What will 85 extra HP get me?
#1
Registered
Thread Starter
Join Date: Jan 2014
Location: Chicora, Pa
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
What will 85 extra HP get me?
I have a 2011 checkmate ZT244 with a 502mag 385hp. I'm getting the stage 2 PCM upgrade by whipple. I spin a bravo 1 26 pitch prop to 69mph at 4600rpm. The tune adds 85hp and raises rev limitter to 5400 rpm. How much RPM will I gain with this setup?
#2
Registered
Join Date: Mar 2012
Location: Syracuse, NY
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
Usually takes minimum 20-25 hp per mph so I would guess 3 mph. You might want to reprop because I doubt that extra hp is going to bring the rpms up any significant level if you are trying to spin anywhere near 5400. I would assume that is should be too high on stock 502 because it is past peak hp but whipple is smarter than me and I know there are a lot better people that can give imput over me. Maybe a lower pitch 4 blade will even run it faster based on current setup not even including the added hp. Maybe try a 3 blade m+ 25p. Hope this helps.
#4
21 and 42 footers
Platinum Member
I think you'll be close to what livefreeordie says and don't think you'll get to 5400 with that prop......but you have to run it and see. I also don't think your getting 69 at that rpm. Is that speed GPS or dream-o-meter?
#5
Registered
Thread Starter
Join Date: Jan 2014
Location: Chicora, Pa
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
Forgot to mention its a raised bravo 1 X outdrive. and the speed is correct. My boat has a GPS speedo and i double checked it many times on my phone and rechecked it with a garmin. I've tried a mirage 25 pitch 3 blade and it sucked, blew out like crazy and had no top end. Seemed to do nothing but slip. I tried a 23 pitch rev 4 which i spun to 4900 rpm at 68mph. Great slip numbers on the rev 4 but the bravo spun less rpm at the same speed.
#6
Registered
Thread Starter
Join Date: Jan 2014
Location: Chicora, Pa
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts
I actually seen 72mph gps at 4900 with a light load and colder weather running a 26 bravo 1 with some lab work. Like i said tho that was only one time and i was on fumes on a 65 degree day.
#9
Registered
Thread Starter
Join Date: Jan 2014
Location: Chicora, Pa
Posts: 84
Likes: 0
Received 0 Likes
on
0 Posts