Rich wrote:Brandon, do you find it a problem that MACs dyno is not load bearing? I think it may have a negative effect on producing enough engine load to hit target boost, but I'm unsure. I was only hitting 14 psi w/ on ECU only, yet on the road I can hold 15+ with spikes to 17+.
The load bearing portion of the dyno is really only useful for tuning at specific engine speeds under partial-throttle. As far as open loop/WOT pulls go, load bearing vs inertial dynos, it really doesn't make a difference. Over the years, I've been on Dynojet's, Dyno Dynamics & a Mustang dyno... all of them had the same result: slightly higher boost on the street. Especially when punching it from a low RPM in a high gear. There are some things you just can't replicate in a semi-controlled environment. In my experience, that's completely normal.
In my STI, after it was tuned at Revolutions (load bearing Dyno Dynamics), on the dyno it hit 19psi... on the street in 4th gear (gear used for tuning on the dyno), at a low enough RPM, it would routinely hit 20psi, and in 5th/6th at a low RPM I saw it spike as high as 24psi... sadly enough, it's normal.
