Still fighting sticking waste gate, how fif you fix it?


Active Member
I have been fighting waste gate issues forever. I am running a 66mm turbo with a .63 exh housing heavy duty regulator with threaded rod and an after market boost regulator (dont know the brand) Anyway I have always had problems from day one,either way too much boost or not enough could never get a middle ground.

When I was at the track I could only get the car to 19psi and it would barely creep to 20psi around the 1000 foot mark.The car ran 12.00 @116 I tuned the rod in and craked on the adjustable regulator and same boost. I then gave the car a few degrees of timing and got 11.54@116 still 19psi just barely creeping to 20.

I have had the wastegate off and reamed out the whole thinking this would keep it from sticking open. Since the being at the track I have had nothing but issues on the street. It will spike to 19psi in fist and slowly drop off by the time it hits 3rd it is at 10-12 psi. I took off the adjustable regulator and hooked it up tuner style. it would do the same thing but only spike to 15psi in first and drop off. I gave the rod a few turns and same result 15-16 psi.

I think I am gonna take my dp back off ream out another .005 and install a new waste gate from RJC.

I am out of ideas:confused:

What are your opinions?
Is the gate stuck when you remove the rod? With a 66 i dont see why you would be running less than 23-24psi. You may have too large a wastegate hole which will give the ex pressure greater MA to push the gate open as the rpm increases. Ive never found a need to run larger than a .110 hole with a stock style swing valve. The smaller the hole the less the boost fall off as rpm increases. Many over enlarge this hole and wonder why they have boost drop off problems. It needs to be a large hole to run the boost under 20psi but when your using a 66 on a 3.8l engine you arent typically looking to run boost under 20psi.
it's a TH down pipe, I was messing with it yesterday and I think I got it nailed down. With the rod threaded all the way in I could easily put it on the waste gate arm with my hand. I ended up cutting about a 1/4 inch off the rod to allow for more adjustment. I ran it down to where I had to put it on with pliers. I took it down the street and it was rock solid 16 psi all the way through 3rd. I pulled over and gave it 4 more turn in and now it is rock solid 18 psi and it absolutely blisters my drag radials through first and second :biggrin:

I still have room to go in and I think I may try to get 20psi just out of the rod and I was looking at the RJC boost controller to get it up from there. Either way I dont see much point going higher because at the moment I cant plant the 18 psi it is making now.

Thanks for the suggestions!