# modding Waste gate actuator



## dburone (Apr 2, 2004)

Is it possible to turn a non adjustable actuator to adjustable? What mods should i make?


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## Zen31ZR (Mar 24, 2004)

dburone said:


> Is it possible to turn a non adjustable actuator to adjustable? What mods should i make?


You want to make it adjustable for what reason ? Use a boost controller (manual or electronic) if you wish to increase your boost level. Anytime you start messing with the at-rest tension placed on the internal spring and diaphragm inside the wastegate actuator , you run the risk of either stressing the spring enough to break it or rupturing the rubber diaphragm , especially if both are fairly old. What happens in that case is that your boost will hit maximum in less time than it takes the car to hit redline , and you'll blow head gaskets and bend rods. Do it the way it should be done and just use a boost controller of some type.


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## James (Apr 29, 2002)

cut the arm thread both sides, tap a piece of pipe and screw both ends in... use a locknut on each end to make sure it stays put.

IMO, I think adding tension on the wastegate is the BEST way to get boost. a boost controller is good but they always have a little air bleed on them to make sure the gate can close so its a small leak...


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## Zen31ZR (Mar 24, 2004)

James said:


> cut the arm thread both sides, tap a piece of pipe and screw both ends in... use a locknut on each end to make sure it stays put.
> 
> IMO, I think adding tension on the wastegate is the BEST way to get boost. a boost controller is good but they always have a little air bleed on them to make sure the gate can close so its a small leak...


Best way to get boost maybe , but best way to ruin an actuator. I've seen it happen on 3 cars. Not pretty. No big deal if you constantly monitor your boost but how many people do that religiously.


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## James (Apr 29, 2002)

[email protected] said:


> Best way to get boost maybe , but best way to ruin an actuator. I've seen it happen on 3 cars. Not pretty. No big deal if you constantly monitor your boost but how many people do that religiously.


Me me me!! 

In my view, modifying the spring constant has so many more advantages than playing with the signal line. The spring is tighter so it doesn't crack and leak boost. Couple that with a good boost controller and its like an on off switch... 

Well I've been running mine this way for a while... on an old actuator too... nothing wrong so far... (knock on wood)


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## Zen31ZR (Mar 24, 2004)

James said:


> Me me me!!
> 
> In my view, modifying the spring constant has so many more advantages than playing with the signal line. The spring is tighter so it doesn't crack and leak boost. Couple that with a good boost controller and its like an on off switch...
> 
> Well I've been running mine this way for a while... on an old actuator too... nothing wrong so far... (knock on wood)



2 of the 3 cars I saw it happen on had T3 turbos (The other was a DSM) , so I guess I'm warning the Z31 guys if nothing else. Perhaps the actuators Garret used had weaker diaphragms , I dunno. That and those T3s were from the mid-80s


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## dburone (Apr 2, 2004)

Its a new t25 turbo, set for 7psi. In the future maybe ill give it more boost, but first i want to give it less than 7 because i have 9.4:1 compression ratio and its kind of high. Here the fuel i get has 97 octanes but i still prefer to start with 5 psi, so if i could adjust the waste gate to 5psi i would be glad and while time goes by i may go to 7 and for more pressure ill have to change the ratio.


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## James (Apr 29, 2002)

so you want to lengthen the arm to reduce boost? well it will work but you will lose power everywhere because it will keep the arm open at much lower boost as well.


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## dburone (Apr 2, 2004)

James said:


> so you want to lengthen the arm to reduce boost? well it will work but you will lose power everywhere because it will keep the arm open at much lower boost as well.


I know, but its only at first to be sure not to blow anything, later ill put it back to 7psi. Thats why i want to be able to change the boost


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## landlord (Jun 11, 2002)

buy a manual boost controler there not that expensive and look very easy to hook up


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## Zen31ZR (Mar 24, 2004)

landlord said:


> buy a manual boost controler there not that expensive and look very easy to hook up


He wants to reduce boost , not raise it. Although I should think 7 psi is fine with 97 octane fuel.


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## James (Apr 29, 2002)

yeah no kidding... I can do 9 psi on 91 with a tiny intercooler.


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## dburone (Apr 2, 2004)

So you think i wont have trouble with 7psi on stock internals? and 97 fuel


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## James (Apr 29, 2002)

that seems very safe.


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## dburone (Apr 2, 2004)

James said:


> that seems very safe.


Thanks, ill recieve the turbo on sunday and start planning


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## Mr SEntra (Oct 7, 2002)

Damn, I wish I had 97 octane gas!


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## dburone (Apr 2, 2004)

Mr SEntra said:


> Damn, I wish I had 97 octane gas!


Here i have 3 types:
93
95
97
all unleaded

an year ago there was:
85 leaded
87 leaded
90 unleaded


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## aggrivator (Feb 12, 2004)

> Its a new t25 turbo, set for 7psi. In the future maybe ill give it more boost, but first i want to give it less than 7 because i have 9.4:1 compression ratio and its kind of high. Here the fuel i get has 97 octanes but i still prefer to start with 5 psi, so if i could adjust the waste gate to 5psi i would be glad and while time goes by i may go to 7 and for more pressure ill have to change the ratio.


I have a us spec de and i am running (i got it at 2am today) a t3 with an external wastegate setup for 8psi, which i havent hit much yet, but the guys that did the swap said that it should be ok, i have a nismo catalog, according to it the nismo turbo is a t25/t3, with .86/.60 a/r respectively with a max pressure of 10.82psi and actuator valve opening at 8.89 psi, thats from the nismo book... so they said i would be fine...


