Exactly what Eddie said, that what I use as well. 1500hp isnt 100 mph, it 1 Mph gain per 15 horse, Ie 500 horse runs 80, if you add 150 horse then you can expect 90, and this only counts per engine, So you cant add 150 each motor in a twin and gain 20mph, you would gain 10!!

The first 0-55 mph is the free stuff, it gets exponentially harder as you go faster especially with a vee. There are a TON of guys though that have built up a typical 25 ft or so vee hull, poured money into what they thought were decent upgrades with the idea they would be in the mid 70's or low 80's just to gain 3-8 mph. Sizeable gains take substantial hp, I KNOW!:evilb:

Yeah, super rough. Going from 82 to 90mph takes more hp than going from 62 to 70mph.

Take the hp of your current engine and divide it by the weight of your boat. I'll assume a 22 scarab is 4000 lbs with a couple people and gas.

330/4000=.0825

Now take the square root of .0825 = .28723

Divide that into your current speed, 62/.28723 = 216

Now take the new hp of 430 and

430/4000 = .1075, square root = .32787 x 216 = 70.8mph

I've found this to be pretty accurate.

I'm guessing 4-6 mph. I had a 235 Baja that I did the exact same thing last winter and I gained 4 mph maybe 5 on a great day. Most of the time 4.

I also agree I would run a mirage plus. I tried a bravo 1 on my Baja and it didn't do well compared to the mirage plus in the speed department. It did have better turning abilities with the bravo.

No offense fellas but what he said... I've had a couple of pops and had to reread it 4X and......well....back to fridge I go

I think you will be very close to hitting the 70mph mark. I added about 60hp in mods to a 24 Outlaw and picked up a solid 4mph. I went from 61-65mph.
Your 22 Scarab is a lot lighter so 100hp should get you close to 70 with the right prop.

thanks for the replys fellas

You will reach your 70 goal with low 400s if proped correctly. Your 330/64mph is low because of the prop your running.
I had the same hull, 420hp/b1/5400rpm spinning a mirage +25 to 73/74mph consistently