Weight vs HP

1. ## Weight vs HP

How much HP would you think it would take to make up for a 100lb gain to a 9 to 10 second jet boat to make the same ET/speed?

2.

3. Originally Posted by Master Sergeant
How much HP would you think it would take to make up for a 100lb gain to a 9 to 10 second jet boat to make the same ET/speed?
I've always heard 60-65lbs equals 1/10th but I've never had the chance to test it at the track.

4. Originally Posted by Master Sergeant
How much HP would you think it would take to make up for a 100lb gain to a 9 to 10 second jet boat to make the same ET/speed?
if i understand this right. a jet runs 9.00s, or 10.00s. you add 100lbs. how much hp to compensate for the 100lbs, and go run 9.00s or 10.00s??
you're not saying where this weight is added or what form it took. you're also not suggesting any setup changes to try and compensate for the added weight?
my wildass guess is 20 hp. could just as easily be 10 or 30.
last year at sitc, there were several whackers that added more than 150lbs to their boats trying to slow them down to the number. helped a few, others were just chasing windmills. somebody else added 30lbs to his boat and it went quicker.

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6. Yea, maybe there are just too many variables to this question? I am buying a new Dart block that weighs in at 65lbs more than my old GM one. It makes me wonder how much HP I will lose pushing that extra weight.

7. 100 pounds over a 1/4 mile in 9sec is roughly 31.7 hp, 10sec = 23.1 hp. Not accounting for any other variables.

8. Originally Posted by Carnivalride
I've always heard 60-65lbs equals 1/10th but I've never had the chance to test it at the track.
Unless it is a whacker..it is more like two or three tenths or a blowover

9. Originally Posted by Master Sergeant
Yea, maybe there are just too many variables to this question? I am buying a new Dart block that weighs in at 65lbs more than my old GM one. It makes me wonder how much HP I will lose pushing that extra weight.
no offense, but do you have a lot of runs on clocks to know that you could have run 10.00s, or 10.20s, or 9.70s? what i mean is, once the new deal is done, and you put it on a track, if it runs a 9.90, how will you know if it is quicker or slower then before??? 65lbs will make a difference, but how much is hard to say. besides, since the engine's bigger, it'll most likely be making a bit more power than before.
adding 65lbs in one location will make a difference in how the boat behaves. not huge, but most likely would lead to setup changes.

10. I think the OP asked the wrong queestion. Shouldn't he have asked how much extra TORQUE do you have to make to compensate for the extra weight? ROFL
Wags

11. Originally Posted by gn7
How much does a legal rope deflector weigh

that would probly depend, whether or not it's chrome plated or gold plated...

12. Originally Posted by bp298

that would probly depend, whether or not it's chrome plated or gold plated...
Don't forget "wood"

13. Originally Posted by bp298
no offense, but do you have a lot of runs on clocks to know that you could have run 10.00s, or 10.20s, or 9.70s? what i mean is, once the new deal is done, and you put it on a track, if it runs a 9.90, how will you know if it is quicker or slower then before??? 65lbs will make a difference, but how much is hard to say. besides, since the engine's bigger, it'll most likely be making a bit more power than before.
adding 65lbs in one location will make a difference in how the boat behaves. not huge, but most likely would lead to setup changes.
No, I have never run at the track and understand that an exact answer to this question is impossible. I was just trying to get a general idea of what effect in added weight would put on the performance of the boat.

14. Originally Posted by Master Sergeant
No, I have never run at the track and understand that an exact answer to this question is impossible. I was just trying to get a general idea of what effect in added weight would put on the performance of the boat.
theoretically, adding weight causes the boat to sit deeper in the water, for a longer period during acceleration. being deeper longer increases drag. that increase in drag causes the boat to accelerate at a slower rate. once you see what it's doing, there are things that can be done setup wise to try and compensate.

15. Originally Posted by Carnivalride
Don't forget "wood"
this may be the solution wags has been hunting for. if you could post the pic over on the alley, he would be eternally grateful

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