Well, it looks like my fuel pump(s) are taking a dump so I was curious what type of pump setup do you guys normally run? I have an '87 Carrera and it is using a twin pump setup. It appears to be a stock fuel pump in the front and a Bosch 044 motorsport pump in the rear. Is this a typical setup, or do you guys with modded 930's typically use a different setup? Large single pump maybe? I'm not entirely sure if the 930 fuel system (supply wise, I understand the differences with CIS of course) is completely different from a Carrera or not.

My car consists mostly of Protmotive Stage 3 components, however there are few different parts from their standard setup. It has Protomotive's large FPR. I've seen up to 6 bar of fuel pressure at WOT and at high end of the rpm. I've looked at some typical aftermarket pumps, though I'm not sure if such high fuel pressure is going to cause a potential problem. Walbro makes a application specific 255 series pump for quite a few Porsche models (mine included), though apparently those can't handle extremely high fuel pressure very well.

Is a pair of Bosch 044 pumps sufficient for 500-600rwhp levels? The 044's are apparently rated at 200lph @ 5 bar and 13.5v, so I think 2 of them should be sufficient. Of course increased pressure will decrease volume, though IMO twin 044's seem like a viable solution. Thanks in advance for any help or insight that any of you can give me.

 

No, actually I think you will find that the stock setup is good for the levels you are looking at. It will sustain over 500RWHP fine. You can not run two 044s in series. There is to much pressure/flow and the front pump will kill the back pump. Keep the 044 in the rear if you will like. That will yield more flow than the stock setup. The 044 is a hell of a pump. Again, it is not needed and the stock pumps are adequate for your quest.

 

Obviously PorschePHD is spot on.

I don't think you need a dual Bosch 044 setup, but if you need to buy new pumps, it is worth thinking about it, they are great pumps. I doubt a stage 3 will see more than real 500rwhp if any (forget dynos). I have a 3.8ltr proto setup and I run mine in series next to each other in the front (993TT), for some reason this is how they were setup, never had an issue, but it does not seem to be the safest bet and maybe the day I have an issue it will be too late? In the meantime, I have my ears out for any whining coming from the pumps.

 

As everyone has said the 044's are great, I run a dual 044 setup with no problems. But they are only needed above a certain power level to supply enough flow/volume...

Jean, my 044 are also side by side right next to the tank as well...

Norm

 

You will know when they go. They scream louder than anything you have heard. I have had it happen twice which is why I use a different front pump. I noticed something was going on as I had tuned the car and over time the program no longer was appropriate for the car. On my way back to the shop the pumps died. This was years ago. I thought it was a fluke but about 6 months later it happened again. I think you will find that very few actually need the volume of two 044s. Normally a 930 and a 044 is more than adequate for 90% of the builds out there.

 

The odd thing is one of my pumps started to whine a bit, though it stopped doing so and sounds normal yet I am still having the fuel issue. Under WOT the pressure jumps up to 6bar and then above ~4-4.5k rpm it starts to drop off as low as 3bar and then the car momentarily cuts out. That's only at .7bar of boost. Does it sound very likely that one of the pumps is just worn out and not flowing to their full potential? The odd thing is my car absolutely did not display any signs of this issue a few weeks ago. The only changes I've made since then were to throw the Nology wires in the trash and replace them with Clewett wires (very nice I might add!). This couldn't possibly be an ignition issue as the fuel pressure is definitely dropping off. Guess I'll by another stock pump and see if that fixes it, and if not replace the 044 as well.

I know the 60-1 will be close to maxed out at ~500rwhp. Before too long I'm going to be switching to an AEM standalone and going with a significantly larger turbo. I'm thinking about a T71 .81 GTQ from a local company, or possibly a Garrett Gt4088r as I want to put out a few high hp glory runs on the dyno. I'm just modifying the car for fun, and not with any race class/series or other particular purpose in mind. I do want to go to some Local PCA and NASA track events soon, though I haven't been able to find the time with my job.

Thanks for the help guys.

 

Hola... Do you know if you have a fixed rate regulator or the rising rate? They use both... His fixed is generally 5 bar....to my memory... the rising rate will go to 6.8 bar I believe.. Jean may know more than I

ed

 

Ed, it's definitely their rising rate FPR. 6.8bar sounds about right. I have a Defi fuel pressure gauge and it's pegging the gauge at just past 6bar. I spoke with the man himself, Todd, and I'm going to run my 044 in the front and use a stock 930 pump in the rear instead. Apparently the PO must have set it up wrong as the 044 pump should have been installed in the front to begin with. With the stock pump up front, it sounds like it's not quite able to keep up with the 044 in the rear.

Hehe, it's always something when it comes to automobiles. Since I bought my car, I've modified it from the way it was when purchased, and I've only managed to make it slower and loose ~100rwhp!

 

Glad you got your answer :-).. Have fun with the 100 HP back soon ;-)

 

I have the Protomotive stage 3 also.
I have been having the exact same problem, and the rear pump fuse blew, I replaced it, but the car still runs lean after 4.5k rpm

About a week ago my rear fuel pump was whining really bad, louder than normal, how can I test the pump?

 

How much boost are you running? Do you know what size injectors? My car came with the 951 stock injectors (37# or ~380cc I believe) and it had a 1bar spring in the wastegate. I put down 431rwhp and even with the 6bar Protomotive rising rate FPR and twin pump setup it was still ridiculously lean (13.5-14:1 above 5.5k!). 37# injectors are just way too small for 400+rwhp IMO. I've switched to Siemens 55# and had Todd retune the chips, though I have yet to dyno it again.

Are you running the twin pump setup from Protomotive. Todd's setup consists of a stock pump in the rear and a Bosch 044 Motorsport pump in the front AFAIK. You might want to make sure that the 044, or whatever type of high flow pump you have is mounted in the front. That is the proper orientation according to Todd.

 

I am running 1bar w/ #56 injectors, I made 489rwhp could of made 20-30 hp more if the intercooler wasn't heat soaked

I am running 2 front 930 pump in sieries.

I just ordered the 044 pump, we will see what happens.