It’s been years since starting this project and now it’s time for the moment of truth; The dyno tune. Working at STM (Speedtech Motorsport Ltd) really does have it’s perks, I managed to twist Chris Wall’s arm into tuning my car after hours.
Once on the dyno it quickly became apparent that I had a couple of problems. The first being boost creep and the second being the fuel pump was not flowing enough for the level of boost we were seeing. Both of these problems aren’t uncommon, most early Mitsubishi EVOs with a big turbo back exhaust suffer from boost creep. I have already ported the wastegate port on the turbo housing to try and remedy the situation. Turns out that wasn’t enough. The ideal fix for this problem is to fit a 38mm external wastegate, at this stage I’m going to try and steer away from this solution. The only reason the creeping boost is a problem is because I’m running out of fuel at high RPM. My preferred solution due to budget constraints is to fit a high flow Walbro fuel pump and see how we get on.
Currently on 95 octane gas the little EVO is making 188kW ATW, not a bad result. I’ll let you know how it goes once the fuel pump has been replaced and we are running 98 octane gas.