I kinda saw this today lol, the UF1 has highest 8000RPM on the RMP meter but maxes out 7k, isnt that to much for a 1000cc, 50BHP little car? I mean, my dad's BMW E90 318 Touring has maximum 5k in red, so how the hell can such a little car have so much RPM?
UF1 RPM to high?
(14 posts, started )
UF1 RPM to high?
#2
- hrtburnout
Maybe it's because the unitary capacity of each cylinder is much smaller.
My bikes 50cc and goes all the way to 9,000+ RPM.
(I'll give you a hint - Engine CC != Max RPM)
(I'll give you a hint - Engine CC != Max RPM)
I have 12 times the volume and 2 times the RPM, so there really isn't any point in comparing engine CC and max RPM
The smaller the mass/cc per cylinder and the shorter the stroke, the higher RPM you can get, at least theoretically.
More like the less reciprocating mass (not mass/cc), particularly in the piston, the shorter the stroke, and the more balanced, the higher the engine can rev. Bore doesn't have any effect except for the fact that it tends to add reciprocating mass.
A short stroke engine will always have a higher rpm than an equivelent displacement long stroke engine. There is less distance to push the mass around and you can reach higher speeds with less chance of something fraging because things arn't moving as far.
My 75cc miniMX redlines at 10,500rpm. My dads 6.5L(6500cc) diesel engine redlines at around 4000rpm. Thats because my bike engine has a wide bore with a shorter stroke. Most gasoline engines (most V8s not included) are made with as short a stroke as possible to reduce the chance of a frag if you over rev them.
Short stroke engines also exibit a higher engine braking effect than same displacement engines with a long stroke.
Most lawn mower engines redline at 3000-4000 rpm, because they are long stroke (don't ask how I know that
)
My 75cc miniMX redlines at 10,500rpm. My dads 6.5L(6500cc) diesel engine redlines at around 4000rpm. Thats because my bike engine has a wide bore with a shorter stroke. Most gasoline engines (most V8s not included) are made with as short a stroke as possible to reduce the chance of a frag if you over rev them.
Short stroke engines also exibit a higher engine braking effect than same displacement engines with a long stroke.
Most lawn mower engines redline at 3000-4000 rpm, because they are long stroke (don't ask how I know that
)Well the UF1 has a long stroke I would imagine, since it has like 65ft/lbs of torque @ 3000rpms.. Longer the stroke = more torque.
The torque curve could be similar to my bike, it's basicaly flat.
My bike has similar torque at 4000rpm as it has at 9000rpm, it only rises a bit after around 3500rpm, after that it's power all the way to redline.
you also have to consider with a large surface area because of the larger piston face you'd still get alot of torque from a small engine.
My bike has similar torque at 4000rpm as it has at 9000rpm, it only rises a bit after around 3500rpm, after that it's power all the way to redline.
you also have to consider with a large surface area because of the larger piston face you'd still get alot of torque from a small engine.
(Cash_FLow)
DELETED
by Cash_FLow
Errr, I did not intend to say mass/cc (as in mass per cc), but "the smaller the mass, respectively cc-per-cylinder..."
please don't make it any slower! :P
Whilst I don't think the redline is inappropriate, reducing the revs wouldn't necessarily make it slower, as long as the torque curve was adjusted to compensate (within realistic limits). That way the only thing that ultimately changes is the numbers on the dashboard, and that would somehow keep some of the moaning at bay by people who don't really understand engines, cars, or driving.
Say what? Are you sure it's not a diesel?
It would be strange for the E90 318 to have a 5000k redline, as the peak power is at 6000k...
Oh my bad, i forgot that to mention, yes mr its a diesel
UF1 RPM to high?
(14 posts, started )
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