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Wastegate Actuator Mod


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O/k guys, you want to increase boost with your external gate.

If you want to fit a helper spring, and you want 3 more psi, just go through all the same calculations as before, but for 3psi.

For the "mythical" gate, that would be 3psi times 10 square inches is 30 pounds extra force, with the same mythical spring height of 1.5 inches.

Just add an extra smaller spring inside the existing stock spring with that rated load and height.

But there is another and better way to do it. You still need more spring force, but you can do it with AIR PRESSURE on the spring side of the diaphragm.

So what you have is a stock original wastegate spring rated for maybe 10psi design boost in your external wastegate. To increase it to 15psi, just feed in a constant 5psi of air pressure on top of the diaphragm on the same side as the spring. The air pressure and spring pressure add together., and the wastegate will not open until 15psi.

All external gates have a pressure fitting on the top cover to do exactly this.

How you do this is you tap off some boost air pressure (15psi) and feed it through an adjustable pressure regulator so a constant 5psi comes out of the regulator. Plumb that into the top of the external wastegate, and it will then work at i5 psi.

If you fit the pressure regulator inside the car, you have adjustable boost. Wind the pressure regulator right down to zero and you get the stock 10psi. Wind it up and boost increases to anything you like. Wind it up to 12 Psi and you get 12 + 10 = 22psi boost for example. Easy.

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this is how my EBC is plumbed, with the solenoid to the top of the gate and a direct boost line to the diaphram. It holds shut ok, just when the gate comes open it drops slightly then fluctuates as it tries to control the boost. This is only when I am running higher boost, ie1.5bar plus.

The fluctuation isnt bad, but at lower boost its spot on, and the power curve is nice and even, with no dips.

So I am hoping that a harder spring will give me the same boost control that I have at 1.2bar with the 10psi spring that is in there at the moment.

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so - sorry for re-iterating, but im still a turbo noob... :P

If you wished to up the boost on an R33 to 11 or 12psi, this could be acheived by installing an HKS wastegate actuator (rated to the appropriate boost, of course) instead of any bleed valves or EBC's ??

Only drawback (if you call it one) would be that you couldnt run any lower boost settings if you wished...

Is this correct ??

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Gizmo - I pretty sure this is right.

If your like me and just have a bleed valve set at 12psi, and that all you want to run (couldn't be bothered with a lower setting) then a HKS actuator might be a good idea.

You might be happy with the just the actuator installed so you may not need a EBC or a bleeder :P

I think someone mentioned that you can get a HKS adjustable one too ! Not sure on price though.

J

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Guest Robo's

I believe you need the whole new actuator rather than the spring as they are concealed unit or the HKS one is allready is a unit rather than a rod and a spring???

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Yep...

Going on

http://www.takakaira.co.jp/performance/main.html

regarding the HKS Wastegates (whole unit)

Depending on the strength and psi required, they start at about $700AUS...

Still - it would eliminate boost fluctuations, as long as you are happy with that level of boost (as per Jay)

Maybe a good option to get an 10-11psi HKS wastegate, and a good bleed valve for the other 2-3 variable psi...

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Guest INASNT
hmm can u explain more about the helper spring :P I can hold around 12psi, but want to hold 1 bar. Its not that much more ;)

Remember it comes down to the ability of your turbo to hold boost up high alao, not only the spring tentioned. Most stock r33 turbos wont hold 1 bar all the way to redline.

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That is correct. The only way to take it apart is to cut it apart. It would be easier to make your own wastegate actuator from scratch, than to try to put a stock one back together again.

Not too hard if you have a lathe, to turn up your own housing. But why bother ?

Just buy a replacement actuator from Garrett or HKS for whatever boost level you want to run.

The last time I bought one it cost $220 about three years ago from AVO in Melbourne.

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Hmm well i just checked the prices on Greenline, quite cheap. So ill think ill get one.

Now i want to run 1 bar. So do i ask for a 1bar wastgate actutator? Or do i ask for somethin like 13psi and make up the rest with my boost controller?

Will there be any problems putting such a stonger W. A on the turbo? Like will the turbo be able to make that much boost. Bare in mind, i dont actually use the turbo much, onlyu some nights and stuff. Most day to day driving, i barely use boost.

Thanks

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Just for everyones info,

I just rang GCG and had a chat to Brett regarding this.

They can supply a brand new actuator, with upgraded spring AND an adjustable rod, with all the brackets and bolts. They are a direct replacement item that will fit in the factory location.

This means that that it should get rid of some wastegate creep (from the stronger spring) and hold boost better up top. And with it being adjustable you can adjust the boost if you find that you want 14psi instead of 12psi.

Brett also said that all you'll need to do is remove the heat shield to remove the stock one and fit the new one.

The price of the unit is $247.50 plus delivery. This price INCLUDES the 10% discount for SAU members.

Now I'm not sure how this compares to the HKS actuator as I haven't used either of them, but to me it seems pretty good.

Just letting everyone know what is on offer etc... I'm not specifically trying to push the GCG stuff, although Brett seemed happy to explain everything.

If we had enough people maybe we could do a group buy ??

J

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