Early Wastegate Refresh

[Rasta Monsta]

I recently pulled the wastegate from Shaggy to pull that pesky .8 bar spring, and took the opportunity to freshen it up a bit.

PARTS NEEDED:

Studs - (4) M8x25, (4) M8x32
Copper locknuts - (8) M8
Gaskets - (2) 930 123 194 01
J-pipe gasket OR seal - 931 111 191 10 OR 931 111 195 00
Crush washers - (2) 900 123 043 30
Diaphragm - 930 123 210 01
Valve guide - fabricated
Asbestos gasket - fabricated
Copper anti-seize
Copper gasket spray

*Note - wastegate dump pipe connection to the cat has an expensive metallic sealing ring and clamp that should be inspected. They did not need replacement on this project.

[Rasta Monsta]

Apply anti-seize to studs, and start them by hand. Run them in with a stud tool until they JUST bottom. DO NOT TIGHTEN.






Here's the guide that a guy on Pelican had made for his 930. I don't have the measurements (and frankly am unqualifed to take properly precise measurements) but once your old one is pressed out a good head shop shoudl be able to replicate it. It was clearanced to .003, and felt much better than the old one, which had a ton of lateral play in the valve.





Here's the factory gasket that goes between the iron valve body and alloy housing. I think I bought the last one in existance from Andial. You MUST have a plan to fab this, as the old one will be destroyed on disassembly, and the seal here operates against intake vaccuum and boost.

[Rasta Monsta]

Hit your gasket on both sides with a little copper gasket maker to ensure a good seal.





A little more antiseize preps the top and bottom halves of the wastegate for assembly.




Note the orientation of the boost signal port relative to the dump pipe flange.



Next we assemble the wastegate "fez," upper housing, and valve.

[Rasta Monsta]

Ready for the final phase.



Factory US spring, compared to the .8 BAR 930 unit:



Don't forget to shim the spring, top and bottom.



Here's where that gym membership pays off. People complain about this part being difficult, but it ain't. Be sure to get the bracket attachment point oriented correctly.

[Rasta Monsta]

Here's the seat, which I found a bit nerve wracking. It is NOT a press fit into the valve body, it actually moves around quite a bit, and is held on only by tightening the dump pipe. Pressure from the wastegate spring aligns it with the dump valve on reassembly.




Add some studs, again with anti-seize:




Install the bracket, but only finger tight. Final alignment and tightening will take place on the car.

[Rasta Monsta]

DONE! Boost in confidence that you won't pop your motor due to wastegate fail!

[mark houghton]

Rasta, you bad! Excellent writeup.

The last time I had my WG apart...considering rebuilding...I did all the requisite research as you have done, even found the reference to the dude that had a machine shop make his guide. And that asbestos gasket...it was leaking beforehand, along with the guide, so I just put it all back together and ran it for awhile longer before buying a Tial.

So, what material did you use in place of the asbestos (or do you have a verboten bootleg source)? And likewise, what material did the machine shop use for the guide?

[Rasta Monsta]

I bought the guide from a guy here who had a couple made. Perhaps he'll chime in on the material. The gasket is actually an OEM part bought from Andial, but I think it was their last.

[tobyp]

Rasta,

Concur that this is a GREAT writeup. Just called ANDIAL and they must have ordered ONE MORE since you purchased yours as I just bought it! Tackling the wastegate on my 930 this weekend. Thanks again for the info. Do you know if the diaphram is the same between your 931 and the 79 930?

Toby

[EmptyGarage]

Hi,

great write-up. I have one question...where do you have your jack stands contacting the car. I'm always looking for a better place?

[Rasta Monsta]

Toby, wastegate is the same part.

EG, on my car there is a marking on the longitudinal box section that shows where to put the stand. . .don't know about your 911, though.

[Miguel Antonett]

Great write up!

How does the car/boost feel after the refresh?

[mooney265]

Who's taking all these pictures??

BTW: best write-up I've seen to date! Makes me want to take my WG back apart and get some copper spray gasket