Ok ill remove the BC to get a baseline, and as for the active pressure, I currently have it set to 10psi.

Why ditch the hose clamps for zipties? Wouldn't the clamps be able to hold pressure better? Or is that the point.

 

Ok, if you want, you can try 5psi and 0% duty and gain. That should make it run wastegate only. Then slowly increase the duty until you see an even increase in boost. Then you can start increasing gain to give it some authority to maintain boost levels.

Personally however, I would ditch it and run boost control from the MS.

 

Those are junk, just FYI. I had issues with AC Delco ones. When I say OEM I mean OEM straight from Chevy. IDK why all the part store ones I tried sucked, but they all did in various ways. But pull coils off a Chevy truck in the junk yard with 300k miles on it and the coils work perfectly.

 

Ok, I bypassed my BC, and I'm still peaking to 19-20psi. I'm starting to think the wastegate supplied with the turbo was fitted with a large boost actuator rather than a medium one?

I've attached a couple of datalogs. First one was a 3rd pull. Second one a 3rd to 4th gear pull.

 

Edit: nvm I was confused. I do have a medium boost actuator, but why am I seeing it at full 20psi?

Shouldn't I be seeing 10-11psi? Directly from turbo housing to wg.

Edit: Looked more into it, I guess I misunderstood the wastegate pressures. The wastegate cracks open at 10psi, and at 20psi, its fully open and the turbo is no longer able to make boost. I thought it was the spring was 10psi, and with a boost controller it could do 20psi.

The more you know.

 

I recently was seeing 16psi on a small wastegate spring 6258, by the time I fixed the preload on the wastegate rod, I was making 5 to red line. The rear nut was a thread or two off the end of the rod.

 

From my understanding. It's not possible to run lower boost pressures if I'm currently using the medium boost actuator which has a spring pressure of 20psi~, correct? Unless you have a twin port wg. And the reason my MAP was all over the place was because my BC couldn't vent enough pressure and got overwhelmed. Or is there a way to mess with the preload to get a lower psi cap?

I got small boost wastegate so hopefully this should fix my issues.

Car runs fine at 20psi, but frankly as a drift car, 20psi is WAAAAYY to much boost. Want to run 14psi in drift mode, then 20psi in full kill mode.

 

On the medium can, you should be able to run about 10psi minimum. The cans are roughly 5, 10, and 15psi. Anything higher than those number is more preload or more ebc duty, or some other problem.

 

According to the chart, I thought preload would only adjust when the WG would crack open and then full stroke would be whatever the spring is rated at, which the medium can is 20psi.

I have my BC totally disconnected, and I'm hitting 20psi. MAP curve is now smooth and doesn't fluctuate.

But what you're saying is if I mess with the preload, I can make it so the full stroke is 10psi min?