Casey

<center><img src="http://pictureposter.audiworld.com/66625/bosch_ms_5_bar_fpr.jpg"></center><p>Though this might be useful for someone searching in the future.

Picture above is some of the FPR choices from 2005 Bosch Motorsports Catalog

The Bosch part numbers for the various FPRs are:
3 Bar 280 160 507,
4 Bar 280 160 575,
5 Bar 280 550 113

You can also buy 5 bar FPRs that are made from crushing a 4 bar regulator. Just as a side note the crushed "5 bar" has a different fueling curve than the Bosch MS 5 Bar version. Tested several FPR and injector setups with an EIP Turbo kit on my Corrado, then an KO4'ed Avant. The differential pressure of the manifold vs resulting fuel rail pressure is different in slope/curve shape. The crushed 4 bar ramps up on a steeper slope resulting in higher pressure earlier (with less vac). You can test it yourself with a fueld pressure gauge attached to the rail and a hand held vac/pres (boost) pump on the FPRs vac line.

Ed-

Quattrosaurus

Good stuff thanks!