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Old 06-15-2006, 04:53 AM
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Coventrysucks Coventrysucks is offline
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Quote:
Originally Posted by spi-ti-tout
So, the rev output has absolutely no linking with the quality of engine.
The rev output of the engine, i.e., the maximum revs that the engine can achieve is linked to quality.

An F1 engine can do 19,000rpm - you need very high quality materials and manufacturing techniques to do this: to stop bits of the engine hitting each other/bending/breaking etc,.

The revs that you achieve at a particular speed & gear in a car is nothing to do with the quality of the car's engine, but is governed by the gear ratios.

Quote:
Originally Posted by spi-ti-tout
Why are the revs so short
At a complete guess I'd say it was due to the flat 6 configuration.

Useful Stuff About Configurations: http://www.e31.net/navmisc_e.html

Quote:
Originally Posted by spi-ti-tout
and does this mean top speed is affected?
Depends on gearing & power.

You need power to overcome friction & drag.

For a certain ammount of power you can get a certain ammount of speed.

You need to have the gearing set up so that the wheels can actually turn that fast at the correct engine revs.

E.g., if you need 500bhp to get your car to 200mph, and it produces 500bhp at 5000rpm, your gearing needs to work out so that when the engine is at 5000rpm the wheels are turning at 200mph.

Obviously if you have top gear set to do 250mph at 5000rpm, you probably won't get to 200mph, because the get the wheels at 200mph, the engine would have to be at 4000rpm, which might only generate 450bhp, which is only enough power for, say, 185mph; that would be your top speed.

With the correct gearing you should be able to get a vehicle to the same top speed whether you power it with an engine that produces 500bhp@1000rpm, or 500bhp@10,000rpm.

Quote:
Originally Posted by spi-ti-tout
are shorter revs more "brutal" and "aggressive" than higher ones?
Depends on what the engine is.

A big 26 tonne marine diesel producing 5000bhp at 1000rpm isn't going to be remotely "brutal" or "aggressive" as the moving parts are very large, therefore more difficult to accelerate.

A 2.0-litre V8 weighing 75kg producing 500bhp to 10,000rpm will be more brutal because the moving parts of the engine are easy to accelerate.

However, a 26 tonne diesel engine with a max. engine speed of 10,000rpm would be just as sluggish, and a 75kg V8 with a max. engine speed of 1000rpm would be just as fast.

(I think...)
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