Back to the basics: Torque

The Crowing · 08-18-08, 07:31 PM

I want more of it. I would even go so far as to sacrifice horsepower for torque.

We all know that power is, really, a simple dirivitation of the following:
More air and fuel means more power.

That said, how does this split into the two powerbands of down low grunt, and top end go? What makes for better torque, and what makes for better horsepower?

I know that gear ratios has a lot to do with it. Final drive can be changed to directly invert horsepower to torque, and vice versa.

However, an engine gets a horsepower and torque rating all by itself, so there has to be a way to modify the way the engine works to make it produce more of either, right?

So, in the end, what makes torque, and how can I get more of it?

Discuss.

sap · 08-18-08, 07:47 PM

Word on the Camaro and Firebird forums (specifically for the third gen TPI models) was that long runners was key. Factory numbers on my Camaro were 285 ft.lbs. but only ~190 HP. Aftermarket parts increasing power generally sacrificed torque by going shorter.

I've never really had the time (or money for that matter) to play with my cars, so I can't give you much first hand info, but hang out around thirdgen.org for a while. The 82-92 camaro is almost spot on stock weight and I seem to recall plenty of torque vs. HP discussion.

The Crowing · 08-18-08, 07:49 PM

My aim with this is not so much a horsepower vs. torque discussion as it is what components and modifications of the engine make each item.

Runners, I remember now. There was a huge discussion/fight about the Type I, Type II, and 3.5 intake manifolds and their respective runner lengths.

sap · 08-18-08, 07:59 PM

Quote:

Originally Posted by The Crowing

My aim with this is not so much a horsepower vs. torque discussion as it is what components and modifications of the engine make each item.

Yeah, I was just pointing to that to see what the thirdgen guys had found impacted torque and HP, not the HP vs. Torque debate itself.

The Crowing · 08-18-08, 08:05 PM

Gotcha

I'm wondering if fuel delivery can be altered to affect one or the other, or is the "more fuel and air" theory going to increase both equally? Also, how will timing play into it?

reboticon · 08-19-08, 06:44 PM

Ok.. this may not be exactly the answer you are looking for, but it may help you to better understand the principles..

Horsepower is actually just a term that describes the amount of torque at a given RPM.

Horsepower = (Torque multiplied by RPM)/5250rpm.

Check out a Horsepower and Torque graph sometime, they ALWAYS intersect at 5250 rpm.

So to increase torque, is the same as increasing horsepower. The real question is where in the powerband is that horsepower added.

Your best bet for getting more low end torque is going to be a custom cam grind. On a ford its as simple as swapping in an RV/Tow cam. You will lose power on the top end this way though. If the engine is setup to flow more air at the low end of the power band, it will flow less at the top end.

The Crowing · 08-19-08, 07:35 PM

^That was actually a very helpful answer. Now, the quexstion I have, is how can we shift a C32 or C35 to the low band?

reboticon · 08-19-08, 11:10 PM

That i am not so sure about. The 3.5 is going to have way more torque potential than the 3.2. The extra .3liters of displacement is a lot for low end torque. Displacement is really the best way to make low end torque.

Example: my 71 stock T-bird with a 429 (7.0L) makes 360HP from the factory. It makes 480lbft.

I dont know if its possible to get more displacement from either the 3.5 or the 3.2. Theoretically you could overbore it, but since its a sleeved aluminum block that doesnt sound like a good idea. You could possibly have a custom stroker crankshaft made, but that would be expensive, and again everything is engineered so tightly on the motors, that the block might not be able to accomodate it.

Honda engines just aren't made to be torque monsters. Thats why they are able to have an 8,000rpm redline. No domestic V-8 is going to make it to 8,000rpm, unless the rotating assembly has been professionally built with A+ grade parts. The reason for this is the distance the piston travels from the top to the bottom of its stroke. The longer this distance is, the more stress it puts on the internal rotating assembly, and the lower the redline before the chances that you throw a rod.

