24 HTM Whipple Upgrade Question...

[Nordicflame]

Question on 2001 24 HTM….
A friend of mine has this boat and it is currently equipped with a stock 502MPI.
He boats primarily at high altitude lakes of 4000-6000 feet. The best speed he can run at these lakes is around 62 mph on GPS. When he drops down to near sea level he can run between 68 and 70. He says the boat begins to lift at about 65 and starts to take off.
He wants me to install a Whipple with about 5 lbs of boost at low elevation and 7 lbs at high elevation.
I’m thinking with this additional hp that the boat will lift and he should see some significant gains. Does 80-85 sound reasonable?
Thanks,
Dave

[KCHOTBOAT]

My HTM with around 500hp ran 87 on radar and a hair over 100 with 650hp. Mine is a light layup and had a few other things done.

[Nordicflame]

I understand that there are two types of 24s. He obviously has the slower

[MIKEHTMSR24]

Originally Posted by NordicHeat

I understand that there are two types of 24s. He obviously has the slower

I have the SR (taller version) My boat weighs about 4800 with two people and 50 gals of fuel.
My motor is a 540 and dynoed 683 at 5700 and 676 @ 4700 on the torque side. The best I have seen is 89.7 on GPS in the humidity and 700 ft above sea level.
I have a buddy that had the same set up and we were side by side. He had a 1.5 with a 2 inch shorty and I have a 1.35 and a 2 inch shorty.
He procharged this summer and from what he told me he was pushing 800 to 850 and he said he could easliy do 100 with 3 to 4 people.

You are correct. The boat starts lifting around 65.

[Whipple Charged]

The HTM picks up big speed with power increases, really more than I've seen any other boat.

If your running 68-70mph at sea level, you'll probably run around 92-96mph at sea level. The lighter, low deck version runs right around 100-102mph with the same package. It's amazing, but we've done it on at least 10 different HTM's. At elevation, with the stock pulley, it would probably be closer to 85, with the pulley change, it should jump up in the lower 90's.

The one thing I've noticed about the HTM is that the hull doesn't really work well until 65-70mph. With little power, it's never consistent on top end speed, depends on the water conditions, trim, etc. With power, its very consistent.

Thanks,
Dustin