Sportfire

JDCornFlakes · Post by **JDCornFlakes** » Fri Jan 18, 2008 9:57 pm

Peter :

In plugging those numbers in to my my Q-71 Exploduim Sled Speed Modulating Gonculator . Then using the combustion co-efficients of the the Trailfire, the weight-power radio (not ratio), the barometric pressure factor. Then of course the assumption of a sport windshield not a trailfire or heaven forbid a cross country windshield !!

I show your race sled is capable of 328 mph using the above equation. Which would then class it as a Nitro-Methane Top Fuel Sled.

Can someone please check my numbers ?

Thanx Dave

JoeRainville · Post by **JoeRainville** » Fri Jan 18, 2008 10:21 pm

Dave,

Using some physics and the energy and mechanical acceleration equations, here is what I come up with:

Force = Mass X Acceleration
Force due to gravity: 9.81 meters per second, per second (or Sec^2)
Free fall acceleration ~ 22 mph, per second of fall

I will use my 2005 Cat SnoPro 440 as an example:

110 hp
435 lbs plus my 190 lbs dressed in SnoCross gear wieght + fuel
Drag co-efficent of probably .41 c(d)

Putting these into some basic equations, and taking into account that my SnoCrosser can jump at least 15' or approx 3 meters off the ground, Peters 174 hp Mock Zee should be able to jump approximately 1 KM into a nearly low orbit.

-Rainville

That Girl Racing · Post by **That Girl Racing** » Fri Jan 18, 2008 10:29 pm

Hey guys the 174 hp MachZ is a stocker. Race sleds are more in the 270 range. Snowmobile top speed has always been open to interpretation. I think 70mph on a Sportfire is really getting it done. Peter

smitfire · Post by **smitfire** » Fri Jan 18, 2008 10:31 pm

i waz wrong on my speed, but the racer that went 88 is correct

traildeere · Post by **traildeere** » Fri Jan 18, 2008 11:25 pm

I've been in a post like this b4 about Liquifires. You can look up that long post but on one morning (after a 28 degree day of hard riding the day before) my 80' Sporty was darn close to 80mph (I was looking at the correct #'s but not long enough to get the exact #) I'd say over 75 but not OVER 80 by any means.
It was -5 degrees F & that speed didn't last long, (as in later that day) nor did I ever hit that speed again. Track slippage????? Who knows....
Just my $0.35......
BTW - my 340 Trail never got over 65mph

Post by **ICCSF 108** » Sat Jan 19, 2008 1:39 am

I knew when I answered that question it would open a BIG debate.

Now I'm going fishing in MN. for a month, have fun guys

Kenny

JDDDeere · Post by **JDDDeere** » Sat Jan 19, 2008 2:03 am

Just a though.. my Garmin Handheld GPS will tell me how fast I'm walking, never mind riding, and I intend to use it this year on the sled..I think they are fairly accurate.

All this talk about top end speed got me to wondering.. how many HP is the SPrint again? I was told that even though a 340, it should do moderately better than my SPit from last year (which hit about 50 - 55).

Happy riding.
Dan

kawtoy_77 · Post by **kawtoy_77** » Mon Jan 21, 2008 10:20 am

Thanks for the lots of info, as my sporty does around 55mph I imagine with some belt slippage due to the fact it has been on the sled since I bought it three years ago, and who knows how long before that. I was worried when I heard th 80mph!!! that didn't sound right. So I believe I am about where I should be. thanks again!

69camaro · Post by **69camaro** » Mon Jan 21, 2008 12:33 pm

Surely that 85mph Sportfire had some COUGAR parts in it.

That is the only way anything can be faster than possible.

Duane