pa944red

Turbo16v,

I'm near Harrisburg, drop me a line if you need a hand.

By the way, with my loose clamp I showed normal vacuum, but was down like 10 lbs of boost and it idled just fine.

Tom

JDeitz951

"Most guys replace their WG" is BS. Some, but most? More crappy shoot from the hip forum advice.

ALL 951s get intake leaks eventually. A hose can hold vacuum but leak when pressurized (boost), so idle can be fine. I would check every hose, tube and plastic fitting before touching the WG. They get fried to a crisp after 20 yrs under the intake. After I replaced all that stuff, the car was perfect, then 1 day I could only make .5 bar. I found 1 smal diam tube (under throttle body ) had come off. That was enough to do it. Buy a vaccum hose set and some intake gaskets, have a look under there.

Swagger93

951 wastegates suck. I can't fathom why anyone would defend their reliability; it seems to me to be an emotional protest to conventional wisdom. Almost everyone I've spoken to who works on their own 951 and cares about the performance has replaced or at the very least shimmed the wastegate.

I've owned a bunch of old turbo cars. Guess which two are the only two that didn't hold boost because of the wastegate? They'd both be 951s.

Laust Pedersen

Funny, I find it emotional getting all upset that a highly stressed part that didn’t hold up more than 17 years and then replacing it with another part that has no similar long term history. Let’s compare notes in 2023.

That the stock WG doesn’t have performance characteristics to our liking is another story. I, for example, have made a few tricks to mine, trying to get the boost characteristics flatter and higher (so far successfully).

Laust

KuHL 951

My shimmed wastegate on the 951 is just now starting to leak down...not bad for the original unit IMO. A new Tial is going in just because they are cheaper than OE replacement or buying a rebuilt one. O bet the Tial doesn't last 20 years.

jerome951

I'll defend their reliability. 115K miles on mine (a lot of hard track miles in the last 30k). My gate had been shimmed (to make more boost, not to stop a leak) then unshimmed to return to stock. No leaks and works fine.

The part is pretty reliable and works as it was designed to a set of requirements. If the design requirements are not the same as your requirements, well, that's a different story.

Oh, and yes, I work on my own car and care about its (stock) performance.

Oddjob

I dont think the WGs are any less reliable than most of the other components on the car: water pumps, turbo chargers, clutches, etc.

The design is for a production/street car. So the setup with the diaphram and weak spring is to work with the computer controlled boost system and cycling valve. If something in the system fails, the car will generally lose boost, not overboost - so its safe for an average driver.

JDeitz951

What is this about reliability anyway? I haven't heard about castastrophic failures, just wear over time. Spring is weak to begin with, then it gets weaker. This is due to design decisions which were made way back when, not design flaws. It performs as intended. It may suck, but that was the plan. Put a new spring in and it's as good as new. Which isn't that great.