t-25 wastegate actuator adjustment?

[rsa928]

i have a 97 honda civic and recently installed the T-25 turbo on my car- i am only looking to run about 8.5 psi from the turbo. i have the wastegate actuator and not an external wastegate like i would like to have- well my problem is around 4,000 rpms im boosting about 10 psi- i was wondering if there is anyway to adjust the wastegate actuator to keep my boost low. any help i would really appreciate

 

[gasguzzler]

Is there a vacuum line going from the compressor cover to the wastegate? Are there any valves or switches in that line? Is the end of the actuator rod threaded? What happens if you disconnect the vacuum line to the wastegate? (which would tell you your base spring rate). If your base spring rate is 10 (which I believe it is on my 1G Talon), then I don't know of any way to lower the boost below that.

If the car is hooked up "tuner style" which has the vacuum line going straight from the compressor cover to the top of the wastegate, you can put a bleeder valve in there to bleed off some of the pressure.

If the actuator is threaded, you could unscrew the end of actuator a turn or two to drop the boost down.

Hope that helps!

- Brian

 

[daren_p]

Is there a vacuum line going from the compressor cover to the wastegate? Are there any valves or switches in that line? Is the end of the actuator rod threaded? What happens if you disconnect the vacuum line to the wastegate? (which would tell you your base spring rate). If your base spring rate is 10 (which I believe it is on my 1G Talon), then I don't know of any way to lower the boost below that.

If the car is hooked up "tuner style" which has the vacuum line going straight from the compressor cover to the top of the wastegate, you can put a bleeder valve in there to bleed off some of the pressure.

If the actuator is threaded, you could unscrew the end of actuator a turn or two to drop the boost down.

Hope that helps!

- Brian

Unless I'm having a brain fart I think your backwards. The line that should be hooked up to your wg is a pressure source. When enough boost pressure is applied to the wg to overcome its spring it opens the wg flapper allowing extra unwanted boost to bypass the turbine decreasing your boost. Disconnecting the pressure line would prevent the wg flapper from opening, increasing your boost until something give, ie your motor. As far as I know there is no adjustment on the stock wg's. By putting a bleeder valve "ie boost controller" you do vent off pressure therefore increasing your boost, you cannot adjust your boost below the spring rate of the wg. (unless of course its an adjustable wg)

 

[GSGoinFast]

If the car is hooked up "tuner style" which has the vacuum line going straight from the compressor cover to the top of the wastegate, you can put a bleeder valve in there to bleed off some of the pressure.

that will raise the boost pressure

If the actuator is threaded, you could unscrew the end of actuator a turn or two to drop the boost down.

that will not turn the maximum boost down, that will only make you take longer to get to that boost. in other words more lag. the wastegate will always be open a little bit if you extend the arm. when you are trying to build boost, there will be exhaust gases already by-passing the turbine because the gate is open a little bit. that means that you will not build boost as fast, but will still eventually reach the same maximum boost level.

Unless I'm having a brain fart I think your backwards. The line that should be hooked up to your wg is a pressure source. When enough boost pressure is applied to the wg to overcome its spring it opens the wg flapper allowing extra unwanted boost to bypass the turbine decreasing your boost. Disconnecting the pressure line would prevent the wg flapper from opening, increasing your boost until something give, ie your motor. As far as I know there is no adjustment on the stock wg's. By putting a bleeder valve "ie boost controller" you do vent off pressure therefore increasing your boost, you cannot adjust your boost below the spring rate of the wg. (unless of course its an adjustable wg)

your right, he is backwards. but there is a way to adjust a stock wastegate actuator.

first you need to go to home depot's spring section(yes they have one ) and buy a fairly long fairly stiff spring. you also need a couple washers that will fit around your actuator rod, and a bolt with a matching die. what you need to do is cut the actuator rod. if your actuator rod already has threading on it(mine did) then you have it a lot easier. i cut as low as i could on the threading, but make sure the threading is exposed on the bottom. now take the wastegate to home depot and find a bolt that fits the threading. if your actuator rod doesnt already have a threading on it, you will need to thread it. now what you do is put a washer on the rod, then a spring on the rod, then another washer, and then a bolt to match the threading you made or the actuator already had. now, the spring is pushing against the actuator housing, and pushing the rod out. this cancels out some of the force the stock actuator spring requires to open, meaning it opens at a lower boost level.

depending on how much threading you have(i didnt have much) this can be adjustable. if you want less boost, tighten the bolt a bit. if you want more boost, loosen it a bit. i have no idea what mine is set at as i didnt have any room to adjust it. im hoping its at or about 5 psi. now you need to weld the bottom of the actuator rod back on the actuator. now reinstall it. im going to include some pictures of what i did on my T3. i hope this helped