This is how my down pipe looked when I had a no boost issue, Prior to my failure to place the air filter properly allowing my turbo fins to be destroyed. Had similar symptoms prior to blowing up my turbo.

I am afraid of the downpipe or crossover pipes being collapsed.

Why does that happen anyway?

It's double-walled.

I imagine that if the outer pipe cooled suddenly, it would shrink and crush the inner pipe. Like hitting a puddle of water or something. (?)

I guess this was the cause of my no boost issue.

http://i856.photobucket.com/albums/a...ps1a58b98c.jpg

http://i856.photobucket.com/albums/a...psfba4e887.jpg

I installed a used Lindsey Dual Port wastegate with an MBC. I haven't driven the car yet or even tried to set the MBC. I am still running stock chips so I will keep it at 10 PSI just to be safe.

Good luck on boosting! That thing looks like something salvaged from the Titanic... Is that valve seized like that?

It was until I hit it with hammer. I guess the diaphragm is busted. I am going to take it apart to see what really failed.

Just got it completely together. I have the boost set at 10 PSI. I couldn't remember if 10, 11, or 12 psi was stock. I figured 10 seems okay.

The car runs great and no longer makes a rattle noise when coming on to boost(maybe that was my wastegate slowly dieing).

Congrats on finding the issue!

This just happened to my '86 951 today.
 

I just had this very same situation happen to me this morning on my way to work. Started out and I was making boost fine (aftermarket boost gauge). The next thing I know, I have a smooth running NA 944. Great vacuum, still 20 inches at idle. Everything else is great, runs fine, accelerates smoothly, quietly, just makes zero boost.

I have suspected that the waste gate might be a weak link since I acquired the car back in May (previous owner shimmed it). Sometimes I would get inconsistent boost levels (have Lindsey MBC, 951Max chips, no cat). Last week it started suddenly increasing boost beyond what I had it set at, 17-18 psi vs 15 previously.

86 951 Driver,
I think I saw in your posts that you went with a Lindsey Dual Port. Sitll happy with this?

Thanks.
Roger

I'm using a lr duel port and love it. It definitely sounds like your wastegate is stuck open though

Is the LR Dual Port legal for use in PCA Club Racing, stock class? At some point down the road, I may want to do some Club Racing with this car.

Roger

I don't think you will get an answer as I believe his car burnt to the ground shortly after this from a fire in a garage.

Ouch! I hope it wasn't the waste gate that caused the fire :( As long as no one was hurt.

I think I will probably find one of the other threads that deals more directly with waste gate selection and get some info there. Probably more appropriate placement than in this thread. Thanks for the heads up.

Roger

The dual port is not CR legal. But they make a "clubgate" version which is a single-port version of their updated WG.

Thanks. If I do turn the car into a club racer, it won't be for another 3-4 years. I see a lot of positive info regarding the Tial. I'm thinking maybe I should just go that route now and worry about club racing when that time comes.

Roger