I could see that would be possible with some effort, however you either have really bad inlet piping on a single head unit or a twin head unit system. Possible, but as cramped as our engine bay already is, if you've gone that far with a twin system and have room for the extra MAF's, you probably have the extra bit to go to a standalone.

On the megasquirt issue - I did some searching a while back after a guy I know who does RX7's adapted it to his car (dont ask me how, I dont know enough about them), but he was telling me some things about it. I dont know how true they are (havent read a lot yet, but after reading this thread I'll search some during lunch) but not many lt1 guys are using it. I searched the forums a while back and you dont find much on it...

There are several options available - the only issue is finding a solution where you dont loose accuracy and are somewhat "plug and play" without too much hassle. I've yet to find something that made me happy. And just to throw some more gas on the fire, there's always the Sy/Ty ecu idea.

 

Jordan, the freq to airmass lookup isn't linear so a simple addmul wont do.

You have to do a freq to mass lookup per sensor, add the results , divide by two (or three with some of your monsters ) then do a mass to freq lookup, finally output that pulsetrain.

I thought of building one of these a while back then I realized that a MAFT could be programmed and retrofitted to do this. Now days, the ProM jobby should work.

 

Exactly. Multiple MAF's take a bit of work that almost negates it, though I say the space issue is more annoying then the electronics (I looked into it a little bit too, but I'm guessing not as much as you Luna) but I dont know enough about the Pro M's construction and the inner works of the lt1 ecu to really make a decision quite yet - and someone (highlander?) was going to try the proM at some point.

 

yea, it would take some tuning in the MAF table to make it work, certainly wouldnt be plug and chug!

I think the prom MAF is the best route.

 

Can someone fill me in on the Pro-m?

 

i would also like to know more about the pro m, i was told by a friend of mine that they went out of business, but started a new company under a new name...

 

I noticed Pro-M site was down.

 

Welcome to the world of P0103. The MAF table, is only translating a frequency received from the Mass Air Sensor for a grams/sec reading to be used in calculating actual air volume entering the intake. Lucky non-FI guys never experience this problem.

If the intake volume is 3" in diameter and the maximum flow of the MAF before frequency overload is XXX gm/s (non FI)...

Can I add another, in parallel, unrestricted bypass port to the intake (a Y connector) that is not measured (no MAF) but equal to the same flow characteristics as the airflow through the MAF, (1:1) that allows air to enter the intake?

Then, the air entering the engine (xxx gms) would be incorrectly (obviously)measured at the existing MAF by some percentage less (~50%) than actual. At that point, you could adjust the MAF table to accomodate for the actual flow of air, for the frequency. If twice as much air was actually entering, (of which 1/2 was routed around the MAF), then adjusting the MAF table would be as simple as just doubling the gms at the designated frequency.

(i.e. Current: 2.46khz=3.442 gm/s; New 2.46khz=6.884 gm/s)

Of course, these numbers would rarely be exactly 1:2 throughout the spectrum, especially at higher frequencies/flow rates and very low frequencies/flow rates. Also, air, like water and electricity, tends to move in the path of least resistance and the MAF would add some resistance that would push some air into the unrestricted port, resulting in some mis-measurement....

So, is this doable or just another crazy scheme? (of course, our SMOG-Gods would hissy-fit like crazy, but we already know their take on anything we want to do..)

 

This is just my opinion and what worked for me ... and it follows that the simplest idea usually works really well.

I have been running my OBDII for almost three years at 611rwhp using the regular MAF?! If you look at my dyno chart in my signature, you can see that it is smooth and the A/F is flat. Secondly, many people ran high power using the regular MAF with OBD1. LJ ran 9.9 with that setup and is still running his car in the lower 9s.

Although we did port our MAF (not recommended), this is not what made it worked. With OBD1, it works just fine, as posted earlier, by tuning the PE table (using this file http://para.noid.org/~lj/PCM%20Tutorial/DynoTune.zip ). All the PCM does is it will send out a code but will not affect any thing else. Go here to OBDI - http://para.noid.org/~lj/PCM%20Tutor...reviations.htm for more information. On OBDII, it is more complicated because when the code occurs the car appears to be cutting the fuel by half! The power drops, engine goes way lean, and you feel like it hit a brick wall. On OBDII, there is a trick that we did on my car. I couldn't say this before since it was not my idea, but since it is mentioned here, I want to clarify that it does work.

LJ helped me dyno tuned my car and it ran in the CA traffic jam in 90F no problem. We did do the dividing the MAF table by half and dividing the Injector Constant by half. Then we dyno tune it and it works just fine. I had dyno tuned the car 12-14 times consistently. It may not be the best solution but it definitely works well. I have been driving this car for almost three years, road raced on the track all day in +90F six times, and autocrossed a dozen times already.

Hope this help people. And always dyno tune your car before you do anything since different car behave differently. For example, I just found out my car was running without the Hi-6 hooked up for these three years and through all the dyno tuning!! I just came back from Thunderhill and it ran perfect if I don’t connect the Hi-6TRCII (which I think is bad now), so well that I finally broke my u-joint and twisted the 1LE DS going 115mph in the middle of the front straight in fourth and fifth gears.

cheers

 

Any more info on this Pro-m maf? And would cutting the injector constant and maf table by half work on forced induction OBD2 cars? how would a 2 or 3 bar map fit into this (possible solution?)?

 

Also, since fuel is cut in half on OBD2 cars once the maf is maxed out, could the maf massager eliminate this problem by fooling the computer into not throwing a code (if in fact that is all the maf massager does)?

 

hey guys, i dont know the first thing about tuning. i dont even have a scan tool. but when i put my blower on my maf freaked out. i hit about 4000rpm and i thought i blew something up. it lost all power and it ran like crap afterward. my brother in law took it to work and ran the code and of course it was 103. we took the maf out and it ran fine, a little rich, but it ran well.

so i figured the easiest thing to do was to get the maf massager. after that it has been running fine and the af mixture was fine when i dynoed it.....

just thought id throw out my maf massager experience.

 

For obd2, LT1 edit version 2,2 has a program feature for setting high maf failure point. I also was running onto the obd2 limit, then, got the upgrade and maxed the high threshold value to 60K+ from stock setting of 10k. Took care of the problem. LT1 edit is around $550, but, you can tune just about everything.

 

Wouldn't you still run into the problem of the MAF sensor itself maxing out (i.e. too much flow for it to read)? Are the PE tables still just taking over after that like in the OBDI cars without issue?

 

Can you tune accelerator shot? (fuel adder for change in TPS)

Mike