when the airflow rises due to unrestricted air you have more pressure upon the wastegate in the exhaust (back pressure). there for your actual exaust pressure is pushing the gate open not the boost reference. a boost controller should fix your problem by pressing down. if not a stronger spring will. what size is the exhaust housing of the turbo. and what size gate are you running. a smaller gate flows less and should give more pressure.

 

Turbo has a 1.08 AR and is t-6. My wastegate is huge it measures 2.5 inches and I cant change it without modifying my kit which probably won't happen since I just got it back. I tried a turbo smart controller and didn't work and now I use a manual one that relieves pressure and gives more boost. I know the turbo will make 30lbs so it has to be something else.

 

Try a stronger spring. My controller is hooked to the top so that it provides extra pressure to keep the gate closed.

 

my controller was hooked up to top and side of wastegate, it held boost better this way.

 

There is a spot on the top that I might be able to hook up to. Will try again later when I get truck fixed. Just broke 1350 rear yoke and ujoints at track today. Hit 7.11 @ 101 in 6000 DA and not hooking. Going to install caltracs and get driveline fixed then go back and get solid 6s in the 1/8. Once I turn up the boost and get bugs worked out I want to see a 9 sec pass in san antonio.

 

what about this? you can use a diaphram style low pressure air regulator that wayn you dont have to worry about a boost spike as like a regulator ball and spring type.

the small 1/16 hole in the nipple will help bleed off air when not in boost and it will let the regulator flow a little while in boost.

what do you think about that? i am thinking about trying it out on my truck. i have a 3lb spring, so i was going to run the hose to the top of the WG and have the regulator in the truck under the stereo

 

i think its all good besides the hole part. i don't think it will help anything. if anything, under high boost/exhaust pressure it will worsen boost loss/pressure. the exhaust seem to to be always higher than boost pressure in turbo systems ( in general). so it helps drive the gate open. so you need mad pressure to hold it closed to make big boost numbers with good flowing heads/intake/cam.

 

The gate being that big 2.5 diameter is not helping.Seems to me there is more force because of the surface area .Sounds like you got a 60mm wg. maybe try a 44 or somthin smaller.You could possible setup a partial block off plate if you wanted to go the cheap route.