Andy5

Well, i've been looking around for idea's to turbo my SOHC. Everyone is talking about HP this HP that. :\ what about TQ?! thats all i want use what u have right? oh well. just thought i'dd ask why everyone cares so much about HP than TQ.

logo20

obviously you don't know what horspower and torque means.
Horsepower, a unit of power if you couldn't tell, is a measurement of how much work an engine is doing. Work is basically force over a period of time. torque is the force pushing a car forward.
So you can safely say that horsepower is how fast you applying torque.
the car will accelerate according to the torque curve(dyno graph), so when you see the curve dramaticlly drop at a certain rpm that means the car is no longer accelerating (even though speed keeps climbing becausse of the force applied before).
another the reason why we want more hp is to have a better use of gears. usually as you increase hp the the peak hp will move up in the rpms, thus taking advantage of each gear before you shift.

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Chernobyl

HP=(TQ*RPM)/5252

The idea is to make more TQ at higher RPM, thus producing more HP. Think about it, TQ at low rpm will not have you going very fast. Just look at diesels.

fleaf

torque is related to acceleration
and horsepower is associated with speed

at least that's how i remember it, correct me if I'm wrong. =)

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Bill Roberts

Horsepower is applied power...can also be measured in watts.

743 watts is one HP.

Torque is pressure, can be expressed in amperage.

Voltage is simply the constant, as in the octane of your fuel.

So we measure our torque in foot/pounds.

We measure our HP in Watts.

To get a grip on this, take a water hose, and the diameter of the hose is the pressure gauge...depending on size of hose. Smaller hose, more pressure less output of volume.

Torque is Pressure.

Horsepower is Power.

Voltage is the tank you are pulling froms volume.

We don't deal in engine voltage..but we can by configuring the burnability of the octane and the compression ratio. It is the air fuel ratio. It is a constant due to the varable of intake.

Volts times amps equal watts.

E=IXR

Electronics formulas apply...of course dragging brakes, wind resistance, ineffective filters, so much going on.

So, this is an abstract but the engine is a simple pump. All therories apply.

DuffMan

I like HP better because TQ doesnt take into account gear ratios. HP doesnt either but it takes into account RPM, which is related to gear ratios, because if you can rev higher and still have power/torque, you can stay in a lower gear longer, as long the redline isnt too low.

Like for example if you had a CVT and floored it, it would stay at the rpm for peak HP not TQ, because the HP peak would provide more acceleration.

Andy5

I always beleaved Torque was what made you go, the more tq the faster u'll get there, atleast to some point? And i thought HP Wasn't much of a factor towards the higher gears and speeds. Like my friends Supra, Dosen't make much TQ But man it trap at 123mph and it has butt loads of HP......

And the comment about desiels, if ur talking about semi's have u thought about the gear ratio's they have to pull so much weight?

Cause i know a girl who owns a Dogde w/ the commins desiel that runs 14s. w/ some modifications, its sure not a slow starter thats for sure.

oh well, forget it dosen't matter i really got lazy and wanted to post something, guess i learned something is new

SilviaDriver

physics all over again Bill

FRpilot

huh?? lol

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Chernobyl

I was referring to diesel cars like TDI vw's and such. I've driven very many cummins rams, I know they are fast, but you shift so much it doesnt matter. SAme goes for the TDI I drove. You can't wind out a diesel engine like you can a gasoline one (at least the diesel engines we get here in the US), so there is hardly any powerband. I've driven a semi too (once), they are way too different to passenger cars to even compare.

Whats my point?.... nothing really... HP is just a product of how fast you can produce torque.

logo20

another thing about torque,
look at older (87-93) mustangs: 215hp, 300tq. now take a look at a 95-97 M3, 240hp, 236tq. which one is faster? the mustang has over 60tq more, and only 25hp less. that 25hp difference make the M3 faster by almost one whole second.
another example, our cars and an s2000, and s2000 has a little less torque than our cars, but it runs mid 14's in the 1/4 mile. so do you still want more torque than horsepower?

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fantasya98

torque is fun to drive, but hp wins the race, thats it.. as for 1/4 mile times? some cars have a lot torque which helps them at the start, but their top speed, which is hp by weight, is low because of their low hp. Simple, light to light, go torque, highway battle, hp wins.

Sundi240

Yea, my Mustang (91 GT) is fun to drive in the city. It has gobs of torque low. It also redlines at 5800rpm, and loses steam past 5500rpm. There are a lot of factors though. A car as old as mine has wear and tear so it loses power, weight of the actual car, etc. That's why V8's like racing from a stop, launches great (RWD) with lots of torque, so you get ahead quickly. If you were to draw out the race then the higher hp import would catch up. I prefer torque.