help with my ka-t

[DRIVESLIDEWAYS]

Hey guys im in the middles of my ka-t build on a 1989 coupe and i just had a basic question. ive tried searching but couldnt find exactly what i was looking for. ok so first off i bought a turbo kit for it off of craigslist pretty much all i paid for was the manifold and the turbo because the rest is pretty much ****. the manifold is a JGs and its a brand new t3/t04 turbo. now my question is the turbo does not have an internal wastegate and the manifold doesnt have a flange for an external one. can i just fabricate a downpipe and mount an external one on the DP? any help is much appreciated thanks

[KATwo40]

NOOOOOOOO.

Don't do that. The wastegate's primary function is to divert exhaust gases around the turbine wheel, keeping the turbo from creating more boost pressure. If you mount the wastegate to the downpipe, all of the ehxuast gas has already traveled through the turbine wheel, and you will pretty much have boost pressures that max out the turbo's capability.

You'll need to make the wastegate port / mount somewhere in the collector, before the turbine inlet. This can be done by attaching the flange directly to the collector, or having a tube from the collector to remote-mount the flange.

Here's an example of one such modification. This manifold was designed for T2 applications, using integral wastegates. It's been modified to fit a T3 and use external wastegate.

IMPORTANT NOTE: See how the angle of the wastegate port is not congruent with the normal flow of gases (i.e. flows backward)? The only reason this works on this setup is that the port is directly adjacent from the #1 runner. If at all possible, you really should make your port perpendicular to, or similar to, the flow direction of the exhaust gases to prevent boost creep.

[Blown240sx]

I dont know if it works but Ebay does sell a Spacer that has the Tial Wastegate flange on it. It is ebay though and could be a crappy piece.

Example of the manifold I have.



See the Wastegate flange location.

[DRIVESLIDEWAYS]

THANX FOR THE HELP MUCH APPRECIATED

[Jookmasta]

if your turbo does have a wastegate hole, you could simply just use an internal wastegate provided that the flange on the downpipe has a swingvalve..........that may be an easier option if you are short on funds.

[mikerbike]

This hole is what he's talking about...

Here's what the stock internal wastegate flapper/flange looks like...

If you get on of those, you'll also need an actuator. I keep seeing universal ones on Ebay but if you can, you should try to find a stock T3 WGA and modify it to fit your T4 comp housing.