One of the lads coming to our club meet last night had a problem with his ERST...

Just accelerating normally and all of a sudden lost boost and pulled over.
It looked like the car had overboosted massively- It had blown the top boost hose off, blown the amal valve apart and distorted the pace alloy intercooler

What would cause this? Anyone?

The car is chipped with a -31 and should peak at about 17psi before dropping to 15...

 

Amal Valves can come apart and then if they do you will have no boost control.
So I think your mates engine has seen a bit more than peak 17 psi.
Worst case scenario is engine damage. Best case it just killed the intercooler and popped off the boost hose before coursing dame to the engine.

Ollie

 

I thought amal valves were failsafe i.e. they just divert the air to the airbox and dont allow any boost?

We were thinking perhaps a failed actuator diaphragm (sp?), so the wastegate didnt open and the boost kept on rising?