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## dburone (Apr 2, 2004)

aggrivator said:


> I have a us spec de and i am running (i got it at 2am today) a t3 with an external wastegate setup for 8psi, which i havent hit much yet, but the guys that did the swap said that it should be ok, i have a nismo catalog, according to it the nismo turbo is a t25/t3, with .86/.60 a/r respectively with a max pressure of 10.82psi and actuator valve opening at 8.89 psi, thats from the nismo book... so they said i would be fine...


You say those are the specs on the turbo y bought??? I think not, because now i have it, and it seems smaller than what you say.
I dont have much experience with turbos, but it seems very small.
Maybe its not small. It is new, no doubt on that, and its very nice. But small
intake housing says .48 AR the openings are 5.5cm and 6cm


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## asleepz (Feb 24, 2004)

T25s I believe are the smallest turbo made (not promising) but they spool up fast as hell. I'm getting a bigger turbo on my 300ZX once I prep my engine. More than likely the JWT Sport 450 Turbo


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## James (Apr 29, 2002)

SKD_Tech said:


> T25s I believe are the smallest turbo made (not promising) but they spool up fast as hell. I'm getting a bigger turbo on my 300ZX once I prep my engine. More than likely the JWT Sport 450 Turbo


actually the smallest turbo made that you can see is the size of a dime and spins at 250k rpms.  

(they have t15's and T2's, and I'm sure sizes smaller and in between those.)


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## Mervic (May 1, 2002)

dburone said:


> Is it possible to turn a non adjustable actuator to adjustable? What mods should i make?


 I put shims (washers) on the wastegate diaphragm holder(not sure what is proper term) to make it closer to the wastegate. This makes it open a lot earlier. My stock IHI RHB5 starts to open at around 8-9psi. After adjusting it, it starts to open at 4-5psi. Remember that I have an IHI turbo not Garrett so it could be different. But at least it will give you an idea. Check the pic.


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## dburone (Apr 2, 2004)

Mervic said:


> I put shims (washers) on the wastegate diaphragm holder(not sure what is proper term) to make it closer to the wastegate. This makes it open a lot earlier. My stock IHI RHB5 starts to open at around 8-9psi. After adjusting it, it starts to open at 4-5psi. Remember that I have an IHI turbo not Garrett so it could be different. But at least it will give you an idea. Check the pic.


Thanks, ill try something like that


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## landlord (Jun 11, 2002)

^^

that looks like a really good idea.


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## SIR GTI-R (Jan 3, 2003)

bit better than coughing up some coin for this but i must say it look's the bis







:thumbup:
http://www.gtmotorsports.co.nz/thumbnail.php?src=temp_images/hks1.jpg&maxw=102&gd=1


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## SIR GTI-R (Jan 3, 2003)

dburone said:


> Here i have 3 types:
> 93
> 95
> 97
> ...


in new zealand we get 
91 (unleaded)
96 (unleaded)
98 (unleaded)
leaded gas hasn't been sold here for years illegal to use it now too


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## 98sentrase (Mar 7, 2004)

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Mervic said:


> I put shims (washers) on the wastegate diaphragm holder(not sure what is proper term) to make it closer to the wastegate. This makes it open a lot earlier. My stock IHI RHB5 starts to open at around 8-9psi. After adjusting it, it starts to open at 4-5psi. Remember that I have an IHI turbo not Garrett so it could be different. But at least it will give you an idea. Check the pic.


Does that really work? Because I need to do something like that on my bluebird motor in my 98 Sentra because Jim Wolf takes 4-7 weeks to send a computer. I have to use my stock computer and run 2-3 psi untill it gets sent. I live in Phoenix so I WILL pre-detinate at 7psi.[with stock injectors(sentra injectors )] Any help would be appreciated.


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## dburone (Apr 2, 2004)

98sentrase said:


> undefined
> 
> Does that really work? Because I need to do something like that on my bluebird motor in my 98 Sentra because Jim Wolf takes 4-7 weeks to send a computer. I have to use my stock computer and run 2-3 psi untill it gets sent. I live in Phoenix so I WILL pre-detinate at 7psi.[with stock injectors(sentra injectors )] Any help would be appreciated.


What fuel are you using and what presure ratio do you have??


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## dburone (Apr 2, 2004)

I moved the housings, but now i have to make holes and threads on the compressor housing to hold down the waste gate.
Is there enough material for me to make the holes and not go in to the housing.
Another question is, after losening the v band, can i take of the compressor housing without having to balance the turbo???
I guess i can because im not touching other parts, but need your advice.


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## James (Apr 29, 2002)

you can take off the compressor housing without having to balance the turbo because its only the wheel you have to balance if you remove it...


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## 98sentrase (Mar 7, 2004)

dburone said:


> What fuel are you using and what presure ratio do you have??


I will run 91 with "the outlaw" super concentrated octane booster just to be safe. I do not have a upgraded radiator yet but I do have a Hotshot intercooler kit. but it is 115 degrees out here so it wont help that much. I'll probobly get a cool can or fuel cooler. for presure ratio 8.5:1 I put two washers behind the bracket already and it should fire tonight. I only work on it after work for an hour or two. So it has taken a long while. I'm accited wish me luck! should I use the sentra or bluebird injectors?


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