3.2 injector specs?

[cowtown]

Can anyone point me to a resource on the stock 3.2 injectors used from 84-89? Flow rate, pressure requirements, impedance, trigger times, etc?

Thanks.

[raceman]

try RC engineering,l contacted them with the same question several years ago and they had all the answers

[beepbeep]

EFI in mind? I wouldn't do Carrera injectors...too small fo turbocharged application.

If someone can give med the Bosch #'s I'll dig out the data for them...

[RickM]

I believe the Carrera injectors are Bosch part # 0.280.150.158. Same as '86-'88 924S and 2/'85-'88 944 (Non-Turbo and Non-S)

240cc/min @ 45 PSI, 2.5 Bar pressure

[cowtown]

Thanks for the information. I'm contemplating an EFI conversion, and have access to 6 Carrera injectors. I know they're small, but was wondering if they were OK just to get the engine up and running, and spread out the expense a bit.

240cc (22.9lbs/hr) looks to be good for about 230HP @85%duty @2.5bar. Very well matched to the original engine (no surprise), but small even for a 3.0 930 engine pushing the stock 260hp with a Euro exhaust.

Guess I need to budget for some new injectors as well.

The other issue I'm hung up on is whether it's worth using a Carrera intake. I'm waiting patiently to see how Magic930's billet injector blocks work out once he gets the EFI injectors running in them. I'm not really after huge power, just driveability and tuneability. I'm also fascinated by the idea of EFI and am looking for a project. I'm thinking MegaSquirt with a wideband O2 sensor.

[RickM]

Colin,

From what I recall Protomotive used the stock Carrera injectors up to about 375-400HP. Then went to the 944 Turbo injectors. I tried to verify but their website is down. (Uh oh)

Have you checked out this package? (First "kit" on the page)http://www.clewett.com/products/emsys.htm

Apparently Wayne mentions these guys on pages 99-102 in the "How to Rebuild and Modify Porsche 911 Engines" book.

[RickM]

Bump...curious on the injectors....any additional info?

[cowtown]

Originally posted by RickM
From what I recall Protomotive used the stock Carrera injectors up to about 375-400HP. Then went to the 944 Turbo injectors. I tried to verify but their website is down. (Uh oh)

I wonder how they are doing that. Maybe they are running (much) higher pressure in the rails, or using an enrichment device. Beep, I will try to get the part numbers from the injectors to you this evening. I think they probably match what Rick posted. Raceman, thanks for the ref. to RC Engineering - I'll give them a call.

I did check out Clewitt, but a kit would take all the fun out of it. Getting there is half the fun . I'm kind of sold on MegaSquirt because you solder it together yourself, it does WBO2, it's open-source, and it can also control a Crane/MSD/Bosch CD box, so you also get ignition timing for free. And, of course, it's dirt cheap.

[RickM]

Fair enough....building yourself is the way to go if you have the time.

Anyone know if there is a new Proto- motive/tech/sport website? I tried two addresses and no luck.

[RickM]

Colin,

Just caught this thread on a search. Apparently my flow data is incorrect. However, raising the rail pressure does support higher HP numbers.

Check this out (including Tsuter excellent calc link): 964 Injector Flow Rates ?

[juan ruiz]

The way we do it is with their non adjustable fuel pressure 3 to 1 regulator, and even do a lot of people disagree with the system as the fuel pressure is all the way to the sky, it does work and does work very good, fuel rails are good for 700hp +


Getting there is half the fun

No Fun Sir.......

Heres the site........

http://www.geocities.com/protomotive/

[RickM]

Juan, Thanks for the link.

Protomotive 3.2 turbo conversion options:

[cowtown]

Originally posted by juan ruiz
The way we do it is with their non adjustable fuel pressure 3 to 1 regulator, and even do a lot of people disagree with the system as the fuel pressure is all the way to the sky, it does work and does work very good, fuel rails are good for 700hp +
http://www.geocities.com/protomotive/

Thanks Juan.
Since I have a fairly new CIS-oriented fuel system with 2 Turbo Bosch pumps and all Aeroqui[p -6 lines, I'm not afraid of running fairly high pressures (maybe up to 90psi or so) with EFI, but I'll want to be sure the injectors can handle it. Still learning a lot about this subject.

[cowtown]

Another snip from Mike the Mechanic in the thread Rick posted:


The thing is, the injectors are rated at a certain pressure. They may be 19lb/hr at 45 psi, which is the standard for measuring injector flow, BUT, if you run more rail pressure, which Porsche may be doing, they will flow more. I can say that my stock Carrera injectors and pump let me get to high 300hp mark, turbocharged, with over 85psi rail pressure while under boost.

[RickM]

Here's an interesting tidbit from an old Rennlist thread: http://members.rennlist.com/dan10101/docs/F_INJECT.doc

"Subject: Stock 951 injector flow rates, 1/21/99L
From: "Tony" toeknee@brandx.net

I have purchased larger injectors recently.

I took my old injectors to RC Engineering to have them flow benched because I could never get a straight explanation on exactly how much the stock injectors flow.

Everybody has said that the stock injectors flow 370cc at the stock 2.5 bar. Well guess what? Not even close!

Per the printed out report from RC Engineering (which recorded the results that I watched with my own 2 eyes):

At 2.5 bar fuel pressure...at 80% duty cycle the injectors produced the following:

Injector #1 262cc/min
Injector #2 262cc/min
Injector #3 261cc/min
Injector #4 266cc/min

At 2.5 bar fuel pressure...at 100% duty cycle (the injectors held wide open)

Injector #1 341cc/min
Injector #2 341cc/min
Injector #3 343cc/min
Injector #4 341cc/min

At 3 bar fuel pressure...at 100% duty cycle (the injectors held wide open)

Injector #1 380cc/min
Injector #2 381cc/min
Injector #3 379cc/min
Injector #4 380cc/min


This just goes to show...don't believe everything you read on this this list.

I also viewed how an injector starts to "screw" up as the duty cycle goes over 90%.

Anyway....that's it. Just thought this would be some good information for people that were looking to raise boost levels."

[beepbeep]

It's not worth the hassle to go with old Carrera-injectors on turbocharged car. There is nothing magic or Porsche-esque with those. They are nothing but bona-fide Bosch high impedance injectors (and pretty small to boot).

Just go out and buy yourself injectors that fit your HP-range. there are lot's of nice hi-po low impedance Siemens and bosch injectors that fit your bill:

http://www.wmsracing.com/pgi-CustomListProducts?Fuel%20Injectors,2,160,=,inject or

If really on budget, go to junkyard and find a car that has injectors that are bigh enough and buy them second-hand. I bet E-bay has lot to offer. Megasqirt can run low-Z injectors so that widens your choice a lot.

Running out-of-spec system pressures on rail is nothing I recomend as spray pattern changes.

Frankly, I'm against progressive fuel-pressure regulators too. They are just a band-aid (and highly non-repetitive ones) and hard to tune in for.

I recommend low-Z injectors with 70 and 80% duty ratio at highest load x 1.2 (for later growth purposes) and bone-stock linear 3-bar regulator.

If you map it correctly you'll be able to do rough intra/extrapolation of maps even if you change injector sizing later on (as long as you don't change impedance).