What do you consider a high revving engine?
Discussion
Something often said is about certain engines revving high, while others don't.
Anyone care to put figures to this?
Personally being "revvy" or not is more about the nature of willingness to rev rather than the outright rpm limit. But curious what others think, as often one revvy motor vs a lazy non revvy motor might only be 500rpm difference in red line.
So for a 'normal' mass produced petrol engine, what would you consider to be a high or low revving engine?
Anyone care to put figures to this?
Personally being "revvy" or not is more about the nature of willingness to rev rather than the outright rpm limit. But curious what others think, as often one revvy motor vs a lazy non revvy motor might only be 500rpm difference in red line.
So for a 'normal' mass produced petrol engine, what would you consider to be a high or low revving engine?
My S4 V8 red lines at about 7,500rpm. I would consider that high revving for a large displacement engine
My Landy S3 revs to about 4,000rpm (although, it feels as if the world is about shake apart much after 3,000!). I would consider that low revving for a small displacement petrol engine
My Landy S3 revs to about 4,000rpm (although, it feels as if the world is about shake apart much after 3,000!). I would consider that low revving for a small displacement petrol engine
- to be fair this may not be what you consider to be 'mass produced'?... and I completely forgot that you didn't mention the word 'car'. Sports bike engines rev much higher of course, my 600 redlined at 14500, others at 15500.
On the other hand my Harley Sportster has the redline at 7000, though it's very unusual for me to be cruel enough to it to hit that, even though it's been tuned to do it. BTW that's a lot higher than most other Harley aircooled engines.
As with so many things the answer is 'it depends'
On the other hand my Harley Sportster has the redline at 7000, though it's very unusual for me to be cruel enough to it to hit that, even though it's been tuned to do it. BTW that's a lot higher than most other Harley aircooled engines.
As with so many things the answer is 'it depends'
300bhp/ton said:
schmalex said:
My S4 V8 red lines at about 7,500rpm. I would consider that high revving for a large displacement engine
Curious, but what exact correlation do you have with displacement vs how high an engine can rev?All other V8s I've owned have red lined lower than that, though.
When driving where do you find the revs are when making normal sedate progress, constantly above 3000rpm or happy between 2000 - 2500?
Above 3000 in normal use I'd say is revvy, my MR2 is like that 8200 redline and little torque. Audi is only over 3000 if going quickly, normal driving its alway below, but then it has something like 250lbs from 1350rpm even though it will do 7200 rpm.
Above 3000 in normal use I'd say is revvy, my MR2 is like that 8200 redline and little torque. Audi is only over 3000 if going quickly, normal driving its alway below, but then it has something like 250lbs from 1350rpm even though it will do 7200 rpm.
300bhp/ton said:
Personally being "revvy" or not is more about the nature of willingness to rev rather than the outright rpm limit. But curious what others think, as often one revvy motor vs a lazy non revvy motor might only be 500rpm difference in red line.
For me it comes down to where peak torque is. All engines feel "revvy" up to peak torque. As torque is increasing, the rate of change of power is increasing. While torque is decreasing, the rate of increase of power is decreasing which makes it feel like you should change up even if the absolute power is still increasing.The nearer peak torque is to peak revs the more "revvy" an engine feels.
Bill said:
6-6.5 seems pretty standard, so above that is high. IMO.
Yep, I doubt you'd find many average cars revving to 7000 without them being described as a sporty model.Faster than 7000 starts to mean things like greater strengthening of rods and valve springs, heads and intakes designed especially for getting the air in, and those things add to the cost of the engine which would be avoided on a regular model.
jones325i said:
But having 8 cylinders (as per the v8 Audi mentioned) means that the displacement can be achieved without a long stroke.
Which is why some are better than others.300 asked what the correlation is, that's it.
The equation for the maximum safe limit is:
25/(2*(stroke)*60
Stroke is in meters. So the S4 V8 with its 92.8mm stroke could do 8081rpm, so 7500rpm is pretty good.
The S2000, with it's 84mm stroke could do 8928rpm, so it's 9000rpm limit is incredibly close, as you would expect.
300bhp/ton said:
schmalex said:
My S4 V8 red lines at about 7,500rpm. I would consider that high revving for a large displacement engine
Curious, but what exact correlation do you have with displacement vs how high an engine can rev?given that 'slow speed' engines as previously mentioned with their 200 rpm red lines have cylinder capacities ranging from dustbin to room sized ...
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