Ah, but to offset this, a large engine typically runs much longer gearing, allowing the engine to turn slower giving lower friction losses and requiring more throttle to be used. Low RPM, wider throttle position usually means that they can return reasonable economy vs a much smaller engine with...
Well, quite. There is a lot of variables! I am not convinced that it easier to lock up the wheels at lower speeds. But some people are.
To my mind, all else being equal, there is the same normal force on the tyres in either case, so the same brake force can be applied. What is not constant (and...
A 100mm stroke at 7500rpm has an MPS of 25m/s.
The peak piston speed with a 150mm rod is 41.22m/s. With a 200mm rod is 40.42m/s.
A change of about 1.9%. Is that significant?
Speed requires power to overcome drag.
An engine consumes fuel according to it's BSCF and the power generated.
BSFC is lower at higher loads, so effectively as the speeds increase, the BSFC decreases.
Obviously, there is a sweet spot, and either side will see an increase in consumption, but...
I am interested in the forces at play determining wheel lock up at different speeds.
Lets say a car is capable of locking the front wheels up at 130mph.
Does it lock up the wheels significantly easier at 30mph? If so, why?
If we assume it can generate the same acceleration level from both...
That might be a trend over the majority of the RPM range, and it makes sense.
Is it definitely the case as the piston is approaching/passing around 27m/s though? Have there been any studies to specifically study this aspect?
Another effect of ZD setups that I have observed on my self built 3D kinematics models (and I do appreciate I might not have the load transfer theory 100% correct here) is that when the inside wheel tops out, the outside wheel continues compressing at it's normal rate. The effect is that the car...
Another plausible reason is flame front speed. I've seen speeds of 100ft/sec mooted. That's 30m/s.
So a combination of inlet mach index and 'outrunning the flame' is the most likely answer. If the mach index doesn't get you, the flame speed will.
I'm not so sure it's to do with materials, and more to do with the mach index in the inlet ports nowadays. The theory is that engines effectively choke above 25-26m/s, without a LOT of work. A drag engine, as I assume a 14000rpm SB Ford to be, are not really comparable to anything designed to...
OP this one does fuel flow rate amongst other things:
http://blackartdynamics.com/Engine/EngineThermodynamics.php
I don't know if it is any more useful to you really as the inputs may be limited for what you want, but might be worth a look.
Accepted maximums are closer to 5000fpm (25m/s) nowadays. You won't find many, if any, production cars exceeding that level. You'll not find many racing engines designed with any degree of endurance surpassing it either. Drag engines are another matter.
FLLTD = Front Lateral Load Transfer Distribution i.e. how much load transfer has happened at the front. It changes with lateral acceleration.
Perhaps it should be called 'Front Diagonal'.
Whatever it is called, the differential between front and rear load transfer is not constant.
