Jump to content
SAU Community

Setting Up Adj Actuator

R TUNE

By R TUNE,
in Engines & Forced Induction

 Share

Recommended Posts

R TUNE Mentor

R TUNE

Posted
Posted

hi guys,

my last boost controller started failing so me and my tuner decided to mod the stock actuator to make it adj.

my target psi is 14psi and using the stock actuator it held at 11psi.

my question is how much shorter/ longer do i need to adj it to reach my target psi. i have it currently set at 1 cm shorter than the stock length.

mods are as follows

45v4 turbo,

3 inch turbo back exhaust

cam gears

blitz fmic

nistune ecu

engine is a RB20DET.

last power out put was 165rwkw with boost topping at 16 psi by 4000rpm and dropping to 12 psi by 7500rpm.

regards

brentton

Link to comment
https://www.sau.com.au/forums/topic/427553-setting-up-adj-actuator/
Share on other sites
MrStabby Grand Master

MrStabby

Posted
Posted

If you add more preload it will make the boost curve worse, like 20psi dropping to 14. Adjusting the preload won't change the point at which the diaphragm in the actuator operates.

Thats the opposite of my understanding. The gate operation is a fight between the spring and diaphram. Increasing preload has the effect of increasing the force developed by the spring. The force that the diaphram produces depends on the boost. So if the spring force goes up, you need more boost to open the gate.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Spring force isn't adjustable, it is a set force/mm.

If you decrease the length of the actuator arm you are forcing the spring to close more before the flap opens. It works, but not as well as replacing the spring with a stiffer one, and you could reach a point where the flap doesn't open enough to bleed boost off in the top end. (boost spike)

Try it out, just make sure you have a good gauge, I have seen too many that read 3-5psi out.

I would be hitting up Hypergear for a 14psi actuator. Install and forget.

Ben C34 Grand Master

Ben C34

Posted
Posted

From Hypergears thread, page 397

If you over pre-load you will get boost spike and then taper. Try to have it hold one consistent boost pressure off the spring only.

That actually looks OK. its making 150kw @ 4000 rpm which isnt THAT bad for a 200k+ auto. Have a fiddle with preload and just check VCT as said.

pg 398

Its extremely important remembering to preload the actuator as the tuner's tuning. keep on preloading if are seeing boost tapering off before the desired level. It might be 5mms or could be 15mms, the more you load it the higher up top boost level it will hold, more boost makes more power.

GTSBoy Grand Master

GTSBoy

Posted
Posted

Superben, that quote from page 398 is to be read as "adding preload stops the boost tapering off at the top end".

The corollary of that, and part of the page 397 quote is that it also tends to cause a spike as the boost comes on, which is not always (or even often) desirable.

bananaweesle Contributor

bananaweesle

Posted
Posted

run a Turbosmart or Kando actuator they have springs inside that can be easily changed and the boost dropping of problem nearly disappears. the only reason boost drops of at higher rpm is because the pressure in the stock exhaust manifold is so high the gate actually gets pushed open and is unable to close. Once open with standard actuators and high boost the actuator nearly becomes useless as at about 4500rpm the actuator is forced open and cannot shut.

MrStabby Grand Master

MrStabby

Posted
Posted

Spring force isn't adjustable, it is a set force/mm.

You are saying the force produced by the spring can't be referred to as "spring force" - I disagree. Force/mm is not a sensible term, you should say either force/distance or if you're expressing it in units, use units both sides, eg. Newtons/mm. This property is known as the spring constant (or rate, or spring rate). I agree that spring constant is not adjustable.

OP - try increasing the preload a bit more, and see how it performs. If its sucks, get something else.

MMM interesting, i have been suggested to remove the ball and spring out of the boost controller and run it like that. Any one have experience with this.

If its one of those $20-30 boost controllers then removing the spring and ball makes it a very expensive bit of pipe.... :)

Kane_R32 Experienced

Kane_R32

Posted
Posted

MMM interesting, i have been suggested to remove the ball and spring out of the boost controller and run it like that. Any one have experience with this.

You do realise the ball and spring are whats needed to "trick" the actuator into creating more boost? So removing both well render the boost controller useless and you will run wastegate pressure.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

No, they have a small bleed hole in the side, so it will actually run as the stock turbo does, bleeding a little of the pressure off to raise the boost. How much boost depends on the size of the bleed hole and the actuator spring.

Kane_R32 Experienced

Kane_R32

Posted
Posted

I would like to see what level of boost increase you would see though. I don't think the 1mm bleed hole would let out nearly enough boost pressure, compared to if the ball and spring was there to restrict flow, and increase boost.

