All good info joe. Taking the engine set up aside though. What is your opinion of the trs and higher speeds.

With the boat getting more rpm and no more speed says the slip is climbing or getting worse. I know you have 5s I think but what have you seen from TRS on a straight bottom?

The straight bottom trs boats I've been on had perfectly acceptable slip numbers until 77-78 mph then it seemed to go up quite a bit. At that point I believe hydrodynamics come into play and the large bullet on a trs displaces too much water not leaving enough clean water for the prop to bite as efficiently

Yea, that doesnt add up what Bill stated, as far as numbers.

But, at 70mph, he is no where near the TRS gear case becoming a problem, unless they have been modified in a bad way. I've had friend with TRS boats that ran over 90mph turning 4 blade props.

I had a 402 Formula with TRS drives. Turning the props out on that setup, kinda sucked. That boat ran 72mph when dialed in. Tried turning the props 'out' on my 38 Fountain, ran much too flat, couldnt carry the nose high enough, to get the boat on its pad. A pad bottom boat, like a Fountain, is no faster than a comparable non padded boat, if its not running on the pad!

I also had a buddy with a 30FT Scarab that ran 92mph with TRS drives and a slightly raised x dimension, turning 4 blade hydromotive props

x 3.

This may be a stretch but I have been thinking about this one ..... is there any way the added HP is causing the trannys to start slipping..... Pre new motors was getting15% slip which is not good but also not super horrible for a bravo type prop.... Since he redid the motors now getting 22% slip. Motors tach 700+ more RPM but little speed increase, that is what is so puzzling.....

I'd like to think, that a BW trans, if was slipping that bad, would have not lasted for the ride back to the marina. I am pretty sure once those things get hot, slip, the clutches are dunzo in no time. Then you just get nothing once they are gone.

I totally agree that the numbers dont make a lot of sense. I am just thinking, maybe the before or after data provided in the original post, might be off by some chance?

As far as the engine goes, what size pulley do you have on the blower now? A 3 inch or 3.25?

That is possible, had one last year that was low on fluid slipping a bit and got hot and set the alarm off. Filled with fluid and finished the season off. It's coming apart this week for a rebuild but it did work for a bit.

Do you have a temp sensor on the trans? I thought about adding one , or a psi switch or something like that. I ran one out of fluid a few years ago. It smoked it. Had to idle back on one engine. Bilge smelled real nice too! :-)

That particular one is in a big cruiser. Just a temp switch tied into the alarm. My trans both have temp senders and gaffrig temp gauges.

Joe he already states the before upgrade numbers may not be 100%. Boat rarely ever is WOT. Cruises mostly.

I already texted him for pulley size.