Jump to content
SAU Community

HOWTO: RB25DET High Boost mode with standard solenoid


paulr33

Recommended Posts

ah ok, i thought maybe the solenoid was to restrict it to 5 from 7. ah well there goes that idea. will keep shopping for a 10psi r32 one. Any diagrams going around to disconnect it once i get the 32 one?

I think i did one a few pages back :down:

Link to comment
Share on other sites

Hi!

There is no restrictor as such.

The actuator is subdued to the manifold pressure unless the car reaches 4500 rpm or so.

At this point the solenoid kicks in and reduces the pressure on the actuator, tricking the actuator into 'assuming' the boost is lower than actually is.

The actuator is a 5PSI type ..

Cheers,

Andrew

ah ok, i thought maybe the solenoid was to restrict it to 5 from 7. ah well there goes that idea. will keep shopping for a 10psi r32 one. Any diagrams going around to disconnect it once i get the 32 one?
Edited by Torques
Link to comment
Share on other sites

ah ok, i thought maybe the solenoid was to restrict it to 5 from 7. ah well there goes that idea. will keep shopping for a 10psi r32 one. Any diagrams going around to disconnect it once i get the 32 one?

once you have the 10psi actuator the solinoids will be obsolite wont they ??

Link to comment
Share on other sites

  • 1 month later...
  • 1 month later...

Attention R34 owners

I have just done this mod without cutting or stripping any wires and it works.

1) Unplug the solenoid

2) Feed wire through the ecu plug side and reconnect plug. (see pics on post 231 on pg12) ignore warning as he had a different problem (see post 355 pg18)

3) Turn ignition on but not engine

4) R34's have an earthing strap from the engine that earths on the chassis just below the solenoid via a spade plug. Attach other end of wire here.

5) You will here the solenoid 'click'.

6) Drive around on high boost below 4500 revs.

Took less time to perform the mod than it did to write this post :P

Side note for those who want a switch for fuel economy. There are 3 pedals in the drivers side foot well. The far right one is the fuel economy switch. It's a good switch as it's progressive and not just an on/off switch :P

Link to comment
Share on other sites

could some one please send me a pic of how the vac hoses are ment to be connected to the solenoid because mine has been bypassed and i want to connect it back up.

Here you go ...

post-33912-1288562192_thumb.jpg

Edited by Torques
Link to comment
Share on other sites

Anyone with an R34 that has done this and felt a difference, before you did the mod, did you see the boost change at 4500 rpm? Using the stock gauge, once I hit max boost around 2800, it doesn't change until the redline.

Link to comment
Share on other sites

  • 1 month later...
  • 3 weeks later...

Is this useless if you have an EBC?

Noobiest question Ive ever asked lol.

An EBC is basically a more advanced/adjustable version of the stock solenoid. Normally to fit a EBC the standard solenoid would be removed/disconnected.

Link to comment
Share on other sites

if you unplug one of the hoses and block it it tricks the solenoid into keeping the wastegate closed for longer coz its getting an inaccurate reading,

by doing this i am running 11psi and only takes 30 seconds to do. seems pretty safe and dont get any boost spikes as far as i can tell

Link to comment
Share on other sites

if you unplug one of the hoses and block it it tricks the solenoid into keeping the wastegate closed for longer coz its getting an inaccurate reading,

by doing this i am running 11psi and only takes 30 seconds to do. seems pretty safe and dont get any boost spikes as far as i can tell

I had mine off and it definately did the same thing.. I ended up connecting it back up and doing it with the wire, but i am hitting 9 sometimes 10psi and i have only got a cat back and pod. Cant wait for my turbo back..

