Jump to content
SAU Community

HOWTO: RB25DET High Boost mode with standard solenoid

paulr33

By paulr33,
in Tutorials / DIY / FAQ

 Share

Recommended Posts

  • Replies 704
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

paulr33
paulr33

HOWTO: RB25DET High Boost mode with standard solenoid Intended Audience: Stock RB25DET owners Technical Level: Very Easy Duration: 5 minutes Effort: Easy Result: Fairly Good !!!Caution/Ach

Sciby
Sciby

Reset the computer by disconnecting the battery, put the brake pedal few times (to ensure there's no residual charge), then reconnect the battery. Good idea to take it for a good drive now, so it rema

Sklyn
Sklyn

Karu it doesn't matter because you won't use the solenoid at all once you install a boost controller. And with stock ecu and turbo do NOT run over 12 psi, naybe even 10 depending on your car.

Posted Images

Sparks Collaborator

Sparks

Posted
Posted
lol @ not liking electrical tape but using it anyway!

Heatshrink is key. So long as you made sure it was long enough to properly cover the connection its all you need. And looks much neater.

Hahaha I just used the electrical tape to tidy the wires up, Not for the actual connections. Heatshrink is the best :laugh:

mosquitocoils Veteran

mosquitocoils

Posted
Posted

Hi all, tried this on the weekend and it worked easy as pie. I cut the black wire and just ran a tiny piece of wire (about an inch long) to the screw that holds the solenoid bracket on. Just unscrewed/unbolted that one bolt, wrapped my wire around it once, then tightened it back up.

7 psi all the time now. Definately feels a lot free-er in the low end around 2500. But I have a slight dead spot now about 2100-2300... it's weird. It's definately an overall improvement though.

Here's a tip too: get some of that black 'cloth' tape and wrap both the original wire and the new wire you just ran to the bolt, in that tape. Makes it look as stock as anything!

Shmee33 Rising Star

Shmee33

Posted
Posted

hey i got a r33 and i think its a non turbo converted to turbo.

i dont have a boost solinoid but i got a boost controller which is hitting 10psi but it sits on 5 untill 4500???

how do i get full boost all the time.

thanks alex

  • 2 weeks later...
boiracer Grand Master

boiracer

Posted
Posted

did this today, and wrapped my coils, gapped my plugs, drives like a different car.

i have a switch i was gonna install but after hard wireing it for testing. decided there is no need to turn it down again, boost can be right foot regulated, if you have a stock car and havent done it yet, do it now!!!!!!!!!!!

you wont be disapointed.

i actually used a male and female blade plug on each wire, so i can just plug it back in as normal if i need to for any reason

stefan-w Apprentice

stefan-w

Posted
Posted

The solenoid is also some sort of a boost controller?

Stock, there is a hose from the intake tube going to the solenoid, and a T'd of hose from the hose between the actuator and intercooler pipe... I removed the piece of hosing from the T-piece, and attached the hose from the intake tube.

When it went to maximum boost, it had some misfiring, like in the coilpack thing.

But I fixed my coilpacks, it never misfires at max boost with the stock hoses... so I think it was 'over boosting'.

Am I right about my theory?

Duncan Grand Master

Duncan

Posted
Posted

spot on, the solenoid is a boost controller, or more correctly every boost controller uses a solenoid. The solenoid is just a big switch that turns on and off, when it is on it lets air out instead of sending it to the wastegate. WHen it's off the air goes to the wastegate, and when the wastegate sees more pressure than it's spring can handle it opens. they call it "duty cycle" for what percentage of the time its open eg50% duty cycle means 50% open, 50% closed

eg if you have 7psi spring and run the boost control solenoid at 50% you will run roughly 14psi at the motor - 50% of the 14psi goes to the wastegate and 50% gets bled off by the solenoid. That's just an example, the duty cycle settings aren't that easy, they normally need some trial and error.

jaycar have a fully adjustable boost controller that uses the standard solenoid

STYLN Collaborator

STYLN

Posted
Posted

did the grounding trick last weekend and it's much better. But i crave more, so im thinking im going to install the turbosmart t valve i have at home this weekend and tune to 10-12 psi.

