4.3 multi-port fuel injection

Ryan Harrell cyborne at murlin.com
Tue Apr 2 05:36:17 GMT 1996


Donald Whisnant wrote:
> 
> Ryan Harrell wrote:
> >
> >As the original poster of this 4.3 discussion, I'd like to know if anybody
> >has some information on Vortec's supercharger they are designing for the V6
> >engine.  I called Fuel Injection Specialities, whose name I found in a
> >magazine, for info.  They stated that Vortech would have a sequential
> >central-port injection supercharger in a couple of months.
> >
> >Also, FI Specialties priced the SCPI kit at $1895 and I was wondering if
> >anybody knew of a cheaper price anywhere else.  I'd like to ask Mr. Spears
> >how hard would it be to adapt a centrifugal supercharger not designed for
> >SCPI to it.  The reason for this is because ATI Technologies makes an
> >extremely powerful superchager that I'd like to use.  Also, I plan to
> >racing heads, roller cam, bore out the engine, and just about any other idea
> >I can find to produce more horsepower (my goal for this engine is around
> >500-600HP on a $6000 budget) However, I know little about programming EPROMs,
> >and have no idea on what equipment or software is required for reprogramming
> >(although I am willing to learn). If you can recommend a book or other
> >instrucion tool to help me I'd be appreciative.
> >
> >Finally, is there any R&D going on for a true port injected 4.3L V6?
> >
> >I GREATLY APPRECIATE all the help I've gotten from this mailing-list
> >
> 
> I've just recently finished installing a '94 4.3 CMFI V6 into my '85 Grand
> Prix -- And (even though it was a headache and a half to put in -- mainly
> because the engine came out of a van instead of a truck) I've been very
> well pleased with its power and performance in sort of a "stock" condition.
> I also put on one of those 4L60E trannies too -- and with the way it is
> presently geared (2.41 -- as designed for a non-od tranny) it will do 80-85
> taching only 2000!!!
> 
> As for mods, I too would be interested in info on superchargers -- though
> my question would be: How much height if any will it add to the intake??  I'm
> already about maxed out on the Grand Prix -- any more and I'll have to add
> a hood scoop....  ... So Ryan, let me know what you find out...
> 
> As for true port injection, I just bought another intake for the engine (I
> paid $150 for the complete intake upper/lower halves, and all of the sensors
> incl. map, tps, tuning valve, etc. -- a heck of a good deal when compared
> with what the dealer wants for one!!!) ...  I plan to do some experimenting
> with true port injection -- I plan to buy six injectors and do some machining
> on the intake and see what I can't accomplish ...  I would also like to
> add distribitorless ignition to it too --- I've thaught about using the
> sensors and general hardware from a 3800 for that, but don't know yet what
> problems I will get into...
> 
> Also, as for the eprom code, I'm in the process of completely disassembling
> the entire eprom from the computer that came with my engine ...  After
> figuring out exactly what processor they used, I wrote a code-seeking
> disassembler and am now wading through piles of source code trying to
> decipher all of the code and lookup tables (300+ pages!). ...  If anyone out
> there has any hints, ideas, suggestions, port number pinouts, etc, let me
> know...
> 
> Donald Whisnant
> dewhisna at ix.netcom.com

I don't exactly get what you mean about CMFI injection, so if you could 
please elaborate I'd be able to help more.  As for the supercharger, 
Accesseble Technologies, Inc. (913-338-2886) stated that their superchager 
could be adapted to almost any application with some tinkering.  However they 
state that they do not sell a kit (they became quite interested when I told 
them that Vortec had one in development -- Hmm you never know).  I don't know 
your level of superchager type knowledge, but the type I am talking about 
installing is a centrifugal superchager.  This is a device that looks and 
mounts (adds no height to the engine) similar to an air-conditioning 
compressor, whose job is to force as much air into the injectors as possible 
using a spinning propellor.  The air is compressed and sent to the injectors 
via a hose.  What makes ATI's Procharger so special is that they offer a 
special billet aluminum propellor that allows more airflow than Paxon or 
Vortec.  This allows them to get up to 25 lbs. of boost versus 9 lbs. of 
boost from steel propellors (Paxon and Vortec). Plus the blower is only 
$2000.

Because all the info on the Sequential Central Port Injection came from 
mainly this list, could someone please describe how the air intake into the 
engine is accomplished (how the plumbing is set up).  I'll probably end up 
going to a dealership and looking at one.

As far as technical info on the eprom, I have a friend who is a mechanic at a 
GM dealership.  He might be able to get such info.  Being a novice programmer 
(I only know basic BASIC), I wouldn't mind being sent the code that you 
dissasembled.  But I need to know what language you are programming it in as 
well as what programs you are using.  I'll try to be as much help as I can, 
but I won't make any promises.

I'd also like to hear more of your ideas concerning creating a true 
port-injection system.  Could you please tell me what kind of intake you are 
using.  Also, could everyone please elaborate on what mods you have done to 
your own 4.3 such as boring the block, heads, cam, crankshaft, etc.  Finally, 
I'd also like to know what works and what doesn't.  It would be nice to learn 
from other's mistakes so that they will not be repeated.

Ryan Harrell
cyborne at murlin.com

"Eat my dust", said the modified 4.3 to the IROC Camaro.



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