I'm running a Ford 5.0/302 with stock heads in my E36 now, and the BMW stock fuel pump is fine for the limited horsepower that comes with stock heads.
This winter it's getting the top end upgrade, and I'm wondering if I need a new fuel pump to keep up. I cannot find, for the life of me, an LPH figure for the stock E36 OBD1 pump. Or the OBDII pump for that matter.
Have other E36 folks needed a new pump with the higher HP LS motors, or an upgraded Ford small block? Could you please note also, whether your chassis was OBD1 or OBD2, since the OBD1s got a weaker pump.
If God meant for man to motor-swap LS engines into track cars, He wouldn't have created Corvettes.
https://www.bimmerforums.com/forum/s...328i-fuel-pump
Above you can see what the stock system is running. Below in the link there's a description of what you will need. Hope this helps.
I have gt40p heads, e303 cam, stock intake, full exhaust, bbk 75mm throttle body, sct chip and running a Mustang oem fuel filter with the stock e36 pump.
https://www.stangnet.com/mustang-for...91-5-0.856821/
I think most people making 400ish would run a walbro 255. Up to 600-700hp a walbro 450
I have an Aeromotive 340 in my tank. Fit in the OEM sending unit fairly well. Rated at 320 lph at 50 psi when supplied with 13.5 volts.
I had an external walbro fuel pump in my last car. It was loud enough that I wanted an in tank solution for this car. Can't even hear this pump running when the engine fires up.
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Walbro 255.
Yeah I would mount a walbro in the tank. External is annoying. I would not be surprised if that aeromotive pump was made by walbro or Bosch.
Thanks guys. I see a new fuel pump in my future, and as long as I'm going to the trouble it might as well be a Walbro 255, which I have used on another motor swap car already. Unless I find a screaming deal on a 155.
Did you guys that installed the 255 use the stock wiring, it's what, 16 gauge? Or did the current draw call for heavying it up.
If God meant for man to motor-swap LS engines into track cars, He wouldn't have created Corvettes.
http://walbrofuelpumps.com/255lph-wa...fuel-pump.html
for the 76$ i would just get the 255. watch out for knock offs
Very good info-thanks for posting!
I wouldn't doubt that most of the common electric fuel pumps are all made by 3 or 4 companies, but that doesn't mean they have the same parts. There are multiple reviews and tests online comparing pumps.
I did increase my fuel pump wire size. I didn't like the idea of drawing constantly well over 10 amps with the OEM harness.
http://realstreetperformance.com/Fue...ison-Test.html
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interesting test, that aeromotive performs well
i would like to see a Walbro 450 in that comparison
The only tests I found online with that pump were done by walbro at 13.5 volts. From what I seen earlier most fuel pumps are tested at 13.2 volts... so they skewed the flow numbers a bit in their favor but it's still 405 lph, 16 amps at 50 psi . Definitely more flow than the Aeromotive unit.
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If you have a trunk mounted battery or need more than a 255, use the stock wires to power and ground a relay. Run a new lead from the battery to the relay and pump and use a local ground.
Based on that article's tests, I doubt I will be pulling 7.5 amps, but I think the stock pump only pulls maybe 5 amps. I'll check the wire gauge and see where it is, because I think the relay is good for like 40 amps.
I'm not crazy about using the stock wiring as relay control. It's a track car, so if I pull the kill switch, I don't want the fuel pump to keep spinning off battery power. There's not much chance of that happening since the kill switch would shut off the relay control power, but it still makes me a little nervous leaving the pump with a second path.
If God meant for man to motor-swap LS engines into track cars, He wouldn't have created Corvettes.
https://www.bimmerforums.com/forum/s...ro-450-install
thoughts are the wiring is good for 20AMPS, just switch the fuse....
Using BMW factory pump on mostly trackable LS2. Works just fine.
- 96 328is 6.0L. (LS1 to LS2 build thread: http://forums.bimmerforums.com/forum...ad.php?2098938)
- 96 328is 5.7L. (LS1 build thread: http://forums.bimmerforums.com/forum....php?t=1289987)
- 95 ///M3 6.0L. (LS2 build thread: http://forums.bimmerforums.com/forum....php?t=1619249)
- 97 ///M3. (e46 Fender Flares/track car build thread: http://forums.bimmerforums.com/forum....php?t=1727098)
- 96 328is (Dual Fuel Pump to Surge Tank thread: http://www.bimmerforums.com/forum/sh...ad.php?1964025)
I have stock E36 pump on stock LS2. Seems fine to me.
A good stock pump will do about 400 rwhp, but I would leave a substantial margin. Changing to a real, not fake, Walbro 255 is probably smart. It's cheaper than a voltage booster to extend the range of a stock pump.
That sounds about right, but check my math:
The ETM for my model E36 says the wire is 1.5mm, which is right between 14 and 16 gauge? Pick your favorite automotive wiring gauge table; mine says assuming I have about 10 feet of wire to the pump, I should keep it down to 25 amps, but if it's 15 feet, I should keep it down to 15 amps?
If God meant for man to motor-swap LS engines into track cars, He wouldn't have created Corvettes.
You can actually buy directly from walbro now. They did this because of all the fakes. But if you buy from a larger outfit like summit racing you will be fine.
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