pretty interesting
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03-20-2006 | 06:32 PM
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pretty interesting
so i was cruisin around the web looking on google for that one site that has the hundreds of QM times/trap speeds for hundreds of different cars (if anybody knows what im talking about, post a link plz) and i found this on another forum. its pretty cool.
found it here. i think its pretty sweet..but im just easily amused with math equations and problems.
this is embedded later in the thread. i wanna know how they figure these things out.
What is the relationship between a car's horse power, torque, weight and speed?
After some some searching and experimenting I found some pages that gave bits and pieces (I found one I really like and am linking to it below).
While there is no substitute for an actual road test, this formula seems to work pretty well for figuring out the the quarter mile time and how fast it'll be going:
Speed at 1/4 mile point = 220 * (HP / Weight) ^.3138
Quarter Mile time = 6.9446 X (weight / HP)^.2841
This forumula doesn't make use of foot-pounds of Torque, just the horse power. So how close does it do?
My unmodified 2005 Jag S-type R is rated at about 13.5 seconds in the quarter mile. The calculated value is 13.45 seconds Not bad.
The 2005 Cadillac STS is rated at about 14.5 seconds and the formula comes out with 14.46.
How about on a monster car like the 2006 Chevy Corvette Z06? According to Car and Driver its 3,150 pounds. It has 500 horse power. And it was tested at doing the quarter mile in an incredible 11.7 seconds going 127 mph at that point. How does our formula do? It comes out at 11.7 seconds at 124 miles per hour. Pretty impressive how close it is.
For fun, I tried out what some of the other Jaguar models do. Jaguar makes luxury sedans, sports sedans, and even (ack) a wagon. The difference between the various S-type models (the Sports sedan) is significant:
S-Type 4.2:
HP: 294
Weight: 3826
Rated 1/4th: 14.4
Calculated 1/4th: 14.396
The difference between the S-Type 4.2 and the S-Type R is about 100 horse power. And that 100 horse power givs it 1 more second on the quarter mile.
So there you go, if you're not sure how fast your car is, you can use this formula and get a decent idea. Have fun!
After some some searching and experimenting I found some pages that gave bits and pieces (I found one I really like and am linking to it below).
While there is no substitute for an actual road test, this formula seems to work pretty well for figuring out the the quarter mile time and how fast it'll be going:
Speed at 1/4 mile point = 220 * (HP / Weight) ^.3138
Quarter Mile time = 6.9446 X (weight / HP)^.2841
This forumula doesn't make use of foot-pounds of Torque, just the horse power. So how close does it do?
My unmodified 2005 Jag S-type R is rated at about 13.5 seconds in the quarter mile. The calculated value is 13.45 seconds Not bad.
The 2005 Cadillac STS is rated at about 14.5 seconds and the formula comes out with 14.46.
How about on a monster car like the 2006 Chevy Corvette Z06? According to Car and Driver its 3,150 pounds. It has 500 horse power. And it was tested at doing the quarter mile in an incredible 11.7 seconds going 127 mph at that point. How does our formula do? It comes out at 11.7 seconds at 124 miles per hour. Pretty impressive how close it is.
For fun, I tried out what some of the other Jaguar models do. Jaguar makes luxury sedans, sports sedans, and even (ack) a wagon. The difference between the various S-type models (the Sports sedan) is significant:
S-Type 4.2:
HP: 294
Weight: 3826
Rated 1/4th: 14.4
Calculated 1/4th: 14.396
The difference between the S-Type 4.2 and the S-Type R is about 100 horse power. And that 100 horse power givs it 1 more second on the quarter mile.
So there you go, if you're not sure how fast your car is, you can use this formula and get a decent idea. Have fun!
this is embedded later in the thread. i wanna know how they figure these things out.
Also found an interesting formula for figuring out the 0 to 60mph time:
0 to 60 time = .0078 * X^2.4849
(where X is the quarter mile time).
Plugging in 13.6 gave me a 5.2 which is about what the standard Jag S-Type R is.
0 to 60 time = .0078 * X^2.4849
(where X is the quarter mile time).
Plugging in 13.6 gave me a 5.2 which is about what the standard Jag S-Type R is.
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