Losing boost at 6400rpm. Help!

[suprahero]

Followed by this...in 2 deg increments per what IJ suggested?

I did some adjusting on the exhaust side but it didn't change anything at all. I didn't make any runs after doing the intake side. I did a compression test after each change and the compression lowered.

Jay, does Keylan maybe have one laying around waiting on his swap you could borrow? I haven't seen his thread in a while, at his pace the swap may have already been done.

Keylan doesn't have a turbo at all yet Scott. Vonda's turbo is made to fit the stock flange.

 

[ForcedTorque]

Well I'm gonna show a little ignorance here. If the turbo you gave me would work, I would take my car down, and send it to you. I just doubt it would work for you though.

 

[suprahero]

Yours is made to fit on the stock manifold also, but thanks.

 

[p5150]

did you try installing a manual boost controller yet?

 

[suprahero]

I haven't installed one yet Cade. I do plan on working on this today though. If my wastegate has a 13psi spring in it, should it keep the boost around 13psi? My wife's car has a manual boost controller that I can try, but she's at work with her car so it will be this evening before I can try it.

I'm going to remove the exhaust this morning sometime and do a run with it off and datalog it. I hope the neighbors don't shoot me or put out spike strips...........:aigo:

 

[suprahero]

I just got back from scaring the whole neighborhood. Damn my car is loud with no exhaust. The datalog didn't change any. The max boost was 18.492 @ 6329rpm and then it fell off to 11.31 @ 6698rpm. It then went back to 13.5 @ 6994rpm and held perfectly between 13.5 - 13.851 all the way till 7240rpm where I let out of the throttle.

I still need to try something that was posted a while back and see if it helps if I redo my avcr setup and change the duty cylce per rpm instead of one set duty cylce for all rmps. I didnt 'have to do this in the past, but I'm willing to try anything.

 

[Justin]

Damnit. Every time I see this thread pop up on the 'new posts' list I get excited to see the cause of the problem :\


Why are you going to change anything with the AVCR at all? If your problem is staying consistent with the AVCR installed as well as uninstalled, why not leave it uninstalled during the duration of the diagnostics/troubleshooting to keep things as simple as possible?

I just got back from scaring the whole neighborhood. Damn my car is loud with no exhaust. The datalog didn't change any. The max boost was 18.492 @ 6329rpm and then it fell off to 11.31 @ 6698rpm. It then went back to 13.5 @ 6994rpm and held perfectly between 13.5 - 13.851 all the way till 7240rpm where I let out of the throttle.

I still need to try something that was posted a while back and see if it helps if I redo my avcr setup and change the duty cylce per rpm instead of one set duty cylce for all rmps. I didnt 'have to do this in the past, but I'm willing to try anything.

 

[suprahero]

I still hook the boost controller up while driving it around. I'm still driving it whenever I go somewhere because it drives fine. I can't feel it lose power at all.

I was going to try to adjust the AVC-R because someone suggested it to me. I've tried everything else accept the manual boost controller. I don't think it will help either, but I told Cade I would try it. It'll just be something else I can mark off of the list of possible fixes.

 

[ForcedTorque]

Jay just paint the car RED, and it will hold boost just fine...............wait.............nevermind.

 

[IJ.]

J: Thanks that rules out the exhaust.

 

[tissimo]

Where is your boost source for your wastegate?

What gear are you testing the boost in?

 

[Turbo Drifter]

Have you checked the inlet from the turbo to the intercooler to make sure you did not forget a rag in the pipe. It would now be in the end take and maybe blocking a good chunk of the core. Maybe worth a check I have seen it happen before.

 

[suprahero]

Where is your boost source for your wastegate?

What gear are you testing the boost in?

Justin, the source is right off of the turbo outlet. I've been making third gear pulls since my neighbors will try and have me arrested. I'm still doing about one hundred in a fourty five mph zone in third. I'm almost positive now that it's my boost controller causing this. I'm going to try my wife's manual boost controller and see if it helps any. It seems to run the same on wastegate and electronic boost controller so maybe that's the problem. I replaced my MAC valve, but that didn't seem to help so maybe it's in the electronic part that's in the dash. We'll see.

Have you checked the inlet from the turbo to the intercooler to make sure you did not forget a rag in the pipe. It would now be in the end take and maybe blocking a good chunk of the core. Maybe worth a check I have seen it happen before.

There's no rag anywhere. I replaced all of my intercooler pipe about two weeks ago and I also checked the intercooler itself while I was at it. Maybe it's the boost controller. I'll know tonight hopefully. Thanks for the help.

 

[rakkasan]

damn Jay, you're still fighting with this? Sorry I haven't able to help you very much....

 

[IJ.]

But you said it does it with the AVCR totally bypassed and the gate plumbed to the Turbo?

 

[suprahero]

But you said it does it with the AVCR totally bypassed and the gate plumbed to the Turbo?

I've had the gate plumbed to the throttle body, not the turbo. I thought that's what I was told to do. If it was suppose to be ran to the turbo then it wasn't.

The manual boost controller didn't seem to affect anything either, but it would be easier to tell if I had a smaller spring in my wastegate. I want it to boost around fourteen psi and it keeps going to eighteen and then falling off. The boost controller doesn't seem to change anything at all.

No problem Mark. I'd give just about anything to figure it out though. Brian said he would mail me his electronic boost controller to try it. I think I will tell him to do so. It can't hurt anything to try it. I double checked all lines and couplings again today.

 

[Justin]

Maybe I'm missing something here, as most of this is pretty over my head but.....


If you are still spiking to 18 PSI then going down to 13 PSI on a 13 PSI spring with no boost controller installed why do you want to add more things into the equation?

The problem is seemingly obviously not the boost controller if the symptoms still exist with the boost controller not installed......

 

[IJ.]

Plumbed where on the TB J?

 

[ForcedTorque]

I admire your willingness to attempt each and everything mentioned. The more you knock off, the more I wish someone had a turbo you could use to rule that out. As it is, it seems like that is the one thing you haven't been able to test, and the thread goes on.

Can the extended heat of running it on a few cylinders for 500-600 miles have caused a bearing problem within the turbo? Or slightly affected it's balance?

 

[suprahero]

Plumbed where on the TB J?

On the front of the throttlebody at the bottom is a ninety degree fitting that the vacuum line hooks too. I'll try to find a picture.

I admire your willingness to attempt each and everything mentioned. The more you knock off, the more I wish someone had a turbo you could use to rule that out. As it is, it seems like that is the one thing you haven't been able to test, and the thread goes on.

Can the extended heat of running it on a few cylinders for 500-600 miles have caused a bearing problem within the turbo? Or slightly affected it's balance?

When I reverse the vacuum lines to the boost controller, the turbo spools up extremely fast. I get 20psi by about 3500rpm, but that's because the wastegate stays shut.