Thats why a custom cam grind is going to be about your only good option.

I would change my focus now from trying to create more torque, to how that torque is transferred to the wheels. Its probably going to be easier/smarter to swap transmission or differental parts to make it "feel" like you have more torque, but doing so will decrease the topspeed of the car.

cheeseman0777 · 08-19-08, 11:15 PM

^^ok robot, what you are saying pretty much is the higher the torque, the more acceleration you got, but lower the speed, and higher the horses, the more speed you got?

dog2525 · 08-19-08, 11:46 PM

HP=speed
torque=has fast you get there
Don't know about the legend but the base model integra (B18b or B18a) has a longer stroke which makes more torque then the gsr (b18c) But the gsr has the vtec which helps it make more hp. Thats why people do the lsvtec

reboticon · 08-19-08, 11:47 PM

Not exactly. Low end torque is what makes your wheels spin when you are stopped and you floor it. By Low End, I mean the low end of the RPM band. Around 0-4000rpms. Horsepower is what is actually measuring the power to accelerate.

Down here, we have Tractor pulls. Guys build tractors with huge wheels and see what they can pull. They have tons of Torque, but not much horsepower. So they can pull anything, but they dont have horsepower so they have low top speed.

Basically, Torque is what gets your car moving. Horsepower is your acceleration.

Now in my post before this, when i talked about changing transmission or differential parts, the way you are looking at it is correct.

By changing the gear ratios in the transmission or differential, you can make it easier for the engine to turn the wheels. By doing so though, you are also making it so the Car will be spinning higher RPMS at the same speed then it was before you changed the ratios.

For an automatic car, the best option would probably just be to get a higher stall torque converter. This would make your transmission not engage until the engine was at a higher RPM than normal, making it faster, at the expense of fuel economy.

sap · 08-19-08, 11:58 PM

If At the end of the day what makes you go is torque applied at the wheels through the transmission and differential, since that is the force applied on the ground. If you increase torque at 3000 RPM, for example, you are also increasing your horsepower at that engine speed. What that higher horsepower is doing is making you able to increase the torque you put to the wheels.

Higher HP means that you're producing lots of torque at high RPM. Lets pick some numbers out of thin air and say you need a driveshaft speed of 3000 RPM to match the speed you're going, and you've got my Camaro that's sitting somewhere around 275 ft. lbs of torque at that speed and driving through at 1:1 transmission gear. If I had a car that could rev up to 6000, but only produced 200 ft.lbs. of torque at that engine speed, I could move down to a 2:1 transmission gear and get 400 ft.lbs of torque instead of 275. If you have torque at high RPMs you can gear the output down to increase torque to the wheels. Conversely, the high torque car is an enjoyable ride because you don't have to rev it up to get that torque to the wheels.

There is a good summary here. The water wheel example is fantastic.

The Crowing · 08-20-08, 12:17 AM

Quote:

Originally Posted by reboticon

I would change my focus now from trying to create more torque, to how that torque is transferred to the wheels. Its probably going to be easier/smarter to swap transmission or differental parts to make it "feel" like you have more torque, but doing so will decrease the topspeed of the car.

I've started doing so already. I took out the A/C system (no pulley) and have gotten the aluminum crank pulley Telion made. I'm looking into getting my own pullies machined for the P.S. and alternator. I've got fairly light rims and tires for a 17" 215/50 package.

But there's nothing that can be done to the engine (short or long block wise) to give it a muscle boost?

DandDEE · 08-20-08, 05:58 PM

OK need more clarification on this matter I was told that the faster the engine produces the hp and tq( meaning in an out of the engine) the faster your car? or did i get miss informed on what he was trying to say.

sap · 08-20-08, 06:19 PM

Quote:

Originally Posted by DandDEE

OK need more clarification on this matter I was told that the faster the engine produces the hp and tq( meaning in an out of the engine) the faster your car? or did i get miss informed on what he was trying to say.

