924Board.org

[MikeDanger]

Just doing some research and have come across several articles so I will link them here.

But heres the basics of it. You tap ( create threads) in the Pin next to the electrical plug, so that you can move it up or down to adjust the pressure. You use the screw which you insert, to pull the pin UP and you simply push it down by hammering it.



http://forums.pelicanparts.com/porsche-911-technical-forum/272502-modified-my-wur.html

http://forums.pelicanparts.com/porsche-911-technical-forum/218814-made-adjustable-wur-step-step-got-pics.html

http://www.pelicanparts.com/techarticles/911_warmup_reg/911_warmup_reg.htm



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It was either this or a giant box of legos

[MikeDanger]

Additionally I read this post, you guys can discuss:

"I am running a volvo 240 turbo WUR. Both the Volvo and Audi 5000s use a WUR with 2 ports, one above the diaphragm and one below it. The lower port uses a check/delay valve that blocks boost and positive pressure change into the lower chamber. I've been wondering why they are plumbed like instead of a single vac/boost line above the diaphragm like the 930 uses.

From what I have observed, I think there is a difference between a vacuum WUR and a boost sensing WUR, both in the range of travel of the diaphragm but also in the "preload" of the diaphragm. The home position of a the Volvo and Audi turbo WUR's diaphram is at the top stop, which means it must be preloaded in that direction. This also means that if it were plumbed with a single vac/boost line it wouldn't provide any change in control pressure until there is positive pressure applied.

I observed this top stop home position on an audi 5000s WUR off the car (with NO fuel pressure) and watched the diaphram move from top stop at 0 psi to the lower stop under pressure. I then tested the volvo WUR on my car plumbed with a single line, with fuel pump jumpered and observing control pressures while applying pressure, then vacuum. I only noticed a drop in CP under "boost", but CP did not raise under vacuum.

With it plumbed with a check valve on the lower port, I get immediate drop in CP (which means better throttle response & less turbo lag). I need to take my spare audi 5000s WUR appart and see if my theory of diaphragm preload is correct.

Here are my findings:
1 Vacuum/boost line to top port of WUR (similar to the 911)
WCP @ 0" Hg = 54 psi (fuel pump jumpered)
WCP @ idle, 19" Hg = 56 psi
Throttle blip to 5" Hg = no change, 56 psi
AFR @ idle, closed loop = 13.2 - 13.4

Vacuum/boost line to top port, vacuum line w/ delay valve on bottom port (volvo plumbing):
WCP @ 0" Hg = 54 psi (fuel pump jumpered)
WcP @ idle, 19" hg = 47 psi
Throttle blip to 5" Hg = CP dropped to 30 psi
AFR @ idle, closed loop = 12.6 - 12.8

In the second test, what is happening is the diaphragm is pulled down some by equal vacuum on both ports. Once vacuum drops (on throttle tip in), the delay valve (like a check valve to keep boost from reaching the lower port) holds vacuum under the diaphragm while pressure rises above the diaphragm, allowing the diaphram to drop to give instant drop in control pressure and excellent throttle response. This works much like an accelerator pump on a carb would. Under boost, the top port sees full boost pressure, the lower port sees nothing."
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It was either this or a giant box of legos

[kcoyle]

[Kenodog]

Or you could just buy one already modified and with a modern, thicker diaphragm from Brian Leask...
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[Carrera RSR]

[Rasta Monsta]

Several things about this make no sense. First, I'm not so sure control pressure dropping on a throttle "blip" (low revs, no boost, and no load) is a good thing. . .at all. I also don't get the author's argument that throttle response and turbo lag are improved by dumping fuel. Leask proved the contrary on the dyno - max power is obtained by enriching LATER than the factory 930/931 setup, not sooner.

And that idle AFR? Way too fat.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Kenodog]

Indeed Rasta is right. The CSV that came with the leask unit I beleive delayed the vacuum going into the WUR so you wouldn't get full fuel until later in the boost cycle.
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1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140

[Kenodog]

It seems Brian is back in business... Just called him and left a message to order my rebuilt, adjustable, solenoid controlled WUR and matching FCU... Choice....
_________________
1979 Euro 931, Olive
1981 931, Sabine
1991 Ford Ranger XLT 4x4, Ricky
1996 Ford E-350 ex-FedEx Van
2014 Mazda CX-5 (Kinderwagon)
2019 KTM 790 Adventure
2024 KLX300
2024 KLX140