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Melon
11-21-2004, 05:51 PM
I've got a Pro-M 75mm MAF on my 'Bird right now calibrated for the stock 30# injectors. I'm planning to upgrade to 42's over the winter. Getting a chip burnt for my 'Bird will take care of the MAF reprogramming? I won't have to do anything with the MAF itself - just have a chip telling the computer the change?

I just want to make sure that I don't have to get a new MAF because the one I have is only calibrated for one and can't be changed.. cuz that would suck :eek:

Thanks
-Andy "Melon"

XR7 Dave
11-21-2004, 06:05 PM
The chip will take care of the programming for AF ratio, the only problem may be that as you start to put out a lot more HP the MAF will peg sooner than one that was calibrated for the injectors you are using. Basically, with the stock calibration the 75MM will peg at the same MAF voltage that a stock MAF would peg at (about 290-300rwhp or so). Until the time that you make that much HP, there will be nothing to worry about.

Melon
11-21-2004, 08:36 PM
The chip will take care of the programming for AF ratio, the only problem may be that as you start to put out a lot more HP the MAF will peg sooner than one that was calibrated for the injectors you are using. Basically, with the stock calibration the 75MM will peg at the same MAF voltage that a stock MAF would peg at (about 290-300rwhp or so). Until the time that you make that much HP, there will be nothing to worry about.

Even with the upgrade to 42# injectores, it will still peg out? Am I possibly looking at getting a new MAF in the future? I'm guessing I'm at about 230 right now and not going for too much more but who knows what the future brings :D

-Andy "Melon"

XR7 Dave
11-21-2004, 08:42 PM
Even with the upgrade to 42# injectores, it will still peg out? Am I possibly looking at getting a new MAF in the future? I'm guessing I'm at about 230 right now and not going for too much more but who knows what the future brings :D

-Andy "Melon" It actually has nothing to do with the injectors. A stock MAF curve will only read up to a certain amount of airflow. Any calibrated MAF artificially lowers the output of the MAF giving you more airflow headroom.

Melon
11-21-2004, 08:54 PM
Thanks Dave... I'll keep what I have and if I get close to 300 or so, I'll consider a new MAF. Otherwise, I'll just wait and see what the future brings :D

-Andy "Melon"

Mike8675309
11-21-2004, 08:54 PM
Melon, I belive you also have the option of sending the MAF back to Pro-M and having them re-program it for your new injectors. Perhaps that would give you some more room as far as peaking out the meter with it's current programming.

thebigslide
11-21-2004, 09:37 PM
Melon, I belive you also have the option of sending the MAF back to Pro-M and having them re-program it for your new injectors. Perhaps that would give you some more room as far as peaking out the meter with it's current programming.

Yes it will. What they do is put in a smaller sample tube. This will make the MAF peg at 42/30 = 140% of factory.

You would not modify both the MAF and the injector calibration in the ECU. It is less preferable to modify the MAF as this will effect the timing also. I would actually recommend modifying the MAF, though, if you're getting a chip as they can compensate for this in your timing map. Make sure you tell them what's going on.