Question regarding Vaccum hose that leads to Wastegate from IC piping

[gts-wpn]

I have a question regarding the Vaccum hose that connects from the intercooler piping and then hooks up with the bleed valve then goes to the wastegate actucator. May sound like a stupid question but is it better drill a hole and to run the vaccum hose before the intercooler(between the turbo and the intercooler) or after the intercooler(between the intercooler and the plenum)?

Does it have much effect on the way the bleed valve will work considering there is a slight pressure drop after the compressed air goes through the intercooler and then into the engine?

[otto]

I would have thaught after the i/c would be better, you want the w/g to see the pressure the engine gets(remembering your boost gauge is also after the i/c so you can see the pressure your engine gets). i think the pressure before the i/c is irrelevant But i could be wrong.

[nedb]

Mine is running of the plenum. Hold 14 psi flat with a GFB bleed valve.

[SLY33]

yeah take it off the top cooler pipe/plenum for sure.

[GTR-Ben]

Why does it matter what pressure the wastegate is seeing compared to the engine? Thats why you have the gauge tapped closest to the engine so you can adjust with that.

Why do aftermarket Electronic boost controllers have a seperate sensor for the guage..?

The wastegate needs good response.. so taking it as close to the turbo as possible would make sense to me? Why alse would factory wastegates get there pressure from right off the turbo compressor housing?

I may be wrong here.. it is probably not too major where you take the pressure from. Seems to work well either way.. ?

Stock GTS-T takes it from the turbo compressor. Stock GTR takes it from after the throttles..

[GTR-Ben]

From the apexi AVC-R manual... gauge at plenum wastegate close to turbo.

[TTT]

R32 gtst's have the nipple on the turbo compressor housing instead of the intercooler pipe like the R33's.

I agree with the above in that it should be taken as close to the turbo as possible.

[Sydneykid]

R32 gtst's have the nipple on the turbo compressor housing instead of the intercooler pipe like the R33's.

I agree with the above in that it should be taken as close to the turbo as possible.

Ditto, keep the hoses short, air compresses and you get more dampening the longer the hose is. That means slower response.

[blind_elk]

The thing is, you don't want the wastegate opening prematurely. If you activate the wastegate off the back of the compressor, then the wastegate opens when the compressor "spikes". Also, you get more wastegate creep having the "signal" close to the wastegate.

If you run the wastegate off the back of the compressor, then the engine "sees" wastegate setting minus pressure drop. If you run the wastegate off the plenum, then the engine "sees" wastegate setting. I know which one I'd rather be running.

[otto]

Why does it matter what pressure the wastegate is seeing compared to the engine? Thats why you have the gauge tapped closest to the engine so you can adjust with that.

Why do aftermarket Electronic boost controllers have a seperate sensor for the guage..?  

The wastegate needs good response.. so taking it as close to the turbo as possible would make sense to me? Why alse would factory wastegates get there pressure from right off the turbo compressor housing?

I may be wrong here.. it is probably not too major where you take the pressure from. Seems to work well either way.. ?

Stock GTS-T takes it from the turbo compressor. Stock GTR takes it from after the throttles..

I thaught the r33 gtst from factory took it from the plenum after the i/c and the r32 gtst from the compressor. now your probably right about which way is better but if the factory is the grounds for your argument tell me why did the factor have it at the comp for r32 then change to the plenum for its next more advanced model the r33!

[Sydneykid]

I thaught the r33 gtst from factory took it from the plenum after the i/c and the r32 gtst from the compressor. now your probably right about which way is better but if the factory is the grounds for your argument tell me why did the factor have it at the comp for r32 then change to the plenum for its next more advanced model the r33!

The R33 has a solenoid the R32 doesn't:cheers:

[GTR-Ben]

The thing is, you don't want the wastegate opening prematurely. If you activate the wastegate off the back of the compressor, then the wastegate opens when the compressor "spikes". Also, you get more wastegate creep having the "signal" close to the wastegate.

If you run the wastegate off the back of the compressor, then the engine "sees" wastegate setting minus pressure drop. If you run the wastegate off the plenum, then the engine "sees" wastegate setting. I know which one I'd rather be running.

For a bleed valve this is probably the case, for a good EBC.. this should not be a problem.

With an EBC the settings are changed from what the engine sees as this is where the gauge part is plumbed, so it really matters not what the wastegate sees as long as it gets a fast responsive signal.

I would rather a spike cause underboosting than overboosting also. With the signal taken futher down the track, with a long pipe to the gate.. the spike will cause a boost spike (bad) But with a good EBC none of that should happen.

otto.. I think the main difference is to do with the boost control systems on the GTR and R33 etc as it is a basic bleed valve in a way.

Just throwing ideas around here as I recently had the same ideas from both sides of this discussion..

I then looked at the apexi installation for external wastegate, and decided to go with this.. it made sense to me and they probably know best for their product..

I have never had any spikes or problems running either way though to be honest..

[Sydneykid]

The thing is, you don't want the wastegate opening prematurely. If you activate the wastegate off the back of the compressor, then the wastegate opens when the compressor "spikes". Also, you get more wastegate creep having the "signal" close to the wastegate.

If you run the wastegate off the back of the compressor, then the engine "sees" wastegate setting minus pressure drop. If you run the wastegate off the plenum, then the engine "sees" wastegate setting. I know which one I'd rather be running.

What difference does it make? I set the IEBC to open the wastegate at the boost I want,. I don't care which piece of air I use to open the wastegate, it's all air. I juts want short hoses so the response is fast, not dampened by a couple of metres of hose.

PS; faster response = less time for boost spikes

[GTR-Ben]

What difference does it make? I set the IEBC to open the wastegate at the boost I want,.  I don't care which piece of air I use to open the wastegate, it's all air.  I juts want short hoses so the response is fast, not dampened by a couple of metres of hose.

PS; faster response = less time for boost spikes

[otto]

The R33 has a solenoid the R32 doesn't:cheers:

They could still have hooked it up to the comp if they wanted to regardless but they decided not to. an ebc has a soilinoid does this mean the ebc would be better hooked to the plenum?? is it better to run a bit more hose and have the solinoid in a cooler place or run it short and have it be fried by the turbo. anyhow most of the time its closer to hook it to the plenum when you start to install ebc/ bleeder or whatever.