jinotown

I just got a barely used Tial 46mm wastegate with the adapter pipe w/flange. Everything bolted up very nicely to my '89 944 turbo. I don't really know which hoses to use on the two control vents. I have the stock hose (factory wastegate control) and I also have a 1/4" hose tapped from the aluminum tube about 2" before the throttle plate. What hose should I put where???

Cory9584

youll need an mbc, Take one hose from the banjo bolt on the ic pipe and tee it off, one hose goes directly to the top port of your tial and the other goes to your mbc, then to the side port on your tial.

jinotown

What should I do with the original factory hose?

Cory9584

everything else gets capped off

facboy

i thought it was the other way around, one goes direct to side-port, the MBC one goes to the top-port?

DDP

This is the correct way to run dual port. You can also simplify it and run single port by running a line from the IC pipe through an MBC then down to the SIDE port on the Tial. The top port is then vented.

facboy

i talk from theorycraft (haven't hooked mine up yet), but what cory says goes against the instructions on Tial's website http://www.tialsport.com/documents/w..._wginstall.pdf. or maybe i'm misunderstanding them?

how does the wastegate actually work? i thought pressure in the side-port (the primary port) acts on the underside of the actuator, pushing the valve open against the spring? in single-port mode you only use this port, and you can increase boost with an inline boost controller like the reliaboost etc which prevents the signal from reaching the wastegate when it is below a particular pressure.

in dual-port mode, you send the unaltered pressure from the manifold to the primary port. you can add additional pressure to the top (secondary) port, which acts together with the spring and pushes down on the top of the actuator, forcing the valve closed. you can control boost by using an in-line pressure regulator on this secondary port - the more pressure you allow through, the higher the pressure holding the valve closed, and the more boost you get.

or have i got myself completely mixed up?

porschefig

BUMP: Was facboy right? I think he is but my MBC isn't working right yet...

To set boost as low as possible you should shut off flow to the top of the Tial wastegate; thus creating the largest pressure difference possible across the Tial wastegate diaphram, right? This is accomplished by closing the MBC, right? Which way do you turn the **** to close the MBC? Lindsey's instructions say counterclockwise, but I was boosting as high as my little 26/6 would go!!!!!!

Today I'm moving my "boost pressure sensing location" from the intake manifold to the banjo bolt on the intercooler pipe. I've seen diagrams from Lindsey both ways..but the newest ones on the website have it at the intercooler pipe....