Hallman manual Boost Controller is very common in performance cars. I just talked to some guys in the tuning business, and they are using this product for 4 cyl turbo cars like Subaro, Evo and MMC Eclipse, all running under 10 sec and over 140 miles/hrs on the 1/4 mile
The controller I have now, is not mounted with a stronger spring (used for 30+ psi), so now we have to get one and try again
The main difference when driving with this manual controller, was this very stable boost from this small turbine, which is quite a big difference from the ECU controlled Amal valve.

But still, it would be very useful to learn from those of you that have experience with the Hallman Boost Controller in a YB engine....