PorscheDoc

Were all the vacuum lines and such replaced after the fire? One disconnected line will lose the boost. You should be seeing about 1.7bar on the stock gauge for a stock car.

f1rocks

The wastegate looks pretty ratty even when functioning properly. I wouldn't go by "looks" on that.

The heat will make them rusty very quickly.

Rock

The vaccum lines were all replaced after the fire. The furthest ive seen the gauge go was about 1.2 and I had to get on it for it to do that.

I drove the car around and felt the wastegate part of the exhaust pipe afterward and it wasnt hot. I was able to hold my hand on there without getting burnt.

Could a bad bypass valve cause this?

WesM951

Rock,
Turn the key on, before you start it and look at the boost gauge. With a good bypass valve it should set at roughly 1bar.

Chas

Doing this doesn't really test the bypass valve at all.

That was the next thing to check. if they wg dump pipe is not all that hot, then you have to look on the intake side, and check the CBV (bypass valve)...if the valve is for some reason stuck in the vacuum (open) position, most all the boost the turbo generates is going to get bypassed right back into the inlet of the turbo. And if you think about it, all the air the turbo is gasping to suck in on the inlet side will in turn "suck" the boost right out of the IC to TB pipe, by means of the CBV. Of course, this all will only happen if the valve is stuck in the open position.

if you get on it at low rpm's and run it through the dial, do you feel a "swell" of power around 3k? Do you hear any turbo whine at all?

Peckster

When the boost comes on, there's no mistaking it. There are lots of things that will reduce boost substantially, such as exhaust leaks and problems with the electornics. I'd get it checked by someone who works on these cars a lot, it will probably save you a lot of time and maybe money to have it checked and diagnosed by a pro.

I've never heard my turbo whine.

Rock

When i get on it, I dont feel a lot of power until around 4k, and it doesnt pin me to my seat or anything, it more or less just feels like its going a little bit faster.

When I turn the key, the gauge does read at 1 bar.

Rock

any thoughts?

Eyal 951

check your vacuum, check your bypass valve. Check your IC pipe connectors, those like to blow off. Though, you'd probably know if it did. Did you guys check the exhaust before installing it? (headers and crossover?) Where did the turbo come from?
Eyal

SD Porsche Fan

In addition to the other things mentioned have you checked your catalytic converter? My car's PO was running with a bad O2 sensor and the cat eventually clogged up. I was only getting about 1.5 bar on the stock gauge, 7psi on the AutoMeter. A quick trip to the neighborhood blacksmith and I a got 1.75 on the stock gauge, 11psi on the AutoMeter.

dme

1.2 is limp mode. Simplify. Take a clamp and close the vacuum line going from the cycling valve to the wastegate. Go drive it. If your boost goes above 1.2 to 1.7+- then the wastegate is working and you have a control proble,m.

Mike1982

Check ALL vacuum lines, exhaust leaks (if there are any) as well as everything above. If you really don't want to spend the money on find a problem, at least see if there is a rennlist member close by with a 944 turbo, they can AT LEAST take a ride with you and tell if it "acting" right for a stock car. With a turbo car, there is SO many things that have to work right to get proper boost for the car, so really trouble shoting on here is actually pretty hard. Hope everything works out for you, once you get the turbo running right, you will **** your pants once the boost kicks in the first time. For the boost to come in SO late, (4,000 RPM I think you said), is VERY late for stock car. Although, I do know that even know boost comes in full you still get pushed back farther in the seat due to increase in power because of RPM's so really from 3,500RPM to 4,500rpm you should keep getting pushed farer and farer back into the seat. After that it stays the same or even drops off, that is at least my experience in a stock 944 turbo. Once you upgrade you can keep getting pulled harder and harded as RPM's increase (such as adding MAF, exhaust, injectors, etc like my car).

Rock

DME, I did what you said and now im scared. I thought I was going to die. Im gonna go shat myself ill be back.

Rock

OK. I clamped the line going from the cycling valve to the wastegate, and i took it out for a drive. I pushed the pedal and my *** went flying into the seat and the car took off like a rocket. The engine made this evil roar in the upper RPMS, it sounded like a damn ferrari.

I turned around and pulled back into my neighborhood and went and cried worse than I did when I was forced watched Biodome for 2 days straight.

The car is getting boost now. What should my next step be? Could running it like that overboost the engine and cause it to get a boo boo? or was the car really that fast and not overboosting at all?

Eyal 951

that was probably a good 20-30 psi or so if your turbo is healthy... don't do that again.