I was wondering. HP/Torque

[Ron240zxt]

Im just curious what is torque on a factory 280zxt rated at. Everyone talks about HP but never torque. Also how do you improve torque of a engine?

 

Thanks

Ron

 

Just Brain storming

[Drax240z]

200ft-lbs @ 2800rpm I believe.

 

Hp is basically torque over time. For a turbo, torque is really easy to create. Just cram more air & fuel into the cylinder each time it fires. (more boost, more fuel) The hp will follow as a result of the torque increase.

[pparaska]

FYI,

The equation relating HP and Torque is:

 

HP = Torque * rpm / 5252

 

That's for standard HP and torque in ft lbs.

So if you know the Torque at a given rpm, you know the HP, and vice versa. And if you know what the torque "curve" is (torque as a function of time), then you know the hp curve too.

 

Note that dynomometers (brake type, not inertial ones like the Dynojet) measure torque directly and convert it to hp in the software.

 

HTH,

[74_5.0L_Z]

As a consequence of the horsepower to torque relationship (hp=torque x rpm/5252), the torque and horsepower are always equal at 5252.

[Kevin Shasteen]

Dont forget the pendulum swings the other way also, if you know the HP at a certain RPM then you can determine Torque as well:

 

TORQUE = 5252 * HP/RPM

 

Kevin,

(Yea,Still an Inliner)

[Sean 83ZXT]

Kevin, you should change your motto of "Still an inliner" to "Still a math major"

 

Nice to know some other ppl still know Algebra.

[Kevin Shasteen]

Thanks Sean, I cant seem to help myself when it comes to Auto Performance...I'm like the Mad Scientist & cant seem to get enough.

 

Now, if I could just make money at what I've learned, then maybe I might be able to get my own project started...& I would no longer be an Inliner!

 

Kevin,

(Yea,Still an Inliner)

[grumpyvette]

this is an old post with some insight,and the links have good info

 

we have all heard it, " you need massive low rpm tq" "you need a screaming high rpm hp peak" well heres some info,

More in-depth description:

http://www.revsearch.com/dynamometer/torque_vs_horsepower.html

http://vettenet.org/torquehp.html

http://auto.howstuffworks.com/horsepower4.htm

http://homepage.mac.com/dgiessel/engine/hpvstq.html

 

first thing to keep in mind is that theres no such "thing" as horsepower,...... horsepower is a mathmatical term to express the results of the formula explaining the RATE at which TORQUE (rational force ) can be applied increasing the torque at a given RPM or increasing the RPMS with a given torque increases THE RATE(HORSEPOWER AVAILABLE TO DO WORK)GEARING ALLOWS YOU TO APPLIE THAT FORCE at a given force level but not at a RATE APPLICATION LEVEL that exceeds the engines peak power.

put a differant way, if we ignore drive line friction loss,if an engine puts out 400 ft lbs at 6000rpm (400 x 6000/5252equals (457 hp)we can gear it to apply 1600 ft lbs at the wheels by running the gearing at 4:1 but that also cuts the application rate by 4:1 so the HP applied stays constant at the 1500rpm at the rear wheels 1600 x 1500/5252 equals (457 hp)

 

the formula for hp is (tq x rpm/5252=hp

example

450 ft lbs of torque at 3000rpm=257hp

450 ft lbs of torque at 6000rpm=514hp

because the torque is available at that higher RPM RATE and at the higher rpm useing gearing the rotational force the engine supplied can be applied faster or slower to the rear tires

 

here read these ALL CAREFULLY

http://www.69mustang.com/hp_torque.htm

 

http://www.ubermensch.org/Cars/Technical/hp-tq/

 

http://vette.ohioracing.com/hp.html

 

http://auto.howstuffworks.com/engine1.htm

 

http://auto.howstuffworks.com/horsepower.htm

 

http://auto.howstuffworks.com/question622.htm

where most guys go wrong is in not correctly matching the cars stall speed and gearing to the cars tq curve, if you mod the engine for increased high rpm performance but fail to also match the stall speed and gearing to that higher rpm tq curve much of the potential improvement is wasted.

example

in the close to stock engine above, the engine should be geared to stay in the 3500rpm-5000rpm range for max acceleration (lower in the rpm range if mileage is a big factor)

in the moded engine above the rpm range moved to 4000rpm-6500rpm requireing differant rear gears and slightly higher stall speeds to gain max acceleration in the same car,

you should readily see that a trans that shifts at 5000rpm will work in the first example but would waste most of the power curve in the second example,where shifting at 6500rpm under full power acelleration would make more sence.

a 3.08 rear gear and 700r4 trans matches the first example well but it would take a swap to a 3.73-4.11 gear to allow the engine in the second example to keep its most effective power band matching that second power curve well.

 

links youll need to figure out correct rear gear ratios

 

http://www.miata.net/garage/tirecalc.html

 

http://www.wallaceracing.com/reargear.htm

 

http://users.erols.com/srweiss/calcmph.htm

 

http://users.erols.com/srweiss/calcrpm.htm

 

http://users.erols.com/srweiss/calcrgr.htm

 

http://www.prestage.com/Car+Math/Ge...io/default.aspx

 

http://www.geocities.com/z28esser/speed.html

 

http://server3003.freeyellow.com/gparts/speedo.htm

 

http://www.pontiacracing.net/trannyratios.htm

 

http://www.tciauto.com/tech_info/gear_ratios.htm

[dj paul]

i believe this should be a sticky

[tfreer85]

i believe this should be a sticky

I think instead we should have little spot called Grumpyvettes' Corner where everything is Sticky worthwhile. SO MUCH GOOD INFORMATION!!!

 

Tyson

[johnc]

where most guys go wrong is in not correctly matching the cars stall speed

 

I called Quartermaster and asked what the stall speed is on their Pro 5.5" triple disc clutch. They said, "When the rpm is at 0, the car is stalled."