used from 24lb to60lb injectors with Pro M (or PMAS) meters and have never had any custom tuning to the ECU to accept them. I never had any problems.

samseed101

Were the injectors matched to the MAF? (i.e when you used 24# injectors you had a 24# MAF, 60# injectors for 60# MAF, etc?) If that is how you did it, then of course there won't be any problems. Well, it does screw up load calculations because it only tricks the computer into delivering the right amount of fuel, but that's a different topic.

But if the parts are mismatched, then you are going to have to do something to get it to work properly. If you drop 42# injectors in a car and don't change the MAF or the tune, then the computer is going to assume that you still have the stock injectors and it's going to adjust the PW accordingly.

Using my car as an example, I have 30# injectors, but my MAF is calibrated for 42# injectors. The only way for this to work is with a proper tune.

FullAuto

Yes, the meter matched the injectors. It's cheaper than a tune.

samseed101

In that situation it will work fine. And yes, it's a hell of a lot cheaper than having a chip burned. But in my situation, I have a Tweecer RT installed. So I can change my tune anytime I want for free. When I get a new MAF, I just enter the flowsheet data and then test it out at different loads to see if I need to lean it or enrichen it any. If I decide to get new injectors instead, then I just adjust my high slope, low slope, break point, and battery offset and I'm good to go. If I replace both the MAF and the injectors, then I do all of the above.

I would have just bought a MAF that matched my 30# injectors, but I was able to buy fine the same exact MAF (only the sensor was calibrated for 42#) for $65 cheaper. So I jumped on that deal.

AdderMk2

also not as accurate

jasonvri

You purchased what, 2 or 3 calibrated MAF meters?
That cost right there could have purchased a tweecer and a wb...

I'm not saying that the custom tune is the only option. For some folks it is the best option.

However, the cost/benefit analysis on 'calibrated' MAF meters is pretty sad...


jason