Actuator Spring Adjustment

[thatlbeme]

Hi all, just trying to get an understanding of how things work. On the bnr34 engine the boost controll solenoid is disconected due to the previous owner having installed a HKS EVC 4 controller. The HKS EVC was disconnected when it went through compliance. As there is nothing to limit the pressure on the actuators they start to open at .4 bar and the maximum turbo boost the motor can get is around .6 bar. It goes straight to .4 bar at 3500 rpm and then seems to creep to .6 bar by the time it redlines.

I will be installing the HKS EVC 4 back onto the car to ge able to control the boost but was wanting to make sure the actuators didn't need some attention.

So is that normal for the actuators to start opening at just .4 bar and if not can they be adjusted. If they need to be replaced are the HKS actuators very hard to install.

And will the HKS EVC 4 work fine with the actuators as they currently are.

Thanks Ian

Edited February 8, 2011 by thatlbeme

[JonnoHR31]

normal for them to open a touch earlier. install the ebc and set your target boost, if you have trouble holding it properly then look into better actuators.

[thatlbeme]

Thanks for the reply Jonno,

I am thinking the .4 bar to .6 bar is just turbo creep. As it goes very quickly to .4 bar and then holds untill revs get up to about 5000 5500rpm and then slowly works up to .6 by the time it relines.

Not sure if the turbo creep will be a problem when the EVC is hooked up or is that one of the things that the EVC or turbotech valves will fix..

[thatlbeme]

Might have to give the actuators some attention. If the posts I found with similiar problems with the boost creeping up in higher revs are correct then the wastegate valves are not opening enough to let the pressure out.

If I had adjustable actuators (havn't got a clue what is on there yet) and they were adjusted to open at a lower rate would that adjustment also limit how far the gates actually opened, or is it the other way around.

[thatlbeme]

Took the opportunity to test the actuators today while I was poking around in there hooking up the EVC, was certain that one of the actuators would show up with a shot spring but to my surprise they both started to open the wastegates at the same pressure. Can't work out whats going on cause I would be very surprised if 6psi (give or take 1psi) is the stock spring rates for r34's.

Unless they use a low actuator spring setting to have an extra low boost level when the ECU detects a problem, and have the solenoids make up the extra.

Or someone in Japan previously replaced the stock actuators with softer spring ones, but can't see what the advantage of doing that would be although they do some funny things over there. They put on adjustable coilovers and actually used them to raise the car up about 1 inch, and replaced all the engine bay nut washers with white plastic ones and I am still trying to work out what the fluo light under the dash was going to achieve.

Edited February 11, 2011 by thatlbeme

[thatlbeme]

EVC installed and setup and it has overcome the problems the soft actuators were causing. Set it fot 1 bar boost and there isn't any spiking (EVC is as close to the actuators as possible) or more importantly for me any turbo creep.

I am very impressed with the HKS EVC 4 even though its an older model it is working flawlessly and would definately recommend a HKS EVC for anyone who was having boost problems similiar to what I was having.

Edit, forgot to mention that the turbo's spool up much more quickly with the EVC than compared to just using the actuators. It hits full boost (1 bar) at about 4000rpm compared to .4 bar boost at about 3500rpm when the soft actuators were spoiling the party.

Edited February 12, 2011 by thatlbeme

[Duncan]

just to mention...7psi may well be standard wastegate pressure.

the factory system has a boost control solenoid which would have been removed when the boost controller is fitted. The factory solenoid regulates boost to 12psi standard.