Teh turbine wheel is a different shape/size. So no, not a direct replacement.

 

Does the exhaust housing itself act as a heatsink for the flapper? So when closed, it would more or less be acting as one large piece of metal, but when slightly open the flapper is much more isolated from the housing and would be able to overheat? Could the order of events be WGA stretches due to stupid design, flapper cracks open then leaks & overheats resulting in warping? Or should a flapper be able to handle that and HKS just used an innapropriately rated metal for the job?

Bought used and you want warranty? That might be pretty tough.

 

The scenario above is very similar to a valve that gets burned. If something sticks between the valve and the seat all the additional flow heats up the valve and the material stuck there and can cause a blowtorch effect and burn the valve. I wouldnt be surprised is the constant leaking and lack of contact allowed excessive tempuratures and warping causing a domino effect.

 

^^^ what I've been saying all along

 

So whats the solution? replace the supplied actuator the turbo comes with, with a Forge or similar?

 

I would think its warping because everyone is running high preloads on the actuator. when you do that the valve barely lifts from its seat even when wide open. tons of hot gas through small space= warped arm from over heating. ultimately the arm wasnt made of the correct material. mitsu housings never warp arms.

If I were to run this turbo I would use evo 10.5 housing and machine it for the wheel.

 

The mitsu arm doesn't loosen up over time... and therefore doesn't float the valve off the seat.... and therefore doesn't have problems like this.

Having NO flow through the wastegate hole does not increase the temperature of the flapper. Think about having your valve lash set loose (for those of you familiar with engines other than neons/Evo's)... what does that do? It results in a burnt valve.... why? Because if you read anything about valvetrain the valve controls it's temperature through the guide and transferring heat through the seat. Of course this isn't a poppet valve, but the same principles apply.

 

What 94AWD is trying to say is that if you put a lot of preload the result is that at the same pressure the valve open less, and the exhaust gasses must pass in a smaller area.
But I think that it cannot be the case of the HKS turbo.

 

I bench test actuator opening before I install any turbo. so yes that is what i am saying. You would be surprised at how little the valve actually lifts even when adjusted like factory wants it. ad three or four turns additional preload and valve will barely leave its seat at all. the video shows the arm is warped. obviously from heat. if the arm warps from heat it will make the actuator appear to have become out of adjustment. I am quite sure the actuator arm is not stretching. its not exposed to any real heat. so its just a matter of decided which is happening first. I choose to believe the arm is warping from heat first. makes far more sense

if actuator stretches first this would allow soggy boost response and allow the valve to open much farther than normal since its starting position is no longer even on the seat. both would heat the valve and arm much less since gasses would have much larger area to go through.

 

I bought a HKS7460 and I put it on my car and ran it for a few months.

The actuator rod WITH THE LOCK NUT TIGHT... would loosen over time. I retightened it probably 10 times in the first month.

It would loosen to the point that when the car idled it would rattle against the seat and be so audible that we stopped doing dyno pulls on the dyno because it sounded like a rod bearing.

So yes it loosens over time. Yes the actuator arm sees some temperature and yes the material properties of stainless degrade with temperature.

I ran E85... so my EGT's were pretty low... and I ran a lot of boost 36+psi. So I wasn't wastegating a ton of exhaust.

 

I''ve ran the HKS for about 1 year, around 26psi, daily driving, autox, and a few HPDEs this past summer. I haven't had isues with the turbo at all, and its not showing any signs of problems. I don't have the KAI version either, being I was one of the first to pick up the kit when it was released with the cam package. I haven't had R/T's issues with the wastegate actuator, but I also agree with the design not being ideal. However, I'm still using mine and its holding 26psi decently.

 

I must have about 20k on it by now... No issues to date. It's a DD so it rarely sees sustained beatings, maybe a couple seconds of 30 psi here and there, but nothing like RR.

I'm honestly not sure if I would even know if the WG was warped, I have my WGDC (3 port) down in the 30s in some places to keep it happy and it still pulls mighty hard down low.

 

and i was thinking of picking up this turbo for my track car

 

i was thinking the same. 10-15min blast around a racetrack

 

I don't think mine is a Kia version. I picked it up from Ivey early September 2010, installed it a week later and drove to Ivey for a tune.

The first thing we noticed, that the W/G's Rod was loose from the factory; it was tightened up and the car was tuned.

After a couple of track events, I noticed that the lock-nuts/adjustment threads backed out a little, and the rod was loose again. It was tightened again with a good amount of force and some locktite and it's been fine for over a year now.

I DD and track my car. As a DD, I normally run 93 pump gas and around 28 psi of boost. On the track, I drop the boost to 25-26 and mix a couple gallons of 100 octane with every tank full of 93.

Is my flapper warped? I don't see it being warped and making 440/412 on 93 pump gas but, I could be wrong.