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BWW · Joined: 21 Sep 2021 Posts: 58 Location: Idaho, USA

I'm rebuilding my WUR and am ready to reassemble. Per the instructions I measured the distance from the adapter ring to the adjustment screw for the spring cup before disassembly. However, I'm 90% sure this unit has been tampered with before, so I'm not sure if my measurement is useful. Does anyone know from experience or factory specs what the distance should be? Thanks in advance. I appreciate all the help I've received from the folks on this forum.
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Brent
'81 931 project car

morghen · Joined: 21 Jan 2005 Posts: 8883 Location: Romania

Wur adjustments are done on a pressure checking bench, dimensional measurements wont be sufficient to get a correctly functioning WUR.
You need to rig it to a bench that puts the system pressure trough it and see what the wur is regulating based on its bi-metal...and adjust accordingly.
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https://www.the924.com

BWW · Joined: 21 Sep 2021 Posts: 58 Location: Idaho, USA

Thanks for the response. Unfortunately I don't have a way to bench test it. I could, of course hook it back up to the system to test it, but this means I would have to disassemble the unit each time to make adjustments. I suppose one way would be to set it somewhere in the middle, then make the WUR adjustable externally using this set up. Is there any reason this wouldn't work?

https://www.924board.org/viewtopic.php?t=20665
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Brent
'81 931 project car

924RACR · Posted: Fri Jul 21, 2023 5:51 am Post subject:

I've done it to mine (the adjustability mod), on the NA racecar, and so far very happy - though we haven't had the car back on track just yet, that's next week...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

BWW · Joined: 21 Sep 2021 Posts: 58 Location: Idaho, USA

Thanks, Vaughan. I will try this approach then. Happy tracking! Now if I could just find a different place to mount it...
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Brent
'81 931 project car

Beartooth · Joined: 05 Apr 2022 Posts: 206 Location: Roberts, MT

I'm not sure how they calibrated them from the factory, but it's got to be a process like morghen described. Give that you're working with fairly imprecise things like springs and the bimetal arm and heating element, I imagine they had some fixture they'd put them in that allowed them to adjust by pressing the chamber and stud until pressures checked out. I'm about to put my system back together (again; I finally bit the bullet and fully rebuilt the FD, plus I've got the intake off so I could get at all the hoses and such), and I'm planning on calibrating my WUR as described about halfway down this thread: https://www.vwvortex.com/threads/wur.9191785/.

I may modify it to be adjustable down the road, but I figure I'll see if it works ok unmodified first. Making it adjustable doesn't hurt - it just doesn't seem that useful given how much of a pain it is to access the thing, and it's not that difficult to adjust the pressures by other means. If I find myself wanting to adjust it frequently, then I'll figure out a way to mount it where it's accessible and probably do the typical mod. Keep in mind too, one quick way to decrease the pressures (when you have it out anyway) is to put a washer or two over the stud the bimetal arm mounts to. You could also tap that stud down (pushing it from the inside outward) a bit to overshoot the target control pressure, then use washers to bring it back down. Lots of ways to skin this cat...
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1980 931 diamond in the rough

Fifty50Plus · Posted: Fri Jul 21, 2023 11:51 am Post subject:

I used aeroquip lines and relocated it to the front of the left fender well. Then I replaced it with an adjustable pressure gauge. Easy peasy. I'm not so much focused on originality. Quite useful for dialing in max HP CO readings on the Inovate.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

924RACR · Posted: Fri Jul 21, 2023 11:01 pm Post subject:

Mine is still mounted stock - I guess we'll see if I decide to change that. But wanted to also mention I actually modded mine while still on the car; just unbolted from the intake (after removing the coil for access), then swung it up top and drilled and tapped on top of the engine...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

BWW · Joined: 21 Sep 2021 Posts: 58 Location: Idaho, USA

Thanks for the ideas, everyone. I think I will make it adjustable, then mount it on the left fender well. Fifty50Plus, I'm having a hard time envisioning your setup. You replaces the WUR with a pressure gauge? Could you explain or provide pictures for those of us less knowledgeable? Thanks!
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Brent
'81 931 project car

Fifty50Plus · Posted: Sat Jul 22, 2023 1:36 am Post subject:

Take the line coming from the fuel distributor (you should convert to AeroQuip) to the adjustable pressure regulator input side. Another line from the output side back to the fuel distributor. Remove both factory lines to the WUR as well as the WUR itself.
I'm at the racetrack in WV this weekend and can't send any pics from my IPad. If you send me an email address, I will send you some pics of the setup in my race car with my iPhone.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

BWW · Joined: 21 Sep 2021 Posts: 58 Location: Idaho, USA

Thanks for the help! I will pm you. Good luck at the track! Sounds fun.
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Brent
'81 931 project car

Fifty50Plus · Posted: Sat Jul 22, 2023 4:03 am Post subject:

Pics sent to Brent. If he wants, he can post them here.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

BWW · Joined: 21 Sep 2021 Posts: 58 Location: Idaho, USA

Yes, of course. Hope they're useful to others. Thanks again, Chuck.

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Brent
'81 931 project car

924RACR · Posted: Tue Jul 25, 2023 10:22 pm Post subject:

Hey Chuck, can you share specifics (brand and part #) on adapters for going from these metric fuel fittings to AN? I struggled through this to convert to AN lines back at the fuel pump, ended up welding up my own adapters. Thankfully, I made that work, but it was a real PITA, and most won't be able to weld up such custom fittings.

Both the banjo fitting and the metric compression fittings were a problem...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Beartooth · Joined: 05 Apr 2022 Posts: 206 Location: Roberts, MT

I might be able to help you there! I bought an Innovate SSI-4 that I plan to use to display and log RPM, MAP, control pressure, and duty cycle (that one won't matter much for power tuning, but could be useful, and just a one-wire hookup). The question of how to adapt it to the WUR circuit was a challenge. I thought fairly early about a double banjo bolt, but the typical automotive and motorsport supply houses didn't carry anything that could work. Neither did the local hydraulic supply. Finally, I discovered this place: https://www.fittings.space/. They had the M8x1 double banjo bolt, and I bought a banjo to barb fitting (1/4") and a barb to NPT fitting that the fuel pressure sensor will go to. Some 1/4" injection rated fuel line (also not easy to find) and fuel injections clamps should complete the deal.

Anyway, it looks like they have M8 to AN fittings. I have to wonder how difficult it would be to emulate the original setup, with mostly hard line and a flexible segment in the middle, but Fifty50Plus's setup would definitely be easier. Mine's a 931, so I'd probably go with a different spot, but I'm guessing a relocation is likely to happen down the road. Woulda been really nice if they'd put it somewhere accessible and made it fully adjustable off the bat, but it seems the attitude with CIS from the factory (probably originating with Bosch) is "Do not touch!"
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1980 931 diamond in the rough