The MR2 turbo stock has a fairly conservative setting for enabling some spirited driving with its turbo. There is a work around that allows you to get some fairly decent horsepower gains by playing around with the turbo boost. I’ve been doing quite a bit of research on how to adjust the boost, and there are a couple of options being either a manual or electronic boost control.
I wanted just a simple and cheap way to play around with the boost. In doing so, what I needed was a way to see how much psi boost the car was running. Thus picked up a mechanical boost gauge. It was pretty easy to install. I put the boost gauge on the pillar mount. I pulled the vacuum hose from the pillar and under the carpet, then into the engine bay. I also had to route the MBC from the compressor to the wastegate. Plain stock, the boost is at 7 psi. I played around with the boost, and had to make minor increments where turning the MBC clockwise will increase the turbo.
It’s been quite a joy ride feeling how much quicker the car is when you increase the boost. From what some of the other MR2 experts say, 15psi is probably the max to safely run on a stock car, so that’s what my car’s at now.