a MAF too small

[Dave Zug]

> From:          EFISYSTEMS at aol.com
> Date:          Wed, 21 Jul 1999 17:47:22 EDT
> Subject:       Re: a MAF too small
> To:            gmecm at efi332.eng.ohio-state.edu
> Reply-to:      gmecm at efi332.eng.ohio-state.edu

> Hi Dave,
>         Is your system a draw through or (blow?)flow through on the MAF?????? 

Draw thru

>  If it is a draw through you might be losing adiabatic efficiency caused by 
> the vacuum situation at the inlet,,,,,creating heat, losing efficiency, even 
> though the boost might show high enough, the mass just isn't there.....but if 
> yours is a blow through(I hope the screens are there) I would like to be 
> involved if you are interested in trying to use a syclone code running a 
> separate computer as a fueler,,,,,,

Kind of out of my scope for now.. unless I really HAVE to.

>hmmmm another thought,,,I think we could 
> even do the spark in 2 or 3 bar and leave your stock computer (165) just to 
> handle the fueling till the MAF runs out,

again.. yea nice to think of the possibilities as a mad science 
experiment.. my initial goal is to go "good nuff".  boy what would 
that dual computer setup win me at the car show ? ;-)

>,,,,btw where did you find a kit for 
> that year or was it homemade???????

Its a common year I thought.. its a Pax*ton  (there, now you can't 
search the archives and find a commercial entry  ha ha). you have to 
relocate the alternator down low.. unit sits on the drivers side 
high. what I CAN'T find is an INTERCOOLER for it (PS: HELP?)


> -Carl Summers
> 
> In a message dated 7/21/99 11:31:47 AM Pacific Daylight Time, 
> dzug at delanet.com writes:
> 
> << Subj:	 a MAF too small
>  Date:	7/21/99 11:31:47 AM Pacific Daylight Time
>  From:	dzug at delanet.com (Dave Zug)
>  Sender:	owner-gmecm at esl.eng.ohio-state.edu
>  Reply-to:	gmecm at efi332.eng.ohio-state.edu
>  To:	gmecm at efi332.eng.ohio-state.edu
>  
>  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
>  
>   >>
> 
> 
Dave Z. www.delanet.com/~tgp