The way I had my old system setup was to use a simple Hobbs switch set to close at 60 psi, the Hobbs was plumbed inline before the nozzles.
1) If the pressure was 60 psi the hobbs would close and I would get full boost (24 PSI).
2) If the pressure was less than 60 psi the Hobbs would not close and my signal to the boost controller would be cut giving me base boost (15 psi).
This way you avoid getting into boost until the alky has pressurized, and if for some reason there was a pump failure while your in boost, the boost would be cut back to base boost (hopefully in time).
All you need is a high pressure hobbs switch and a GM boost solenoid.
BTW: I ran straight methanol for 1 year without hurting the switch.
Mark L
03 Cobra
1) If the pressure was 60 psi the hobbs would close and I would get full boost (24 PSI).
2) If the pressure was less than 60 psi the Hobbs would not close and my signal to the boost controller would be cut giving me base boost (15 psi).
This way you avoid getting into boost until the alky has pressurized, and if for some reason there was a pump failure while your in boost, the boost would be cut back to base boost (hopefully in time).
All you need is a high pressure hobbs switch and a GM boost solenoid.
BTW: I ran straight methanol for 1 year without hurting the switch.
Mark L
03 Cobra
