I have the BimmerWorld kit in my car, works great! No issues at all, can run down to the fuel light without issues....
'03 911 Turbo 6MT fun car
'18 Toyota Land Cruiser Daily driver/Ski Machine/Off Roader
'15 Cayenne Diesel Wife's DD
'17 KTM 690 "Adv" 2 wheeled Adventurer
If you don't have starvation, that means you're not pushing hard enouth
- 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)
So bringing back up an old thread, but one with a lot of good information. We're running a 98 E36 M3 for a local endurance series and have huge problems with starvation, we can run about an hour 10 into the event and then it starts starving with an indicated half tank left. We've had it plumbed with the dual pumps scavenging from the drivers side across and that doesn't change anything. It starts in a long right hand turn that then starts to go uphill and the car will sputter through that corner.
We recently found the article on the dual pumps so we've switched to a T system from the scavenge but now I find this thread which says that's not what most folks are doing, so I'm curious what else would the issue be? I feel like the scavenge system was pitching fuel across that was going back the rear left corner of the car before it could get picked up. In a practice day I was coaching some of our drivers and we ran it down till it was below 1/4 tank, but that was with 200 lbs on the passenger side of the car, keeping it flatter.
From this thread the things I'll go check is to make sure the pumps are wired in the correct polarity, we put two brand new pumps in before the last event and that didn't help it at all.
thanks!
I am running dual pumps t'ed into the feed like you are considering and no starvation issues on my LS Swap race car yet. Personally seemed like the simplest method to ensure fuel flow into the FPR, but I do not run much lower than maybe a 1/3 tank during the day.
The pump-over setup works fine, if both pumps are actually running (and running in the right direction). I routinely run 13 gallons out of mine without starving.
I’ve had all kinds of issues with one car I work on. Bad connections, burned out fuse holders, relays not making contact, and even a wire that was broken internally. I finally rigged up switches to run each pump separately, and LEDs to monitor power to the pumps.
'95 M3 S54 Track Toy
'19 X5 40i M-Sport
'16 Cayman GT4
‘23 GR Corolla
Dual with a transfer pump is the way to go.
I have had it where the bigger problem was the original pump failing. The transfer pump won't fix a failing main pump. Best is to replace the original pump with the new pump and use the old pump as the transfer pump. The transfer pump does not need to move a lot of volume or build any real pressure. So a substandard pump is probably still fine there.
Peter Carroll - http://www.driversmeeting.com/pcarroll
BMW Club Instructor & Club Racer, 1997 BMW M3 GTR #321
2008, 2009, & 2011 BMW CCA National C-Mod Champion
Videos channels at:
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As you can see you will get as many opnions to what works as there are number of setups.
I tried dual pump and it did not work for me, so I wet to something that will work 100%, surge tank. I can get it down to fumes without any starvation. Also keep in mind that some people go to certain types of tracks that don't induce starvation, some driving styles, etc...
- 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)
Yeah I'm getting that now. Thank you all for your input. Sounds like I have the right next steps.
The pumps are both new, and we've tried two different sets of pumps so I don't think that's the issue
I think checking that they're both wired correctly is the next obvious step, going with the T setup I can unplug each one and make sure the car still runs, this will let us know for sure that hey're both wired correctly. If one is wired incorrectly (and it would have to be the LHS one as the car did at least run, meaning that the RHS pump worked fine) then I may go back to the scavenge pump method, but that was for sure not working for us.
I don't believe the rules allow us to have a surge tank, as I believe they would count it as a "Second tank"
- 3.H.1 General Fuel System Regs. All fuel systems, including OE fuel tanks and aftermarket fuel cells, must be sound and in good working order. Maximum allowed capacity is 24 gallons or less. Fuel tanks or cells must be completely behind, or completely in front of, the driver (unless OE parts in their OE locations). No second fuel tanks allowed (unless OE parts in their OE locations). OE tanks must retain all OE systems (filler, mounts, vents, etc.).
