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How to set wastegate?

14K views 18 replies 5 participants last post by  silvergsx623 
#1 ·
Hey guys,

Is there any way to set the wastegate "open" pressure with the engine off?

Today, (after i filled up with 111 otc) i wanted to see how much boost the "10 psi" spring would get, i saw close to 20 psi... wtf? After i cleaned my pants out...:wtf:

I'm wanting to lower my boost for now till i get all of the bugs worked out.
If i connect a pressure source (air compressor) to the wastegate line... and set it to 10 psi... will the wastegate valve start to actuate? (if gate is set to said pressure?)

Its a 60mm external gate, 10 psi spring in, adjustment screw w/ lock nut on top.

Any help / ideas is greatly appreciated.
 
#2 ·
what wastegate do you have?

are you sure you are not talking about a Blow off valve?

From you question it seems you are confusing the two.
I personally do not know of a Wastegate that controlls pressure by sprngs AND adjsutment screw. In a Normal gate like Tial,you put the spring in that you want your lowest (base spring rate) to be, but even then its not a solid number. For expample, a Tial 44mm wastegate on a 63mm turbo with a silver 10psi spring might have an effective spring rate of 12psi, but on a 73mm turbo the exact same spring will yeild an effective spring rate of 16psi.
If you notice from HKS, their "springs" are given in range, there are variables suchs as manifold design, turbo, and engine effiency that all effect the acutal spring rate.
On my selt up, Tiall 44mm wastegate, the 1bar spring (14.7psi) will get me the lowest setting of 17.5 psi, if i wanted to get a lower base psi i would have to go with their 10 pound spring. You must remember that there are many factors and manufacture spring psi recommendation is just that, you must test and varify it to your individual application.

Post pic or exact brand/model of item in question. If you are getting 20psi effectively on a 10psi spring then try lower spring, say a 6psi spring and see if it lowers your effective psi. It should but if it does not then make sure your system is right, vac source is good, your wastegate line is routing correctly, make sure you in/out com/port is correct.
 
#3 ·
what wastegate do you have?

Post pic or exact brand/model of item in question. If you are getting 20psi effectively on a 10psi spring then try lower spring, say a 6psi spring and see if it lowers your effective psi. It should but if it does not then make sure your system is right, vac source is good, your wastegate line is routing correctly, make sure you in/out com/port is correct.
+1
 
#4 ·
Sounds like you have a HKS wastegate which do have a adjustment that can slightly change the spring pressure in the valve. You may have a hard time getting that 60mm monster to control boost down to 10psi but you need to make sure you have the lightest spring and the adjustment bolt as loose as it can get. Good luck but that wastegate wasn't really designed to control boost to 10 psi.
 
#8 ·
I stand corrected on the wastegate. After a quick search, the adjustment screw is only ment for minor adjustment, not a full 10psi.

To the original poster, you need a lower spring rate if you have already varify that your lines are all routed correctly among other things
 
#5 · (Edited)
Picture attached
http://i177.photobucket.com/albums/w230/silvergsx623/Turbo Swap/CIMG3588.jpg

Its a godspeed 60mm.

Yep I'm sure its a wastegate... because i just fabbed it up on my manifold. (my twin hks bovs are on my intercooler pipes)

Ive seen a few wg's with adjustment screws. (godspeed, turbonetics, etc..)

Gotcha, i didn't think about different size turbos affecting the psi the wg opens.
I went with the lowest spring rate. (came with 3 different springs, i went with the easiest one to crush with my hands)

boost source is coming right off of the charge pipe connected ot the outlet of the turbo. (don't have a pic...)


Thanks for the help so far guys!
 
#6 ·
There is only 1 nipple on this wastegate. so I assume that is the boos source.

If i could get the boost between 10-15 psi I could live with that, think thats possible on a 60mm?
 
#9 ·
Should be the where the boost source goes, you have to look up the manufacture diagram



My question is... if i hook up my air compressor to the wg, will it actuate at a given psi?

I'm sure the exhaust pressure would make it open earlier/faster than no pressure...

Yes, pressure is pressure if you are using it to varify the opening/closing of the wategate.


here is my advise. ditch that wastegate, when I bought my car it had a knockoff gate, they leak! from my experience a quality gate such has tial, greddy, HKS, has dual ports (top and side) which is able to control boost to a lower PSI.
If you already put in the weakest spring and losen up your adjustmet bolt all the way then your SOL, thats all she has got in her with your particular setup. Someone correct me if I am wrong but the 60mm size of your gate does not have much to do with your problem if everything else I mentioned checks out, instead it has to do with the quality/ or lack of quality gate controller you have.
A wastegate will open and close at its lowest setting without any form of boost controller, take all form of boost controller off and you will know what your lowest/base boost setting is.
 
#7 ·
My question is... if i hook up my air compressor to the wg, will it actuate at a given psi?

I'm sure the exhaust pressure would make it open earlier/faster than no pressure...
 
#10 · (Edited)
Ok, Thanks Tony!

My boost controller is disconnected, i have a vacuum line from the nipple on my pipe, 2 feet of hose to the nipple on the WG.
I will see if i can back the adjustment screw all the way off.

I figured a $200 wastegate would be fine.. how hard is it to fuck up a vacuum actuated valve? lol :scratch:

Thank you for all the ideas and help. I greatly appreciate it.
I'll tinker with it tomorrow and report back.

Thanks again!
 
#11 ·
Ok, Thanks Tony!



I figured a $200 wastegate would be fine.. how hard is it to fuck up a vacuum actuated valve? lol :scratch:


Thanks again!
$200 fuck that, return it and buy a new tial for 350 or find a used on in the forsale section. Its not the vaccume stuff that is wrong, its just the lack of quality. I had the HKS "Style" gate and had the same problem, im now running the Tial 44mm.

Good luck.
 
#12 ·
LOL, gotcha.

Thanks!
 
#13 ·
Well i pulled the wastegate off today and...
I found that it has 2 ports.. top port where i had the boost source, side port that was plugged ? :scratch: so... the WG would have never opened because of the vacuum would be impossible to over come.

Picture attached of plugged port.


i uncapped the port so it is open to atmosphere.
I have boost pressure to the top port.
My question is now... will this work correctly?
 
#14 ·
Or do i need boost going to both ports?
 
#15 ·
Ok... after a bit of reading i think i understand. Please confirm or correct (if I'm wrong)

The top port on the waste gate can be left open.
The side port will need to have the boost source.

Like so?:scratch:
 
#17 ·
ok cool, Thanks
 
#18 · (Edited)


Line from pressure source is "T" off, one goes to the side of the wastegate and the other to the In port of your boost controller, the out from the boost controllr goes to your top wastegate port. You do not need to "T" or vent the line coming out of the boost controller that goes to the top wastegate port.
 
#19 ·
I guess it helps if you hook the wastegate up properly!

Was able to test it today with the boost source moved. could only build 3 psi and i could hear the wg open. so seems like it was successful.
Tomorrow i'll swap the 10 psi spring in and see what that gives me.

Thanks for all the help guys!
 
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