Just in case you are feeling adventurous, I'll quickly outline Sparky's high-mileage MHI VIII actuator cure as follows: Disconnect the vacuum hose from the WGA cannister. Remove entire actuator from turbo by popping out the cotter pin and prying the turnbuckle/actuator rod away from the flapper valve's pivot arm. Remove the two bolts that fasten the actuator bracket to the compressor housing.

Once you have the WGA up on your work bench, proceed to unscrew and remove the turnbuckle as well as its backup nut from thethreaded end of actuator rod. Next, secure the actuator rod by clamping the actuator rod itself between the jaws of your bench vise. Once secured, proceed to cut 3-4 threads off the threaded tip of the actuator rod(I use a hacksaw). Three threads equates to approximately 3/8". Reinstall the turnbuckle WITHOUT the backup nut. Tighten the turnbuckle down all the way until it bottoms out on the actuator rod. Remount the modified actuator assembly onto your turbo.

Note: You may need to back the turnbuckle off ever so slightly so that the hole in the turnbuckle's flat properly aligns with the peg on the flapper valve's pivot arm.

 

4th gear on a 5-spd., on level ground or even better, on a slight uphill grade, is a good gear for testing boost levels in. I am not liking the slight taper though.

When you say, full boost, is that 19-20 PSI? Optimally preloaded, you should be seeing 19# in 4th by 3000-3200ish given an inconel wheeled turbine in a 10.5cm housing. So, all in all, 19# by 3500 is not too shabby.

 

I'll try to log it in 4th tonight and see how I do. Thanks for the advice.

Any thoughts on just moving to a TurboSmart 14#?

 

So, I haven't cut the rod, but I removed the nut and have the turnbuckle all the way down.

Did a 4th gear pull this morning.

Logged max boost of 19psi at 3656rpm.

 

That's wrong. That was 3rd gear.

And now to look at the data.

The other day I hit 17.10 psi at 3687. Today I hit 17.58 at 3531.

Looks like progress to me.

I'll try to get a 4th gear put to verifty that I'm hitting 20.

 

Just did a quick pull. Granted it's 20 degrees warmer than it was this morning. 18psi at 3531.

Might just need a little more WGA adjustment. I'll probably end up cutting it until I can get an upgraded actuator.