electronic boost controller for ALH?

hey, been a long time!

i have a dawes device on my ALH, but i find its not consistent. i have boost set to 22psi. most of the time its ok, boost will spike to 22 and stay there pinned. but sometimes it will overboost to 28-29 slowly. i replaced all hoses seemed to help, played with different springs but its not 100%.

i will add its over 10 years old probably. maybe there is something updated or newer i can try?

edit: vnt 17/22 turbo

Could you just be hitting the flow limits of the hot side? It is a hybrid. Dawes devices are pretty much fool proof from what I understand.

There could be crud in your N75 valve. Crud will cause the vacuum not to bleed off. Do you have VCDS? Logging the N75% will tell you a lot, as well as boost: actual vs. requested.

stock one is good? i think i replaced my stock one for the pd130/150 a long time ago before dawes, i forget...

are there better N75's to get these days?

How much power are you making? I had boost creep with my 17/22 around the 200hp neighborhood...

ya around 200hp

another thing that happens is when shifting FAST 3-4 or 4-5, the psi drops to about 5psi and it hangs there for a good 1.5s and once it shoots up thats when it over boosts

so weird because it only happens 1/10 times, i replaced n75 today with a new one and no difference.

what does that leave, all the vacuum hoses and the rod on the turbo?

Only so much farts you can force through a 45ish mm turbine exducer

either add a wastegate (the vane control maps won't care one bit so long as it's sprung to open around requested max boost. You will lose some snap-response though, as it'll reduce the large EMP spike before vane opening)
or fit a better turbo

ETA: on the intermittent weak response on WOT shifts, the vanes are going full-open to nearly closed in order to build boost again, when it has intermittent sluggish response like that it is just the vanes getting hung up open.

you may want to try adjusting the stop screw 1/4-1/2 turn up so the actuator can't pull the mechanism completely closed.. if it's pulling it ever so slightly too far closed, it'' give it some intermittent lag between shifts..

might also help to temporarily tee in a vacuum gauge to the line running to the actuator. this will let you see if there's a delay in vacuum being applied and help you isolate whether it's a control issue or mechanical issue..

I've also seen some issues with the smoke map where they won't fuel heavily immediately after a shift until maf readings start to come up