GTR 32 controlling boost

[elxr8393]

Hi, from all the experience here, can someone help please.

Recently imported a GTR promptly blew the ceramic exhaust turbo wheel off the rear turbo (was running about 0.9 when it arrived) so rebuilt both with steel wheels (otherwise stock turbos). Now I know these can run higher boost.

The restrictor in the hose to the controller had already been removed but still only achieved 0.85 - 0.9 max. We bypassed the controller altogether (I know this is normally bad) by running the two hoses together, ran it up carefully and we only get 1.0 - 1.1 bar - goes well but I know there's more.

Isn't this the most we would get ? Surely putting a controller back in the line can only restrict it ? How do we get the extra boost ?

Stock ECU as far as I know, good (big) front pipes, std dumps, 3.5 inch exhaust, pods, the usual stuff.

Any help greatly appreciated.

Paul

[Boosting]

to run more boost i conected my boost controller to the actuators them selfs and ran 1.3 bar

[elxr8393]

Thanks for your reply. Isn't the std controller already connected to the actuators on one side and the manifold on the other ? wouldn't this only restrict the bleed more ?

[GTR032]

Done the same thing on mine..install an electronic boost controller

[elxr8393]

ok, but wouldn't an electronic boost controller only further restrict the line - at full open ie no controller as it is now, no restriction, isn't this like the boost controller being on max boost ?

[always_me]

pull the vacuum hoses off the turbo actuators and run at full boost. easy fix

[[WLDCRD]]

Hahahaha!

[elxr8393]

Thanks for the (some) useful replys. So does anyone know why restricting the hoses with a controller will increase the boost ? Doesn't make sense to me but willing to learn if anyone can explain !

[DAN00H]

Mate, the B/C is there to provide the suction to OPEN the wategates when it reaches a pre determined boost. your way of connecting the two hoses is causing the wastegates to be oopening all the time - the opposite of what you are trying to achieve...

get a good aftermarket boost controller (I run the SBC iD III)

[elxr8393]

Thanks Danooh, sort of makes sense, just that when we joined them together, the boost went up from 0.8-0.9 to about 1.1 ?? If they were open all the time, wouldn't I be getting less boost ? Sorry if I'm sounding thick, just don't get it yet.

Mate, the B/C is there to provide the suction to OPEN the wategates when it reaches a pre determined boost. your way of connecting the two hoses is causing the wastegates to be oopening all the time - the opposite of what you are trying to achieve...

get a good aftermarket boost controller (I run the SBC iD III)

[paulR32gtr]

Thanks Danooh, sort of makes sense, just that when we joined them together, the boost went up from 0.8-0.9 to about 1.1 ?? If they were open all the time, wouldn't I be getting less boost ? Sorry if I'm sounding thick, just don't get it yet.

No no no no no - bum steer you got there dude. The wastegate actuators hold the wastegate flaps closed through a spring / diaphragm arrangement. When pressure is applied to the other side of the diaphragm it compresses the spring, pushes the rod, and the integrated wastegate flaps open, allowing exhaust gases to bypass the exhaust wheel, and therefore control the speed at which the turbo rotates.

The R32 GTR (and 33,34) boost control is set up as follows:

1. There is a hard line that runs from the intake manifold directly to both the turbo wastegate actuators.

2. There is another line tee'd into this line that runs to the factory boost control solenoid.

3. The outlet of the factory boost control solenoid then returns air bled back to the intake.

This means that the factory computer can use the solenoid to control bleeding of air off the lines to the wastegate actuators to increase the boost. Without any air being bled the actuators open around 0.6 - 0.7 kg / cm^2 (about 9 to 10 psi), the factory computer will then bleed air off this line to increase boost as it sees fit (based on input values from the knock sensor amongst others). The maximum I have seen the factory computer increase boost on my completely standard R32 GTR to is 0.82 kg / cm^2 (about 11.5 psi).

Best way to increase boost is to install an elec boost controller and run lines directly to the wastegate actuators (See my last post on http://www.skylinesaustralia.com/forums/sh...ead.php?t=66207 for an easier way using the stock lines) - or you could install some kind of restrictor in each of the hoses running off the wastegate actuators.

Btw the vacuum diagram in the r32 gtr manual is pure gold for understanding the system.

[elxr8393]

No no no no no - bum steer you got there dude. The wastegate actuators hold the wastegate flaps closed through a spring / diaphragm arrangement. When pressure is applied to the other side of the diaphragm it compresses the spring, pushes the rod, and the integrated wastegate flaps open, allowing exhaust gases to bypass the exhaust wheel, and therefore control the speed at which the turbo rotates.

The R32 GTR (and 33,34) boost control is set up as follows:

1. There is a hard line that runs from the intake manifold directly to both the turbo wastegate actuators.

2. There is another line tee'd into this line that runs to the factory boost control solenoid.  

3. The outlet of the factory boost control solenoid then returns air bled back to the intake.

This means that the factory computer can use the solenoid to control bleeding of air off the lines to the wastegate actuators to increase the boost. Without any air being bled the actuators open around 0.6 - 0.7 kg / cm^2 (about 9 to 10 psi), the factory computer will then bleed air off this line to increase boost as it sees fit (based on input values from the knock sensor amongst others). The maximum I have seen the factory computer increase boost on my completely standard R32 GTR  to is 0.82 kg / cm^2 (about 11.5 psi).

Best way to increase boost is to install an elec boost controller and run lines directly to the wastegate actuators (See my last post on http://www.skylinesaustralia.com/forums/sh...ead.php?t=66207 for an easier way using the stock lines) - or you could install some kind of restrictor in each of the hoses running off the wastegate actuators.  

Btw the vacuum diagram in the r32 gtr manual is pure gold for understanding the system.

Paul, thanks very much for taking the time and effort to explain this properly. So in your opinion, and my interpretation of what you have written, it's not unusual to only be getting 1.1 bar with the factory controller bypassed, but by re-plumbing, we can get more using a good boost controller ? Thanks again, best regards Paul

[paulR32gtr]

Paul, thanks very much for taking the time and effort to explain this properly. So in your opinion, and my interpretation of what you have written, it's not unusual to only be getting 1.1 bar with the factory controller bypassed, but by re-plumbing, we can get more using a good boost controller ? Thanks again, best regards Paul

Yep, 1.1bar is about right, but this may jump around a bit based on air temp etc. What you essentially have is a set size hole in the line that feeds the two wastegate actuators.

An electronic boost controller is definately the best place to go after this - I have an Apexi AVC-R which is good and does exactly what I want, however I think there is a thread where a few people have gone to the Blitz i-D and found it quicker to set up / more versatile (more $$$ tho).

Cheers - Paul