Sorting out a fuel system for a turbo bike project. Have a custom fuel rail so I will need to use an inline fuel pressure regulator of some sort. I prefer the idea of using a fixed pressure one so as to not have to worry about it adjusting itself. Seen a couple of options. Either the weber alpha one: http://www.webcon.co.uk/shopdisplayproducts.asp?id=196&cat=Fixed+Pressure
Or this Jenvey housing that you put a standard bosch 3 or 4 bar one into: http://www.spoox.co.uk/en/fuel-pressure-regulators/1865-jenvey-fuel-pressure-regulator-housing.html
Was also thinking maybe I can find something OEM instead. I know the old Jag ones are inline but told they are fixed at pretty low pressure (not sure how low).

Anyone used the above and recommend/don't reccomend?

Vw use various filters with integrated pressure regulators from 3 - 6.4 bar.
6Q0201051C is a 4 bar regulator version, mahle equivalent kl156/3.
They all look externally identical, and are stamped with the rated pressure on the feed/tank return end of the casing.

Dave

Well thats interesting! so they filter the return side of the system?

The feed from pump and tank return pipes are at one end of the filter, the rail feed is at the other end, so no return is required from the rail.




Dave

Great info, and fixes a problem for me too, my RV8 only has a feed to the rail, no return, this would work well.

Cheers.

Well I just brought one of these intergrated filter/fpr and it has no vacuum/boost reference pipe. Not sure if that's a problem although I imagine it will cause a relative pressure drop in the rail when it sees boost. Possibly ok as long as I have sizable injectors. It has a stubby little pipe (that you can see in the photo) which is blanked off. I wonder if that is a reference and can be opened up and used.

It is a fixed pressure regulator, and doesn't use a manifold reference pressure.
That shouldn't be a problem once mapped, but there will be some degree of skew in the map to account for the changes in manifold pressure, ie at idle 4.0 bar at the rail will be ~4.7 bar at the injector nozzle, at 1 bar boost it will be 3.0 bar at the injector nozzle.

If you're looking at wilder levels of boost you may have to use a rising rate pressure regulator to compensate for the relative rail pressure loss caused by the boost pressure. Another alternative is to use one of the higher pressure rated alternative versions ie 6Q0201051B or kl156/1 which is 6.4bar, care will be needed to ensure correctly sized injectors to allow idle fueling to be accurately controlled and full boost/load to be fueled correctly.

The little nub on the side is for fitting/location purposes on the original vehicle.

Dave