That is an impossible question to answer. There is too much variability in cylinders and other parts with the rotax. Mt prevo responded good to the upgrade, others better or worse. I have seen evo’s that run about the same as mine and other much worse than min side by side. If you have a good engine with a legal lettered cylinder then I am confident it will still be a good engine. Copmparing that to a brand new engine is difficult as you will be getting ht eluck of the draw on the cylinder you get with the new engine. Over the next year everyone that spends a lot of time, money and effort on rotax will begin to identify the good from bad cylinders. I have not seen a brand new engine that ran on the same track on the same day that was measurably better to my upgraded engine.
Mark (Parker), my friend Mark (Traylor) is 100% correct. There exists no actual baseline to test one vs. another. For example, we’ve beaten some brand new evos with our upgrade, but guess what, those evos had 2013 and 2012 cylinders. The 2015 cylinders that came with the motors were, after dyno testing, chucked into the spare parts bin. They could have been running pipes from 2008 as well for all I know. What would you call that? An EvPro?? PrevEvo?? Any truly competitive Rotax motor is going to be a mishmash of various parts anyway, so short of part testing every component between an Evo and a Prevo, you’ll never know which part makes which motor better.
Micros are by far the toughest motors to get right…engine builders go through countless parts and hours looking for .1 hp (noticeable on the track in the hands of a good kid driver).
We can’t speak to the advantages or disadvantages between the EVO and an upgraded Prevo as we have yet to receive our upgrade kit that was ordered back in February.
However, I can tell you that we don’t come close to competing with the other teams at our track that have received their upgrades or have purchased a new EVO engine. We’ve gone from setting fast times at the beginning of the year to nearly 1 second off of the pace since the EVO has become legal. Hope I have some news from Maxspeed for my driver before the next race.