wastegate / boost controller question

[Impact Black]

So the other day I decided that I'd get on the car a little bit. Currently I'm just on the "stock" boost.
I looked at the boost gauge as I accelerated and it jumped to 15psi then dropped to 9-10psi. I believe my wastegate is going out....*damn*

After talking to a friend of mine he said that the HKS adjustable wastegate and getting a boost controller will fix the problem since the wastegate on the turbo is the factory one.
I had the turbo rebuilt by majestic with the T28 internals, could this have affected the wastegate?

Another question, if the HKS wastegate is set to 15psi, and I put a boost controller on it, with the boost controller set at 10psi it won't go pass that, and then with it set at 15psi it won't go past taht amount because the boost controller along with the HKS wastegate won't allow it to.....correct?

[shifts13]

are you running a boost controller right now?? if you are, sounds like you need to retune it. if not then check the vac line on ur wastegate




Another question, if the HKS wastegate is set to 15psi, and I put a boost controller on it, with the boost controller set at 10psi it won't go pass that, and then with it set at 15psi it won't go past taht amount because the boost controller along with the HKS wastegate won't allow it to.....correct?

I dont quite understand this but you dont need to run an adjustable wastegate and a boost controller at the same time.

[cotbu]

Wrong, if the wastegate is set at 15psi that's the max + the spike, so if your boost controller is set at 10psi you'll get the 15psi + the spike. Boost controllers raise boost above the wastegate setting, they cannot go lower than the wastegate setting. Use the adjustable actuator as you low boost setting, say 11psi. Then use the controller to raise it to 15psi.

[Impact Black]

are you running a boost controller right now?? if you are, sounds like you need to retune it. if not then check the vac line on ur wastegate





I dont quite understand this but you dont need to run an adjustable wastegate and a boost controller at the same time.

I don't have a boost controller on it right now, and I'm going to replace that vac line from the hotpipe to the turbo wastegate today and see what happens.

[Impact Black]

Wrong, if the wastegate is set at 15psi that's the max + the spike, so if your boost controller is set at 10psi you'll get the 15psi + the spike. Boost controllers raise boost above the wastegate setting, they cannot go lower than the wastegate setting. Use the adjustable actuator as you low boost setting, say 11psi. Then use the controller to raise it to 15psi.


So dial the HKS actuator fo 10psi, then have the boost controller set at 15psi. Got ya

[jspaeth]

Even manual boost controllers suck at controlling spike.

You need an electronic boost controller (I would reccommend AVC-R, but it is expensive).

An electronic boost controller allows you to bleed off air that would be going to the wastegate to "trick" it into thinking the boost is lower than what it really is......as a result, it stays shut longer, making the boost rise quicker. Then, when you get really close to the target boost, it allows the wastegate to see the "true" boost (by NOT letting any air be bled out of the line from the hotpipe to the wastegate) and the wastegate begins to open.

With a good electronic boost controller, you can run your turbo safely. I have mine set up relatively aggressively (I want the boost to get to max quickly) and the most overshoot I get is a few %.....so if I set it to 1.15 bar, I will SOMETIMES see 1.2 bar very briefly and occasionally 1.25 bar, but this is only usually on hard downshifts.