Turbo trouble, too much too little

[Chaz]

I just got back from the exhaust shop. It was my first run with the new turbo (new to me) installed. I did two WOT runs from two thousand RPMS in third gear. It produced very little boost until about 3000 rpms and built up to around 11 or so lbs at 3800 rpms, which seemed too little to me. Then it went crazy. Between 3800 and 4200 rpms, the boost shot to 21 lbs and when I let off the boost guage read 23 lbs (like the BOV was delayed), which was way too much! I drove normal for the next thirty minutes until I got to the muffler shop. I raised the hood and found the turbo to be very hot (Duh). I mean VERY HOT. Even after an hour, it was still to hot to put your hand on for more than a few seconds. Now this may be normal. I don't know. I've never messed with turbos much. But I don't know how the boost would hit 23 lbs with a yellow spring (11-17 lbs) in the wastegate and the adjustment all the way out (spring with the least pressure applied).
When cold, the turbo shaft had no play in it, but I did notice a small amount of play in it when it was hot. I'm thinking that may be OK on a hot engine. I backed off the blow off adjustment to soften it up, but didn't notice any change on the drive back. The turbo makes zero noise and spins freely at an idle for a few minutes until slowly coming to a stop, then picks up as soon as you touch the throttle.
Could this be a wastegate problem and how do I check.
I have:
Trust Greddy t78 33d with greddy 40 mm(I think) wastegate (yellow spring).
Greddy Profec B spec 2 boost controller
Apexi SAFC, 2JZ Map, All exhust piping heat wraped down to the bottom of the down pipe, Turbo blanket
ANY HELP?

 

[Chaz]

Me again
I just went out for another run to heat it up again. I have a lazer temp gun so I thought I would run the car and check the temp. I was looking at the tach instead of the boost guage and before I could let off, the boost spiked at 31 lbs at 5400 rpms. I'm not taking the car out again until I resove this. In the meantime, the turbo temp, when I checked it, was 300 F on the exhaust turbine housing and about 120F on the cold air turbine. The cold side was actually lower than that when I stopped, but the more it sat an idled, the hotter it got, which sounds reasonable as the turbine isn't pulling much air in.
I got to think that this is a wastegate problem. I don't think its opening at all. I will probably remove it and see if it is stuck or something. I also found that the turbo is hitting the strut tower, so the turbo has to come off to fix that.
Anyway, I sure would appreatiate some advice

 

[blazerkd]

.........to be sure, either turn the boost controller completely down, or remove it completely from the system so that only spring boost pressure is achievable......

make sure that you have correct vacuum routing (ie-good sources)


........my guess:

someone accidentally put a hole in the diaphragm of the wastegate (since boost pressure is becoming a progressive problem, leads me to think it's the degeneration of some component) when changing springs or during assembly (could be as small as a pin hole)

.......good luck

 

[Chaz]

I did take the wastegate apart and spun the bottom around where the vacuum fitting didn't hit the downpipe. The gasket/diaphram was kinked when I took it off. I straightened it when I reassembled but it was some effort to compress the spring down to where the bolts would thread, so I guess it could of got cockeyed again. I didn't notice any holes, but wasn't really looking for any. The material the diaphram is made of was very tough and would take a drill or razor to get through it. The boost controller is completely turned down and off.
I'm going to take the wastegate off again and see if I can find something.
I'll post back what I find
Thanks

 

[Chaz]

OK I took the waste gate back off and there is still a kink in the diaphram. Where is a good place to get one of these? There are no numbers anywhere, just the word Greddy.

What about the temp. readings. Does that sound about right?

Thanks

 

[blazerkd]

Assuming that you are running a tubular turbo manifold……I would cut this wastegate flange off of it, and go to a v-band tial 44……..this will be newer, and much more fail-safe (mechanically and in terms of assembly) than the older greddy style wastegates………or you can take your chances with another greddy wastegate.

FYI- the temperatures that you mentioned aren’t too far fetched……sounds to be fine ---->if your turbine temperatures become too high, this COULD be a result of the car running too lean, the exhaust cam (if you have adjustables) being too far retarded, and/or ignition timing being too far (overall) retarded.....

GLHF

 

[Chaz]

We'll, I'm pretty much tapped as far as going with another wastegate setup, or as least for now. Is there not somewhere that I can get parts for this Greddy wastegate?

Thanks for the input

 

[blazerkd]

you'll have to figure out which you have......

"The GReddy Type S Wastegate (34mm) is intended for Turbo Systems Running 11-14 lbs of Boost.
The GReddy Type R Wastegate (47mm) has three variations that range from 11-30 lbs of Boost.
The Greddy Type C (47mm) and Type CH (56mm) can be used from 11-40 lbs of Boost."

http://www.racingworks.com/images/greddy_wgsmall.gif


try these guys possibly.........http://www.nengun.com/trust-greddy/wastegate-replacement-parts

.....then call greddy

......then utilize the search button

 

[Chaz]

Its a type R. and their not giving the diaphrams away, are they.
Thanks for your help, Blazer and taking the time. Hope I can return the favor one day