Boost Gauge Into R32 Gts-4

[Kozeyekan]

Hi all.

Just wondering if any GTS-4 drivers have put a boost gauge into their car. I've searched and found instructions for a GTS-t and a GTR, but say to splice the stock boost gauge line, which the GTS-4 does not have. I could have a crack at finding a solution, but thought I may as well ask if anyone has done it before.

The GTS-4 really is the oddball of the family, maybe we need our own section.....

[mad082]

there should be a vacuum hose coming off the back of the plenum. just hook it into that.

[blind_elk]

No, there isn't. But there is provision to put a fitting in the back of the plenum. (While you are there, why not re-locate the turbo wastegate line up there as well.)

Or, you can 'T' into the FPR hose.

[mad082]

While you are there, why not re-locate the turbo wastegate line up there as well.)

don't take this advice. it can cause spiking. and you want your wastegate line as short as possible. thats why a lot of turbos have the wastegate line come straight off the compressor housing. it is also best to have the wastegate line before the intercooler so that your turbo only ever works at a certain max boost. if it is after the cooler, and the cooler ads a fair bit of restriction at higher boost, the engine may be only getting 12psi, but the turbo may be producing more. which means more pressure, more heat, less life.

[blind_elk]

don't take this advice. it can cause spiking. and you want your wastegate line as short as possible. thats why a lot of turbos have the wastegate line come straight off the compressor housing.

so that as the compressor spools up, it spikes the wastegate, and before the engine has even seen the increased boost, the exhaust gas is dumped past the exhaust wheel.

it is also best to have the wastegate line before the intercooler so that your turbo only ever works at a certain max boost. if it is after the cooler, and the cooler ads a fair bit of restriction at higher boost, the engine may be only getting 12psi, but the turbo may be producing more. which means more pressure, more heat, less life.

so that the engine never sees the "wastegated" boost. Unless you pick up the signal for the boost gauge off the back of the compressor, your turbo will always be producing more boost than the boost gauge is indicating.

which means more pressure, more heat, less life.

[mad082]

the ideal place to have your boost gauge is on the line to the wastegate, just before the controller. however then you never see vacuum. most people like to see vacuum so they hook the gauge up from the manifold.

[Cubes]

RE: The actuator boost signal

The ideal place is to always receive the boost signal from the plenum. But this is not really optimal as it requires a long run from the plenum to the actuator. Only possible when using an EBC.

So... Just do what Nissan did with the R33. Run it from the IC pipe directly before the cross over pipe. Close enough is good enough.

[mad082]

The ideal place is to always receive the boost signal from the plenum. But this is not really optimal as it requires a long run from the plenum to the actuator. Only possible when using an EBC

if that is the case then why to hks and other turbo makes put a nipple on the compressor housing of the turbo? if the intercooler causes a restriction of 5psi at 15psi manifold pressure (example only) then the plenum is reading 15psi, but the turbo is actually running 20psi. thats why it is best to have both wastegate and gauge read before the cooler.

[Cubes]

They don't place a nipple on the comp cover for the reason your suggesting.

Unless your talking stock turbo then running 20psi at the turbo isn't an issue providing the motor is tuned to run 15psi and all is well. At least you achieve a stable boost curve that doesn't tail off as airflow increases (as your ic restriction example would suggest)

Its only my view, I care less how much the turbo is pushing out as long as boost holds and makes power.

[mad082]

i care more about how much the turbo is pushing out so i get a longer life from it. i'd rather know that my turbo is running at 12psi for sure than thinking my turbo was running at 12 psi when it is actually getting up as high as 14psi. then having it blow and wonder why it blew if i'm only running 12psi.

[mad082]

but yeah, i'm talking stock turbo only. on an aftermarket turbo where there isn't as much chance of the exhaust wheel ending up in the cat it isn't so much of an issue.

[Cubes]

Its not actually that bad if you run an fmic.

My small bar/plate fmic (bar and plates known for being restrictive) has a pressure drop of 1.5psi at 580hp worth of air.

So unless your running on the stock IC worry not.

Years back Tim from RPM (Where used to take my car when I first got it) had an article in Zoom showing the pressure drop caused by the stock IC. It was measured up to ~7psi from memory on 11psi, at the same boost level 11psi the pressure drop was next to nothing.

Its not the boost that kills the turbo's anyway..

Tuning, detonation, high EGT's and a little bit of bad luck is what throws the wheel in to your (or lack of) cat.

[Cubes]

but yeah, i'm talking stock turbo only. on an aftermarket turbo where there isn't as much chance of the exhaust wheel ending up in the cat it isn't so much of an issue.

So are you suggesting we take the boost reading from the turbo's nipple and set boost to 12psi from there NOT the plenum as every one else does?

[Kozeyekan]

OK, now I'm really fkn confused.

Maybe I'll have to go to a workshop.

I got a bunch of other parts to go in anyway.

[thomassilv]

I am currently figuring out where to run the gauge from and this thread also confused me so if someone could reply with a clear answer as to where to run the vacuum line from that would be much appreciated.

Thanks in advance

[GTSBoy]

Ignore nearly everything said in this thread. I can't even bring myself to read most posts after the first completely stupid thing said in each one. Usually the first sentence.

The answer is so very very simple. Any tapping point on the plenum. Any tapping point at all. Any hole in the plenum that has a fitting that you can connect a vacuum hose to, and that does not have a one way valve or other stupidity in it. Any port in a storm.

And that's just to sort out the boost gauge connection silliness in this thread. The wastegate stupidnesses up there still have me shaking my head and I can't frame a coherent sentence to debunk the nonsense. Suffice to say....the correct advice has been posted on this forum umpteen dozen times.

[KiwiRS4T]

As above boost gauge from plenum.

Do NOT tap anything into the FPR line.

I drilled and tapped the compressor housing for a nipple for the wastegate line.