motor

marciodcmendes · 02-07-2004, 07:39 PM

I was watching a top gear vid about the new mazda rx8. It has 230 bhp but low torque. What does that mean?

godspeed06 · 02-07-2004, 07:41 PM

basically it means for the car to pull hard it has to be in a high rpm range.

godspeed06 · 02-07-2004, 07:42 PM

basically it means for the car to pull hard it has to be in a high rpm range.

edit- sorry delete this, my computer had some serious lag.

marciodcmendes · 02-07-2004, 07:45 PM

but what is most important? Lots of bhp or torque?

jon_s · 02-07-2004, 07:46 PM

when they say 'low torque' did they mean it had a small amount of torque? Or it kicked in low down??

As it is an RX8, I think it is the latter. Torque, very generally is a good indication of in gear acceleration. Whicle raw BHP is a good indication of top speed. If you have a small amount of torque, when you put your foot down, it takes ages to pick up speed, but if you have a lot of torque you pick up speed quickly.

There is a certain rev-range in earch car, where torque is at an optimum. So when they say 'low torque', they may mean the torque is strong at low revs, which means you can be lazy with your gears.

If, lets say, your torque kicks in at 5,000 rpm, then while you are accelerating, you will feel the car accelerate quicker when you hit 5k, but if it kicks in at 1500rpm, then the car will in general accelerate quickly.

marciodcmendes · 02-07-2004, 07:47 PM

but what is most important? Lots of bhp or torque?

jon_s · 02-07-2004, 07:49 PM

A balance. BHP is nothing without torque, and torque is nothing without BHP.

A lot of torque is what causes the wheels to spin while accelerating...so if you have too much it may be a bad thing. As I said before, the more BHP you have, in general the higher top speed.

marciodcmendes · 02-07-2004, 07:50 PM

I get it. thanks a lot.

jon_s · 02-07-2004, 07:53 PM

No problem, there are people on here who know a LOT more than I do on the subject, but I think I am right in what I say lol

Maverick7K · 02-07-2004, 07:54 PM

If a car doesn't have torque, it wouldn't go anywhere. Smaller cars with a descent amount of horsepower can get away with having a lower amount of torque (i.e. honda s2000 240bhp and 161lb*ft of torque). This car also weighs only 2850lbs.

The Mazda RX-8 has 238bhp and 164lb*ft of torque (which weighs 2950lbs).

Muscle cars have traditionally about the same or a higher amount of torque than horsepower. It all depends on what kind of feel you want when you step on the pedal.

marciodcmendes · 02-07-2004, 08:02 PM

So dragsters have lots of both, right?

zevolv · 02-07-2004, 08:13 PM

dragsters have bitchloads of both yes. Torque is all about turning those wheels (torque=force*distance) so if your car has the power to turn the engine it can create alot of torque and that's why most larger engines have a longer stroke and that's the advantage of a long block over a short block.

marciodcmendes · 02-07-2004, 08:16 PM

Thnks. And I love your "little" collection. I have one myself, but all the cars have 20, 25 centimeters. lol

zevolv · 02-07-2004, 08:19 PM

I have quite an extensive model collection too if that's what your getting at. I have 3500 Hot Wheels/Matchbox cars and about 30 other size models both made and bought complete.

Maverick7K · 02-07-2004, 08:20 PM

Originally Posted by zevolv

dragsters have bitchloads of both yes. Torque is all about turning those wheels (torque=force*distance) so if your car has the power to turn the engine it can create alot of torque and that's why most larger engines have a longer stroke and that's the advantage of a long block over a short block.

Very true...except isn't Work=Force*Distance and Torque=Force*Lever Arm(in m or ft)?