speed vs weight

[Sonny]

Are there any calculations out there about how much weight costs how much speed? If I am 20 lbs over the min weight in my class can I expect to be 1-2 mph off. I think my newly found fatness might be slowing me down. I hate to go crazy trying to find that last little bit in the rig if I just need to do a few push backs..lol

[blueskyracer]

Here in Montana we call it winter fat. Last year I had four firsts and this year after winter fat that never when away I have four seconds. The wife say it has slowed me down. Must cost at least a couple miles an hour

[Andrew 4CE]

Many things affect it... but if you look at straight power to weight ratio...

Say you have a 30hp motor... your outfit weight is 400 lbs... if you weigh 420 lbs you need to find 31.5 hp to go the same speed as you did when you weighed 400 lbs.... push up are easier and cheaper than finding 1.5 hp, haha

[Sonny]

I'll start with some push backs. I'm trying to avoid push ups. A push back is when I push the pork chops back up on the table...lol

[Rex Hall]

Weight to speed

I do not think that 20 or 30 pounds will make you go slower, but it will definetly make your acceleration slower. Once you are up to speed the boat will run as fast but it will definetly not run around the course as fast because of lack of acceleration off the corners.

[Sonny]

I do not think that 20 or 30 pounds will make you go slower, but it will definetly make your acceleration slower. Once you are up to speed the boat will run as fast but it will definetly not run around the course as fast because of lack of acceleration off the corners.

This makes a lot of sense. I seem to be ok in the corners, But I keep getting caught and passed down the straightaways. That being said, a faster prop may be the answer.

[T Chance]

If you want to lose weight I suggest running. I've been running off-an-on for the last 20 years but became serious about two years ago. Marathon, 1/2 Marathon 5K, 10K stuff. I went from a 36 waist to a 32 and dropped 15-20 pounds.

How did this translate to boat racing. I don't know, I'm still too slow.

[Andrew 4CE]

My wife is always talking about sacks of potatoes...

If you're 20 pounds over weight... picture that you are carrying two 10 pound bags of potatoes ALL THE TIME as your motivation to help lose some weight... Just stand there some time and hold a bag for 10 minutes... it's heavy! haha. Atleast for my pipe cleaner arms, haha. Certainly turns me off unhealthy food for a little while.

[Graham 18ce]

Another way to look at it is 5 pounds off the waist and 5 ilbs off the hull is 10 pounds. trim here, shave here.
Fralicks are too skinny to take it off the waist, we'd fall over forsure!

[johnsonm50]

I think from trying to always lighten stuff up that you waste time for the most part with wood or aluminum, whatever steel you could do without would help but bottom line is YOU... 'If' ya carry a few extra . I was 6 lbs over 1st race [dry before the race], is that why I didnt win ??,, dont think so I doubt a few to several pounds will hurt much but more can. As is Im almost exactly the same weight as my boat & motor & my HP to weight ratio is 13 lbs per HP.

[Gootz 142M]

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

[Silas_53A]

Last year I over heard Bill Giles talking. He said on two different occasions he saw different speeds with different weights. In one situation he was driving someone else rig and saw 1mph difference several times. but he also weighed 20bls lighter then the owner. And on another occasion he was driving someones rig and saw 1 or so mph slower, but he weight about 20lbs MORE then the owners weight. so he said about 1mph per 20lbs difference.

[PETEG]

Rex is right. High school physics says that acceleration = force/mass. force is HP. Mass is weight. Top speed will be pretty much the same, but it will take much longer to get there.

[pro350hydro]

This makes a lot of sense. I seem to be ok in the corners, But I keep getting caught and passed down the straightaways. That being said, a faster prop may be the answer.

Rex is right.

But I disagree with you about a faster prop. You need one that will accelerate to top speed faster. With this said, it may be a bit slower on top end, but if you get to top speed quicker and can hold that speed for a longer distance in the straightaways, and get through the corners good, you will actually lower your lap times. I have props that run faster at the end of the straights, but take awhile to get there. My acceleration props that run a bit slower are actually faster around the race course. Oh yeah, and they just eat like mad through the corners. This will put you in Victory lane.

[pro350hydro]

Rex is right. High school physics says that acceleration = force/mass. force is HP. Mass is weight. Top speed will be pretty much the same, but it will take much longer to get there.

Exactly