WTB wastegate

[HSKR]

So my new car won't build over about 4psi of boost. Think I have it narrowed down to a weak wastegate since unhooking the vacuum line does nothing to change the boost levels. Does anyone have a spare one laying around I could get? Car is a '92 IROC but has had the older T2 garrett installed.

[iTurbo]

So this is a 'Turbo I' car and not 'Turbo III'? Big difference as they used different waste gate actuators. A lot of the '92 IROCs were TIII..

[HSKR]

This is the 2.5L T1 with an '86 TII Garrett installed in place of the Mitsu turbo.

[dwh4784]

Your years don't match up. Need a picture of your turbo to help. If it's really an 86 that someone converted there might be something obviously wrong to the trained eye. Might as well start there.

[HSKR]

Spent all day working on it chasing vacuum lines and everything else with another guy and we narrowed it down to this. Not only does removing the vacuum line not change the boost levels, I can move the actuator rod by hand with ease.

- - - Updated - - -

I may be new to the forum, but what I have posted about the set up is what is on the car. The previous owner put an older garrett turbo from an '86 on it in place of the smaller mistubishi turbo.

[dwh4784]

Not trying to be a pain, but I have the same engine as you and did the same old Garrett turbo modification as your PO and it was a pain. That's why I wanted to see your WG can because in the end to fix mine we ended up having to cut the WG arm in half and thread it with a coupler to tighten it down and increase the tension for it to build boost. This isn't something you'll see commonly recommended on the forums which is why I wanted to see your turbo first to see if it's set up like mine. If you truly have the old style turbo and your WG arm is loose buying a new one isn't going to help at all.

[iTurbo]

I used to have an '89 Shadow ES. The stock Mitsu gave up the ghost and I replaced it with a Garrett T03 from a Chrysler TII application. It was about as bolt-on as it gets. I used a grainger valve manual boost controller with it and it worked great. As far as the oil/coolant lines, I got them from TurbosUnleashed.

When the original Mitus died, I'm almost positive it was from overspinning it. I had already modified the car with 3" exhaust and a TII radiator/intercooler setup. This caused the stock Mitsu turbo to overspin itself by trying to produce 14 psi boost at WOT. With the 3" exhaust, it would 'creep' up past 14 psi and hit the over boost shutdown at WOT. It was just too much to ask of the poor little Mitsu. The Garrett on the other hand was great! Much more durable turbocharger, even at 18 psi at WOT.

[iTurbo]

If you post a picture of the exact waste gate actuator you need, I may have it here. On the TII turbos, there were small and large can variations. The large cans were generally more desirable and held boost better. They were on the '89+ cars.

If you are experiencing low boost, even with the vacuum line disconnected from the waste gate actuator, you may have a torn/damaged diaphragm inside of the actuator, or possibly a VERY plugged exhaust system (doubtful). Best thing to do is try replacing the actuator if you are sure that is the culprit. Also try running a grainger valve type manual boost controller to control the boost level at WOT. If you have the 'small' waste gate actuator, you can try shimming it with washers to increase the preload on the waste gate puck. That might very well be more cost effective than trying to find the rarer and more expensive 'large' waste gate actuator.

[HSKR]

I will get pics tomorrow when it's daylight again. Further clarification, the turbo is off a 87 Daytona. Not sure why i was thinking 86.

[HSKR]

http://i1078.photobucket.com/albums/w486/hskr23/2013-12-01_11-37-28_263_zps39ac5bf4.jpg (http://s1078.photobucket.com/user/hskr23/media/2013-12-01_11-37-28_263_zps39ac5bf4.jpg.html)
http://i1078.photobucket.com/albums/w486/hskr23/2013-12-01_11-37-49_934_zpse55ddb98.jpg (http://s1078.photobucket.com/user/hskr23/media/2013-12-01_11-37-49_934_zpse55ddb98.jpg.html)
http://i1078.photobucket.com/albums/w486/hskr23/2013-12-01_11-38-20_286_zps270b561e.jpg (http://s1078.photobucket.com/user/hskr23/media/2013-12-01_11-38-20_286_zps270b561e.jpg.html)
http://i1078.photobucket.com/albums/w486/hskr23/2013-12-01_11-39-39_618_zpse259f5b3.jpg (http://s1078.photobucket.com/user/hskr23/media/2013-12-01_11-39-39_618_zpse259f5b3.jpg.html)

[supercrackerbox]

I've got a large can hanging on the shelf. It's not pretty but it worked when pulled. I'll sell it for what I paid for it, since the project it was reserved for isn't going anywhere any time soon. PM sent.