250cc turbo - part throttle boost
 

I have a 250cc single cylinder engine in a mini buggy with a rhb31/vz21 turbo on it. Microsquirt controlling fuel and spark, intercooler, BOV, 1 litre plenum.

I'm running the wg at 9psi with some testing at 13psi. Spools almost instantly.

Problem is it boosts to 4-5 psi with very little throttle - around 20% TPS, just cruising around, I'm in boost. This may be the nature of a single cylinder engine but I'd like to find a way to eliminate boost at these part throttle situations. It's heat soaking my intercooler and really not necessary.

I'm thinking of either relieving the pressure via the BOV or the wastegate with some sort of mechanical solution using the throttle location. My first thought was to valve the intake reference vacuum line to the BOV at part throttle conditions and let the boost pressure open it up and escape. The valve would then trigger at a determined throttle position to return to normal operation.

Any other solutions out there that I've missed?

Thanks!