  • 2 months later...
Blackkers Experienced

Blackkers

Posted
Posted

Hey guys sorry for bringing up an old topic. I'm having trouble with an EBC + RB20 actuator. max boost set to 1 Bar. The trouble is I can't find a good balance between response and overboosting with the EBC GAIN setting. I think it's because of the difference between my boost setting and the hardware setting (wastegate pressure)

Has anyone used the Kinugawa actuators on an RB25det highflow? using standard comp and turbine housing. They sell a 1Bar spring that would be perfect.

heres a link: http://www.ebay.com.au/itm/Kinugawa-Adjustable-Turbo-Wastegate-Actuator-Nissan-Skyline-RB25DET-R33-/281163573117?pt=AU_Car_Parts_Accessories&hash=item4176a7a77d

Thanks

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

    • myrbgivesmeheadaches
      RB25DET NEO Cylinder Head

      By myrbgivesmeheadaches · Posted

      Did this end up working? Did you take some pictures?
    • Duncan
      V37 Suspension change

      By Duncan · Posted

      And finally, the front lower mount. It was doubly weird. Firstly, the lower mount is held in with a bracket that has 3 bolts (it also acts as the steering lock stop), and then a nut on the shock lower mount itself. So, remove the 3x 14mm head bolts , then the 17mm nut that holds the shock in. From there, you can't actually remove the shock from the lower mount bolt (took me a while to work that out....) Sadly I don't have a pic of the other side, but the swaybar mounts to the same bolt that holds the shock in. You need to push that swaybar mount/bolt back so the shock can be pulled out past the lower control arm.  In this pic you can see the bolt partly pushed back, but it had to go further than that to release the shock. Once the shock is out, putting the new one in is "reverse of disassembly". Put the top of the shock through at least one hole and put a nut on loosely to hold it in place. Put the lower end in place and push the swaybar mount / shock bolt back in place, then loosely attach the other 2 top nuts. Bolt the bracket back in place with the 14mm head bolts and finally put the nut onto the lower bolt. Done....you have new suspension on your v37!
    • Duncan
      V37 Suspension change

      By Duncan · Posted

      And now to the front.  No pics of the 3 nuts holding the front struts on, they are easy to spot. Undo 2 and leave the closest one on loosely. Underneath we have to deal with the wiring again, but this time its worse because the plug is behind the guard liner. You'll have to decide how much of the guard liner to remove, I undid the lower liner's top, inside and lower clips, but didn't pull it full off the guard. Same issue undoing the plug as at the rear, you need to firmly push the release clip from below while equally firmly gripping the plug body and pulling it out of  the socket. I used my fancy electrical disconnect pliers to get in there There is also one clip for the wiring, unlike at the rear I could not get behind it so just had to lever it up and out.....not in great condition to re-use in future.
    • Duncan
      V37 Suspension change

      By Duncan · Posted

      Onto the rear lower shock mount. It's worth starting with a decent degrease to remove 10+ years of road grime, and perhaps also spray a penetrating oil on the shock lower nut. Don't forget to include the shock wiring and plug in the clean.... Deal with the wiring first; you need to release 2 clips where the wiring goes into the bracket (use long nose pliers behind the bracket to compress the clip so you can reuse it), and the rubber mount slides out, then release the plug.  I found it very hard to unplug, from underneath you can compress the tab with a screwdriver or similar, and gently but firmly pull the plug out of the socket (regular pliers may help but don't put too much pressure on the plastic. The lower mount is straightforward, 17mm nut and you can pull the shock out. As I wasn't putting a standard shock back in, I gave the car side wiring socket a generous gob of dialectric grease to keep crap out in the future. Putting the new shock in is straightforward, feed it into at least 1 of the bolt holes at the top and reach around to put a nut on it to hold it up. Then put on the other 2 top nuts loosely and put the shock onto the lower mounting bolt (you may need to lift the hub a little if the new shock is shorter). Tighten the lower nut and 3 upper nuts and you are done. In my case the BC Racing shocks came assembled for the fronts, but the rears needed to re-use the factory strut tops. For that you need spring compressors to take the pressure off the top nut (they are compressed enough when the spring can move between the top and bottom spring seats. Then a 17mm ring spanner to undo the nut while using an 8mm open spanner to stop the shaft turning (or, if you are really lucky you might get it off with a rattle gun).
    • Duncan
      V37 Suspension change

      By Duncan · Posted

      You will now be able to lift the parcel shelf trim enough to get to the shock cover bolts; if you need to full remove the parcel shelf trim for some reason you also remove the escutcheons around the rear seat release and you will have to unplug the high stop light wiring from the boot. Next up is removal of the bracket; 6 nuts and a bolt Good news, you've finally got to the strut top! Remove the dust cover and the 3 shock mount nuts (perhaps leave 1 on lightly for now....) Same on the other side, but easier now you've done it all before
×
×
  • Create New...