power to weight comparison

[zx2guy]

ive been trying to figure out for a while now, which is better: big power and big weight, or good power low weight. one of the ways im trying to put it into perspective is. say a 69 chevelle (massive power.... but its also nearly 2 tons of sheet metal), and a built.... for shits and giggles.... a turbo 3000gt. (less power, however it also has less weight) pulled to the line.who would win? i know this kinda ranks up there with the viper v metro. but im trying to figure out if power to weight plays as big a role as i think it does. to use an example lets say the chevelle makes 1 pony for every... 100 lbs( which is wrong its just a top of the head figure), and the gt has 98lbs per pony. does that mean the 3000gt would win? or am i missing something that should be added to the mix?

[TatII]

hahah a 3000GT wouldn't weight much less then a chevelle. those things weights 3800 lbs. so its almost 2 tons.

the main rule is this, weight is more of your enemy from a dead stop. so if you weight two tons, you better have a shit load of tq and good gearing to get that initial weight moving.

a 3000Gt makes good tq and has AWD so on the street traction is not an issue. i'm sure hte chevelle with suspension work done and slicks or drag radials would out launch it. but once you get rolling its all about aerodynamics and power.

to double your speed, you need 8X's the power. so if your as aerodynamic as a brick, you'll be limited fast.

bikes are considered to be aerodynamically bad, a 600cc bike with a pro rider can run the 1/4 in 10 second @ like 130mph. however they only have a top speed of 165mph.

a high 12 second 1/4 mile C6 vette has a higher top speed. this is becasue it has more grunt and is sleeker.

so it depends on what type of racing you do, and how long the race is gonna go for.

[SuperHighOutput]

I wouldn't be surprised if the Chevelle is actually the lighter of the two cars.

One thing you're forgetting is gearing.

[TatII]

yeah i mentioned gearing when i was talkin about the chevelle.

[clawhammer]

If you want to compare power to weight, look at these:

4000 pound 400 horsepower Chevelle (roughly)
vs.
2000 pound 200 horsepower Elise (roughly)

Same power to weight ratio.

[zx2guy]

Originally Posted by clawhammer

If you want to compare power to weight, look at these:

4000 pound 400 horsepower Chevelle (roughly)
vs.
2000 pound 200 horsepower Elise (roughly)

Same power to weight ratio.

then in a race it would be pretty much the drivers and not the cars? thats what im trying to get at.

[BlackGT2000]

There is alot more that goes into it than just a formula between power and weight and gearing. It would really be hard to tell who is faster just from seeing a few simple stats on a car.

[drunken monkey]

i'm thinking chassis set up and handling/behaviour of the car plays a major part too.
going back to the examples given, you'd have to assume that both cars behave in the same manner (even given their differerent transmission set-up) for it to be a meaningful sample study.
of course, we all know that they're not like that so the examples don't really mean much.

[blakscorpion21]

lighter is always better. better handling, acceleration, brakind and fuel economy. heavy cars can be fast with alot of power but will never handle as good as a light car. the 400hp chevelle may run on par with an elise on the drag but would get absolutley slaughtered on a real track. thats why most old muscle cars are not that impressive acceleration wise. they just weigh too much. sure it may have ungodly power but still does 0-60 in 6-7 seconds. fast, but not THAT impressive by todays standards. thats why little civics can put up decent times with less that 200hp while it will take a muscle car 350-400hp to pull off the same times.

[BlackGT2000]

Well there was also alot more to it than their "heavy weight", many of those old muscle cars really only weighed in around 3000. there were a few that were actually under that. Most had sloppy suspensions and they all had inferior tires compared to todays vehicals. Not to mention those were the days of 3 and 4 speed manuals.

[blakscorpion21]

really that light? then again they did have very few of the things todays cars have. there is just no excuse for 4000lb cars today. look at the charger, it is a discrace imo. a true sports car shouldnt weigh more than 3k although there are some good sporsts cars that do.

[zx2guy]

you forced me to get my big book of american cars out... there are actually lots of chevelle variations but here are 2:

the 69 (chevelle) 300 Del coupe v8 weighs 3,165 lbs (the greenbrier wagon version v8> 3,740) heres a fun fact for you the difference between the htp cpe v8 (hardtop coupe) and the inline 6 was 105 lbs.
it also had one hell of a motor selection:
i4: 153 ci
i6: 230, 250 ci
v8: 302, 307, 327(2 versions), 350 (2 versions), 396 (3 versions), and the god above them all the 427

but there must be an error in my book it says chevy didnt use a v6 til '78

[deadbolt_35]

Originally Posted by blakscorpion21

really that light? then again they did have very few of the things todays cars have. there is just no excuse for 4000lb cars today. look at the charger, it is a discrace imo. a true sports car shouldnt weigh more than 3k although there are some good sporsts cars that do.

for one thing, the charger was meant to be a true sports car, and i'm not surprised that old muscle cars are that 'light'.

it's incredibly hard for modern carmakers to make light cars. all of the safety regulations today compared to back then add lots of weight, and now people need their cars to be so stiff and rigid, as far as the cars chassis goes, and that adds a lot of weight. still more, today cars have cd players and complex climate controls systems and computers and sound deadening material all throughout the car and whatever else, and that adds weight too.

Originally Posted by blakscorpion21

the 400hp chevelle may run on par with an elise on the drag

an elise hits 60 in 4.4 seconds, so i doubt it. even if a 400hp chevelle has a better power to weight ratio then an elise, like blackgt was saying, there's a lot more that goes into acceleration then just power to weight ratios, the quality and width of it's tires along with the suspension and chassis, and i bet the elise has better gearing for acceleration too

[Fuzzy_C]

power to weight doesn't really matter when you have gearing and torque on your side, take me for instance, i got my 80 trans am, 301, bone stock, 150hp, 3700lbs, yet i can humiliate a 250hp honda civic from a solid launch or rolling start, i actually heard one guy after a race say to his friend "he must have a 454 in that thing" lol, very, very few people know what i actually got under my hood, but if they found out it's a stock 301, they'd go trade in their mustang in a heartbeat.

and the 150hp is just what a book said the engine should have stock, so it probly has even less than that.

[kman10587]

Muscle cars in general from the 1970's were heavy as shit, but in the mid-60's, before they got all glitzy and glamourous, most of 'em didn't weigh much more than 3000 pounds. It's not like they had seatbelts, airbags, overhead camshafts, or electronic equipment to weigh them down, and they actually weren't very big compared to a lot of cars today. I'd wager that a V8 Chevelle from anywhere in the 1960's weighed less than any twin turbo 3000GT.