MKTurbo Black Friday 2025 Sales Thread
So I'm thinking this is a wastegate actuator issue. The only way I have been even close to getting near my target in 2nd gear and at my target in 3rd is by adding a **** ton of preload. Even then boost falls off up top. With this much preload I'll over boost in 5th.
With normal preload I can only spool the turbo up properly in 4th and 5th. So I'm thinking it might be that time again when I go back to the kinugawa actuator.
For my closed loop settings I have tried using both the basic slider and PID. I'm not a newb when it comes to closed loop. I really think it's the actuator where it is lacking. I can run 10psi all day just fine nice and flat. However 14-15 psi is no dice. I might have a bad actuator or they could all be this way. Who knows.
With normal preload I can only spool the turbo up properly in 4th and 5th. So I'm thinking it might be that time again when I go back to the kinugawa actuator.
For my closed loop settings I have tried using both the basic slider and PID. I'm not a newb when it comes to closed loop. I really think it's the actuator where it is lacking. I can run 10psi all day just fine nice and flat. However 14-15 psi is no dice. I might have a bad actuator or they could all be this way. Who knows.
So what I do is I screw the actuator until it easily slides on to the wastegate arm. Then I add 6 half turns to that for preload. That's how I've always done it.
Thread Starter
Joined: May 2006
Posts: 15,235
Total Cats: 1,700
From: Charleston SC
Get the megasquirt in and running for a while before you install the turbo. Just so you have time to familiarize yourself with it and learn to tune some without blowing up your motor due to something stupid.
Thread Starter
Joined: May 2006
Posts: 15,235
Total Cats: 1,700
From: Charleston SC
For reference of what I told bahurd in our pm's. I basically just rotated the front compressor housing to put it where I wanted it and bolted the wastegate back up. I did not adjust the preload at all from how it came out of the box. I also have not ran any more boost then the stock wastegate so far. One of these days when I get done with the rest of the GB setups I will go back and finish playing with the test car. It is more of in my limited time available getting customers setups done and out to them was a bit higher priority to messing with my setup on my test car.
So I was comparing my old 2560 actuator the 8psi on to the 7psi on the China charger and I noticed there is no wheep hole in the canister. When I bench tested the 8psi to the 7psi I noticed that the 7psi will just keep pressurizing with out bleeding air where as the 8psi actuator will bleed air as it is pressurized. I noticed a wheel hole on my kinugawa actuator as well that I had on my old setup. So anyone think it just might need a wheel hole? Does anyone else's Chinacharger have a hole and mine just didn't get drilled at the factory.
I'll check mine tonight, don't recall. It would seem the spring would be the main means of controlling the actuator working or not. Weep hole is for condensation?? Question cause I'm not sure...
Thread Starter
Joined: May 2006
Posts: 15,235
Total Cats: 1,700
From: Charleston SC
So I was comparing my old 2560 actuator the 8psi on to the 7psi on the China charger and I noticed there is no wheep hole in the canister. When I bench tested the 8psi to the 7psi I noticed that the 7psi will just keep pressurizing with out bleeding air where as the 8psi actuator will bleed air as it is pressurized. I noticed a wheel hole on my kinugawa actuator as well that I had on my old setup. So anyone think it just might need a wheel hole? Does anyone else's Chinacharger have a hole and mine just didn't get drilled at the factory.
Scotty,
Check the puck on the actuator to make sure the edge of it doesn't catch on the hole you opened up, not allowing it to close flush. I've seen it before. That's why the holes are smaller than the pucks on the flappers by a good bit or they are D-shaped.
Check the puck on the actuator to make sure the edge of it doesn't catch on the hole you opened up, not allowing it to close flush. I've seen it before. That's why the holes are smaller than the pucks on the flappers by a good bit or they are D-shaped.
So an Update. I got the car to run around 11-12psi 1-2nd and 12-13 3rd-5th I think this might just be as good as is gets. I am re configuring my timing table a little bit now and need to let the car cool. Im pretty sure I dont have any hair left on my right calf. As far as im concerned(others may get better results) I need a new actuator. I drilled a weep hole and it did help some what but not a significant as I would have liked.
Would I recommend other do it? No not worth it.
I will hopefully soon purchase a different actuator. Im curious to see what others results are.
Would I recommend other do it? No not worth it.
I will hopefully soon purchase a different actuator. Im curious to see what others results are.







