15 psi wastegate spring, but i boosted to 22psi

[hottscennessey]

OK, looks like i'm making progress.. It appears to me that my internally gated turbo may have conflicts with my downpipe. Does anyone else run the SP61GT with a cooleze?? I dont know anyone that does. I think that either the lever which attaches to the actuator arm is hitting the bottom flange of the cooleze (it sticks out, easy fix with a dremel). OR The wastegate door is hitting inside the downpipe. The second option would not be fun, but could be resolved with a hammer and a torch. PLEASEEE POST IF YOU RUN THIS SETUP..

 

[hottscennessey]

okay.. i connected an air compressor to the wastegate as IJ told me to. I found that my wastegate barely cracks open at 20psi.. WTF? I found that the wastegate did not fully open until 35psi. That is not normal wastegate operation, is it?! If this thing is supposed to have a 15psi spring, and doesnt even begin to move until around 18 or so psi, and even then if its barely open.. this has to be the problem? right?

*awaits IJ's knowlege*


As regaurds to my previous post, i do not think the cooleze downpipe is a problem at all, BUT, if i overlooked something please inform me.

 

[IJ.]

What sort of gate is it Hot?

 

[dbsupra90]

okay.. i connected an air compressor to the wastegate as IJ told me to. I found that my wastegate barely cracks open at 20psi.. WTF? I found that the wastegate did not fully open until 35psi. That is not normal wastegate operation, is it?! If this thing is supposed to have a 15psi spring, and doesnt even begin to move until around 18 or so psi, and even then if its barely open.. this has to be the problem? right?

*awaits IJ's knowlege*


As regaurds to my previous post, i do not think the cooleze downpipe is a problem at all, BUT, if i overlooked something please inform me.

uh, no that isnt good. esp on an int gate.
by design, these should start to open before the preset boost amount. the reason why is creep. if the valve is small it needs to open a little early or it will overshoot boost. on an ext gate, it doesnt need to open until the desired boost level since it can flow so much more due to size. smaller the valve, the lesser the flow, the sooner it will need to open to get the exh gas out so it wont creep. there is a little more to it than that, such as turbo size, a/r, etc like IJ was talking about.
you say it has an adjustment on it. play around w/ that and see if you can get it to open any sooner.

 

[hottscennessey]

thanks for the quick reply guys..

I dont know what you mean my what sort.. its just an internal WG that came on the SP61GT.

Would i need to shorten or legnthen the actuator arm to fix this problem?

 

[IJ.]

Can you hear a leak?

I normally preload the rod by half a hole to get the desired opening anymore and you run the risk of creep.

 

[hottscennessey]

no, no leaks from the actuator, It'll hold boost all day.

and.. can you run that second part by me one more time. lol.

 

[IJ.]

Unbolt the actuator.

Turn the adjuster rod so when the mounting holes are lined up the hole in the end of the rod is halfway past the pin.

When you bolt the actuator down this will slightly preload the WG Spring.

 

[hottscennessey]

haha thanks for breaking it down IJ. My turbo is sitll under warranty, so if all else fails i can just call them up and tell them my problem. I apprecaite all the help!

 

[IJ.]

No probs at all Hot!

Might be an idea to see what they say!

Where are you picking up the boost from to open the gate?

 

[hottscennessey]

Yea, I think I'll give them a ringer tomorrow.

I'm getting boost from an air compressor right now, when its running its connected from the compressor outlet to the wastegate.

 

[IJ.]

ok can't get better than that Hot!

It's either bad creep

faulty/misslabled actuator

too much preload!

What AR is the turbine housing?

 

[hottscennessey]

I have no clue whatsoever what the A/R is on this turbo, i've wondered this for awhile.

 

[IJ.]

If it's a tight AR it may just be creep!

Not stamped on the housing anywhere?

 

[hottscennessey]

nah, i looked, but nothing i could see. I'll have to ask SP tomorrow.

If it is boost creep then its pretty religious. Third gear and up has major issues with overboosting.

 

[IJ.]

Yep creep will do the exact same thing time and again until something is changed!

 

[oldschool85]

you have a bad wastegate probably. Reason why theres more creep from higher gears is due to more load that is applied.

Just switch out the wastegate and make sure it doesnt hit your downpipe and you should be fine. malloynx had this problem as well i believe.

charlie

 

[hottscennessey]

Thanks for chiming on oldchool85, was this on malloy's SP61GT?

 

[arz]

i read that boost leaks could cause boost creep.. how?

You obviously figured out how boost leaks could cause creep and you nailed down the fact that you dont have a leak between the WG actuator and manifold pressure.

What I think you are over looking, or not getting from IJ is the fact that the turbine or compressor housing bolts that fasten the housings to the bearing/center section of the turbo can inadvertantly/easily be rotated (possibly during install/fitment). When you have an integral WG this rotational relation has a lot to do with how much tension/preload is placed on the WG door/rod.

IJ can you post pictures of this hole to pin relation, I know exactly what you are talking about but it took me a few reads to figure it out. A picture is worth a thou...

I will give a stab at a verbal picture,

Disconnect the end of the rod from the WG "actuator door pivot arm". Adjust the arm with no tension on it so that you can see half the pin thru the hole. Tighten it all up (all the other loose bolts, "not the actuator arm") and re-install the rod back on the pin (IE: pull/stretch/preload the WG spring) and this should be the proper tension/prelaod on the WG spring.

 

[hottscennessey]

I understand what you're saying arz. Unfortunatey, i cannot disconnect the actuator arm from the "actuator door pivot arm". it has some sort of.. kinda like a pin/clamp thing which keeps the rod from sliding off the pin on the door's lever. I'm gonna post some pictures of it later, i believe i would have to legnthen the actuator arm to fix the creep problem.