Ok I eventually want more power than the stock fuel system can handle and I want to do it without meth and without blending E85 (pure e85 might be ok). That being said there is the huge problem of the lack of fuel system upgrades. Is it the LPFP or the HPFP that needs to be replaced or both? Is anyone still working on this?
The fuel system problem.
- Thread starter sunwolf
- Start date
That makes my stomach churn. I had TWO BMWs with HPFP issues. Read the blog here:
http://bittangents.com/2009/01/24/2008-bmw-335xi-fuel-delivery-lemon-story/
I would stay far FAR away from anything that is BMW HPFP related.
http://bittangents.com/2009/01/24/2008-bmw-335xi-fuel-delivery-lemon-story/
I would stay far FAR away from anything that is BMW HPFP related.
panther427
New member
Simplest bolt on solution is to get a secondary in tank pump or bigger one. Then run a second hp pump off a belt drive system. Piggy back electrical connectors and not sure about an extra fuel port. Could have one pump feed each bank with a crossover.
That's my thought on the matter. Unless there is a bigger fuel pump or reputable rebuild service that can work some magic .
Far as the bmw pump goes does the factory pump have much head soon to supply extra fuel like ours.
Otherwise it could be the same part
That's my thought on the matter. Unless there is a bigger fuel pump or reputable rebuild service that can work some magic .
Far as the bmw pump goes does the factory pump have much head soon to supply extra fuel like ours.
Otherwise it could be the same part
Yeah you can command different pressures by rpm vs load and some other stuff I don't know much about.
But you get to a point where you command a number that it just won't support....like when I'm at 20 or so psi in the upper rpm and I'm commanding 2200psi but only getting 1000 at the rail....or at 15 psi at 2500 rpm and commanding 2200 and only getting 1000psi at the rail....it just doesn't have the capacity
I thought a saw a scalar in my tune that the stock value for a relief valve to open and return fuel to the line at 3000psi...so I guess in theory you could command up to that...I'm not sure how healthy that would be though and the pump could never sustain that anyway under high load
But you get to a point where you command a number that it just won't support....like when I'm at 20 or so psi in the upper rpm and I'm commanding 2200psi but only getting 1000 at the rail....or at 15 psi at 2500 rpm and commanding 2200 and only getting 1000psi at the rail....it just doesn't have the capacity
I thought a saw a scalar in my tune that the stock value for a relief valve to open and return fuel to the line at 3000psi...so I guess in theory you could command up to that...I'm not sure how healthy that would be though and the pump could never sustain that anyway under high load
