MAF TBI

[George M. Dailey]

At 01:21 AM 3/30/97 -0800, you wrote:
>Dear George
>
>Not to take the wind outa ur sails but TBI metering is not terribly
>accurate. 


No arguments me me on the above, but it's cheap and adaptable to any engine
with a carb manifold.


>I suppose you could use the TPI ecm, reset the mode
>to aynchronous and change the injector constant. Prob quite a few other
>things to make it go. But why. If you did this you would be 
>able to completely reprogram your tbi. 


I was thinking more on the line of adding a MAF input to an ecm like the
1227747 (truck tbi), modifing the fuel maps to match fuel to maf (for a
given throttle body and fuel pressure), add some "generic" enrichment fudge
factors, Then let the ECM do what it does best, that 20% adaptive learning
or on-the-car compensating.


>To be honest when I ran the TBI on my truck I had more off idle
>torque than the TPI right now. TPI comes on about 2000 rpm and is
>better there.


I noticed that on Maxine also. I assumed that it was caused by not having
the overdrive tranny which has lower first and second gears.


>And remember these systems have a self tuning factor of about 20% or so.
>So oem even Map are relatively adaptable. Summit now sells a adjustable
>regulator for TBI which would help more.


You've confirmed that the MAF TBI would be the most universally adaptive EFI
system that could be made. Non discrimanating to cylinder quantity,
relatively insensitive to intake manifold and cam characteristics, the
capability to feed rotary, turbine, or piston engines.


>Also in the GM parts basket is a adapter which was used on 454 SS trucks
>about 90 or so which takes the weird tbi bolt pattern to a slightly less
>weird guadrajet/thermoguad bolt pattern. 


I fabed my adapter from scratch for about $10 parts. Bet the GM equivelent
is over $100.00


>GL George: peter who really doesn't know that much:
>and is quite bogged down with DSP course


Yea, right...and porn queens don't know any thing about sex.

GMD