oldguy50
wisconsin
Joined: 04/10/2007
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would you rater have more hp or torque? 130 vs 86
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watcher
where is waldo
Joined: 10/08/2002
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i'll take the Torque, beat them to the corner every time (i hope)
watcher
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Petawawarace
Petawawa ON
Joined: 04/25/2005
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High HP numbers are great to talk about and make you feel all warm inside...but....TORQUE WINS RACES plain and simple
DeJongMotorsports.com
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Flatout
Ottawa Ont.
Joined: 11/20/2001
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Torque without rpm will not do anything. You can have 5000 ft lb torque at zero rpm = 0 hp. Rpm without torque will have the same result. HP is the rate at which work is being be done and is a calculation based on torque in ft lb X rpm divided by 5250. You need both rpm and torque to produce horsepower.
What you are asking I think is it better (ie faster) to go with a lower peak rpm setup to gain some torque. Example is 10500 rpm with 60 ft lb better than 9500 rpm with 65 ft lb. Lets calculate and see.
10500rpm X 60 ft lb \5250 = 120 hp.
9500rpm X 65 ft lb \ 5250 = 117 hp.
The fact that you have 3 more hp seems to be the better choice. It now boils down to clutch efficiency and to test this you need a clutch dyno or some good field testing to see which is more efficient. Clutches lose efficiency at higher rpm. If you lose 5% efficiency at 9500 rpm and 10% at 10500 rpm then the lower rpm setup will be faster
(117 hp X .95 = 111.15 net hp versus 120 hp X .9 = 108net hp
All of this said it is not the peak power that I look for, it is the area under the curve within the most efficient clutchable rpm range. There are many more variables such as clutch efficiency at different shift rations, inertia, pipe heat rate etc that all tend to vary the transfer and production of power to the track. Best advice is test,test, test,
HG
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proracer
st-cuthbert, québec, canada
Joined: 01/03/2004
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There you go now Howie, you told all your secret! 
Nice guy. 
Good thing that out there, everery body thinks they have their own setup  for hp,torqe or whatever and that's whats make racing interesting, Cause then there's a lot of talk of who's as the most HP or TORQUE and why is he going so fast and winning.
Bye
JV#96 
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diskvalve
sudbury Ont. Canada
Joined: 12/26/2001
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It all depends on the rpm in question along with the torque numbers ; as what Flatout states is correct.. If you are getting 86 ft lbs of torque at anything over 8000 rpm with a 440 with 34 mm carbs ; you will be capable of winning... Lets see... 86 x 8000 divided by 5252 = 130.99 hp ... doubtful but possible... lets try 9000 which is still lower than everyone runs at ... 86 x 9000 divided by 5252 = 147.37 hp...again; not likely ... now 86 x 7000 divided by 5252 = 114.62...; this is the most likely scenario with producing those torque numbers but it probably won,t win races because the HP (aka work ) isnt enough to overcome the greater hp of a higher rpm setup that still carries enough torque to make more hp ( aka work). To get 130 hp with the lowest rpm would be best for efficiency but with a 440 you will need approx 68 ft. lbs of torque at 10000 to get those kind of hp numbers ... 68 x 10000 divided by 5252 = 129.47 hp ... now that is the area that most front runners run at.... Just for giggles lets see what 86 ft lbs of torque at 10000 will give ... 86 x 10000 divided by 5252 = 163.74 hp ... very not likely ... What rpm are you getting those torque numbers at ??? ---- mike
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mbenoy119
IWA World Headquarters
Joined: 01/17/2005
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Numbers are fun to look at!
The reality is simply though: We don't race dynos, we race snowmobiles and the sled with the best setup and the best driver is going to win regardless if the guy next to him has 10 more HP or 10 more ft.lbs of torque.
What I look for, especially in a mod motor, is consistency and reliability. I want the pipes to work without taking a lap and a half to get hot, I want the motor to cool efficiently enough not to heat soak, and most importantly of all, I want it to live for 25 laps under load.
My Dad taught me a long time ago that in order to finish first, you must first finish!
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MinnesotaJoe
Cold Minnesota
Joined: 05/05/2004
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Ya but funny how it is that the guys with the dynos do most of the winnin.
JJ
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Petawawarace
Petawawa ON
Joined: 04/25/2005
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I agree Mike, Although even with all the fancy number that Howie and Mike quoted and all the secrets they gave away (just kidding) we only had one major engine failure this year.
10 extra HP or 10 extra ft.lbs. of torque is huge though..that can mean the difference between being the first to the corner or being 5th and getting into the heavy snowdust.
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PDRacing
Sarnia, Ontario
Joined: 03/16/2004
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And not to mention, Jeff that extra 10lbs of torque, just makes those bales all that harder
Richard Scroggs #13
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