Technical Help Please!

[Rob Plummer]

I'm running a Mitsubishi Lancer Evo1 and have just started to tweak it a little.

Runs 10psi boost standard, but I've put a decent exhaust, uprated fuel pump and fancy plugs in.

Trying to get to 15psi, but it won't go higher than 12.5psi. Even disconnected the pipe going to the actuator, so it should run unlimited boost - guess what? 12.5psi.

Even replaced the actuator - guess what? 12.5psi!

Any ideas why it won't go higher anyone?

[Rob Plummer]

Thanks for all responses guys.

I know the turbo should be able to produce 15psi, cos I know other people with Evo 1,2,3 running 15psi.

I've disconnected the electronic boost controller, which is the only limit on allowed boost - it's inline between turbo and actuator and is effectively an electronic bleed valve.

Wastegate opens at 12.5psi whether the actuator is connected or not.

Seems like a leak somewhere is the most likely culprit, but wouldn't I be able to hear it?

I've followed what other people have done before me, and they seem to get the required boost level no problem..................

[Rob Plummer]

Thanks for suggestions guys. I've sussed it now.

The dump valve is not up to holding the extra boost.

Need a new/uprated one.

Cheers,

Rob