Boost Cut At ~5Psi - R34 Gtt

[Everlong-S13]

Hey guys,

A friend and I installed a Turbosmart Manual Boost Controller plus aftermarket boost gauge today on my R34 GTT Neo, and we've hit a bit of a problem and I'm not sure we've connected it right.

So far I've installed the controller between the wastegate and intercooler hoses, and I currently have the lower solenoid hose blocked off. The top solenoid hose I've keep connected.

At the moment it won't boost past approx 5 psi and with the controller wound to maximum boost it gets to 5-6psi and then (I think) the ECU chucks the sh!ts and applies a fuel cut.

Is there a problem with the way I have connected everything? Many thanks in advance.

[zebra]

Id say the boost gauge isnt reading right.

[Everlong-S13]

I've uploaded a couple of pics to show what I've done.

First pic is the MBC setup:

Also I noticed when installing the boost gauge, that one of the hoses wasn't even connected to the following valve in the pic, forget what it's called, VSV valve or something? Anyway it was never connected and I've only just noticed since purchasing the car. I can't reconnect it without getting a new one so I just clamped the hose. Wondering if this would cause any issues. See pic:

[Everlong-S13]

You might be right zebra. I did a few test runs on different boost settings and the stock gauge read 0.75kg on one trip and just over 1kg on another trip, while the aftermarket gauge read the same.

Perhaps the way I have connected it is wrong.

[paulr33]

are you sure the guage is in PSI?

it might be mmhg or hg or kgcm2

from memory the stock ER34 has a manifold boost sensor and it trips out around 12psi

it definetly would trip out at 5/6psi as the stock boost on ER34 would be around 10psi (give or take)

[Everlong-S13]

The stock gauge is in Kgcm2 and my aftermarket one is psi.

I'm now pretty certain the aftermarket gauge isn't working properly. It may have something to do with broken valve highligted in picture #2 - thats in a similar area where I am feeding the vacuum tube to the aftermarket gauge. I think I may need a new one of those valves.

The boost controller does work now though. I got the solenoid hoses mixed up - need to block the top one and remove the bottom completely. I can set the boost using the stock gauge which isn't entirely accurate however it's set at around 0.75 kgcm2 which is not too high.

[Randon_I_Am]

I also snapped the plastic bit off that valve. It just runs under the crossover pipe to the carbon canister. I beleive that the solenoid flushed out the carbon canister of something... Just block it off so there's no vac leaks

[Everlong-S13]

Awesome. I'll plug up that hole and see if that fixes the vaccum leak.

[mature gent]

Hey guys,

A friend and I installed a Turbosmart Manual Boost Controller plus aftermarket boost gauge today on my R34 GTT Neo, and we've hit a bit of a problem and I'm not sure we've connected it right.

So far I've installed the controller between the wastegate and intercooler hoses, and I currently have the lower solenoid hose blocked off. The top solenoid hose I've keep connected.

At the moment it won't boost past approx 5 psi and with the controller wound to maximum boost it gets to 5-6psi and then (I think) the ECU chucks the sh!ts and applies a fuel cut.

Is there a problem with the way I have connected everything? Many thanks in advance.

[mature gent]

Hi I am thinking of doing the same,have you noticed much of a difference

Cheers

Steve

[bubba]

are you sure the guage is in PSI?

it might be mmhg or hg or kgcm2

from memory the stock ER34 has a manifold boost sensor and it trips out around 12psi

it definetly would trip out at 5/6psi as the stock boost on ER34 would be around 10psi (give or take)

Are you sure? because looking at the factory maps they run the same sort of TP Load limit (afm cut) as the earlier models but the values seem to have a little more meat in them.

[paulr33]

yeah it would have AFM cut and boost map sensor cut

but it wouldnt cut at 5 or 6psi, that would be silly

the std actuator would be 7psi at a stab in the dark

anyone with stock ER34 can confirm stock ER34 boost ?

[Hanaldo]

yeah it would have AFM cut and boost map sensor cut

but it wouldnt cut at 5 or 6psi, that would be silly

the std actuator would be 7psi at a stab in the dark

anyone with stock ER34 can confirm stock ER34 boost ?

7psi full boost.

[paulr33]

ace thanks

now if someone can confirm what BNR34 is

[jrm]

7psi full boost.

That's with the 2psi bleed from the actuator post 4500rpm

[Hanaldo]

That's with the 2psi bleed from the actuator post 4500rpm

Which is why I said full boost.

[jrm]

Which is why I said full boost.

I understood and understand what you're saying, but I also know Paul has been searching for authoritative information on the factory wastegate actuator.

[Randon_I_Am]

which is 5psi then.

[simpletool]

ER34 isn't 7psi. The R34 runs more boost than an R33 which runs 7.5psi and the stock tables don't run into R&R until at least 9psi. If the stock gauge is reading 0.75 kg/cm^2 then that is a touch over 10psi. This is likely the start of R&R - which from what I read is more aggressive than the R33 R&R.

You may also like to note that the stock gauge is mainly inaccurate in that it tends to read LOWER at higher boost than reality. ie. as boost rises it under reports so 0.75kg/cm^2 can be approaching to 1.0kg/cm^2 (14psi)!

You could check the stock pressure by removing the bleed valve and testing again (also confirms you have removed the 2-step boost properly). The compare to readings after reinstalling the bleed valve. Compare and contrast.

To recap - your aftermarket gauge is reading wrong almost certainly.

You are probably running 10+psi. R34 doesn't like too much extra boost - get Nistune.

[Everlong-S13]

Thanks for the help again guys.

So it seems my boost controller setup is working fine and I have bypassed the 2 stage solenoid OK. The issue is just with my boost gauge setup.

Can anyone tell me from the picture I supplied in my first post, that where I have tapped the vacuum lines for the aftermarket gauge in is correct, and if the broken hose from the valve nearby would cause the incorrect reading on the said gauge? I'm going to have a crack and solving this tonight.

Also out of interest, when not on boost the aftermarket gauge reads quite low, towards -20 and I'm thinking that should be more like -10?

Edited May 3, 2011 by Everlong-S13