[QUOTE]Originally posted by jeffbrig
[B]http://vettenet.org/torquehp.html

One of the best articles I've read explain torque vs. horsepower.

 

best mod to increase low end torque would be to change to lower ring and pinion.


-Steve

 

wow i just read that stanford article...that really was the best article on the subject i've ever read. It was even more interesting because it talked about 2 engines that i have and know very well!

-Steve

 

John, ol Bruce Augenstein is right, and you, unfortunately, are not in this case. Bruce is a great fellow and goes back a long, long way. Used to own a Vette, then bought an M3, have no idea what he drives now.

But, I suggest you examine the case in this way:

- Compute torque at the wheels (take a torque curve and multiply it by a total gear ratio).

- Select two points on the torque curve. The torque peak and the point on the torque curve that corresponds to peak power on the power curve.

- Compute thrust for each point on the torque curve in the gear you have selected. The equation is:

Thrust = Wheel torque/(radius of tire)

- Now compute acceleration:

Accel (in g's) = thrust/mass (just use lbs of weight in this case since we're operating with english units in Earth's gravity well).

Now, at which point on the torque curve do you have a higher g value?

Alas, Bruce is right, but that doesn't necessarily mean everything, because it isn't peak acceleration forces that determine how quickly you get from speed to speed and point to point, its average acceleration.

UL

 

the "problem" is hooking up....not a deficiency in power.
with an S/C S2K and a full drag race clutch and 6500 rpm launch the car leaps off the line like a Z06....as expected. the problem lies in the catastrophic driveline failure that will ensue, because the delicate driveline can't handle that. don't waste your time trying to do drag race starts, this is the worst car to do it in ,which is BY DESIGN!!!!...its lightweight driveline is for 50/50 weight balance and go road race this car. it will be cheaper and more enjoyable to get a F150 LIGHTINING. If u want it in a single car...E46 M3...if u don't mind the cult of hairdresser cars

 

Did you guys miss the thread where the vortech SC s2k's were getting heavy wheelspin by slipping the clutch at 3000-4000 rpm!! I imagine the same would be true of the speedcraft turbo as its torque numbers at this given rpm are higher. I highly doubt that with a 3000-4000 rpm clutch "slip" launch that drivetrains will be breaking anytime soon. The drivetrain isn't weak... side stepping the clutch at 7000 rpm is just abuse.

Can you address this issue ultimate lurker or anyone... from a physics point of view! My understanding is that since the engine is spinning at 7000 rpm one would have to take into account the inertia of the moving parts (which would be the mass of the rotating parts multiplied by the angular velocity of the output shaft.) I know this is somewhat simplified but it's the best way I can describe it.
It would be like taking an electric motor that puts out the same amount of torque accross its rpm range and trying to immediately stop the shaft from turning.... Here the amount of force it would take to stop the shaft at say 7000 rpm would be significantly more than stoping the shaft at 3500 rpm simply due to the fact that the same mass of rotating parts have a higer velocity.
I dont know a whole lot about dyno's but correct me if im wrong. 153 ft/lbs of torque at 7000 rpm is quite different than 153 ft/lbs of torque at 3500 rpms if one considers the mass of the rotating parts of both systems are equal?

I get a feeling that some people put the vortech sc on or speedcraft turbo and imagine they still have to side step the clutch @ 7000 rpm. Can someone here address this issue because everytime I've posted this no one seems to respond... I however have never heard.. "I've tried slipping the clutch with aforementioned turbo or sc application and have bogged (excluding the comptech sc) or broken something."

 

least expensive plan for " Feeling" more torque
would be to get a cai, denso irridium plugs, hydropulley, light wheels ( 11-12 lbs) and a 15 lb lighter battery. Of course with a cat back you may feel more but I do not like the noise.
A header may help too.

 

[QUOTE]Originally posted by ultimate lurker
[B]

 

Good thread! Just wanted to say that to those who say that turbos don't improve low end torque - that's rediculous. You just have to drive it, but the turbo is always pushing air even at low low rpm, and as soon as you crack the throttle body open it's pushing air in there, much sooner than you would N/A. There is tons of power down low.

Chris

 

First of all, some guy is a dope. A stock S2000 is faster than a stock GT of any era in all categories, 0-whatever, around the track and back to 0. Period.

Now, all this torque vs. power nonsense is just that. What pushes you back in the seat is ACCELERATION, not torque nor power nor speed. I can blast your ass out of a cannon with 0 torque and 0 HP and you'll feel plenty of Gs. What's better, torque or power? Who cares! Peak numbers are meaningless.

Tell some guy to shed a couple hundred pounds (like from his fat head) and he might stand a chance.