FAQ  •  Login

What are Torque and Horsepower really?

<<

stm316

Naturally Aspirated

Posts: 42

Joined: Sun Jan 25, 2015 9:57 pm

Location: Melbourne, Australia

Cars: Ford Falcon BA XR6 (2004)
Ford Focus LS (2006)

Post Mon Feb 02, 2015 6:32 pm

Re: What are Torque and Horsepower really?

The 800NM "8Lt" engine would have a painfully long stroke, and thus not rev very high, or respond quickly, so I'd bet it wouldn't be geared to allow mass wheel spin.... but I could be wrong (think Kenworth at 60KM/H)
Image
<<

RobtheFiend

Supercharged
Supercharged

Posts: 640

Joined: Wed Oct 10, 2012 12:35 am

Location: Sweden

Cars: Opel Astra -99 1.6 16

Post Tue Feb 03, 2015 7:30 pm

Re: What are Torque and Horsepower really?

Chevy LS7 engine 7.0l 101.6mm stroke, max rev 7000. Max torque =640 nm
Dodge Viper engine 8.4l 100.6mm stroke, max rev 6200. Max torque = 813nm


So, why would a 8 liter engine have PAINFULLY long stroke? And not rev very high? Low responce?
<<

BlastersPewPew

Posts: 628

Joined: Wed Jan 15, 2014 7:01 am

Cars: Mazda 3

Post Wed Feb 04, 2015 7:14 am

Re: What are Torque and Horsepower really?

RobtheFiend wrote:Chevy LS7 engine 7.0l 101.6mm stroke, max rev 7000. Max torque =640 nm
Dodge Viper engine 8.4l 100.6mm stroke, max rev 6200. Max torque = 813nm


So, why would a 8 liter engine have PAINFULLY long stroke? And not rev very high? Low responce?


These are pushrod engines and because of that they are inherently limited to lower RPMs than a typical SOHC/DOHC setup UNLESS they are VERY well engineered. These two engines would be in that category, the Vipers V10 doesnt really have a "painfully" long stroke, its bore is actually larger than the stroke 4.055"x3.96" while the LS7 has a bore & stroke of 4.125"x4.00", to me these are engines that are quite "square" and not overly stroked. The main limitation for the LS7 is not due to the stroke but due to: "During GM's reliability testing of this engine in its prototype phase, the LS7 was remarked to have been repeatedly tested to be 8000 rpm capable, although power was not recorded at that rpm level, due to the constraints of the camshaft's hydraulic lifters and the intake manifold ability to flow required air at that engine speed." For the Vipers engine I would say its biggest limitation is also not the stroke but the fact that its engine design dates from the 1960s and is limited by its pushrod configuration.
<<

Jakop750

Naturally Aspirated

Posts: 6

Joined: Thu Nov 27, 2014 5:54 am

Cars: Volkswagen Caravelle 2.4D-93
Toyota Urban Cruiser 1.4 TD-12

Post Fri Mar 13, 2015 8:06 am

Re: What are Torque and Horsepower really?

Daffyflyer wrote:There are a lot of misconceptions around torque and horsepower. If you're still a bit puzzled after Robbo and Stevo's explanation, I suggest a read of this.

http://hooniverse.com/2010/01/14/dont-b ... -it-means/

for newbies the best explain is. Horsepower=Speed and Newton-Meter= acclration
<<

Daffyflyer

User avatar

Developer - Lead Artist
Developer - Lead Artist

Posts: 3444

Joined: Wed Apr 14, 2010 8:36 pm

Location: Wellington, New Zealand

Cars: 1993 Mazda Lantis Type R V6 Racecar, 2006 BMW 530i

Post Fri Mar 13, 2015 8:14 am

Re: What are Torque and Horsepower really?

Jakop750 wrote:
Daffyflyer wrote:There are a lot of misconceptions around torque and horsepower. If you're still a bit puzzled after Robbo and Stevo's explanation, I suggest a read of this.

http://hooniverse.com/2010/01/14/dont-b ... -it-means/

for newbies the best explain is. Horsepower=Speed and Newton-Meter= acclration



Errr. No.

Killrob silently facepalms in the background and shakes his head.
3d Artist, Game Designer, Marketing Guy

Follow us on
Twitter - http://twitter.com/AutomationGame
ModDB - http://www.moddb.com/games/automation
Facebook - http://goo.gl/omJzt
Chat http://automationgame.com/irc
<<

PhillipM

Silver Supporter
Silver Supporter

Posts: 272

Joined: Mon Aug 15, 2011 7:51 am

Cars: Peugeot 306
Peugeot 405 Mi16x4
Peugeot 406 V6 Coupe
Mazda MX-5 Mk1
Triumph GT6 MkIII
Mazda RX8-engined off-road race buggy.

Post Mon Mar 30, 2015 11:41 am

Re: What are Torque and Horsepower really?

I've been away for a full year and people still don't understand HP and torque?

Let me find a wall to bang my head against.
<<

Daffyflyer

User avatar

Developer - Lead Artist
Developer - Lead Artist

Posts: 3444

Joined: Wed Apr 14, 2010 8:36 pm

Location: Wellington, New Zealand

Cars: 1993 Mazda Lantis Type R V6 Racecar, 2006 BMW 530i

Post Mon Mar 30, 2015 12:42 pm

Re: What are Torque and Horsepower really?

PhillipM wrote:I've been away for a full year and people still don't understand HP and torque?

Let me find a wall to bang my head against.