Link to comment
Share on other sites

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • this explains the possibility of several maps with different boost levels
    • ok, I understand much better how we can control the boost and increase the number of psi before opening the wastegate
    • Well.... yes and perhaps no. It depends on what you mean by "spool". For most of us, the point that we would describe as where the turbo is "spooling" is the point where the wheel speed gets high enough for it to start making some boost. This is coincidentally around about the point where it starts making noise - hence the "spooling" sound. If that is what you mean, then no - the wastegate should still be shut at this point. The boost will still be way below the point where it should start opening. If, on the other hand, you mean "spool" as "reach full boost", then yes. At the point where the boost has reached target, then boost control has already started. The wastegate is already open, and has been for some time. Some short time, definitely, but still, some time. If you have no boost controller - just the wastegate actuator connected to the boost source, then you have a mechanical system working as a pressure balance. There is pressure on one side of the wastegate actuator's diaphragm from the spring, and pressure on the other side coming from the boost measurement location (the "source"). This is not a digital thing. The wastegate does not stay shut until the boost pressure reaches the spring "pressure". The spring will start to compress as soon as you start to apply any pressure onto it. This can be controlled somewhat by adding pre-load into the spring, but you cannot add enough preload to make it into a digital switch behaviour. The wastegate will crack open and start to leak exhaust out (and therefore not though the turbine) well before you reach the target boost pressure. Electronic (and some mechanical/pneumatic) boost controllers will act to prevent the boost source applying pressure to the actuator until just before you reach target boost, thus preventing the wastegate from creeping open. And some boost controllers will apply boost pressure on the spring side to further push it shut. And this can be be necessary because the exhaust pressure in the manifold also pushes on the wastegate valve and tries to open it and you cab get it leaking even without it being connected to the boost source.
    • A stand alone boost controller will not give you the control you need, unlike a modern ECU. Your boost will always naturally target the wastegate's opening pressure first, your controller then will allow you to add more boost as required.
    • I recently discovered that I could not remove the outer bolt on one of my rear UCAs. Looked like it was seized to the crush tube. It wasn't all that long since I had last had that arm out (I dunno exactly, but certainly <2 yrs), so I was a bit surprised. I thought I had stock bushes in the rear knuckles, so I ordered some new PU bushes and resigned myself to having to do some dismantlery....and some butchery. It was clear that the seized bush was going to need to have the bolt cut out of it and then possibly some more brutality after that. Upon getting the 3x arms on each side disconnected from the knuckles (with the exception of the seized one, of course), I discovered that I had in fact put PU bushes into the knuckles when I did the subframe conversion about 12-13 years ago. So, I say "Oh, good, I might not have to swap any of these others out". We set to work butchering the bolt out of the seized arm. Stainless blade in a big-arse Milwaukee recipro made short work of it, and also damaged the arm, which added a welding and grinding and painting step to the whole exercise. During the butchery it became clear that the bolt was not just seized but bent. Head scratching ensued, as it is hard to understand how that bolt could get bent. I did suffer a broken (stock) toe control arm on that side a few months ago, and drove some miles with some significant rear wheel self steer and lack of control, which probably was the cause. But it's still hard to understand how it would bend that bolt, rather than just bend the arm. But here's the start of the real discoveries. The crush tube was rusty as all shit. I mean seriously rusty. A little on the inside, contributing to the tube seizing to the bolt (along with the bend). But the outside had at least 2-3mm of compressed flaky iron oxide jammed in between the parent metal and the PU bush. This one was brutalised and still took some effort to get the PU off the crush tube. So I thought I'd inspect the others more closely. The one on the tension rod adjacent the bent one was first. I had to use a 2-jaw puller to get the crush tube out, and it took some effort. It came out looking like the first one. All 6 of them were the same, except for one that looked not too bad. Had some corrosion on it, but was mostly OK. There was also a significant amount of corrosion on the inner surfaces of the knuckles. They took some convincing with pointy tools to let go their grip on the inside of the holes they were in. There was no sign of the original (SuperPro) lube anywhere. I and my bro-in-law have never seen any crush tube end up looking like this. It was seriously like the car has spent time putting boats into the water at the boat ramp. So, it seems like the PU might have been bonded to the steel on both sides, which would have to make them work more like stock rubber bushes (where arm deflection results in twist inside the rubber). Despite this, I have never had cause to believe that they were so tightly bound up. The suspension moved up and down much as you'd expect. The car never made any noises in those bushes that would have led me to believe there was a problem. Maybe the rusty interfaces actually were "sliding". Anyway, lesson learnt. Even quiet, non-troublesome PU bushes should be inspected every now and then!
×
×
  • Create New...