Adjustment Bolt on HKS Wastegate??
 

There's an adjustment bolt on there just like the HKS ssqv bov has to tighten or losen it. Is this possibly why my car spools up my turbo slow? I get 5psi@ 2800 in 4th and then it takes all the way to 4000 to get up to 10. you'de think I'd have 10 by 3400. Any way this bolt is backed out a good amount. What do you fellas think because I've checked the boost controller and there are no leaks or anything either. It is the 50mm HKS external wastegate. It has 2 nipples on it as well.

Thanks

Yanni

Yanni,

The bolt on the top middle is for adjusting the spring tension. If you have a 10lb spring in there and the bolt is back out all the way the gate should open at 10 lbs. If you tighten down the bolt it will increase your spring tension and release at a higher lb. I think mine releases at 12 lbs and the bolt is tightened all the way down approximately 1/2 inch long.

Chris

Yeah, I have a HKS GT wastegate and I played around w/ compressed air and a gauge and found some interesting things.

I took it apart and the construction seemed to uphold my findings.

You can adjust the preload on the spring, but not the springs rate.

So, if you have it on the looser settings it may crack open at a lower pressure, but it won't fully open untill the same pressure as when it is cranked down to the highest setting.

Looks to me like this means it will open sooner and slow down boost response, but won't really limit boost if your system is dependent on FLOW and not BACKPRESSURE. One wouln't need such a big wastegate if running on high backpressure system....

So, not really adjustable in my eyes.

So Chris...I just spoke with Bryan at BNR who built my turbo and we've been trying to figure out this slow spool issue because he gets ~14psi@3400 on cold nights.

He said maybe if I had it a little too far out it would affect spool. He said the same thing about if I put it in too much it will make my lowest boost higher.

So Chris are you saying that if the bolt is out then it should get 10psi as fast as it can still. And Blue T2 you are saying the same thing right? That that doesn't adjust the spool at all just the boost that it will make with no control?

Thanks guys I guess this isn't my problem I will now have to get a manual boost controller instead of the profec b.

My HKS wastegate is on one of Bryan's turbos :).

From what I have experienced on my car and from my experiments w/ the wastegate off of the car-

backing out the adjustment screw DOES adversely affect the rate of spool while NOT lowering maximum boost much at all.

Buy a spring that has an upper limit that you want as your boost and crank down on the adjuster to get some preload on the valve for good spool.

Or

Run a boost controller that will stop all pressure to the WG actuator until desired boost level is attained and it doesn't matter what the adjuster is set to.

Alright guys here's what I just did

I put that adjustment bolt in ALL the way and locked it down. Then I went out and I got 10psi at 3600rpms! instead of 4000rpms. It made my lowest boost .92 bar though. ~13psi instead of 10 which is ok for me I guess since it is a fucking single turbo setup that I have all my allowances since I was 11 into lol.

I then unplugged the vacuum lines to the wastegate and I got no increase in spool at all. So I put them back. Then I turned the adjustment valve on the profec b for balance all the way low and I noticed ~200rpm slower spool again. Put it all the way high again and was at 5psi@2800 and 10@3600 with no creep.
I also went to 15psi and I got that at 4000 on the dot.

So this is much better but I'm still about 500rpms behind Bryans spool.
So my boost controller is perfect, there are no leaks, what else could be the deal. Is this just what my car does? Could my wastegate be bad? the spring? What do you think I have about 3 weeks to figure it out before it gets retuned.

I'm very happy with the 400rpm faster spool though!

Thanks for all the help guys this rocks!!!
yanni

Is this on the stock ports, because if they have been ported, they affect the rate of spool. Also do you both have the same intercooler?

I have the older style greddy 3 row and I'm not sure what Bryan has

Also, my engine has about 2500 miles on it maybe. The intake and exhaust ports were done. Bryan told me that if the intake was done too big that will make it spool slower as well. Any other info? I guess 500rpms isn't that much but I'd like to hunt for it to make sure I'm not missing out on anything. I can see how weather, ports, intercooler, tuning all that could combine to 500 but it hurts me to think that his car is spooling faster when my setup is beautiful

Yanni

I've got the 50mm wastegate with the 1.1~1.4 spring that I am going to run without a boost controller. I was told by HKS that if the adjustment screw is back'd almost completely out, the wastegate would open around the 1.1 range and if it was tighten down completely it would open around the 1.4 or 1.6 range. Now my question is will the spring stay closed until whatever psi the spring is set @ by the adjustment screw or will it slowly open until it reach's that setting?

The wastegate will slowly open, it will crack open at a lower pressure and be fully open at your set pressure. That is why people use boost controllers, they apply pressure to the opposite side of the WG valve until the desired boost level is hit, then the WG gets the pressure and opens quickly.

Yeah you cant expect it to open right at the desired boost level and not have a little creep for a sec
it probably opens at 7 for 10 etc....

I'm really happy with the info I got from this thread. I guess I'll be satisfied with my 10psi@3600 and 15@4000 not too frigen shabby!!

What is everyone else doing with their 62-1 1.00 divided??