Darin said:I know this is an old thread...but...
I think somebody would be nuts to run 15psi on a stock FS...
I've seen guys bend rods at HALF that level. I'm not sure how anyone could reccomend those levels of boost. Even Flyin Miata can't attest to running 15psi on a B6 - which is a stronger motor.
Thoughts?
Your missing the point that with the proper engine managemnt those boost levels are possible. With the properly set up FI system and intercooler efficiency these numbers are accurate. People have blown their motors on this board from lack of ignition control. They throw fuel at the problem. You cant expect to have an FMU to satisfy fuel enrichment and run higher than 6psi. You need to have a steady A/F ratio thru out the rpm band along with optimal timing curves for every load and throttle position. If you keep PCP's at around 5-7 degrees ATDC there is no reason why these boost levels are not attainable. I will agree that the miata 1.6and 1.8 are much better motors for boost. But we are talking about 2 bar here . once you start to get to 17-20 psi on the stock internals then we will see some areas of weakness with both the rods and pistons. I dont think that they can take those kinds of pressures along with disapating the heat.