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I have my 460/ 429 in a cobra kit car and my machine guy was saying with all the torque i have ,i don't need to worry about hp is this true. He also said i sould be in the 10's at the track. Im running a c-6 with a a 3:55 gear if i can get the car to hook. What you guys think (car weight 2400 lbs) thanks for all the help
Your machine guy doesn't know what he's talking about. Torque is a force that produces rotational motion. Torque is a measurement of work. Work is the combined product of force and distance. Horsepower is a measure of power. Power is the rate at which work is done. Horsepower is measured by:
[(Torque)(RPM)]/5,252
One isn't better than the other. They are measurements of two different, albeit related, quantities. If you're wondering which number is indicative of a car's performance on the drag strip, then you should focus on horsepower. It's impossible to predict a car's performance by looking solely at torque because torque is not measured at a given speed. To help you visualize this, picture a person standing on a (long enough) lever. A human could theoretically produce torque equal to that of a Honda Civic but they clearly couldn't run a quarter mile in under 20 seconds. If your Cobra is running 10s at the quarter mile it's producing a lot of horsepower. If you tell us your engine's maximum torque and where in the rpm band that maximum torque is produced, (factoring in the weight) I can tell you whether or not the machine guy's remark that your car will run in the 10 second bracket on a quarter mile is a credible claim.
- Max
Without going into anything too explainatory;
You can have all the horsepower in the world, high revving, blah blah; but you compensate the RPM peak with steep gears- or a "sort of" replacement for torque.
I would honestly say, that horsepower and RPMs are the whip, but you've gotta have the torque to get you through the powerband, without feeling like a dog at low rpms. IMHO
What kind of numbers is your engine pushing?
If your car is 2400 and you and fuel add 200 for a total of 2600 pound, 500 HP will produce a 10.09 ET provided you launch and lock up perfectly..
See: http://golenengineservice.com/calc/calcehp.htm
We run a big block Ford in a 2550 pound car. The engine makes a bit of 500 horse and torque at the wheels on a chassis dyno and easily runs 9.90 Super Gas class.... I like to go for the big torque increases on the big inch engines. Good torque numbers at a moderate rpm makes for a very consistent and durable engine.....
With a street car torque is king. Basic term's, torque get's a car moving, and horse power keep's it moving. Not to mention torque is cheaper.
Hoserpower is a function of torque that relies on high rpms. How you want to build your engine depends on a great number of things.
In aperformance build, the torque almost comes naturally with these engines; if I had a Cobra kit car, I'd like it to rev/have some peak power too, even though it would certainly be ahandfull in a little car like that.
That being said, you don't need to generate massive horsepower to be quick and/or fast.
Paul
I am trying to guesstimate my horsepower im thinking 400+ i have another post called how much horse 429/460 mix i didn t get much feed back mabey you guys can help me out
Killer Cobra I not only build the 429/460 engines but I specialize in them. I believe that I have already answered this very question in the other thread...you have about 370 hp and with a nice broad range of power.Quote:
Originally Posted by KILLER COBRA
Paul
www.highflowdynamics.com
What can i do to get more
This is absolutely incorrect. Horsepower is the rate of energy transfer in the engine. Energy transfer moves the car. Horsepower gets a car moving and keeps it moving. Why? Because motion is factored into the equation and torque doesn't describe speed. It's only when combining torque with engine speed (horsepower) do we get any meaningful numbers for how fast a car will move. A 300 horsepower car with 200 lb-feet of torque will always be faster than a 200 horsepower car with 300 lb-feet of torque. It's all about looking at the right dimensions.Quote:
Originally Posted by Ron B.
Depends on your gearing
Assuming the car is geared correctly, yes.Quote:
Originally Posted by KILLER COBRA
His car weighs so little that it would be a rocket with 300 horsepower.Quote:
Originally Posted by Paul Kane
Here is the formula used to estimate quarter mile performance:
Cube root(weight/power) x 5.825
If his engine is making 350 horsepower at the flywheel, he has a 12 second car. If it's making 400 at the flywheel, he's got a mid 11 second car. If he's got 470 at the flywheel, he's got a high ten second car.
Regardless of how much power he's making, he's got a beautiful car that's a blast to drive. :)
Thank you. What kind of horse do you think i am making i have another post with engine details
I'd say 350 tops given the cylinder heads but there's plenty you can do to make more power. However, 350 horsepower in such a lightweight car is fast enough for most purposes. Unless you're into competitive bracket racing, not going with a more aggressive build is likely to increase the lifespan of your engine. If you want to make a lot more power, forced induction is the way to go.Quote:
Originally Posted by KILLER COBRA
super charger?
Just another thought for you... All the horsepower and torque in the world won't do you a bit of good without the correct gearing, chassis, and supension... When the car doesn't work right, about all that happens is big long burnouts.....
i would say that they go hand in hand, But a hi torque motor usually does not need to be revved as high and does not need as much gear to get things done. it also turnes on just after idle and stays on for a while. If you have a torquee 460 with 350 to 400 hp it will be a ripper in a 2400 lb car without abusing the motor much at all.
my bucket is a fat 2800 lbs with a just better than stock caddy 500 i run 12.6s in the 1/4 and with a 2000 rpm convertor 3.55 rear gears and 30 inch slicks. this is a 5000 rpm shift motor and i go though the lights at around 4500 rpm if i lost another 400 lbs off the car it would go even better.
At our track we run a open format and line up againt all kinds of cars, my 1st about 200 ft is amazing and i actually can get up on a lot faster race cars for the first part of the race this i would think is tourque getting the car up and moving
You will have traction troubles on street tires no matter what but thats the fun of it
The #s you seek were answered by Paul Kane a few posts back, and in the other thread. He is bar none without a doubt the resident expert on ford big blocks on this forum.
High horse power makes a good drag car and takes street driveability away, high Torque pulls stumps out of the ground. You have a good mix with what you have now. If you are wanting more ponies ditch the edelbrock street carb for a Holley HP, Upgrade to an open plenum high rise intake, some pocket porting, flat top pistons, and a bigger cam. Super Charger not needed for your small size car.
I have to thank everyone again for all the info.