GTX wastegate issue

[3Katz]

I bought this turbo (Garrett GTX3582 gen2) brand new with porting and a 39 flapper already done. It's probably done about 1000k and a few dyno sessions. I bought this model as I expected the lag to be not much worse than the stock GT3582. I was surprised to find out it was quite a bit laggier but just lived with it. Due to other issues I've pulled the turbo off and found that the flapper won't fully close 9 times out of 10. It jams open enough to fit your pinky finger in. This would be the lag issue, here's a pic of it jammed open (with 0 pressure in the actuator)

 

 

What's my best option from here? Is there a larger flapper I could have done? Modify the height of the flapper arm? Give the leading edge of the flapper a touch with a stone? This is a pic with some air in the actuator to open the valve a little and this is the edge I was considering giving a bit of a touch up.... (just the flapper not the seat)

 

 

Better ideas? Best option?

[JETURBO]

Setting up an actuator/bracket/angle can be tedious especially with bigger sized port & flaps so if you’ve got a flap that’s catching 9 times out of 10 it might not necessarily be the actual flap or port edge but the way the actuator arm is pushing/pulling in motion and as you can see from your top picture the arm of the flapper is right hand down, left hand up in regards to tension. 
 

This can lead to excessive flapper arm boar wear and cause “Wiggles” in the arm activation. 
 

If you play with housing rotation, bracket location, actuator can seating you can work a way for the flapper arm to be less pulled/pushed off kilter and operate on a inset outset method which conducts less angled pressure to flapper arm. 
 

Failing that and assuming the arm boar has excess wear now you might need to take a bevel edge approach to the port OD

[k31th]

now that's an engineer ^^

[3Katz]

57 minutes ago, JETURBO said:

Setting up an actuator/bracket/angle can be tedious especially with bigger sized port & flaps so if you’ve got a flap that’s catching 9 times out of 10 it might not necessarily be the actual flap or port edge but the way the actuator arm is pushing/pulling in motion and as you can see from your top picture the arm of the flapper is right hand down, left hand up in regards to tension. 
 

This can lead to excessive flapper arm boar wear and cause “Wiggles” in the arm activation. 
 

If you play with housing rotation, bracket location, actuator can seating you can work a way for the flapper arm to be less pulled/pushed off kilter and operate on a inset outset method which conducts less angled pressure to flapper arm. 
 

Failing that and assuming the arm boar has excess wear now you might need to take a bevel edge approach to the port OD

 

Thanks Aaron, that makes sense. By operate on an inset/outset method do you mean to try to bring the rod to more of a 90deg angle as per the below pic, or to have no sideways tension on the rod ie disconnected from the actuator arm it should freely pretty much line up by itself. Do you recommend touching up the port with a beveled edge rather than the flapper if it comes to that? Fortunately it han't done much work so any wear from me having it set up incorrectly will be minimal.

Thanks again 👍

 

[JETURBO]

Spot on with your mark up and what I’m trying to project !

 

There is no detriment to giving the port edge a chamfer in any case and does help with flap re seating 

 

obviously in some circumstances you can’t always get this beautiful dead on angle and this is where the additional tension can cause issues. Again we want pre load on the clevis to arm locator but be careful to not overshoot this as it’s very fine line when trying to control a lower boost target on a big turbo/big actuator and for anyone playing along about 1/4 is more than enough on a 12psi Genuine Garrett actuator to give 50/50 scope in the WGDC in the tune. 

[3Katz]

Excellent I'll play around with the setup and get it lined up better.

I see.... this explains why we had trouble controlling boost. I had way too much preload on the arm, I won't say how much on a public forum lol. When you say 1/4 Aaron do you mean 1/4 of the hole on the rod end or 1/4 turn on the rod adjustment?

[Puffwagon]

30 minutes ago, 3Katz said:

I won't say how much on a public forum lol

 

Haha don't worry mate, we've all made mistakes! Rule of thumb is 2mm but throw that out the window. How much preload you need depends on a multitude of factors, so you can't just say this much or that much...but...in this scenario it's better to be looser than tighter if you had to pick one, and looser means a quarter of a turn past touching. A bees dick, fark all, next to none, barely in, just the tip. Make the flap touch the seat and preload it just a whisker. Yes there are exceptions but ain't nobody got time for a novel.

 

In future set it up on the bench, open and close it a bunch of times with air while spinning the flap slightly to make sure the farker doesn't bind up. Also don't stick your dick in it, no matter how tempting, the flapper closes quite quickly when the air is disconnected

[3Katz]

Haha! I'll try to resist the temptation.  Awesome, no worries. Thanks all, appreciate your help 👌