I think you've got it right. If the engine produces a lot of torque when it's revving fast (high HP) the car will accelerate quickly as long as you can get the revs up.

The ideal is to have high torque at any engine speed, as that would allow you to both enjoy a good low RPM pull for casual driving and be able to run the revs up to get more force to the ground when you're looking to show another car your tail lights.

08-19-08, 06:44 PM	#6 (permalink)
reboticon Registered User Join Date: May 2008 Location: Knoxville Posts: 1,119 Car 1: 95 Black 4dr Car 2: 92 Blue 4dr Car 3: 71 429& 87 5.0Tbirds iTrader: (3)	Ok.. this may not be exactly the answer you are looking for, but it may help you to better understand the principles.. Horsepower is actually just a term that describes the amount of torque at a given RPM. Horsepower = (Torque multiplied by RPM)/5250rpm. Check out a Horsepower and Torque graph sometime, they ALWAYS intersect at 5250 rpm. So to increase torque, is the same as increasing horsepower. The real question is where in the powerband is that horsepower added. Your best bet for getting more low end torque is going to be a custom cam grind. On a ford its as simple as swapping in an RV/Tow cam. You will lose power on the top end this way though. If the engine is setup to flow more air at the low end of the power band, it will flow less at the top end. __________________ Fixing legends is easier than fixing lolcats, but the parts are way more expensive.. My Wiring Nightmare..http://www.acura-legend.com/vbulleti...59/index3.html

08-19-08, 11:10 PM	#8 (permalink)
reboticon Registered User Join Date: May 2008 Location: Knoxville Posts: 1,119 Car 1: 95 Black 4dr Car 2: 92 Blue 4dr Car 3: 71 429& 87 5.0Tbirds iTrader: (3)	That i am not so sure about. The 3.5 is going to have way more torque potential than the 3.2. The extra .3liters of displacement is a lot for low end torque. Displacement is really the best way to make low end torque. Example: my 71 stock T-bird with a 429 (7.0L) makes 360HP from the factory. It makes 480lbft. I dont know if its possible to get more displacement from either the 3.5 or the 3.2. Theoretically you could overbore it, but since its a sleeved aluminum block that doesnt sound like a good idea. You could possibly have a custom stroker crankshaft made, but that would be expensive, and again everything is engineered so tightly on the motors, that the block might not be able to accomodate it. Honda engines just aren't made to be torque monsters. Thats why they are able to have an 8,000rpm redline. No domestic V-8 is going to make it to 8,000rpm, unless the rotating assembly has been professionally built with A+ grade parts. The reason for this is the distance the piston travels from the top to the bottom of its stroke. The longer this distance is, the more stress it puts on the internal rotating assembly, and the lower the redline before the chances that you throw a rod. Thats why a custom cam grind is going to be about your only good option. I would change my focus now from trying to create more torque, to how that torque is transferred to the wheels. Its probably going to be easier/smarter to swap transmission or differental parts to make it "feel" like you have more torque, but doing so will decrease the topspeed of the car. __________________ Fixing legends is easier than fixing lolcats, but the parts are way more expensive.. My Wiring Nightmare..http://www.acura-legend.com/vbulleti...59/index3.html

08-19-08, 11:15 PM	#9 (permalink)
cheeseman0777 Registered User Join Date: Mar 2008 Location: north of Denton TX Posts: 222 Car 1: 1993 Acura Legend L 4Dr Car 2: expidition Car 3: 95 ford f250 xlt 7.4 iTrader: (0)	^^ok robot, what you are saying pretty much is the higher the torque, the more acceleration you got, but lower the speed, and higher the horses, the more speed you got? __________________ loving life and my legend. Alpine 2-ways in front, Sony 4-way's in back baby! will be getting it painted when i got the $$

