Quote:
Originally Posted by t*cat speed
Although it seems clear you don't dislike or hate any brand of atv i would sure like to know how it is or where you have the literature to say different about the torque of the T*CAT. I t seems you are somewhat rounded when it comes to areas of engines and they're hp/trq ability so that being said i would like to see that for further referance.
|
well my number 1 reference would just be my own common knowledge of engines torque output for its size. On average most engines will make around 1 ft lbs of torque for each Cubic Inch. this is not exact of course but is usually pretty close to a factory engine(i.e. not highly modified) be it a car or atv. Just remember this.... An engine ONLY makes torque, which is a twisting force. horsepower is merely a calculation that tells us how much work an engine is doing. horsepower is directly proportional to torque output. Almost all engines will make the same amount of torque for their given displacement. The difference is horsepower usually varies because some engines can rev higher and maintain their torque curve as they are more efficient at filling the cylinder at higher rpm.... if you can make more torque at higher rpm you will make more horsepower. you will understand why when you see the calculation for horsepower... torque curves generally start out flat and then start to fall off(produce less torque) as the heads cam and intake cant keep up and fill the cylinder...
Lets just for one second assume a few things for the thundercat engine. Arctic cat rates the torque at 188 ft lbs correct? In the worst case scenario at peak horsepower, torque may fall off 20% in the upper rpm range
horsepower = (RPM * TORQUE) / 5252
so lets say we have 188 ft lbs of torque at peak. at peak horsepower lets just knock 20% off of that. That leaves us 150 ft lbs of hypothetical torque. i dont know where the thundercat peaks for horsepower but lets just say peak horsepower comes in at 7000 rpm.
hp = (7000 * 150) / 5252
So horsepower guesstimate would be ~200 horsepower if the cat engine really did make 188 ft lbs of peak torque. Notice something here? Most 3L v6 engines make around 200 hp... like when i said most 3L engines make around the 188 ft lbs of torque that AC claims.
Remember torque curves are relatively flat, they will not spike signigicantly...
Since the arctic is known to produce 65*70 horsepower we can therefore see that 188 ft lbs of torque is not rated at the flywheel but at the output shaft, after gearing multiplication because it would have significantly more then 70 horsepower if it had that much torque! If i had to guess id say the ac engine is making around 55*60 ft lbs of torque at the crank. the ac engine is 58 cubic inches... seems to be spot on for the size of the engine and horsepower rating!!
sorry for the book... its late and i cant sleep lol...
Worth every one of the one million pennies payed for it
