My stock wastegate just crapped out. I'm considering going to the Tial 40mm unit. My questions are;
1.) Are there any special mounting/fabrication requirements?
2.) Is 40mm the correct size?

My engine has the following mods;
B&B Headers, Web 158R grind(SC type), Kokeln IC, twin plug, K27
Thanks


__________________
Dave
85 Factory Slant
78 911 SC RoW

 

46mm, 100% bolt on, there very nice.

 

Are you getting too much boost or none? The stock 930 wastegate is also a good wastegate, and you may simply just need to replace the diaphragm or signal hose. These are simple devices and have few moving parts. You might consider disassembling it first to check to see what the issue is, just be sure to have it secured in a vise and have a hand on the cover as you take it off so it doesn't launch into the ceiling.

 

Just one more thing to add to Brent's advice is that the old boost line and breather hose wil not fit the Tial. You'll have to fabricate news ones. I used a 1/4" fuel line and hose clamps, but a better solution would be to go with braided hose and Aeroquip type fittings. I think the threads on the Tial are 10mm x 1 pitch.

 

My stock wastegate appears to have a casting flaw. The finned chamber has a small hole in it. I suspect the diaphram is ruptured since the wastegate valve is not lifting. It 1.4 bar and broke the tires loose before I caught it by lifting. I'm going to use some JB Weld to fix it temporarily. I have a spare diaphram. For the price, you can't beat the Tial. It costs less than the factory unit and has a very good reputation.

 

A930Rocket,

Just don't use the old boost line(s) and hook the 1/4" hose to the barb fitting you get from TIAL.

WERK-I,

Even if you do all that you might get air leaking through the valve stem and you can't do anything about that. Don't waste your time and get the TIAL and be done with it.

 

Brent,
I'm definitely getting the Tial. I just have to wait two weeks(availability) to get it. Big weekend coming to the Glen next week...Zippo Vintage Races. I just have to put a temporary fix in on the stock wastegate till the new gate arrives.
Thanks everyone for the advice.

Dave
85 930 Factory Slant
78 911SC RoW

 

Dave,
I have one on the shelf....

 

Stephen,
Good to hear from you. Send me a private message on the price.

Dave
slantnose@rennlist.com

 

I noticed a few pin sized holes on my wastegate fins. How is this affecting my boost?

 

I saw that too until I looked very close and they were not pin holes. Look really close to verify if they really are. If so, they couldn't be affecting your boost that much since you asked.

 

Is anyone besides Randy going to give this guy good advice??? If your boost hit 1.4, the FIRST thing you check is signal (broken hose).
Unless you just want to lay out $500 on a new Tial - they are pretty cool looking.

 

Sure, what the hell happened to his fuel cut off switch??? Broken hose, stuck valve somehow or a big time leaky diaphram could also do it. BUT, if it isn't a broken hose somewhere between the IC and the WG then the wastegate is bad and isn't worth fixing I don't think.

 

The diaphram isn't to expensive, but the the valve and seat is. By the time you rebuild it you are cheaper and money ahead to replace it. As far as a broken line, you would know if the line was broken based on the whistle and the lumpy idle due to the intake leak. It is pretty obvious when there is a break. You also can pressurize the wastegate to determine exactly when it opens.

 

Everyone,
I did some troubleshooting before I posted this. I should have given more background info in the initial post. Some of the readings I got on the Andial boost gauge may have been an overshoot condition. The wastegate exhaust dumps directly to the atmosphere. So the distinctive exhaust note when the gate opens is very apparent. Since I installed the B&B headers after the engine rebuild, the boost comes on so strong and fast, you really have to be on your toes to catch a condition such as this, especially in the lower gears. I am using a .8 bar boost spring, just for an additional margin of safety during the post break-in. The gauge is hooked up the signal hose that goes to the waste gate via a T-fitting. I checked all connections from the T-fitting down and there is no leakage to be found. If there were, my gauge would have been showing it.
The fuel cutoff switch should have caught the overboost. It is either acting sluggishly or not functioning at all. I will check.
The reason why I posted, was to get info on the Tial in terms of the selection of the correct wastegate and installation. Since I have no exhaust fabrication tools, I wanted something that was close to a plug-and-play as possible.
I have an Apexi unit that will be controlling the boost signal to the wastegate. Other mods are as follows;
Electromotive crankfire twin-plug
Web cam (SC grind)
K27 7200(7006)
Kokeln IC
B&B headers/muffler(single out)
It's an '85 930, so it's got the better CIS fuel distrib.

Dave