Un controlable Boost (Need Help)

[Col-GTSX]

OK.

Situation. I have an R31 GTS-X this comes standard with a RB20det NICS motor. Anyway, I have changed the turbo over from standard to a turbo off an R33 (Rb25det motor). This has worked very well. The conversion was fairly simple however boost control is very different in-between the 2 models of motor car.

In I have drawn a couple of pic’s and they can be found on the second page they show the standard configuration of plumbing of the turbo and all the different ways I have tried.

Now if you bleed the boost or positive pressure line that is going to the waste gate then this should have it open later and therefore be able to produce more boost. But my R33 waste gate is opening even when setting the bleed valve to fully bleed…..

This one has me stuffed. Apparently you can change the sensitive of the water gate by changing the springs. However the standard R33 boost controller is somewhat electronic I believe. How do you guys with the R33’s do your bleed valves can u draw me a quick picture? If the guys at the performance shop are correct then im F$#ked.

Next question, does the Apexi AVC-R run a pressure out put that is variable until the desired boost is achieved. For example in my car it would only take 3psi to open the waste gate and that’s where my current problem is. But if the Apexi AVC-R can just monitor the positive pressure and then modify the output pressure to the waste gate so it does not open so soon then I could just buy one of them and the problem will be solved.

To expand on what im trying to say in English (it makes sense to me) anyway, I want 14psi… OK so the waste gate cannot open until I get to 14psi and then it must only remain open slightly as so I can hold 14psi… Now I understand that the AVC-R can modify the waste gate control as the rpm increase due to boost drop off in some cars….. If this is true then it can also modify the output pressure to the waste gate for the build up of boost and get you to 14psi faster than a bleeder….

Sorry guys im confusing my self here… Im just tired of performance shops giving me the run around… Tokyo toys have been a great help, but are very busy with their own work and I don’t like bugging them all the time….

Please post your responses here or just email me either I say Thank you in advance…

If you could help or just brain storm on this page I will read it every day… TA

PS. I will send this to apexi as well and see if they will respond….

[Col-GTSX]

Sorry guys i cant post the pictures as their too big...

Anyway id like it if you could help... Thanks

[Jay95R33]

The stock wastegate on the R33 GTS-t turbos are set at about 0.5 bar (6-7psi).

So if you run a hose from the inlet pipe straight to the wastegate you should get about 6-7psi - try that and see if it's correct.

If it opens sooner than this then I would say that the wastegate spring is stuffed and is to loose, in which case it won't make much boost regardless of what you do (apart from disconnecting the wastegate hose all together !!).

If correct then tee in the valve inline with this hose - that's all I've done to increase my boost. I've taken the stock solinoid out of the car totally.

The boost solieniod in the GTS-t's only bleeds off 2psi above 4500rpm. It does nothing else.

I would say that the valve can't vent enough air to make a difference to boost maybe?

J

[Col-GTSX]

The alve bleeds heaps of air... Maby not enough.. Havent got any others to compare with... However with the pipe directlly connected the car will produce 6psi foot flat so I think the wastegate is ok... Might be a little touchy however... Thats why i ask if i go the AVC-R will it just modify its output to suit the amount of boost i want????

I mean will it basiclly learn how much output is needed to maintain 14psi????

[Col-GTSX]

Anyone???

Just need some suggestions...

My motor depends on you!!!

[Roy]

If you are getting 6psi with bleed valve removed then im guessing that wastegate is ok

Buying a HKS actuator, i think they are around $250 and set the turbo to run about 14 psi.

Replacing the actuator with another is a cheaper option then an AVC-R.

With regards to the AVC-R, you can set it so that it reduces wastegate creep (opening at less then set pressure)

It does this by simply closing its solenoid valve so that the actuator sees no pressure, then as you get close to your set boost pressure it pulses open and close to maintain the set boost level.

You can also do this by placing a regulator before your bleed valve. This gives you another method of eliminating wastegate creep.