But remember, you need lots of torque to successfully knock yourself unconscious. Also welcome back!
3d Artist, Game Designer, Marketing Guy

Follow us on
Twitter - http://twitter.com/AutomationGame
ModDB - http://www.moddb.com/games/automation
Facebook - http://goo.gl/omJzt
Chat http://automationgame.com/irc
<<

PhillipM

Silver Supporter
Silver Supporter

Posts: 272

Joined: Mon Aug 15, 2011 7:51 am

Cars: Peugeot 306
Peugeot 405 Mi16x4
Peugeot 406 V6 Coupe
Mazda MX-5 Mk1
Triumph GT6 MkIII
Mazda RX8-engined off-road race buggy.

Post Tue Mar 31, 2015 12:52 am

Re: What are Torque and Horsepower really?

Need a lot of horses output to post some of the stuff on torque though....:D
<<

JayZee88

User avatar

Supercharged
Supercharged

Posts: 70

Joined: Fri Mar 28, 2014 5:36 am

Location: Nebraska

Cars: 1970 Buick Electra 225 Convertible
2002 Buick Rendezvous CXL

Post Sun Aug 02, 2015 10:35 am

Re: What are Torque and Horsepower really?

1 more thing about torque I don't think anyone really mentioned. With higher torque numbers you can space gear ratios further apart, so you can 'jump ratios' faster. That (in my understanding) is due to the engine being able to handle that load better then given lower torque engine with same hp.
Buick Club of America and 1959 Buick Division Member
*1959 Buick Lesabre 2 dr hardtop
*1970 Buick Electra 225 Convertible
*2002 Buick Rendezvous CXL
<<

nialloftara

User avatar

Supercharged
Supercharged

Posts: 1983

Joined: Wed Feb 05, 2014 2:07 pm

Location: Northeast USA

Cars: 2006 Scion Xb

Post Wed Aug 12, 2015 10:11 pm

Re: What are Torque and Horsepower really?

Found this quick but interesting and relevant article. On butt dynos, torque, and gearing. http://www.roadandtrack.com/car-culture/features/a25271/fool-your-butt-dyno-for-fun-and-profit/
Chief designer and CEO, Centauri motor works, Centauri Performance Vehicles (CPV)
"Centauri: The Stars Are Within Your Reach."
Centauri engines Centauri cars
CPV engines CPV cars
Company ID: 1943047
<<

PhillipM

Silver Supporter
Silver Supporter

Posts: 272

Joined: Mon Aug 15, 2011 7:51 am

Cars: Peugeot 306
Peugeot 405 Mi16x4
Peugeot 406 V6 Coupe
Mazda MX-5 Mk1
Triumph GT6 MkIII
Mazda RX8-engined off-road race buggy.

Post Tue Sep 22, 2015 3:12 am

Re: What are Torque and Horsepower really?

Arse dyno's, unless very finely calibrated, (lets put it this way, I work with a lot of racers, I trust one of them to give me accurate arse dyno feedback. One) feel the change in acceleration, acceleration squared, effectively. Which is why engines with a broad spread of torque (S2000, RX8), get blasted by idiots on the internet for being torqueless. Because they can't feel a constant surge, they're waiting for a kick that never comes.
To the extent that Honda actually deliberately put a dip in the torque with the S2000 so that when it kicked back in again you got to go VTEC YO!

Engines with inconsistant torque curves that suddenly jump up and drop off (big turbo's, etc), feel fast because the rapid change in the acceleration of the acceleration. Even if they're not.
I can make your car feel a lot faster with the engine mapping even when it's actually going slower by putting ramps in the torque curve - a fact many flight-by-night chipping/remap firms exploit.
<<

zag

Posts: 1

Joined: Sun Jan 24, 2016 2:28 pm

Cars: A Golf Buggy!

Post Sun Jan 24, 2016 3:20 pm

Re: What are Torque and Horsepower really?

It's a shame, you completely disregard diesel engines. Which actually put their "power" as the torque they produce rather than HP which is a lot lower than petrol motors, a 2000lb/ft diesel will blow the doors off any petrol motor on the dyno. even though it could be a 1000HP motor.
<<

Killrob

User avatar

Developer - Lead Beta Tester/Producer/German Efficiency Expert
Developer - Lead Beta Tester/Producer/German Efficiency Expert

Posts: 3711

Joined: Fri Mar 11, 2011 1:00 am

Location: Lower Hutt, New Zealand

Cars: I owned a Twingo... totally bad-ass!

Post Mon Jan 25, 2016 7:40 am

Re: What are Torque and Horsepower really?

zag wrote:Which actually put their "power" as the torque they produce rather than HP which is a lot lower than petrol motors

No they don't. Read and look at the various links posted in this thread, you are spewing nonsense.
<<

isomgmsghs

Supercharged
Supercharged

Posts: 87

Joined: Tue Apr 29, 2014 7:40 am

Cars: 2014 ford fiesta sfe ecoboost.

Post Wed Jan 27, 2016 10:19 am

Re: What are Torque and Horsepower really?

easy, horsepower is torque times RPM divided by 5252.

I have made a gasoline/petrol engine that has efficiency as good as diesel and a torque curve just as good. Using premium gas.
Attachments
Untitled.png
Untitled.png (1.38 MiB) Viewed 15593 times
<<

isomgmsghs

Supercharged
Supercharged

Posts: 87

Joined: Tue Apr 29, 2014 7:40 am

Cars: 2014 ford fiesta sfe ecoboost.

Post Wed Jan 27, 2016 11:27 am

Re: What are Torque and Horsepower really?

I also just made a replacement for the factory Cummins 4BT engine, originally 265 TQ at 1600 RPM and 105HP at 2500 RPM.
This gasoline version has 45% more torque at 1600rpm and 140% more HP at 4000RPM. same bore and stroke. nearly same efficiency.
Attachments
Untitled.png
Untitled.png (1.42 MiB) Viewed 15583 times
PreviousNext

Return to General Chat

Who is online

Users browsing this forum: No registered users and 0 guests