You think it can be the bearing in the turbo.. I'm having same issues. Wastegate is tightened all the way down, no more boost leak. My tuner says to check the flap just like you said. I just don't understand, if the wastegate is tight how can the flap not be fully closed.. :/ I'm thinking the turbo is ****. It's taking me 5.5-6k rpm to hit 22-23 psi. It used to be 19 till I fixed my leak so now idk. I'm loosing my mind with this ****.

 

It's not the turbo. It's the user. You need a stiffer spring. If you don't believe me. Zip tie the wasgegsfe shut and give it a go. Don't knock the turbo. There are numerous people running this. They just don't post here.

 

Sounds like a preload issue to me get a better spring

 

it's turbo, because doesn't matter how much more i screwed preload adjuster. maximum or middle. difference in boost from 0.1 to 0.3 on the top, but airflow not changed, its maximum 350 g/s and that's all folks...

 

Change the spring out. The exhaust gases are forcing the waste gate flapper open.

 

That turbo is not even close to being maxed out my friend, i had same issues with wastegate actuator pressures, once resolved the turbo flows very well.

 

So what are you suggesting to do to correct this issue?
I have the 2.0 bar spring installed already.
I've been considering replacing the kinugawa wg with maybe a forge or fp wg.
Toms got a good soulition with the map o2 pipe with external wg.
He swears by it. But it about 709.99 a litle expensive.
But if it will correct it all then money well spent.
But maybe a bette wg wo uh ld do the trick for a 1\6 of the cost?
What do you and tom think try replacing the wg or just go to the map o2 pipe?

 

Their 2 bar spring is like 1.5 bar. Maybe get a custom spring made. The map 02 dump will work spending money on another internal wastegate might not work. Maybe borrow a friends and try it out before you waste the money.

Or you could make your own external wastegate dump.

It's a pretty simple design just get a O2 flange and well a V band flange on it.

 

I remembered one more thing that FP puts on his turbo 10.5cm hotside, because the @alt@ 11.5cm hotside not well work.

what hotside with your kinugawa?


kinugawa's 2.0 bar spring is real 2.0 bar. it is checked.

IMHO, external WG for bolt-on turbo does not make sense, wasted money.

 

10.5. I could only get 26 on my 2 bar spring.

 

My turbo always had the 10.5 hotside, i removed the internal flapper and arm and modified a Muse O2 dump with a Turbosmart 44mm external wg.

 

The most i could ever get out of their internal 25 psi wg actuator was 32 psi, even after modifying it and preloading it, so i went with a Modified Muse O2 dump with a Turbosmart 44mm wg, that solved the problem pretty good.

 

I understand, my tuner put this together for me before he sent it out. I had to remove the wastegate and bracket to get the turbo to fit and in that I think i messed it up. I'm at 100% wgdc and literally supposed to boost till the moon. My tuner said that i should take the wastegate vacuum line off and log. If I'm still hitting same psi, it means my wastegate is opening under throttle etc. Maybe flap isn't fully closed idk. He said I have 1bar spring and he was using that before on his set up with 31 psi. Idk, I'm paying him to come down here and build my motor and solve my issue...

 

1 bar spring in that waste gate hitting 31 psi? I find that very hard to believe.

Your exhaust gases are probably pushing the flapper open meaning your wg spring is too weak.

 

why not? stock wg 0.8 bar spring