Was hoping somebody could help me as I emailed three different HKS dealers in the US and after two weeks none have bothered to respond...thanks guys. Be happy to identify them if anybody is interested.

Ok, details are as follows:
HKS GT60 Wastegate
The spring has two paint markings on it, white and then blue next to it
Spring is 5.75" long x 2.25" wide (unsprung)
Coil thickness is ~5/32"
There are 5 coils and the whole spring is about 1.5" when compressed

Question is: What is the spring pressure rating?

 

If you can't find an answer you can always put the spring in the wastegate and apply air pressure to it and watch for it to crack open. This is assuming it's easy to take the wastegate off the car.

 

There is a white blue spring posted on Overboost, with part number. Give them a call, they should be able to tell you.

http://www.overboost.com/obs/search....=&search_sc_id=

 

It's easy to take the wastegate off but I'd prefer not to work on the car in the cold (so I'm a big wimp, ok). Thanks for the link Jesus, I will call them on monday as their "live" help isn't available on saturday's, or at least this particular one.

 

I don't blame you at all. I have a list of things I want to do to my car but that cold sure is a deterrent! Making a call sounds like a better idea

 

http://www.hksusa.com/products/more.asp?id=1472

 

I have done the whole bench testing of wastegates, but there is a variable not always considered. IN fact it screwed me on my last round of tests on multiple springs in a 50mm setup.

WHen the WG is installed, the plunger seals the manifold gases off to force them into the turbo. There is a certain amount of backpressure there pushing against that plunger and ultimately the spring. So if you bench test the spring itself which might open at 10psi, the backpressure acting against the spring might allow it to open around 7-8psi in practice. This was the case when I was fooling around changing springs trying to get an exact 10psi baseline...on the car I only had 7psi baseline when nothing else changed.

 

Yep,


I tested my HKS GT 60mm wastegate on compressed air and a gauge after I was having problems with boost creep with it.

With the "hard" red and green spring (rated 12.8-18.5 psi) it would crack open at ~14psi, but wouldn't fully open until ~20psi or if I pushed on the valve bottom a bit.

I put in the "soft" white and blue spring (rated 8.5-14.2 psi) so it will be fully open at the lower boost I want to run (17psi). I will add a simple manual boost controller to keep it from cracking open at lower pressures.

Twidling the adjuster screw on top seemed to affect when the WG cracked open, but not when it fully opened. That makes sense since it is just adusting the preload on the spring and will have no effect on actual spring rate.

 

Thanks guys. I would like to run 1 Bar of boost (~15psi) so the white/blue combo is the appropriate spring then by the sounds of it.

I'm running a brand new motor with a very raw tune which is still under break in. I've tried to see how much boost I could get with the set screw on top both all the way backed out and with it all the way in.

What I've found was that with it all the way in, boost is substantially more responsive going from vacuum to 0psi instantly. However, I have a very very difficult time making pressure and can't get above 7psi at all. In fact, it's very hard to maintain 5#. With the screw all the way out it's not nearly as responsive but I can get into the 5# range easier.

I run an apexi avc-r for boost control and have played around with the settings a bit and have confirmed that it works (had it on another engine in the past).

I know their could be a number of factors contributing to this, I just wanted to rule the wastegate out as being one of them.