38r surging bad under load

[300000 and counting]

A couple weeks ago I pulled a 315 new holland square baler (3000lbs) on a 28' gooseneck trailer about 200 miles one way. At 65mph 1900rpm, 950*egt, 15psi of boost, pulling any steep hill my 38r surges like crazy it's so Loud I almost wanna stop so I don't hear it, this can't be good for the turbo or the truck, so is there a problem with my turbo or is this normal for a 38r.

Also if I get up to 70mph, 2100rpm, 1050*egt, it won't start surging until 20psi but it surges just as bad

Any help would be great

Extra info: I have bellowed up-pipes, ebpv completely deleted, 38r has 14,000 miles on it, surges with or without my water meth on, I run -20 blue windshield washer fluid,

It didnt surge at any rpm on our way home, I got up to 20psi once on the way home but mostly ran below 15psi the whole way

My phone won't record sound and the video is kinda crappy but it gets the point acrossed.

http://i1282.photobucket.com/albums...26399A6-9290-00000B99DE96C203_zps4ae87253.mp4

 

[dynoproventuner]

You may have tried this already but I think the first thing I would do is check and make sure you do not have any boost leaks.

 

[TARM]

That would be my first guess is you have a boost leak as it seems to happen once you get up to a certain boost. A slit or leak that opens up under pressure.

Next would be the tuning. I had tunes that would cause such bad surging and then tunes that had none. How the fuel is brought in seems to also make a difference. But if this is something that just recently started that did not happen under the same circumstances before I would be looking at a leak somewhere. Make a boost leak detector you can clamp tight and hook some pressurized air to it.

 

[300000 and counting]

These are the first times I have towed on the highway since I did the 38r, but on county roads it never has surged. I'll pick up a pvc cap tomorrow and do a leak test on the system and if there's no leaks I'll look into better tunes.

Also I already check my turbo and its not dusted and all my boost and map sensor lines are hooked up and are in good condition.