Ok, I could see him pulley'ing up and creating a furnace and losing power that way with if it was a 177.

Did you upgrade to the 250 blowers? 525's had 177 blowers.
Also please bump your timing to 32* before you send your exhaust valves out the back of the boat!
Sounds like your doing something different now than you did before possibly over trimming
Merc 525 factory timing was 35*

Is it possible that you are only getting to 5600 rpm by over trimming the drives? That would explain the high slip and lack of speed gain.
Eddie

Looks like a few of us posted at once

Good point Eddie. I have trimmed the boat the same on all runs as far as Fountain indicators never past the number 4 mark with the TRS drives it seems to loose speed beyond that

If pulls right to 5600 yea sounds like a major prop slip issue. Call Fountain and get there input on the TRS with that hull they may have some thoughts.

Agree with Red, if your total timing is 26 degrees then you should consider bringing it up to at least 30. There should be an increase in power for this as well. At 6 lbs of boost should be fine with 91 octane. Make sure you are setting timing to total, not initial.

Youngs question is a good one, were you overtrimmed and slipping the prop?

the op said base timing at 26 nothing mentioned about total timing.

That's total at 26 mike. It was a typo. Lol

Bringing the timing up is a good idea but started there. defiantly not over trimmed

my mistake.if he has total timing at 26 and running the jets he has in it i would be afraid to go wot,imo its way to lean and the exhaust valves are glowing red hot.