Quake3World

Okay, so I need a little help here understanding the basic principles behind an accelerating car, mainly the importance correlation between acceleration, gear ratio, horsepower and torque.

I mean, as I understand, the best acceleration is achieved at the peak horsepower point, but why the fuck do people supply me with torque charts to measure how well a car accelerates then?

more torque mean's you'll get there quicker.

edit: whoops hold on

I'm sure somebody less lazy then me will explain it better.

check pm's

Okay, I think I got the general hang of it, cheers.

maximum thrust is achieved at peak torque not peak horsepower

Here's a very good article on Analyzing hp vs. torque

Ask ToxicDud.

Horsepower = Revs x Torque

Petrols generally rev much higher than say a diesel, therefore needs less torque to produce the same output. A diesel revs much lower therefore needs lots of torque to produce the same power.

I have a diesel, and it produces twice the torque of a friend of mines car, yet their both roughly the same speed because his is petrol and revs more.

i have been seeing alot more chipped TDI Jetta's around now...

its interesting to sat the least seeing a TDI beating the shit out of other VW's ( including the 1.8T's ) wile spewing black smoke out of the pipe.

and i mean spewing.

AmIdYfReAk wrote:i have been seeing alot more chipped TDI Jetta's around now...

its interesting to sat the least seeing a TDI beating the shit out of other VW's ( including the 1.8T's ) wile spewing black smoke out of the pipe.

and i mean spewing.

Stock or chipped 1.8T's?

Stock obviously.

a chipped TDI can do in the ball park of 250Ft/pds.. wile a 1.8T will do 275... stock chipped on both sides.

Yea I know, thats why I asked. A stock 1.8T is so slow that you wouldn't really compare it with anything... a chipped one is better.

allright, if you want to talk about torque.. you should take a look at this..

http://video.google.com/videoplay?docid ... 3077382755

if all else fails, just give er.

AmIdYfReAk wrote:allright, if you want to talk about torque.. you should take a look at this..

http://video.google.com/videoplay?docid ... 3077382755

if all else fails, just give er.

LOL TOXIC YOU WILL LIKE THIS

http://videos.streetfire.net/Player.asp ... 54E0A3&p=0

Okay I still can't wrap my head around one thing:

Take a big truck that has lots of torque. Take a small jap car. Put said jap motor in big truck. To make the truck go, you would have to rev the small engine incredibly high to gain the same amount of torque. Seems to me like making it accelerate depends on torque*revolutions, so HP is the determening factor here. No?

At the same time, torque would basically be number of revolutions that the crankshaft makes, but (with a constant ratio of transfer losses between the gearbox etc) should still be the number of revolutions the truck makes, e.g. higher torque would make it accelerate.

(edit) While thinking about it with a clearer head, it would still seem that torque makes the car move. So ideally the car accelerates the best when it has max average torque, correct?

BTW, wtf would horsepower then be? The amount of work the engine does, which is not in direct correlation with how fast the car goes? (Torque and horsepower peaks in different places)

Would energy input(amount of gas) and horsepower in a 1:1 correlation?

related note.. anyone got that video of the ridiculously overmodded car at 1000s of BHP on a rolling ramp surrounded by fans? I can't remember the car, think it had GT40 stripes, but it was on the ramp, and it spins up and just keeps getting louder and louder and louder and then they show you the output graph at the end.

EDIT: I think it was a corvette

On another slightly related note, concerning the power of TDIs, I find it quite impressive that Audi has been kicking ass at Le Mans with a diesel. At least I think they are...

Anyway, is that the only TDI that's being used at Le Mans? Anyone know?

Scarface wrote:maximum thrust is achieved at peak torque not peak horsepower

Here's a very good article on Analyzing hp vs. torque

Taken from this article:

"The trick to a strong powerband is to reach peak torque at a relatively early point then hold that consistant torque output to get a good horsepower number. It's really a compromise of having a big peak number and reaching peak torque at an early point, since low end and high end power often don't mix."

"In the high RPM's it doesn't take much torque to make more horsepower, so when dealing with motors of similar peak HP numbers, you can bet the one with the larger peak torque number is going to have the stronger powerband."

On Jan 14th my car club is having a dyno day... I'll post the dyno sheets. i am kinda curious what it will be putting down, since I should have an aluminum driveshaft and 3.73 gears put in by then.

what mods? i/h/e?

Scarface wrote:what mods? i/h/e?

full intake, 93 octane tune, and catback exhaust. depending on how much shit i can get for a paintball gun and watch on ebay, I'll get some hooker super comp LT headers
The car hasn't been dyno tuned yet. that will be in a few months