HKS 50mm racing wastegate.
 

Ok putting everything back together on my babynow. I however noticed that on my HKS 50mm wastegate on top right smack in the middle there is a hole that is threaded. Do you leave it open to bleed off?

Mine has a screw in it with a lock nut, it should be there for the internal spring like on greddy BOV's and such...

^not sure what he is talking about.

it should be the same as your 40mm you just sold. use it if you have an EBC...leave it alone if you are using a MBC.

Thanks bro.... I looked on the HKS site and in the pic it shows a allen head screw with what appears to be a lock washer. My HKS 50mm has 2 openings on top, one directly in the middle and one offset to the side on top. I know the the hole that is offset to the side on top is used along with the side hole for EBC purposes. Hmmm...

ah...weird...my bad, don't listen to me...I don't own that gate, haha!

I have a HKS 50mm knockoff, so this may not apply, but i believe they are built the same.

The centered top hole needs to be plugged if you want to use an EBC to provide pressure to the other side of the diaphragm to provide control(The configuration where you are using both nipples on the wastegate). If you don't plug it, any air that you attempt to rout to the top side of the diaphragm will be vented to atmosphere and you will just get spring boost response.

how do you like that knock off?

Hmm guess mine is missing for some reason. Picked it up for a good price, I have no problem replacing a .25 screw and lock washer.

Knockoff works great so far(1 season, > 10000km), vented to atmosphere. It's seen leaded gas as well.

The high boost springs it comes with are not very accurate, I would advise against using them unless you need to go well beyond their boost level.

If it's a knock-off it won't have the hks logo cast into the top cover.

I just have mine open. Hope that is fine.

so have u tried the black spring that it comes with?

If that question is directed to me, I think I have tried the black spring (the 1.1 bar) that was the one giving me 18+ psi in fourth, while 1.1 bar should be 16. I may be wrong about the color, but I did try the 1.1 bar one.

If anyone needs a 14 lb(yellow) spring, I have a brand new one in the unopened bag. I bought it for my 50mm, but no longer need it. I paid $55 for it, I'll sell it for $40 shipped if anyone needs it.

The yellow spring is 10# and the purple is 14#.

Oh, well it's a 10 lb spring then.