BMW E28 turbo M30 build- Car is boost creeping

[Nnobile]

hello everyone. I am a bit new to this forum and still learning about megaquirt. I recenlty got my 1988 bmw e28 turbo build running a few weeks ago. I bought the engine, megasuirt unit, harness etc used out of another e28 that this set up ran great on. Did the swap myself over the past few months. Noticed car boost creeping upon first few runs at about 4-5k rpms fuel cut kicking in, wastegate spring is set to 15lbs, boost controller set to 219kpa. boost readings hitting 20-25lbs. wastegate is a tial mvr-44mm, turbo is a precision 6266mm. found base timing to be off by 10 degrees its now at 94 bdc instead of 84. 60-2 trigger wheel teeth. took car for test drive again hit 25lbs on a pull and blew welds on intake. here i am 2 weeks later just got intake manifold rewelded. running car on just wastegate spring pressure assuming something was wrong with boost control. car is still boost creeping badly and just seems to be overall running a bit rough. i am also running on open downpipe not sure if no back pressure from exhaust system could be doing this but i am convinced there is something else going on im over looking, maybe i even need 2nd wastegate? any input or suggesstions are greatly appreciated thanks so much. attatched is data log from today doing a 3rd gear pull car overboostin to 17lbs at 4500. the current tune and picture of engine bay. i do have air filter over turbo inlet

[hybrid]

Surely either the wastegate is not working, or it's not big enough. Have you tested it with some pressure from an air compressor etc?

[Nnobile]

I havent tested it with a compressor what is best way to go about that? I assume a vacuum pump set to 15lbs on spring pressure hooked up to the line could test it also?

[hybrid]

Vacuum is no good - you need positive pressure to open the wastegate.
By the way, where's the wastegate located?

[Nnobile]

Right under turbo you can see it sticking out in the picture of the bay. Hand pump couldnt be pumped up to 15lbs? I do have an air compresor also what would be best way to use that?

[hybrid]

Well a vacuum pump generates a vacuum, not a positive pressure.
Unless you have one that can do both?

I'd be surprised if it would do 15psi though.
You could try a bicycle pump if you can get it to seal properly. It would easily do the pressure.

With a compressor you'd need to have a pressure regulator and set it low enough. Then just use a blower attachment on the wastegate hose.