I've heard that its preferred to reprogram a hopped up MAP motor rather than one equipped with MASS and it'll make more power because the MASS is a liabilaty due to its OEM only avail size for reading air.
Any thoughts????

 

I assume by MASS you're refering to the Mass Air Flow(MAF) sensor's limitations. I'll make another assumption that your talking about LT1/4's because the 93s where the only ones originally speed density 'map motors'.

You can reprogram/calibrate the PCM to accept a larger Z06 MAF. There are some aftermarket units out there available in different sizes too. If you simply unplug your MAF the PCM switches to speed density mode, so there is no reason to start with a 'map motor', you can easily convert any motor.

I have heard of people switching to speed density on extremely aggressive setups. What are your plans? N/A FI N2O? You're going to have to do quite a bit of "hopping up" before you need to worry about converting to speed density I'm working on a 450-500 rwhp NA setup right now and planning to retain the MAF sensor.

What is the most NA or FI hp anyone is pushing through a MAF sensor? Nitrous doesn't really count because it avoids the limitation.

-brent

 

Sorry, I need to clarify some more, my fault.
I'm referring to the MASS air and Speed density on the 3rd gens. I have a lot of mods, cam, ported polished and the likes and still run my factory MASS with screens removed. I hear that (Know) that speed density is more sensative to mods and the best cure is a new burnt custom chip. What I want to know, is if I get a burnt chip, can I run up there with these guys with reprogrammed stuff. I hear the OEM MASS limits output and is not good past a certain mod/hp point.

Whats your toughts/suggestions?

I feel right now, my biggest holdback is my programming and posably the limitations of the MASS.

As for my setup, I push roughly 420hp to the flywheel and will add nitrous when the suspension and cage are addressed. I plan on spraying aboiut 150-175shot. I cannot run a S/C with my 10.6:1 CR so and have hyper pistons.

 

A wet-shot shouldn't affect either fuel-metering system (MAF or speed-density).

In LT1 pcm's, the MAF is limited to a frequency range without throwing a code. You can get the MAF reprogramed to fit within that range, but you have to scale the fuel injector constant to compensate... the LT1 MAF tables (which are used by the PCM to convert the MAF's output frequency to a grams-per-second value) are limited to 511 gps (think 2^9... and 0 counts as one option ).

The 3rd gen PCM's may have a similar limit, but I imagine that your fine if you hook up the juice as a wet-shot. If you go bigger in the future it may be an issue to deal with, but it's nothing a good tuner couldn't handle.

 

The 3rd Gen MAF sensors, made by Bosch, are complete dogs. They have seriously limited flow capability, although you can improve that quite a bit by removing both screens, and the cooling fins that stick out into the air stream. Then you are faced with the fact that they are very unreliable, and complicated with the "burn off cycle" that heats the wire to 1,000degF at every shutdown to burn off any contaminants. The output is not at all like the 4th Gen/GM-made sensor, and does not produce a variable frequency output. I would think speed-density would prove superior in a 3rd Gen, but I don't have any direct experience.

You might find you get a better response on "3rd Gen Tech", since those are the people who have wrestled with this issue.

 

I thought all 3rd gens were carb'd or speed density. Whoops, I was way off the mark :foot in mouth:

 

You can still add fuel after the maf maxes out. The only problem is the size of the sensor. There are plenty of guys with maf cars running good numbers with the maf meter. Don't worry about it.