[oab_au]

Originally Posted by Wreckless

Phil,

I'd definitely whip up a boost leak tester first and make sure it's a problem before you go and fix it!

I actually un-bolted the balance valve and re-sealed the large O-ring that seals the whole assembly into the intake manifold, only to button it all back up again and have the same intake leak hissing away like I'd not changed a thing!

After pulling apart a second time is when I figured it had to be the seal on the shaft itself. Upon disassembly, the seal was in pretty poor shape so it's possible that a good new seal would have solved the issue, but I didn't even want to think about how much trouble it would be to acquire just that shaft seal, or find a suitable replacement without replacing the whole balance valve itself for $$$$ or take a random gamble on a used one.

Since I'm trying to really narrow down the issues with the car, I made the decision to eliminate the valve itself altogether. I don't really like simply eliminating something with such an obvious purpose if it's not necessary.

So.. boost leak test first, then fix as necessary.

You can see the 'tester' fitted to the front of my turbo in the first pic with the intake manifold off.
It's a simple 3in PVC cap I got at Lowe's for under $4 (which ends up being perfect for a 4in inlet compressor cover) that's drilled/tapped for a hose barb that's RTV'd in as well.
From that hose I used leftover vacuum line & vacuum tee to tee off to an old mechanical boost gauge, and the air-spray-duster nozzle that came with my air compressor. With 150psi in the tank it only takes a few short bursts before it gets to ~15-20psi in the intake system, and it works pretty well aside from a minor backleak through the air nozzle itself.

Hope that helps a little.. I'm certainly looking forward to some more videos of your Turbo'd SVX!

Jeff

It would be best to retain the valve, as it does supply a lot of the torque, between 2200 and 4000, where the Turbo is just getting going. Not so much a problem with a manual, but the auto will use that lower rev range more, so it can use the extra torque that the valve supply's.

Harvey.