GTX2867R GEN 2 NO OUTPUT FOR BOOST SOLENOID

[timmy94]

Where is the best location for boost pressure source when running mac 3port boost solenoid? 
my new turbo does not have a fitting for that on the compressor housing. 
how come Garrett make a turbo without that? 
im confused 

[hypergear]

I usually source pressure on inlet manifold after throttle body

[Dose Pipe Sutututu]

On the hot side pipe work, or if you want to compensate for pressure loss from the IC, post intercooler on the cold side, pre-throttle

[robbo_rb180]

Drill and tap housing or weld a bung on hot pipe.

[MBS206]

That's Garrets way of saying it will manage boost itself. Give the wastegate no boost reference...

[timmy94]

10 hours ago, MBS206 said:

That's Garrets way of saying it will manage boost itself. Give the wastegate no boost reference...

That wouldn’t work especially well? 🤔

[timmy94]

10 hours ago, robbo_rb180 said:

Drill and tap housing or weld a bung on hot pipe.

Like on the intercooler pipe between turbo and intercooler? 
Still weird why they don’t put an output on the turbo since you will need one. There is one for the RPM of the turbo.. 

are they doing this because they want you to take the boost reference from somewhere else except the turbo?

[timmy94]

12 hours ago, Dose Pipe Sutututu said:

On the hot side pipe work, or if you want to compensate for pressure loss from the IC, post intercooler on the cold side, pre-throttle

What do you mean with ”hot side”? 

From what I’ve heard is that you should take it as close to the turbo as possible? 

[timmy94]

13 hours ago, hypergear said:

I usually source pressure on inlet manifold after throttle body

After throttle body? I’ve heard that you should not do that. Even if you look at the diagrams they show you that you should take boost from turbo.

[GTSBoy]

1 hour ago, timmy94 said:

That wouldn’t work especially well? 🤔

The sarcasm should have been easily visible. It was dripping off it.

[GTSBoy]

1 hour ago, timmy94 said:

Like on the intercooler pipe between turbo and intercooler?

Yes.

1 hour ago, timmy94 said:

are they doing this because they want you to take the boost reference from somewhere else except the turbo?

It's not aesthetically pleasing. And most turbos sold these days are sold for aesthetic purposes (Insta likes/fame, etc). Also its cheaper to not machine it.

1 hour ago, timmy94 said:

What do you mean with ”hot side”?

The hot side is the pipe with hot air in it from the turbo to the intercooler. The cold side is the pipe with cooled air in it from the IC to the engine.

1 hour ago, timmy94 said:

From what I’ve heard is that you should take it as close to the turbo as possible?

Anywhere after the turbo will do. Certainly before the IC is better than the IC. But there is no massive imperative to get it from the turbo scroll itself, or from no more than an inch downstream. Those are nonsense thoughts. The only thing we want is a pretty honest measurement of the pressure at the turbo outlet, and anywhere from the compressor housing itself to the inlet of the IC will read approximately the same thing.

1 hour ago, timmy94 said:

After throttle body? I’ve heard that you should not do that.

Yeah, I disagree with Tao on that one. It's fine for an engine that only runs on the dyno at full throttle (or, equivalently, a drag car that only really runs at full throttle also). But some turbos that are particularly sensitive to overspeed (ie EFRs) would quite possibly get into a lot of trouble if run that way.

[Dose Pipe Sutututu]

I wouldn't run it post throttle.

You might run into scenarios where on partial throttle, pre throttle there is more pressure than post.

Anywhere before the throttle and after the turbo.

[hypergear]

16 hours ago, timmy94 said:

After throttle body? I’ve heard that you should not do that. Even if you look at the diagrams they show you that you should take boost from turbo.

The boost pressure at the compressor cover will be higher than at inlet manifold. lets say, trying to hold 20 psi flat at 7000 RPM. If your wastegate opens at 20 psi measured at the compressor cover, the engine may only be seeing 16 psi. Your base pressure reading at engine would be 20psi by 4K and 16psi by 7K while your MAP at compressor housing still reads 20psi at 7K. For this reason your ECU's MAP source is never on the compressor cover. This difference isn't a major concern if you're using an electronic boost controller (EBC).

Edited Thursday at 02:15 PM by hypergear

[GTSBoy]

7 hours ago, hypergear said:

The boost pressure at the compressor cover will be higher than at inlet manifold. lets say, trying to hold 20 psi flat at 7000 RPM. If your wastegate opens at 20 psi measured at the compressor cover, the engine may only be seeing 16 psi. Your base pressure reading at engine would be 20psi by 4K and 16psi by 7K while your MAP at compressor housing still reads 20psi at 7K. For this reason your ECU's MAP source is never on the compressor cover. This difference isn't a major concern if you're using an electronic boost controller (EBC).

Tao, we're not talking about the ECU boost ref. We're talking about the wastegate signal source.

[timmy94]

On 5/6/2025 at 12:59 AM, GTSBoy said:

Yes.

It's not aesthetically pleasing. And most turbos sold these days are sold for aesthetic purposes (Insta likes/fame, etc). Also its cheaper to not machine it.

The hot side is the pipe with hot air in it from the turbo to the intercooler. The cold side is the pipe with cooled air in it from the IC to the engine.

Anywhere after the turbo will do. Certainly before the IC is better than the IC. But there is no massive imperative to get it from the turbo scroll itself, or from no more than an inch downstream. Those are nonsense thoughts. The only thing we want is a pretty honest measurement of the pressure at the turbo outlet, and anywhere from the compressor housing itself to the inlet of the IC will read approximately the same thing.

Yeah, I disagree with Tao on that one. It's fine for an engine that only runs on the dyno at full throttle (or, equivalently, a drag car that only really runs at full throttle also). But some turbos that are particularly sensitive to overspeed (ie EFRs) would quite possibly get into a lot of trouble if run that way.

Where is the most common place to locate it? Disappointing that Garrett won’t make a fitting for it since they know everyone will use it

[GTSBoy]

Just weld it onto the hot pipe. If you want it right after the turbo, put it right after the turbo.

Or rip the comp cover off and drill and tap a hole into it.