How do Torque and HP differ?

-
70DusterBob said:
I think Moper hit the nail on the head of my question...

My HP and Torque were the same at 4400 RPM 272 HP and 272 Ft Lbs. At 2860 RPM the Torque was 257 while the HP was 140. RPM has everything to do with the gearing of the trans, rear end gears, and size of tires. The gearing of the car has everything to do with how quickly you can go from 0-100, thus the more gears you have the quicker your car can go, provided they are synchronized correctly with the engine's output. If I had a 6 speed, while someone else had a 3 speed, and both top gears were set to top out the engine at 100 mph, the 6 speed would definitely win.

It seems to me that Torque is required to "manufacture" HP with the right gears. You can't go anywhere without HP, but you can't get HP without Torque. If you ask me, gears are the racer's best friend, behind an engine with a lot of Torque. I think, and this is just me, but I think RPM's do have a lot to do with HP, while the size of the motor, CID, Bore, Stroke, Intake, Cam, Air/Fuel provided, all go into how much Torque it can produce, how quickly you get that Torque to the ground is gearing.

I could be wrong, but seeing how the dyno printout suggests that it is the gearing that manufactures HP out of Torque by converting RPM into rubber burning power, I think RPM + Torque manufacture HP too.

I don't know how everyone else's car is, but every car I have been in accelerates quicker the faster the RPM's, up to a point. After the engine can't breathe any quicker, HP and Torque fall off. I think the trick is to get the gearing to match the breathing capabilities of the engine, like low RPM Dual Plane vs Higher RPM Single Plane intakes. If the gears match so as to maximize the breathing of the motor, I believe you will find the quickest, fastest car is the one that breathes the easiest with the right gearing. IMHO But I could be wrong...
Click to expand...


Get ready for the hate. You just used facts to arrive at your understanding. You will catch hell for that.

You hit it all. Exactly correct.

Reread a bit slower. HP is a function of bore diameter. The bigger the bore the more HP. Also, you can use bigger valves with a bigger bore.
Rod to stroke ratio also affect HP output, especially in induction limited application.
 
Oldmanmopar said:
Torque is the strength to move something. Horse power is the energy to keep it moving.
Click to expand...


Yeah I agree, one of my other cars is a fox body GT convertible and of the 1986 variety, and a guy who thinks hes' smart was telling me how his Huyndai Sonata has more HP than my Fox vert. I told him yeah, but I have torque which means Ill take you off the line, and for most if not all of a quarter mile. He didn't get it. On paper he has more HP than my 225 HP stock 80's Mustang, but I have torque and an almost perfect power to weight ratio. He was trying to bench race with HP numbers, but in the real world, I had him beat.
I don't know if this explains it, but torque is what makes my Fox Vert **** and git, HP is what makes the Hyundai catch up on the interstate, but it will need more than a quarter mile to do it.
 
I think you should build for Torque. Why? because to many people buy the big HP cam and are vary frustrated in the performance on the street. Yes the right compression and Gearing will make the monster HP show up.

And yes I have been accused of being in that catagory (Many People#-o)

If it won't 60 foot, that grate HP number has gone to waste.
 
All street light to light are not 1/4 mile long.60 feet is the most needed at times...
 
And when racing 1/4s, you usually have exactly one final drive ratio to get the max out of your combo, so you can't play the ratio game anymore.She is gonna have to do it on motor.Mega-torque at idle to 3000, will not help one bit.
But on the street mega hp at 7000 will not help very much,mostly cuz 7000 even in first is usually speeding.And you are gonna have to drive through that lower part of the rpm band for a good bit of time to get where the power starts.
Whereas mega torque at idle to 3500 to 4000 is really big fun.Make it stick, and even more funner.Here you can play the torque-multiplication to good advantage, especially with more tranny gears.
A few years ago, I was running an 833o/d box with a GV behind it. This gave me 7 very tight useable tranny ratios with a double o/d. This turns 4.88s into 2.53s for hiway cruising, and put my 367 at 6100 at 60mph at the top of second gear.Using the GV to split gears this was 3 actual ratios; 1st, 1o/d, and 2nd, with just 1 manual shift.
Yum!
On the street, if you can't do it with motor,gears and more Average HP per unit of time, will often get it done!
I went from a 292/509/108 cam with a 2.66 low 4spd plus 3.91s to 4.30s,
to 270/.549/110 cam,with the above 7spd combo, and was waaaaay happier.It didn't take long tho and I pulled the 4.88s, in favor of the 4.30s,and eventually settled on 3.55s.
Currently I'm running a 276/.571/110 and the GV behind the 3.09low/Direct 4th box, and 3.55s.This is my favorite,mostly.............. It doesn't get the fuel mileage that the 270 got. :(
 
Wow, what an overwhelming response.

I am new here and really appreciate the input.

I better understand the difference now, which I can say I am glad I got an increase in torque more than the HP. I do know the car is much quicker, pulls much harder than it did before. Money and time not wasted is a good thing...
 
AJ/FormS said:
And when racing 1/4s, you usually have exactly one final drive ratio to get the max out of your combo, so you can't play the ratio game anymore.She is gonna have to do it on motor.Mega-torque at idle to 3000, will not help one bit.
But on the street mega hp at 7000 will not help very much,mostly cuz 7000 even in first is usually speeding.And you are gonna have to drive through that lower part of the rpm band for a good bit of time to get where the power starts.
Whereas mega torque at idle to 3500 to 4000 is really big fun.Make it stick, and even more funner.Here you can play the torque-multiplication to good advantage, especially with more tranny gears.
A few years ago, I was running an 833o/d box with a GV behind it. This gave me 7 very tight useable tranny ratios with a double o/d. This turns 4.88s into 2.53s for hiway cruising, and put my 367 at 6100 at 60mph at the top of second gear.Using the GV to split gears this was 3 actual ratios; 1st, 1o/d, and 2nd, with just 1 manual shift.
Yum!
On the street, if you can't do it with motor,gears and more Average HP per unit of time, will often get it done!
I went from a 292/509/108 cam with a 2.66 low 4spd plus 3.91s to 4.30s,
to 270/.549/110 cam,with the above 7spd combo, and was waaaaay happier.It didn't take long tho and I pulled the 4.88s, in favor of the 4.30s,and eventually settled on 3.55s.
Currently I'm running a 276/.571/110 and the GV behind the 3.09low/Direct 4th box, and 3.55s.This is my favorite,mostly.............. It doesn't get the fuel mileage that the 270 got. :(
Click to expand...

two thumbs up! :glasses7:
Gear Venders are very nice had one in my 91 diesel. would make a grade add on for my now 408 and 4:56 geared car. since it's mostly a drag car, with vary limited street, can't just justify the price. my 408 was built for bottom end torque more than High rpm power. it's all over by 5800 rpm but love the way it make my cheep a$$ converter work now!
 
You must log in or register to reply here.
-

Back
Top