??? Fuel system needed 800rwhp
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First page has a flow diagram of both OEM 996TT pump and a Bosche 044...
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fuel
One issue I ran into running dual parallel pumps on my Supra was too much flow at low RPM - I would overrun the return line and see raised pressure at idle and low revs. As soon as the RPMs went up the pressure was again regulated by the FPR and it would run fine. Drove me CRAZY tracking this down! The weird part was that it didn't do it when the pumps were first installed but began after they broke in - this was dual Walbro 255LPH HP pumps. To solve it I used an output on my ECU to turn on the second pump once RPM and TPS were high enough. I also used a pressure switch on the meth injection such that if I didn't see pressure in the line the boost target remained low and safe. The Aeromotive, Paxton, and other "coffee grinder" pumps never did it for me, like others I have seen a bunch of DEAD ones. I prefer the OEM style if flow and power used (!) can be sized right. People used to rave about Supra pumps but look at the power draw! Walbro 255 were much better, especially paired. Pay attention to the electrical draw and wiring, makes a huge difference..
An RPM switch and pressure switch together might work to protect against a single pump failure maybe?
An RPM switch and pressure switch together might work to protect against a single pump failure maybe?
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Yes, an adequate sized return line was exactly the issue. On that particular car I was using the OEM return and it simply was NOT enough, this wasn't a spike but rather just pressure too high but wavering down low as demands changed. However having already run a pair of -8 lines under the car I really did not want to run yet another and have to reconfigure things further. Driving around on one pump was a pretty easy software solution that turned out to be doable using the OEM wiring too - I was thrilled! The lesser amount of fuel recycling was also a bonus as I'm sure fuel temps were lower when only one pump was thrashing the fuel. The bottom line is that you must take into account all aspects of the fuel system. On that car I was lucky in that I had full access to datalogs that make this OBD-II crap look like stone tablets and a chisel to a laser printer. I could SEE the issues with A/F and injector duty and modify anything I wanted but compensating was next to impossible. If I hadn't had that sort of access it would have taken me FAR longer to figure out why the car ran so poorly down low but so well once moving down the road. No one I knew seemed to have run into this issue before either, very weird. That it cropped up after having the pumps in the car for months was even weirder, I guess they broke in and increased flow? Happy to see that the P-car pumps are so capable, I'm not sure how much fun it would be to have to put a fuel system in this car...
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BTW I'm not a huge fan of dual pump setups and try to do one pump if possible. The reason being is that if one pump goes out then you'll never know until it's too late. The car will run fine until the fuel demand goes up and then you'll run lean enough to kill the engine. If one pump goes out then you know you have an issue. I know there are scenarios where a single pump can start to go bad too and lose flow, but the risk is just doubled with two pumps.
Just putting this out there to think about.
-Martin
Just putting this out there to think about.
-Martin
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On my Supra I had a warning LED in the pillar that couldn't be easily seen unless lit. It was wired to the ECU such that if I was WOT, under boost, and A/F fell outside of certain parameters it would light right in my eyes. I could think of no way to more easily tell if there was an issue.
Certainly if pressure falls that's an indication but you need to monitor both intake pressure and fuel pressure since they cancel one another out to keep pressure steady on a return system. How to do this with a simple box is a tough question I'm afraid....
I suppose you could always use three pumps and simply have one as a redundant but the amount of returned fuel would be high and you might not know a pump went until the backup failed. I have to admit this wasn't something I lost much sleep worrying about since pumps usually give some indication before just up and dying and so much else could more easily go wrong...
Certainly if pressure falls that's an indication but you need to monitor both intake pressure and fuel pressure since they cancel one another out to keep pressure steady on a return system. How to do this with a simple box is a tough question I'm afraid....
I suppose you could always use three pumps and simply have one as a redundant but the amount of returned fuel would be high and you might not know a pump went until the backup failed. I have to admit this wasn't something I lost much sleep worrying about since pumps usually give some indication before just up and dying and so much else could more easily go wrong...
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My system is good for about 1200-1300rwhp. It consists of -6an lines ran to each side of the stock rails, 1000cc injectors, 5bar FPR (but I wish I would have gone with an adjustable), and a surge tank w/ 2x Bosch 044's and Aeromotive Filters. The pump in the actual fuel tank is still stock.
I'll try to get some pics of it up later.
I'll try to get some pics of it up later.
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i dont know lol , i was hoping you could tell me , i was thinking something like , as long as power is going through the pump you could wire the light in somehow so if it died no voltage no light ? make sence ?again its just somewhat of an idea
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work
Art, the engine, trans, motons and brake upgrade were done by Werks 2 in Burbank. I and finishing up the intake piping, fuel system, boost controller, Marskis intercoolers, and the GT2 clutch upgrade. Greg