Why are inboard boats faster??? Say a 30' deep v with twin 300's (outboards = 70mph engines weigh around 1000#. Same boat (inboard) 500hp = 80mph, engine around 1000#.....Why??

Austin

Mainly because they don't make any 500 hp outboards.

General knowledge says outboards are faster with less horsepower.
What hull are you refering to in your example?

Let's say a 28' pantera......twin outboards 70mph, single 500 inboard 80mph.

I'd like to be wrong, because outboards are easier for me, but it just seems people are getting better speed #'s with inboards.

Austin I believe a 28' pantera with twin 2.5s rigged correctly would run much better then 70mph. And that is only 310cid total.
A 24' with with twin 245hp 2.4s we rigged ran over 80mph but was mostly out of control at those speeds. I don't know what speeds the 500hp IO runs but 80mph seems optimistic for a pleasure boat, but I could be wrong.
A 30' spectre cat with twin 500hp runs Just about 104mph. The same boat with twin 300x ob runs Just a bit faster. Of coures the IO is better in the rough water.

MMwalters,

Thanks for the replies......it's what I really wanted to hear - I just didn't think it was ture. I know nothing about inboards though, just for some reason had in my mind they were faster. When you say they ride better in rough water... is that because of the extra weight??

Austin better ride due to a better balance, weight farther forward. Big trim tabs help