Fuel pressure reg

[adrian h]

Hi people I'm mid supercharger build but after reading a couple of build threads on drift works etc people seem to leave the standard fuel pressure regulator in place my 2 questions are

1.is it not vacuum controlled?

2.if it is able to be left what bhp is it good for

Many thanks

Adrian

[Butters Stoch]

The factory BMW 3.5 bar regulator is good up to 500 rwhp. Some people have pushed them more. No supercharger setup will max out a factory FPR.

[pbonsalb]

I think it is good for 600 rwhp, as are the stock lines. Pump, injector, and HFM all must be changed. It is vacuum/boost sensitive at 1:1 ratio. 3.5 bar at 0 vacuum and boost draws down to 3.0 bar at 20 inches of vacuum and goes above 3.5 bar under boost.

A worn out tired one may not work we'll even on a stock car. The 96-99 have a fancy electric valve in the assembly that reforms some strange function called running loss. The 95 and earlier use just a simple regulator.

[adrian h]

At what bhp does the standard fuel pump need changing at??

[Butters Stoch]

At what bhp does the standard fuel pump need changing at??

400 or so.

[ChuckDizzle]

The factory BMW 3.5 bar regulator is good up to 500 rwhp. Some people have pushed them more. No supercharger setup will max out a factory FPR.

^ that sums it up very well.