Scott - what kind of wastegate controller and where for $20!?

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

ebay... they're all over the place search 'manual boost controller'

I bought from nxsmotorsports seller. Straight up deal.

Mind you, most if not all of them come with the wrong nipple size for Mercedes. Look for one that looks like it's made of conventional plumbing parts, with replaceable nipples. Unscrew and replace the nipples with two of the correct size right size, I forget I think 5/16? is correct. (I think I posted on this topic before in this forum, search for posts by me with 'boost controller' or something)

You'll note once inside the device, it's a ball bearing that is seated against the backside of the brass nipple held by a spring to make the seal. I took the time to lap the seat of the brass nipple to get a good fit (seal) with the ball bearing.

Although, if you're getting 11 psi under load, that's good enough even at WOT for standard IP delivery.

Maybe your IP is overfueling, or maybe you're sucking and burning engine oil?

If it's your IP overfueling, lucky you! Turn up the pressure on the turbo (manual boost controller will do fine), add an intercooler, put in an EGT gauge, and enjoy the extra power!!

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Cheers!
Scott McPhee

1987 300D

I believe that the original spec for the .96x engines is .95bar or just under 14psi.

__________________

Gone to the dark side

- Jeff

Hey guys, now after removing the ALDA and cleaning the intake with some Seafoam, I retested the boost pressure and am now getting 14 psi!

I'm not sure that those steps did anything to boost pressure. It may have been that this time I connected the line directly to the manifold instead of "t-ing" off a line to the ALDA. I suspect my ALDA leaks pressure like a sieve, so that would account for the 3 psi lower reading that I got before.

thanks for all of your input!

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

Is a boost controller all that is needed to boost the turbo up if I want more?

__________________
1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

Seives don't leak, they're supposed to do that.

If you bypassed and went directly to the ALDA from the intake plenum and it works properly, the ALDA is probably okay / holding pressure.

Check the tubing, the switchover valve, and the BFS. The tubing might be blocked/leaking. The switchover valve is often clogged, WD-40 makes an excellent cleaner; shoot it in one port until it comes out the other. Bottom port to the intake plenum, middle port to the ALDA, top is a vent. Bottom to middle is Normally Open. Blockage here is common.

Block the line to the BFS/BlueFlyingSaucer. Mine leaked on one car, prevented ALDA function.

Do not use brake cleaner to clean the switchover valve, it eats some plastics and rubbers.

__________________

Gone to the dark side

- Jeff

Thanks Jeff, forgive my colloquialism ("leaks like a sieve")

The first thing I did was to clean the lines going to/from the ALDA, then bypassed the overboost switch. New vacuum tubes to the BFS and proper routing dramatically improved shifting.

Great tip on cleaning out the overboost switch. I'll do that.

ALDA was not ok, because when I removed it the car began running much better. I am repairing the ALDA (hopefully) with careful use of permatex black silicone sealant.

Will report back when I put it back together.

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]

The fitting in the intake plenum can slso be plugged (thanks to the Exhaust Gunk Recirculation system), blowing through that line will tell.

__________________

Gone to the dark side

- Jeff