924Board.org

1982Porsche924 · Joined: 14 Nov 2002 Posts: 679 Location: Cupertino, CA

Any chance you would be able to whip out some of those fuel rails and sell them to 924 owners?
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1979 Porsche 924 "S"
Engine: Euro pistons, Light Flywheel, Weber TB, Bursch Header, Cam Wheel
Suspension: Front coil-overs, adj sways, Solid bush. Thicker tors. bars, 5-bolt, BBS rims
Body: Fiberglass widebody kit, 931 Nose

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Maybe when summer is over. They are short here and I like to play

Todd

1982Porsche924 · Joined: 14 Nov 2002 Posts: 679 Location: Cupertino, CA

That would be great! I would have done this swap a long time ago if it I had a welder and could fabricate my own fuel rail and injector adapters.
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1979 Porsche 924 "S"
Engine: Euro pistons, Light Flywheel, Weber TB, Bursch Header, Cam Wheel
Suspension: Front coil-overs, adj sways, Solid bush. Thicker tors. bars, 5-bolt, BBS rims
Body: Fiberglass widebody kit, 931 Nose

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

AppleBit · Joined: 16 Nov 2002 Posts: 1516 Location: Minneapolis, MN

I'd be interested in a rail as well if you are planning on making a few!
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Classic British Sports Car Restoration v6 + v8 Engine Conversion Swaps

Porsche 924 Wide Body LS1 Corvette 500 Horsepower Engine

Hugo · Posted: Fri Aug 13, 2004 3:54 pm Post subject:

Nice work Endwrench, I'm just curious if you don't have a problem with the spray pattern of your injectors, the original injectors are very long. I work mostly on euro cars so i don't know much about mopar parts. but most of the EFI injectors i have seen are comparing to original short nozzeled. Wondering if your could use 944 injectors and fuel rail???

Lizard · Posted: Sun Aug 15, 2004 4:10 pm Post subject:

@ endwrench,
I dont see from your list of parts or any of your descriptions that you are using a MAF or MAS or anything like that, does the system use one or how does it get around that? as if it didnt need one and could be setup w/o one that would be very nice and easy to setup a individual throttlebody setup on the car
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3 928s,

Manning · Joined: 29 Feb 2004 Posts: 151 Location: Akron O-Hi-O

I know TWM Induction used to make an ITB kit for the 924. They don't seem to list it anymore that I can see. Not too cheap, but it was a straight bolt on using MAP.
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Michael Manning
1988 924S Undergoing weight loss program

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Lizard · Posted: Mon Aug 16, 2004 3:08 pm Post subject:

thanx cbass, that is what i needed
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3 928s,

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

I've been reading a bit in the megasquirt manual about using low impedance drivers, and having issues... Are the injectors you're using low impedance? I know the turbo 2.2 Mopars were all low imp, and alot of megasquirt users are having to wire in resistors for low impedance injectors.
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'81 931 in various states of assembly

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Sorry I have been gone a while. Like I said summer is short here and I must play.

Hugo, I wondered if there may be a problem with this also and I have to assume the setup I am using is not "ideal" but so far I seem to be able to tune around any problems that may have arose from fuel dribbling due to short injectors. I did build my injector bungs so they allow the injector to seat on the bottem of the hole rather than the bung itself. One oddity during tuning that may be related to this is the fact I need to nearly turn off any accelleration enrichment (i.e. accelerator pump) or else I get a nasty tip in stumble at all speeds. And even weirder is the fact I need to tune in a HUGE priming pulse (like pumping the throttle on a carb) to get the car to start on the first crank no matter how warm it is.

Cbass, I have read a little about that issue also but I think it is only a problem with the guys running huge injectors for forced induction. I think anytime you get below 1.5 ms injector pulse at idle you start having problems. My injectors are a little large but have given me no problems I have identified to this point.

Lizard, Cbass is correct about the use of a MAP intead of a MAF. It is what is generally referred to as a "speed density" system. It works very well and is very tunable compared to "mass air" systems but not nearly as forgiving to performance modifications. Once a mass air is setup it will generally adapt to modifications without retuning (to a limit) where as the speed density will need to be tuned everytime you make a modification. I assume if the Megasquirt is converted to use the wide band O2 sensor it would be nearly as forgiving as the mass air systems (to a point).

Todd

Lizard · Posted: Tue Aug 17, 2004 3:27 pm Post subject:

Todd or Cbass,

what different injectors would work with the 924/931 heads? and what exactly did you do to the head on your Todd?
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3 928s,

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Lizard, just about any bosch style injector that flows 19lbs or more will work. Some with extended nozzels might give a better spray pattern but I am not sure what uses these other than 3.0 L Nissans. Mine are not extended and I haven't detected any problem yet.

Here is a table of injectors and there flow rates just to give you an idea of what is available. If you look towads the bottem of the page you will find a chart on HP per cylinder versus flow rates. 19lbs injectors from a 3.0L Taurus will easily support 125HP.

Not sure what you are asking about my head modifications. Only thing I had to do was build some injector inserts that screwed in place of the stock ones.

Todd

CBass · Joined: 03 Nov 2002 Posts: 2807 Location: Vancouver, Canada

Here's that link without the extra URL on the end

http://users.erols.com/srweiss/tableifc.htm

My first goal with this swap is reliability, performance tuning will come later. If the low impedance injectors work well, I'm happy.

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'81 931 in various states of assembly