Originally Posted by Cookee
I raced against a 200HO with an XR2 (barely 195hp) so I did my homework and I also raced XS's
Vipermax - Can I take it that the photos show the motor jacked up? You should be able to get the boat stable with the engine jacked up - at worst it will cause problems with acceleration and cornering, the height of the powerhead will obviously not help but if you can get the prop to bite rather than slip then it shouldn't be the cause of your problems - being able to drive the boat would help assess what the issues are. I am more concerned by the heavy steering - at what trim levels does this occur? If it is still occurring when the motor is trimmed out then I would address this first once again by changing the prop - it's easier than cutting out your transom!
I don't have static photos showing my engine heights for the race boat, but it was stable at over 90mph jacked up as high as it would go!
Thanks for your concerned cookee.
Yes on the picture the jack is in up position. But not at the maximum height I think.
Concerning the prop I have been looking everywhere for tempest plus 25 or 26 in LH but I can't find any. So I think I will go for a Rev 4 25 lh which has got the same diameter as the tempest plus. What do you think ?
Then concerning the hard steering is has occured only with Bravo 1 26 and 28 and Maximus 26 ( I have not try other pitch). So I think it comes from the diameter of the prop which are bigger than tempest (no steering pb with the tempest 23).
Finally the boat is stable at top speed at WOT no pb. It is going side to side only when I reduce speed. And to avoid this effect I have to put the throttle back on.
But it is important to notice that the top speed is reached with the jack at only 2-2,5cm of height (so with the engine at 10-10,5cm above the hull).
I think I may (as said Oliver) lower the engine by 1 hole on the transom and then use more my jack to compensate the lost height. What do you think ?