Too much back pressure
 

1986 300SDL. I haven't been able to get my turbo to put out over 6psi of pressure, and didn't think that the turbo was working correctly. After reading many posts on the subject, I removed the alda valve, and replaced the vcv ( when I was working on the tranny shifting, fine now) the vacuum system is working well now.
The engine would not go over 3500 rpm under any circumstances, and no more than 6 psi of pressure in the intake manifold. Today I've taken the exaust pipe off the turbo. Now it easily will go over 4100 rpm with 10 psi of psi boost, that is a static test, so I'm not sure how much that it means. But it seems clear that I have too much back psi. My question is how to clear it out without buying a new exaust system? Can this be cleaned out some how. This system doesn't look that old, and I would like to use it. Any ideas?

There should be a something of a catalytic converter on the passenger side of the transmission. Fit a straight pipe in place of it or use a rod to break through the clogged core.

How the heck did you manage 10 psi with no load?

Sixto
87 300D

I really don't know how I got 10 psi out of it, I was suprised to see that myself. I was just revving the engine and thats what the boost gauge was telling me. I will try poking something through the converter, it will be difficult though because its all welded together as one piece.

Get a length of pipe just longer than the cat and that will just slip over the exhaust pipe. Use u-bolts to clamp the straight pipe in place. You're doing this because you won't be driving on public roads right?

Or cut the pipe close to the cat so you can rod it easily then put it back together with something like this - http://www.summitracing.com/parts/WLK-33240/

Sixto
87 300D

This is what you're likely dealing with (from the gsxr collection) -

http://www.w124performance.com/image...t_plugged3.jpg

Sixto
87 300D

Straight pipe it and while your ahead do the whole shebang (resonator, muffler) :D

From the looks of that, splicing in a straight pipe is the way to go.

Thanks Dan

More data
 

Trap Oxidizer, LINKS thread
http://www.peachparts.com/shopforum/showthread.php?t=229522





Have a great day.

The trap oxidizer has been changed over.

straight pipe if in non smog state.Or order large after market racing cat.