I have a 04 29ft Fountain Fever powered by the Mercury Racing 525HP with the XR drive turning a 4 blade 26p prop. Only gas 180 hours on it. I'd like to get the boat into the mid to low 80's. Was looking at the Hardin Marine Stage 2 Upgrade for Mercury 525 EFI. Just wondering if it's worth the $2k or save a little bit more $$ and put a whipple on it for an extra $4k. Just skeptical with long jevity with installing the supercharger. Also wondering if doing a prop change to a herring 5 blade?

Thanks for any help or input!!

You need 20-25hp for 1mph increase. What's your current speed?

I'm currently running a solid 78mph right now. The stage 2 kit claims that it increases the maximum power by more than 35HP* and 38 pounds of torque*.

Several 29 s on this sight all doing almost 80 with superchargers and 600 plus hp So maybe we start with a new G P S Just sayen

If he is a 1.5 gear in the drive and a close to stock b1 26 pitch the number work out if he is spinning it close to the limiter.
Just saying

Im believe me no big expert but my 28 powerplay has 725 hp and same speed with imco shorty and lab finished 28 And ive never run into a 29 with that kind of hp that was going more than low 70 s just seems pretty fast for 525 Im also kiden around just havinfg fun with this

My Gps speedo recall must not be working properly then?? I run 72 all day with full gear, 4 people and 3/4 tank of gas.

Just going by what i have seen at the poker run with reg merc power and no supercharger we always walk by them and there s a few out there And ya low 70 s always with or without passangers iT takes usually at least 650 plus to get up to high 70 s 80 there are a lot of boat owners on this sight with big power can do 78 80

I know the Fountain advertised top speeds are, shall we say, obtained under optimal conditions but the ads claim the 525 equipped 29' will hit "close to 80." My 29 Fever with twin 6.2s is advertised at "close to 74." I've seen 70.5 GPS - slack tide - with 3/4 tank of gas, chain in the anchor locker and water in the tank and ports-potty, boat full of regular gear. (1:65 Bravo drives at 5300 r.p.m.s - I would guess my boat would hit the limiters - and/or run out of h.p. before it would hit an honest 74.) I can see no reason why a 525 equipped boat would not hit 75. Mob_05 claim of 72 with full gear and 4 people seems right to me as I hit about 67 under the same circumstances.

Best I have seen in my non stepped 27 with a 525SC (balanced, 060 over, 9.0:1 MSD ignition and 5psi boost) is 75mph on Livorsi GPS with light load. -2 Imco and 24" P5X 5450rpm. No dyno, but guesstimate is 550hp.