Just so you know, vtech has had this motor running 9900 rpm's and at 20 lbs of boost and still no issues with it. It is a stout little motor. Plus, with the tune, you get 109 hp.I'd like to know what "options" or different types of tunes are available, last thing I'd want would be too much RPM or too lean/too much advance for just a couple more HP. Yet the ability to get 90-100HP sounds inviting if it's in the right power range.
On their turbo setup, they are only using 6 lbs of boost to get 140 hp. If I only had the moneyMight be time to turn up the boost, see how much more this beast can take, but of course what we all fear is something messing up and costing us big.
I believe your way of thinking is wrong. The higher the RPM'S, the faster the impeller spins, therfore the faster your ski. The reason why the solas is faster at a lower RPM is due to the pitch. If you add the vtech tune you will gain power, which will gain you rpm, which will gain you speed. How much, I don't know. The stock impeller is balanced, hp-rpm's-rpm limiter. Look up impeller pitching at that other forum, GH.Keep in mind though it was found that the Spark is actually performing better with lower revs. ITs not simply just about MOAR RPM's you have to consider where the engine is making its power in the range.