15 PSI Mitsu Actuator

[Maxtor]

Still working on stabilizing my boost - thought I would try the upgrade Mitsu 15 PSI actuator on my 20g, 12cm2 mitsu turbo with internal wastegate.

Once I received it, I thought the actuator seemed VERY stiff compared to the 10PSI, almost impossible to move the rod by hand.

Installed it anyway - gradually took it to 22 PSI on my gauge (ultimate set to 17PSI) and boost was still climbing. Came home, took it off and sent it back as defective.

Ordered a new one, and the rod feels the same - difficult or impossible to move by hand. Haven't installed it yet. What am I missing here? A 15 PSI actuator should open with approx. 15 PSI of boost - right? Anyone messed with this thing?

 

[kwick6]

The ultimate is set up for boost control using a stock spring.
If you change the spring, changes will have to be made to the chip.
Or you can get a seperate boost controller all together.
I have been thinking about the Blitz, as I have heard they work well.
What kind of problems were you having with boost control that made you want a bigger spring? When I had my ultimate boost control was solid.

Later,
Scott

 

[JSM]

unhook the boost solenoid, and go for a drive.

it is the dual wire connector mounted on top of turbo.

you should see ~15 with it unhooked.

with it hooked up, you will need to find somebody to modify the WG tables in the chip, as the ultimate is not designed for the heavier actuator. The 50# chip is though (FYI).

Anytime you change WG pieces, except to change the chip. Computer can't read your mind.

 

[Maxtor]

Yeah - I know the Ultimate is set up for the stock spring. I have been working on the WG tables already in programmer, I was hoping the stiffer spring would allow more solid boost control along with the changes I have been making in the chip. Currently I am fluctuating as much as 3-4 PSI at WOT in 3rd gear. I know most of it is due to the Mitsu design, but I guess I like the challenge or something. My goal is to have 1-2 PSI fluctuation using the stock design.

BTW - I did unhook the actuator and it didn't open at 15PSI. That's why I was confused. Should have opened and didn't. Thought I was losing my mind, now I'm sure I did.

 

[JSM]

Ok, wasn't sure how much background you had.

How is the WG arm? is it stiff to move? If it drags or sticks, could be 1 idea.

Anybody that owns a syty has lost their mind, join the crowd.

 

[smeagol]

Go to mechanical control, get the base boost dialed in.

I'd first adjust the rod to near stock specs (7/8 overlap etc), and you should have ~15psi base. If you don't have decent control with purely base boost, mechanical setup, you need to start troubleshooting mechanical stuff (exhaust leak, boost/intercooler leak etc). Then move on to the chip stuff. I'd start out in open loop boost control mode. It may actually work out better for many trucks.

 

[Maxtor]

Thanks, guys. I'll get it running right with mechanical control (15psi base) before going back to the chip. I'll also look into open loop - thanks Brian.

I don't think a donkey and ten horses could pull open that last actuator I had, I'm not sure what was wrong with that thing.

Thanks again.