HP vs Torque

[DGthe3]

Originally Posted by stratman

It's going to accelerate faster at any point along the rpm range it has more torque.

Yup, thats why I'd rather have torque than revs -more area under the curve. But if they were both using a CVT it would be dead even because each would operate at its peak power. Most cars don't do this so torque is more advantageous for nearly all applications.

[DGthe3]

Stratman, I forgot: if you compare the same time period, Bob would lift 100 lbs 10 ft/ min while Joe would lift 50 lbs 20 ft.

Originally Posted by camaro_corvette

Okay, trying to learn here, Lets say I get the V6.

Do most mods to horsepower increase your torque, or are their specific modifications out there that i would want to do. For example, i know that putting better exhaust on my car will let it breath better, and inturn increase hp. I would assume that this would get me a few torque points as well, but not many (i mean, it is a V6). Is there a modification out there that will really give me some added torque. Also, will that modification also bring down the reliability of my ride, i mean i want power, but not at the sacrifice of being in the shop all the time. Thanx.

There are 2 and only 2 ways to increase power. Increase torque, increase revs. Changing fluids and using a less restrictive exhaust will reduce your losses. That will cause an increase in fuel economy, as well as more power and more torque. Increasing the revs is rarely much use unless you are racing. So basically, everything you do to increase power will be done by increasing torque. Everything from advancing the timing to stroking out the engine to adding forced induction. It all increases torque, and subsequently power.

Since I like my analogy so much. A supercharger is like giving Bob steriods so that he can lift 250 lbs at a time. Removing a rev limiter allows Bob to lift the weight in 1:50 min instead of 2 min.

[stratman]

Originally Posted by DGthe3

Stratman, I forgot: if you compare the same time period, Bob would lift 100 lbs 10 ft/ min while Joe would lift 50 lbs 20 ft.

Yeah that's what I was saying about even multiples of 100lbs. I guess this is why it isn't a "great" analogy. Assuming the constant goal is to move any given wait a constant distance of 20ft., they both do the same amount of work in different ways. One guy makes two 20ft trips with a 50lb bag each time while one guy carries 2 50lb bags at once but at half the pace. It still takes Joe 2 min to move 100lbs. Carry twice the load or travel twice the distance. And this has officially turned into one of my old engineering exam questions.

[DGthe3]

Originally Posted by stratman

Yeah that's what I was saying about even multiples of 100lbs. I guess this is why it isn't a "great" analogy. Assuming the constant goal is to move any given wait a constant distance of 20ft., they both do the same amount of work in different ways. One guy makes two 20ft trips with a 50lb bag each time while one guy carries 2 50lb bags at once but at half the pace. It still takes Joe 2 min to move 100lbs. Carry twice the load or travel twice the distance. And this has officially turned into one of my old engineering exam questions.

Strong and slow vs weak and fast.

[radz28]

That's a nice write-up DG' You beat me to it

[The_Blur]

Horsepower is how fast you hit it. Torque is how far you take it after the collision.

It's not scientific, but it works.

[stratman]

I think the Bob Joe Frank thing has taken us off topic. Lets get back to the main issue. All things being equal (i.e. aerodynamics, weight of car, gear ratio, trans, driver), a car with a motor making 300hp and 320ft.lbs of torque will beat a car with a motor making 300hp and 273ft.lbs of torque in a straight line or through curves (assuming like suspensions also). It all gets back to talking about the engine. As far as strong and slow versus weak and fast what would likely happen if the stronger Bob only carried 50lbs or Joe carried 100lbs. The output of the motor doesn't change but the result based on what it's moving will.

[Dom]

I just skimmed over the thread. Here is my take on it. When I had a 4200 stall and 4.10s in my V6 it didn't matter how much less torque I had then a Mustang GT. I had the gear ratio advantage to cover up the low end torque disadvantage. I never saw anything below 4200 from the line and then anything lower then 5000 in 2nd and 3rd. I remember racing one GT. Don't know the mods. I beat him to the 1/8th even though his mph showed 7 more. Then at the end he passed me like I was standing still at much higher mph although my final et was only a few tenths worse. I think that was during my low 14s runs. Best documented run I had was 14.3.

This A6 is geared much higher in 1st then the previous A4. It's almost like you have 4.10s off the line. This will make up for the lack of low end torque. Car has the hp up top to keep up. Does it really matter what torque is over lets say 5k? Remember this engine spins all the way up to 7k. The shifts are close so the shift extensions might keep this car above 5k all the way down the track. I know this is not a performance model, but this engine is really advanced. Just like the previous 3.8 crossed over into mustang GT territory, this 3.6 crosses over into the current mustang GT territory. Last time all I needed was gear/stall to match the 210hp/300ft-lbs GT with my 200hp/225ft-lbs 3.8. This is a similar situation where hp is same but torque is lacking. A6 already provides the high gear form the factory to get this going off the line. If anything a converter will definitely put this in mid 13s. I went from 15.7 to 15.1 by doing a 3.42 to 4.10 swap. Then from 15.1 to 14.9 by doing the intake. Then from 14.9 to 14.3 by doing the 4200 stall. And that's all with 200hp. As you all are aware the mods get magnified with more powerful engines. So to summarize I don't worry about the low torque so much. No one races at 1-2k rpm.

[stratman]

No one races at 1-2k rpm but what car has the meat of their torque band down there either. Upping your rear gear effectively increased the torque it put to the road because you increased the distance over which the force from the drive shaft was applied to the rear axle. All you needed was a gear and a stall but you needed that gear and that stall to increase your net torque and keep you in the power band. Numbers from the fly and numbers at the wheels are two separate discussions. If they are making it up on the rear end, that is of course worth noting.

[matt55]

^^ like he said no one races at LOW RPM
The main thing to compare a High TQ motor to a Low TQ is Rev range while racing .
Lets use drag racing , in my car I only use 5.5k-7.2k RPM (LESS than 2k RPM range) . The car with the most HP in that range will win .

So car #1 with LESS TQ(280) could beat a car #2 with MORE TQ(320) at the same (300HP ,weight, gear ....) , IF car #1 has a more avarage HP through the rev range of drag racing

The TQ'er car #2 would be way more fun the drive day to day .

But the main reason the GT should win is weight diff .

[stratman]

I do agree the torque range or as someone else put it "useable torque" is the most important. That gets to final drive ratio. That extra torque does you no good if it's in the wrong area of the curve for what your needs are.

[10redrocket]

Hey guys, new to the site. Been reading over the days posts and one thing stood out at me.
Obviously there is differing opinions on the quicker tranny/engine combination.
Yes, I too read that the auto has optimized shift points to be very quick.
Agree that direct drive over fluid drive equals less power loss.

ALSO, I've already ordered my car with the auto and build sheets state that the rear gear is 3:45, same as the standard trans.

To stay on topic, the auto may have lower gearing to multiply the torque and be quicker than the standard trans.

Anyone have the ratios to compare?

This would explain why the auto is said to be quicker!
As rear gears are equal, weight and actual torque are the difference.
Does the gearing in the auto make up the difference?

Just a thought