924 Turbo injectors

Roastin944 · 09-14-2003, 11:11 PM

ok, I have a set of 460 CC RX7 injectors that are also low impedance like the stock 944, and will work just fine, they just dont seal the same way in the rail or in the intake manifold, it can be done to fit right but im still a little sketchy about it, i dont want a fire! So i was wondering what the stock rate of the N/A injectors, the 951 injectors and 924 Turbo injectors. There is a 924 Turbo at the Local junkyard that i could get the injectors from, are they any higher flow than the N/A. As far as different impedance and whatnot, i know what needs to be done to make any injectors work correctly, its just the sealing im concerned about. Need to know if 924 Turbo injectors flow more and if they are a direct bolt in, Greatly appreciated, Thanks....... hopefully i will be done in a few weeks!

John

Roastin944 · 09-15-2003, 09:40 AM

Bump...I need to know because i need to figure out my injector situation and what to do, thanks

Scott R · Scott R's Garage

Your going to need an adjustable FPR or rising rate FPR as well.

Now on to injectors, the 924T Injectors simply won't fit the fuel rail. So don't consider them, besides they were less than 35lB/hr anyway.

944T Injectors did not work for me the DME in the NA didn't make very good use of them. Just use your stock injectors, you can't pump more than 7PSI into that NA block without cooking it, and your existing injectors will be just fine with a new FPR.

Your last option would be to go to Lindsey Racing or Huntley and purchases some higher rate Siemens or Bosch injectors.

Roastin944 · 09-15-2003, 02:02 PM

Scott, all i need to know is do the 951 injectors fit directly in the fuel rail? If they do, then it will work just fine. They are bigger injectors, so you need an adjustable base FPR to turn down the base FP. Then you get the FMU to give more fuel throughout boost, and it all works great... Thanks

John

Scott R · Scott R's Garage

They fit if you have a "late model" fuel rail.

ae1969 · 09-15-2003, 03:09 PM

As I recall Marksportscts used the 951 injectors and it did not work properly........... for the life of me I can't recall why....

Does the NA have the same squirly impedance on the injectors as the turbo injectors???? If that is the case you will need to run resistors if you use other aftermarket injectors (Delphi, SIemmens) to make sure your injectors don't fail under sustained loads.......

SoCal Driver · SoCal Driver's Garage

I still haven't figured out how he's going to use 924 injectors in a 944?

Scott R · Scott R's Garage

Me neither, but hey why not? I had the same problem as Marcsports, I could not get them to work correctly either, even with a resistor pack in line. The 944 NA DME does not seem to play well with modifications.

I would imagine to get this turbo setup to work correctly stand alone engine management, or custom chips from FR would need to be involved.

But I still don't think you will need any additonal fuel to run 5 PSI or so of boost. The stock injectors will work fine. If he goes over 5 my money is on rings. Thats what went first on mine, had a 30% average leak on each cylinder after only a week at 7psi.

SoCal Driver · SoCal Driver's Garage

Was thinking at one time of using two injectors per cylinder. Bringing in the second injector under load. Get's around the critical fuel pressure issue.

Yes some custom electronics would be necessary.

Roastin944 · 09-15-2003, 07:51 PM

well with a little imagination, anything can be used, just test and tune till it works. Well obviously 924 injectors will not work, because they dont fit in the rail. Not just because they ARENT from a 944, any injector will work! If it seals in the rail and manifold.

Scott: I have a 86, everything on my car is 86, so yes i have a tapped hole on the balance shaft housing, a plug on the oil pan for oil return, and i have the later model fuel rail so 951 injectors should seal correctly right? As long as they seal, i can take care of the rest. i dont know specifics about the 944 DME but any other computer can use any injector.....

General info on injectors: Low impedance run around 3.2 Ohms, High impedance injectors run around 13.2 Ohms.
This is the deal....If the ECU is a High impedance, then ONLY high impedance injectors can be used without a resistor inline. If the ECU is low impedance, then low or high impedance can be ran. So in theory, since the 944 N/A is a low impedance system, then the 951 High impedance(if i remember correctly) can be controlled right, will work without frying the ECU. The reason why they dont work, just sticking them in, is because the base fuel pressure needs to be lower, since they are larger and squirt more fuel in. so larger injectors with lower than stock fuel pressure=stock injectors w/ stock(higher) Fuel pressure.

Anyone have 951 injectors for sale?