Thanks guys this was top mod!

Birds Grand Master

Birds

Posted
Posted

WHY is your signature only showing the top half of miss Fox?

Does anyone know if the RB25DET retains two stages of boost when you fit a boost controller without doing this mod?

  • 2 weeks later...
33drifta Community Regular

33drifta

Posted
Posted
WHY is your signature only showing the top half of miss Fox?

Does anyone know if the RB25DET retains two stages of boost when you fit a boost controller without doing this mod?

just click on the pick for the rest of her lol

Newy Collaborator

Newy

Posted
Posted

sorry if im way off the mark, but can't you just run vac line from actuator to manifold pressure?(one of the nipples on ur intake piping) Wont this run actuator pressure? without the need of boost controller? Sorry if this is wrong, just seems easier to do to get 7psi across the rev range?

  • 4 weeks later...
Torques Mentor

Torques

Posted
Posted (edited)
sorry if im way off the mark, but can't you just run vac line from actuator to manifold pressure?(one of the nipples on ur intake piping) Wont this run actuator pressure? without the need of boost controller? Sorry if this is wrong, just seems easier to do to get 7psi across the rev range?

Hello there!

Yes, I think in theory that would be working (connecting red and green in the picture),

however there might be some kind of calibrated bypass in the solenoid so not too much pressure is bled off the actuator.

See this picture: (red=compressed air, green=atmospheric/negative pressure)

blowoff.png

Edited by Torques
gotRICE? Veteran

gotRICE?

Posted
Posted
sorry if im way off the mark, but can't you just run vac line from actuator to manifold pressure?(one of the nipples on ur intake piping) Wont this run actuator pressure? without the need of boost controller? Sorry if this is wrong, just seems easier to do to get 7psi across the rev range?

You are correct, BUT the R33/34 Actuator is only set to 5psi, and the solenoid bleeds off an extra 2.

So running directly off the actuator would only net you 5psi. Hence why alot of people go for the R32 actuator upgrade. They run a 10psi actuator. Do away with the stock solenoid all together. Win win.

Torques Mentor

Torques

Posted
Posted
You are correct, BUT the R33/34 Actuator is only set to 5psi, and the solenoid bleeds off an extra 2.

So running directly off the actuator would only net you 5psi. Hence why alot of people go for the R32 actuator upgrade. They run a 10psi actuator. Do away with the stock solenoid all together. Win win.

I thought he meant bleeding the actuator line all the time ... but actually he didn't?

  • 2 months later...
Citizen Rookie

Citizen

Posted
Posted

I tried this today, opted to splice the ECU wire and earthed it on the pod filter bracket. Worked a treat, much more power in low-to-mid range with the extra boost, don't have to wait for 4500RPM to get a kick anymore! Got a boost controller on the way too but this will do temporarily :)

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Welp, good to know. Will have to wait awhile until steady hands with drills and taps are available. In other news, these just arrived! I will weigh them for posterity.
    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      100% the factory sender is tapered, that is how it seals (well, that and teflon paste or tape)
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      Thanks folks - I've saved a few links and I'll have to think of potential cable/adapters/buying fittings. First step will be seeing if I can turn the curren abortion of a port into something usable, then get all BSPT'y on it. I did attempt to look at the OEM sender male end to see if it IS tapered because as mentioned you should be able to tell by looking at it... well, I don't know if I can. If I had to guess it looks like *maybe* 0.25 of a mm skinnier at the bottom of the thread compared to where the thread starts. So if it is tapered it's pretty slight - Or all the examples of BSPT vs BSPP are exaggerated for effect in their taper size.
    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
×
×
  • Create New...