Bosh 044 fuel pump, stock, or my '77 CIS fuel pump?

[laughac]

I'm putting an '87 930 engine in my '77.

The '77 CIS fuel pump puts out 80+ lbs of pressure, so I'm wondering if it will do well.
Of course, going lean is the last thing I want to do, so I'm considering adding a Bosh 044 or a stock 930 fuel pump in the rear.

Any experts out there with sage advice in this regard?

[Ken911]

Mine runs out of gas on full boost it is very modified though. I was told if i replaced just one of the pumps to replace the front one. The 044 pumps perform better than the stock 930 pumps and are actually quite a bit cheaper. So you might want to consider two of them one front and one rear. I have a new pump sitting on the bench to go in probably this weekend.

[spuggy]

My stock '77 fuel pump only made 80 PSI or so system pressure, but still had good AFR's as the only pump with a stock(ish) 930/60 motor.

Replaced it with an 044 and upgraded turbo/intercooler/headers - seemed to make acceptable AFR's on Euro gas.

No longer getting good AFR's over 5,000 RPM with E10 - plan B is to fit a second 044 (Real Soon Now).

[WinRice]

Read this:

ELECTRONIC CIS fueling & BOOST control

Then read the rest of the thread.

The 1987 930 CIS runs a system pressure 6.7 to 7.4 bar, thats 97 to 107 psi, you can't get that kind of pressure reliably with a single pump. And even if you could, the pump volume would probably be falling well below the volume you need for a solid AFR. And it would probably pull some many amps it wouldn't live long.

Remember, most pumps are measured at free-flow, and as the demand pressure increases the flow goes down and current draw goes up. There's a good graph in that thread that shows this.

Long story short, there's a reason Porsche used two pumps in series on 930's.

[laughac]

Ok, I'm shopping for a Bosch 044 pump online now.

Thanks!

[laughac]

Got it on Amazon for $199.

Now let's hope my insurance and poort little 205 tires can keep up with this '87 903 engine.

[quattrorunner]

how did you deal with the oil tank and scavenge issues?
Your going to roast any 205 series tire you have on it.

[TurboKraft]

The only difference with a Turbo's oil tank is the scavenge pump oil return port. You can return the scavenge pump's oil elsewhere, ex: to the crankcase (993 Turbos did)

[quattrorunner]

Great, now you tell me. I spent quite a few dollars making that conversion, and for what? O-well, it's correct.

[TurboKraft]

Now you're an expert, too! ;-)

[quattrorunner]

well no.

[spuggy]

Originally Posted by quattrorunner

Your going to roast any 205 series tire you have on it.

+1

My car already had 21/30 TB's, 255/40/17 rears and a 3DLZ when I got it. With the "light switch" powerband and no LSD it was a handful if you over-amped - when it broke traction in a straight line, it would rotate 45 degrees almost instantly and you had no idea if you would go into the next lane/on-coming or the ditch.

Took a K27/HF and a 40/65 LSD to make it practical. A more progressive turbo also tamed the unmanageable amounts of squat that it had previously.

I'm very fond of adrenalin - but I think a 3DLZ 930 with stock '77 suspension, wheels, tires and brakes wouldn't be much fun to drive.

[Ken911]

Just swapped out the front pump with an 044 pump Mt fuel delivery went from 1200cc in 30 seconds to 1950. the pump is about a half an inch longer than the stock one. I will be doing a few data runs tomorrow to see if it's still leaning out on full boost or if it's too rich now.