ptuomov

Yes, but one IMO can avoid replacing the return lines, if one controls the pump(s) smartly.

hans14914

So, since the regulator in the system essential dictates the line pressure, wouldn't a higher pressure pump be able to push more fuel at a lower load? I am only curious, as there are pumps available from a known good source one ebay in the high-pressure variant for $120... which seems like a screaming good deal. I am hearing some curious noised from the back, and suspect that the pump is starting to ingest some of my in-tank pickup. Figured it would be a good time to buy if the pump will work.

Thanks
Hans

Lizard928

Tuomo,

He means replacing the rubber lines in the engine bay so as to avoid a fire like Shane Elliot had.

ptuomov

I am planning to run bigger, reinforced lines all the way from the pump to the fuel rail. I am hoping to get away with the stock return lines and fuel cooler.

I'll wire up a rugged video camera to the car so if it explodes in a fire ball at least I'll get some footage to post on youtube.

Lizard928

I will be running new lines for return and supply.

Bill Ball

George is right on the edge of needing the extra pump. He's been just shy of 540 RWHP when tuned in the past. We made some changes to improve flow, including twin pickups in the fuel cell each into high-flow Holleys bridged into the 044. We recently eliminated the convoluted plumbling from the feedline on the fender to the front dampner and rails, eliminating the dampner in the process. We haven't tested these changes yet due to rain but will in a few days.

Lizard928

Sorry for the slight thread derailment here, but it is partially connected.

Bill, I am curious (asked on Reutter too), as to how you are going to keep air from being picked up.
I saw the fuel system routing, but it looked to me like the moment he turned he would be picking up air with one of the holleys and pumping it in just before the pump. I didnt get a responce as to how he is planning on curing this issue.
I am planning on making a few modifications to my fuel cell and hoses to prevent air pickup into the fuel lines under high G cornering.

If you wish to discuss this further please feel free to email me and we can discuss this. I do believe that I have come up with a good solution to maximize keeping the pumps from getting nothing but fuel.

PorKen

Would the fuel pump amp load affect the injectors at max effort?

I only recently noticed that the injectors, O2 sensor heater, IAC/ICV, and fuel pump, are all powered by the fuel pump relay (only the fuel pump is fused).

I've seen them fitted for the 044s, but would a relay near the battery for the fuel pump help a stockish system?

Lizard928

Ken,

All 044 pumps must run the relayed setup with the stock wire simply switching it.
Unless of course you are wiring your hole car with just a couple switches.

90 S-4

I will eventually need to upgrade my fuel system too, just haven't got there
yet. I was considering a single pump (boosted application) and saw this one
from " FueLab" they make different models depending on the hp level needed.
Yes there a little pricey, What do you guys think of this approach as a replacement pump that can handle any flow requirement ?? Thanks..
http://www.fuelab.com/

heinrich

There's nothing special about our fuel pumps other than the threads. So ... as long as you have the right fittings and meet pressure and voltage specs, you're fine. Yes?

heinrich

Hence the frizzy hair

jorj7

I run a relay, mainly to ensure that I get the most amps to the pump that I can. The amperage has
a direct relation to the max flow/pressure of the pump.

As a side note, as the pressure increases the flow rate decreases, so you'll get more flow through the
injectors, but only until you've reached the max flow rate for the pump at that pressure. So you could
lower your max potential power by raising the fuel pressure instead of increasing the injector size.

jorj7

Here's Bill attaching the new fuel lines to the modified fuel rail:

slate blue

A couple of things, I heard that the fuel rail damper is important, I got this from Motec. They say it is important not to get surges/pulses in fuel pressure as this will affect the mixture.

The other thing with the lines, the pressure increase we are taking is not that much, say from 65 psi to around a 100. The lines are steel and pretty small and that is an important point. I believe that the bigger the diameter is the stronger the pipe will need to be. Those lines IMHO opinion are well big enough, I will be leaving them alone. Even the fuel hoses I replaced when I built my custom fuel rails for my 2V manifold I think the hoses had something like 200 psi or more burst pressure. I will ring them today if I get a chance.

So If I up the pressure I will be looking to change any old lines, but not of the return side unless that look bad, the reason is that I replaced a return line on my 84, it was just a bit old looking, when we cut it open, we found that Porsche had used plastic lined hoses and that it was still in perfect condition, the return line wont be seeing much pressure in IMHO.

Greg