Throttle Body FelPro Gasket

[KeithAZ]

Hello I have a 1990 Talon TSI,

I had an OEM throttle body gasket that had to two holes punched out for the top vacuum nipples on the throttle body. The new felpro gasket does not. I looked on the intake manifold and there is no ports in the intake for the top throttle body nipples to pull vacuum from. Why are these nipples here and what is the point if they are just sealing against the intake manifold? Or am I missing something?

 

[bonecollector]

The gasket with the "2 holes" is for the 2G 4g63 style manifold. 2g manifold have holes drilled for the map sensor.

Is the throttle body on your car from a 2g by chance?

 

[1990TSIAWDTALON]

I've used that gasket on my 90 without any problems at all.

 

[KeithAZ]

Are the top two holes on the 90 throttle body suppose to have vacuum going to them?

 

[KeithAZ]

Its a 90 throttle body, and intake manifold. The 90 throttle body has two vacuum nipples on top. That is what i'm referring too.

 

[1990TSIAWDTALON]

I don't recall seeing any vacuum port holes on my intake and it was all stock 90 also. My TB nipples are looped back to each other since I don't use them.

 

[KeithAZ]

Yeah, where should I pull vacuum from on the TB then?

 

[bonecollector]

The high pressure air coming from the air cleaner into the throttle body is what pulls/creates vacuum, The nipples off of the TB are there for the emission equipment.
The diagram below shows where the lines hook up to. The letters between the lines are a reference to the color of the dashes marked on the oem vacuum line.

http://www.k-labs.com/DSM/dallasdsm/1gFactoryVacuum.gif

Link to the DSM bible is below.
http://www.scribd.com/doc/15602872/90-91ecb

 

[Colt4G63 also]

You can block those holes with the gasket. They are just main galleries where they drilled the vacuum ports. They meet up with slots/holes inside the throttle body bore where vacuum is drawn upon them near the throttle valve. There are other drillings up top by the vacuum nipples that go in on an angle to intersect them. Since the ones up top are exposed to atmosphere, they are capped with brass plugs.

 

[KeithAZ]

I have a 90 Intake manifold so there is only 2 Nipples on top. My question was if they even pull vacuum/boost. I need somewhere to tap my boost control solenoid into and people where saying nipples on the throttle body AFTER the throttle plate. Those are the nipples that are suppose to be after the throttle plate but, they didn't seem like they worked.

 

[bonecollector]

IDK if i would use the throttle body vacuum nipple for a boost source, yeah it pulls vacuum, but how much? the holes that create the vacuum for the nipples on the TB are tiny.

A better source would be anywhere on the intake manifold or off of the turbo compressor housing/j-pipe. For instance, i have mine "T'd" off the vacuum from the BOV to the intake manifold.

What BCS are you using? Ingersoll-rand or stock?

https://www.ecmtuning.com/wiki/bcsinstall

 

[KeithAZ]

Electronic BS, Apexi AVC-R. Many people stated to use the nipple on the TB after the plate. I already have something T'd off the BOV and FPR. I don't wanna T more than one thing off each one.

 

[1990TSIAWDTALON]

You may need a vacuum tree, its a vacuum manifold that you hook existing manifold vacuum to and then it distributes it to other ports for various purposes.