speed vs weight

[crfabbro2F]

In a lot of testing I've done in the past couple years with a stock Yamato 302
powered runabout showed a 1 mph+ loss in speed for every 25lbs. This was proved with two drivers with different body weights, and was consistent with several boats.

[Silas_53A]

assuming the top speed wont be affected by weight it like assuming you could take a motor out of a honda civic and put it in a 18 wheeler and assume its still capable of its previous top speed. Granted that example it to the far extreme. Your top speed wont be affected nearly as bad as the acceleration. Like previously stated if you are 20lbs over you will need a to get another 1.2hp out of your 30hp motor to keep up with people at the actual weight limit. To actually calculate the affect on top speed you would have to calculate all the forces acting on the boat, wind+water resistance VS force of the motor. But with testing instead of calculations, it seems to be about 1+mph loss for every 20-25lbs over.

That 1mph isn't going to be what hurts you the most. its going to be the loss of acceleration.

Also think of this. How many people can say that when they hit that corner they are actually going their MAX speed? Say your 0-60mph distance is 1/2 mile and you are exactly at weight. now add 20lbs. Your 0-60 is going to be longer then 1/2, so the guy who is at the minimum weight is going to beat you to that 1/2 mile mark every time. (assuming equipment, boat motor prop are all the same).

[jeff55v]

Ditto!

And then there is always DSR..Plenty of motor for the "Big Boned'......LOL

LOL! I was about to say the same thing before I read your post!

Buy a D. And throw out the bathroom scale!

[johnsonm50]

Ive read posts about being too light for rigs in the larger class boats... goin the other way now

[Kev43V]

I have only seen one record run on a closed course (Pineville la.) someone had a radar gun there. He told me to watch. He said the average speed for the course would work out to almost exactly the speed of the boat as it left the corner. I found that hard to believe. But for once I managed to keep my mouth shut. He showed me the radar gun after every corner(front boat) Boy was I glad I kept my mouth shut! He was right heat after heat

[Graham]

Speed vs. Weight: When my Son raced ASH in 1994 we always tested without the 15lb. weight. With the weight in the boat was 1mph slower on the strait and lagged a little out of the turn. This information showed up when we used the speeo and tach. together. The speedo pickup tube also creates drag especially with the "A" class where there is not much power.

Sincerely,
Don Graham