External wastegate question

[Gerg]

I have a tial 38mm ewg installed on a car I recently purchased. The problem is that the top vacuum nipple is gone. There is a pretty good size opening at the top of the wg. I'm wondering if this could have an effect on some of the problems I've been having. The turbo won't spool up like it should. It's a 20g set on 15lbs, but now it won't even reach 10lbs by the end of a gear.

 

[JusMX141]

If you're not using a separate system to hold the wastegate shut, then the top port remains open.

 

[Gerg]

If you're not using a separate system to hold the wastegate shut, then the top port remains open.

Okay I have a mbc going to the bottom port, but would not having the top port on the wastegate be a problem? It is just a good sized hole in the top of wastegate, could it cause it to open too early or any adverse effects?

 

[dsmcurse]

The top port is onlt used on a electronic boost controller. Otherwise top port is open. The botom port is what you wanna feed a boost referance line straight off the turbo's compressor cover into that bottom port. That way you will run off of wastegate spring pressure. If you want more boost tap your manual boost controller inline from the compressor cover to the wastegate BOTTOM port.

As far as no spool, verify that you have no boost leaks. Double check all intercooler pipin, its condition of couplers, re-tighten all hoseclamps

 

[Devilsfutbol17]

I didn't use the top port on my evo 3 16g at 14.7psi(spring pressure) or while at 26 psi using a MBC inline between the intake and the lower port on the wastegate, both with no lag.

I am not currently using the top port on either of my tial 38mm wastegates on my T/S HX35 and they hold 14.7psi(spring pressure) perfectly with no lag that I'm aware of.

 

[Gerg]

Alright thanks everyone, I'm about to replace all my exhaust gaskets to eleminate exhaust leaks but I wanted to make sure I wasnt overlooking anything small.

 

[dsmcurse]

Top port being open has absolutley no effect at all on the way you have it hooked up. (MBC inline from compressor cover to bottom wastegate port). If it did than that would mean your WG is shot and broken. Tial is good brand so I don't see that being your issue.

If you took the wastegate apart you would find the exhaust plunger attatched to a rod that goes into the "hat" lookin part of the WG inside the hat is a diaphram shaped like a parachute. The hole on the very top that your questioning would simply blow air ontop of the parachute. An electronic stepper motor from a electronic boost controller would be ontop there controlling.

Your set-up however, has boost referance blowing air into the diaphram UNDERNEITH this inflates the "parachut" and pulls the rod/plunger open to bleed off the exhaust and controller your boost.

The top port can be totally wide open unplugged not even have a hose barb screwd into it. It is fine like that.

Verify no boost leaks and that you have the "in" & "out" of the MBC hooked up correctly. But you are indeed corect having MBC only plumbed into WG bottom port.