08-19-08, 11:47 PM	#11 (permalink)
reboticon Registered User Join Date: May 2008 Location: Knoxville Posts: 1,119 Car 1: 95 Black 4dr Car 2: 92 Blue 4dr Car 3: 71 429& 87 5.0Tbirds iTrader: (3)	Not exactly. Low end torque is what makes your wheels spin when you are stopped and you floor it. By Low End, I mean the low end of the RPM band. Around 0-4000rpms. Horsepower is what is actually measuring the power to accelerate. Down here, we have Tractor pulls. Guys build tractors with huge wheels and see what they can pull. They have tons of Torque, but not much horsepower. So they can pull anything, but they dont have horsepower so they have low top speed. Basically, Torque is what gets your car moving. Horsepower is your acceleration. Now in my post before this, when i talked about changing transmission or differential parts, the way you are looking at it is correct. By changing the gear ratios in the transmission or differential, you can make it easier for the engine to turn the wheels. By doing so though, you are also making it so the Car will be spinning higher RPMS at the same speed then it was before you changed the ratios. For an automatic car, the best option would probably just be to get a higher stall torque converter. This would make your transmission not engage until the engine was at a higher RPM than normal, making it faster, at the expense of fuel economy. __________________ Fixing legends is easier than fixing lolcats, but the parts are way more expensive.. My Wiring Nightmare..http://www.acura-legend.com/vbulleti...59/index3.html

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08-18-08, 07:47 PM	#2 (permalink)
sap burning dinosaur bones Join Date: Jul 2008 Location: Edmonton, AB, Canada Posts: 620 Car 1: 93 L Coupe 6MT Car 2: 86 Camaro IROC Z Car 3: 05 Grand Caravan iTrader: (0)	Word on the Camaro and Firebird forums (specifically for the third gen TPI models) was that long runners was key. Factory numbers on my Camaro were 285 ft.lbs. but only ~190 HP. Aftermarket parts increasing power generally sacrificed torque by going shorter. I've never really had the time (or money for that matter) to play with my cars, so I can't give you much first hand info, but hang out around thirdgen.org for a while. The 82-92 camaro is almost spot on stock weight and I seem to recall plenty of torque vs. HP discussion.

08-19-08, 11:46 PM	#10 (permalink)
dog2525 How Do I Downshift? Join Date: Jun 2006 Location: NC Posts: 422 Car 1: 93 legend 5 Spd L iTrader: (0)	HP=speed torque=has fast you get there Don't know about the legend but the base model integra (B18b or B18a) has a longer stroke which makes more torque then the gsr (b18c) But the gsr has the vtec which helps it make more hp. Thats why people do the lsvtec

08-19-08, 11:58 PM	#12 (permalink)
sap burning dinosaur bones Join Date: Jul 2008 Location: Edmonton, AB, Canada Posts: 620 Car 1: 93 L Coupe 6MT Car 2: 86 Camaro IROC Z Car 3: 05 Grand Caravan iTrader: (0)	If At the end of the day what makes you go is torque applied at the wheels through the transmission and differential, since that is the force applied on the ground. If you increase torque at 3000 RPM, for example, you are also increasing your horsepower at that engine speed. What that higher horsepower is doing is making you able to increase the torque you put to the wheels. Higher HP means that you're producing lots of torque at high RPM. Lets pick some numbers out of thin air and say you need a driveshaft speed of 3000 RPM to match the speed you're going, and you've got my Camaro that's sitting somewhere around 275 ft. lbs of torque at that speed and driving through at 1:1 transmission gear. If I had a car that could rev up to 6000, but only produced 200 ft.lbs. of torque at that engine speed, I could move down to a 2:1 transmission gear and get 400 ft.lbs of torque instead of 275. If you have torque at high RPMs you can gear the output down to increase torque to the wheels. Conversely, the high torque car is an enjoyable ride because you don't have to rev it up to get that torque to the wheels. There is a good summary here. The water wheel example is fantastic.

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