3.2 Damper to 930 WUR Circuit

[BoxsterGT]

I am informed that adding a 3.2 Fuel Damper into the 930 WUR circuit will aid in performance.

Can someone elaborate on this?

I am making up custom fittings to add this to a customer 930.

Len

[flightlead404]

If by "performance" you mean "production of horsepower" I can't see how it would aid in CIS performance at all. The intent is to smooth out fuel pressure fluctuations, but I don't see how that would increase performance.

There is one in the FrankenCIS setup and it helps a bit there, but its more around where there is a big swing in pressure like tip in or coming off the throttle. Without it there can be some hesitation and surging.

[BoxsterGT]

I think it is related to full throttle acceleration while on the track.

Hopefully someone will chime in with the full scoop.

Nevertheless, I am machining some special fittings to give it a try.

Len

[Series900]

Not a performance upgrade, but a longevity fix. The stainless diaphragm in the WUR of CIS takes a beating in track use. It’s a matter of on and off throttle coupled with boost enrichment. Pictured below is the result of the hammer effect of FD plunger back pressure on the diaphragm. The fractured disc will then leak fuel, hence the vent on the WUR. Back in the exploding air box days, Porsche added a second disc in WUR’s as the “pop” slammed the air disc closed, the FD plunger slammed, internal fuel pressure hammers the disc. When the plenum was redesigned, along with pop off valves this exploding box is less prevalent.
Adding a dampener reduces the Hammer effect of plunger back pressure shock against the stainless disc. This info provided to me from good source at Porsche motorsport back in the day. Vintage racing a 930 requires the CIS in place, thus the stock regulator takes this beating.

[BoxsterGT]

UNDERSTOOD! This Dampener does not aid in ultimate performance but allows the WUR to last longer under track conditions.

Thank you Damon.