a MAF too small

[CSH-HQ]

It''s not that it is a restriction, it's the lack of being calibrated for 
enough flow.  While on your NA engine you might barely peg it is one thing, 
but maxing it out at 3K S/C is another matter entirely.
  Same with the Hot GN's.  Just cause you can use it that way, doesn't make 
it right.
  While if the range that the MAF missses covering the engine ain't much 
then the error is slight, but as the RPM/error increases, get your wallet out.
  On one dyno test in back to back testing the MAF was 30 HP.  Course was a 
hot rodded engine.  ]
  There ain't no universal good bad enough MAF answers.
Pegging one at 3K rpm in my book is gonna have a short life in my book.

One other thought I had was using the 808 code, and use a ford MAF.
The 808 is MAP, but I've heard that no start up look at MAP involved,
ANY Thruth to that??????.

I would have thought with all the folks looking at the 730/165 lately 
someone would know how/share how to make one a 2 bar application.
Bruce



>Hi Dave:  There are a number of options.  First I would say that the maf
>will flow 750 cfm at 28".  So the maf sholdn't be  a flow restriction.  If
>you go to http://www.thrasher-ep.com/
>Look at the ECM Secrets and Tuning Hints.  They have a ton of good info.
>The buick Turbo's run a maf and have no problem.  I would suggest that once
>the maf is maxed you add fuel based on rpm (At wot) and also use a FMU.
>This should resolve any problem with fuel flow at wot and also allow stock
>driveability at part throttle.
>I suppose also if you "HAD" to you could adapt a larger Porsche 928 maf,
>which is also by Bosch and recalibrate the settings in the ecm to match up
>with the larger maf.
>Mark
>-----Original Message-----
>From: Dave Zug <dzug at delanet.com>
>To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
>Date: Wednesday, July 21, 1999 11:38 AM
>Subject: a MAF too small
>
>
>Heres a brief intro to my project, for those new:
>
>I have an 89 5.7l Iroc, 165 ECM, ARAP (vette) binary. I have put a
>supercharger on it and the computer has no idea what airflow is
>coming in after about 3000 rpm cause the MAF reads 255 right about
>there.
>
>The definite solution is to go to a MAP system. I dont want to hack
>the wiring apart and have to use a binary that I'm not skilled enough
>at to tune from scratch.
>
>Heres my thoughts as to a solution to the MAF max problem:
>
>If I drill holes PAST the maf sensor, effectively forcing it to
>read 75% of the actual air entering the engine.. I can alter the MAF
>tables to re-compensate. If it works, I can wrap foam around the
>holes and lube with K&N oil for now.. until I can get a pipe made.
>
>Voila.. don't have to buy a twin MAF, dont have to use a translator,
>don't have to go to a MAP system. only trouble is at idle, the
>resolution might make idle quality suffer. If (there should be)
>there is a fairly linear relationship between volume thru the
>sensor and unmeasured volume into the "post sensor holes" or larger
>single  "post sensor hole", it should work.  one snag is the
>difference between the filter restrictions but it may be neglidgable
>enough to tweak the MAF values at WOT manually using an EGT or O2..
>
>
>Am I missing an easier solution? Do I even really care what's going
>on at WOT above 3000 rpm?  I MAY max the MAF at 70% TPS and 3500 rpm
>so my thinking is I DO care.
>
>I have a few more days and I'll have the alum heads, 28#
>Buick GN injectors (12.7 ohms (??)) and new fuel pump on so the
>problem is about to get worse.  PS I blew the head gasket probably
>from being lean so my mission is that much more critical now with
>1200$ heads to warp 8-(
>
>Dave Z. www.delanet.com/~tgp
>
>