Thank you, sounds like my ideas on next steps are sound
As I mentioned in my first post, both fuel pumps are new, (as were the ones we initially put in) so I don't think there's an age issue at play here. We had them plumbed in a pump over and that wasn't working we started to get cut out around 1/2 tank or so on a long up hill right hander (The Ridge in Shelton 8-10 complex). So next steps are to ensure both pumps are actually running in the correct polarity. Seems like having them wired in parallel is a great way to do this because we can just unplug each pump and if the car still runs we know we're okay. The only pump which could be backwards would be the LHS pump as it does run now and wouldn't if the RHS pump was wrong in the pump over configuration.
My reading of the rules we race under is that we can't use a surge tank, so that's out (specifically says only one fuel tank is allowed)
if I find a mis-wired pump I'll fix it and decide if we try the pump over one more time, but it sounds like for some folks it worked and for others it didn't.
I've put the pump-over setup on five different cars with good results. All of them run at Roebling Road, and turn 2 there will definitely starve the standard setup at 1/2 tank. Try putting an external 12v source to the secondary pump. You should be able to hear fuel flowing to the other side with the engine off.
My reservation about the "T" setup would be the potential for getting a slug of air in the line. May be a non issue, as lots of people use it.
'95 M3 S54 Track Toy
'19 X5 40i M-Sport
'16 Cayman GT4
‘23 GR Corolla
Although external 12V is a good idea anytime you add a pump, but in this case it will not do anything starvation vise. If it is good enough for the straight line, voltage won't care about cornering G's.
- 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)
While I agree with Bimerok about a surge tank being the ultimate solution, for most people that's way overkill. The dual pump is a well proven fix.
My money's on the pump polarity issue.
Another thing to check is that the transfer hose isn't kinked. When I installed my BW dual pump kit back in 2003 I had to clock the pump on installation in a way that forced both the intake and discharge hoses to make a sharpish 180 turn. This was in order to allow the float arm to move freely inside the tank. To prevent the hoses from kinking I inserted hardware store coil springs into the bend areas. (Note from the date mine was a very early kit. Later versions may differ.)
My BW dual pump kit has been working like a champ for the last 15 years. I never even give a thought to fuel starvation any more.
Neil
Yeah we initially found some kinks that we fixed, and thought we had it solved, but so far nothing. The head's off right now and I'm re-wiring the kill switch to include a resistor to prevent the alternator from being killed, but as soon as I have power back I'll be looking at the pump wiring.
I can't explain why some folks have their problem solved with the dual-pump setup, and others do not. I have a dedicated race car, and had to come in during a race with about 1/4 tank of fuel because the car kept starving.
I made a dramatic change to the fuel routing, and put one of these in the spare tire well:
https://www.summitracing.com/parts/hpf-40007
I would like to say my car pulls a lot of Gs and thus the need, but there are faster cars than mine that didn't need the surge tank.
Some have said the depth of the pump within the plastic pickup matters. I can't see how 1/4" matters to the 7-8" of saddle tank height.
Others have said the Holley Hydramat worked for them.
For the money and time, if I had originally gone with a cell and all the stuff, I would have come out about the same and not had the dumb stock tank.
2002 BMW M Roaster.
1998 BMW 328is SCCA E Production road racer.
Your link isnt working for me for some reason, but pretty darn trick piece for the money! Let me try
https://www.summitracing.com/parts/hpf-40008
Edit: mine isnt working either.
As stated the rules under which we race forbid secondary tanks and I could easily see that being considered one. I checked last night and unfortunately both pumps are wired correctly, so that wasn't the issue with the scavenge setup not working. We'll be validating that the parallel system allows the engine to run with either pump, then taking that to the track to see if it solves the issue. Chalk me up to one of the folks who's the scavenge system doesn't work for.
Follow up on this, we got the car out to a test and tune for Friday, then the race saturday/sunday and we were able to run on friday until the light came on with no stalling. Ran 2 hour stints in the race with no issue, something we were unable to do before. So chalk our car up to one where the pump over failed, but the dual pump method worked fabulously well. (Same pumps, same wiring in both techniques only change was in the pump plumbing)
Great news! Glad to hear the race went off without a fuel hitch and thanks for reporting back,
Anyone make a turn-key surge pump kit for the E36?
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