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I have the boost creep problem as well. it only occured after i added my turbo back zorst and fmic. with the standard solenoid my car would hit one bar by about 6000rpm, i removed the solenoid from the system and now boost still creeps from 7 to about 10 or so by redline. i chucked on a boost controller which is set to 10 but by redline its at about 12... i'm pretty sure it's a problem with the gate.

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Well the easies thing is to port the standard gate. Here is a pic of a normal gate, now form that you can remove some 4mm down the lower side and 2mm on the upper side, not only that, but port the inlet to the gate aswell, to allow for ease of gas entry.

ALSO Slide sugested the following.

Hey mate

This is a very common problem and most people tend to just port out the wastegate hole.

This is not necessary and in most cases can be fixed by a good electronic boost controller.

Gizmo in my experience with tuning hasnt been all that great running extra boost on standard turbo's and i have always had overboosting problems.

Wastegate creep can usually be solved by a stronger spring in the actuator so that you are not relying on air so much to do mechanical work.

Mpst people go for the HKS Adjustable actuator and it is a straight bolt on for the T3 RB25 turbo.

As is is adjustable it in most cases will be more reliable to set the boost and hold it with just that then with a cheap electronic boost controller or boost tee.

Once you remove the standard exhaust system you decrease back pressure.

The R34 housing will fit directly onto most R33 turbo's.

One thing that most people are not aware of is the clearances between them as they cannot be seen without a line camera.

If the housings are even slightly off center this may cause the clearance to be more on one side of the turbine then the other and in some cases even touch the housing which will result in failure.

This is not required to be done to fix your problem though.

The standard turbo's are really poorly matched with too small a wheels being used to focus just on quick response for highway overtaking etc.

Most cases with my highflowed turbo's the standard actuator is used with a standard boost controller or a electronic boost controller and boost creep/overboosting is not an issue.

A quick fix that you could try is simply bending out the wastegate arm to bring up the crack pressure to start the boost hold higher so that the gate opens a little later.

Otherwise the HKS or Garrett adjustable actuators should fix your problem and porting the actuator should not be required.

I have never bothered mass porting on an RB series Hitachi T3 and always found the best way to control boost is with a better actuator and it has always solved the problem.

Hope that helps

Hang on a min WogRus... what are you on about.

One mine your saying

once exhaust and other mods are introduced. It is easier for the exhaust gas to go through the turbo then the gate, and hence you get creep. I am in the process of porting my stock gate 2.5mm either side, enlarging the area by 38%. This will be a big difference. and the stock gate is DEFINATLY the problem. It's more of a problem on the R33 the R32.

As for boost controll, if you wire teh gate fully open, it will still creep, this is because the gate is too small.

And then your saying its easier to port the turbo (removing it) than installing the adjustable actuator?

Come on man. Thats just silly talk.

There is no way on this earth removing the turbo, porting the rear of it... is harder than installing an adjustable actuator.

And funny... its what i said on page one. And what Slide has also said...

Boost controller

And actuator is a controller of boost.

I've got to say I've never heard of any issue with these turbos. How is it that many of us run high-flowed RB25 turbos at around 14psi or more and never have creep issues? You'll note below that the wastegate on the high flow turbo has NOT been ported....

Personally I find if anything once I hit peak boost I loose boot, due to the crappy bleed valve I'm using.

100_1188.jpg

I've got to say I've never heard of any issue with these turbos. How is it that many of us run high-flowed RB25 turbos at around 14psi or more and never have creep issues? You'll note below that the wastegate on the high flow turbo has NOT been ported....

Personally I find if anything once I hit peak boost I loose boot, due to the crappy bleed valve I'm using.

100_1188.jpg

Sorry Adzmax something i don't understand in what you said..

You have 2 turbos there and you said you have had no trouble with them, but the one on the right doesn't really look like it's in good condition compared to the one on the left...

What gives you the impression the one on the right is still alright considering it's visual state??

He's talking the rear wheels and the int gate... that doesnt really have much to do with the state of the turbo.

As you can see one is hi-flowed, one is not, going by the rear wheel size...

And the hi-flow (from sliding) has the same sized internal gate as the stock version (un-flowed) turbo.

He's talking the rear wheels and the int gate... that doesnt really have much to do with the state of the turbo.

As you can see one is hi-flowed, one is not, going by the rear wheel size...

And the hi-flow (from sliding) has the same sized internal gate as the stock version (un-flowed) turbo.

ohhh right ok...

so the one on the left has been made all hectic??

From experience (both those turbos have been installed on my car) the satandad hole is more than enough to prevent creep.

if yoiu are haning troubles with an RB25 turb on rb25 use an RB20 actuaaor or take off your actuator and elongate the holes or bend the rod to give more preload.

i think the point with the boost creep is that when you are trying to run lower amounts of boost (say 10psi or less) then the gate cant control the boost to those levels as it is maxed out trying to dump the required amount of gases.

when you are running higher amounts of boost, say 12-14psi, then the gate is not maxed out controlling the boost, so no creep occurs.

this is why, for example, when you are running an external wastegate - you need a BIGGER gate for LOWER boost levels, as you need to dump MORE gas - higher boost levels can use a smaller gate as not as much gas needs to be dumped to keep the boost steady.

What i am saying is that the gate is the problem, but some solutions are to simply put an adjustable actuator on it, but it is a bandaid solution, it works, but if you want lower boost setting, like for my wife, it's a no go. But hay, eash to their own.

So why doesnt the stock boost level car suffer from boost creep, going by your theory, it should spike also :)

no it shouldnt, since it has a restrictive exhaust.

as said several times earlier in this thread, and a couple of other threads, it only occurs once you get a free flowing exhaust on the car.

i had boost spike, but that was due to the placement of the controller. i redid the plumbing for the controller and it went away.

i get a bit of creep during the rev range, but i am only running a $22 boost controller, and at the top end of the rev range i am maxing the turbo out so it is bleeding off a bit.

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