HKS Wastegate Actuator: Let's Set The Record Straight

[Hoffman5982]

As popular as this actuator is, the only information I can find is vague as hell. They always say "adjust until it's where you want it". I've been getting mixed messages that making the rod longer will increase boost while shortening decreases boost, and vice versa. Which is it?

I also need help. I just bought one of these, used. I get it and immediately notice that the bracket mounting holes don't match. I cross referenced the number it comes up as the t25/t28 kit, and the pictures on FRSport match. Instead of drilling the holes out, I decided to undo the spot welds on the stock actuator and use that bracket since it will match perfectly. Not a problem. Get it on and notice that even on it's longest level I have to pull it pretty tight to reach the flapper.

Everywhere I'm reading says it should be able to get long enough to reach and only slightly hold the flapper shut. I went for a test drive and it shot to 17psi(idk if it would have climbed further, I let off). I drive it home and try to see if it will loosen any further. It will but will only have 2-3 threads holding. I got out my air compressor and with it threaded out to this unsafe level it barely opens the flap. Any tighter and it won't open it at all. Did I get a shit actuator? Any help would be great.

[s13 drifta]

Shortening the rod will increase boost because it puts more tension on the actuator, and lengthening the rod will decrease boost.

[KendallH]

I believe shortening the rod would increase your boost, as it would be preloading the spring. Are you on a genuine OEM T28? I know the OEM T25 and OEM T28 actuators are different and won't swap over.

[Hoffman5982]

Originally Posted by KendallH

I believe shortening the rod would increase your boost, as it would be preloading the spring. Are you on a genuine OEM T28? I know the OEM T25 and OEM T28 actuators are different and won't swap over.

Are you asking if my turbo is a genuine T28 or if the actuator is a t28? The turbo is the stock turbo on my notchtop. Unless someone upgraded the turbo on an automatic motor in Japan, I'm positive it's genuine. As I said with the kit, when I search the number on the side it comes up as the t25/t28 actuator. I see that the s13 kit is the RN004 and the s14 is the RN005. I'm not seeing either of these numbers on the actuator. Where would they be located?

[ghoti]

IIRC this actuator is compatible with both OEM T25 & T28 as long as you switch over to the correct bracket.

[Hoffman5982]

Originally Posted by ghoti

IIRC this actuator is compatible with both OEM T25 & T28 as long as you switch over to the correct bracket.

If that's true then the only thing I can figure is that this one is for a completely different application. I have to use a compressor to push the rod out to get it on the flapper. Even then it opens it maybe a mm or two and that's it. I'm just going to order a brand new one once paypal refunds my money from this jackass.

[ultimateirving]

One bracket might be thicker or shaped slightly different so the actuator reaches differently. I had a t28 with a hks actuator and used the hks bracket. Also the longer the rod the softer the boost. Stock on the hks should be 11-12 psi I believe.

[wutangben]

this is an old thread, but for what it's worth to you:

my hks actuator for a t25 requred some "widening" of the holes on the bracket to get it to actually line up for my turbo. not a big deal.

also, it does take some muscle once you've made the arm shorter to reach the flapper. it's been a while since i had/used one, but i remember i'd try to get the flapper to sit as far towards the front of the car as possible, then i'd muscle the rod on.

the original one you bought was probably fine.

it's not rocket science.

[Hoffman5982]

No, it definitely wasn't fine. At the longest I could get it, past the point of having enough threaded on to be deemed safe, it would not extend any further, making the turbo boost until it eats itself alive. It'd a simple item to install, I'm not that dumb but thanks for suggesting that I am.

I used an air compressor to fully extend the arm, which was still almost a mm too short to get to the flapper. The one he sold me was nowhere near the right one for my turbo, and I took care of that through paypal. Thanks for your condescending suggestion though.

[wutangben]

glad I could help. thanks for "setting the record straight."

[Hoffman5982]

You didn't help at all, you came in claiming that mine was probably right when I know for a fact it wasn't. Thanks for bullshitting.

[songgsan]

As popular as this actuator is, the only information I can find is vague as hell