F1technical.net

xpensive wrote:Correct flyn, but I didn't say the two cars were accellerating, why we can forget wheel-mass and engine-characteristics.

so what is the question?

Try back-tracking this thread a bit.

I am a few pints into the night

but you are asking if the wheel size makes a difference

assuming a perfect world no both are doing the same amount of work. one has more TQ one has more RPM

so the one with the larger wheel is applying more tq to the axle at a lower rpm

xpensive wrote:

Scotracer wrote:Maybe I'm just tired but it appears we're getting two different analysis methods confused...

well, it's certainly confusing me

Sorry for coming across as arrogant Scot, but see it another way;
Two identical cars, travelling at the same speed, applying the same amount of Power, while one of the cars has wheel-radius of 0.6 m, the other's got big 0.8 mothers.

With the same Vehicle-speed and Power applied, and when power is Torque times Rpm, two different Wheel-radiuses must give different Wheel-rpm and as a consequence different Wheel-torque, no?

If they are travelling at the same velocity, yes. I get what you mean now.

So at the end of the day, what really matters is the amount propulsion force generated, not in which way it is produced, through engine-torque or engine-speed

Not exactly, xpensive. You have "secondary" effects, and how you handle those secondary (or tertiary) deviations from theory is what distinguishes a great engineer (like us) from lousy wannabes (like other engineers that doesn't belong to this forum).

As Scotracers said, well, yes, the torque at the wheels is different if the wheels have different radii, but the HP is the same. To repeat what has already been said many times, HP is the integral of torque respect of angular velocity (RPM).

This thread is exactly like asking: what is more important, force, mass or acceleration. Duh.

However, to answer xpensive "neutrality", engines with larger torque and less RPM (but with the same HP as another engine) are (usually) heavier, aren't they? So, from immemorial times, the race is for RPM.

For example, you could use larger tires, sure. You would have more torque at the wheels (and less RPM, for the same HP). But then you will have more weight on the car and a larger unsuspended mass: a no-no, definitely.

So, my conclusion: an ideal car would have wheels of zero radius with zero mass and infinite RPM (which would give you infinite HP). I wonder why they haven't invented those wheels already. Probably the gearbox would be a nightmare to design, if I follow correctly Riffraff ideas.

I haven't figured out yet what would happen with infinite RPM and zero torque, btw, but any person in this forum who has driven a Fiat 600 knows what I mean.

In this particular car (I mean, in the Topolino) RPM are almost infinite, or at least the car engine sounds like it has infinite RPM when you floor it, but the torque is almost zero. Maybe that's the reason why Fiat bought Ferrari: to be able to race AND, at the same time, avoid infinitely complex questions, like the ones posed by the little Topolino.

Actually, when you drive a Fiat 600, sometimes you wonder if you have pressed the brake instead of the gas pedal... sometimes the car brakes when you accelerate.

On the other hand, as I already said, we have cars like the Hummer. This car (this is a military top secret, don't tell anybody outside the Internets, please) has infinite torque, it can climb vertical walls with zero friction. I think it doesn't need a clutch: you simply accelerate. Why would you need a clutch with infinite torque? It's a waste.

On the other hand, Hummer's engine max RPM (in the american tradition) are almost zero, so the end result is zero HP. That's the reason why people race in Topolinos, but I haven't heard of a Hummer race yet.

So, in the end, at the "quaternary effects" level, it's the RPM, stupid.

End of the thread, I hope (yeah, sure).

You have a way of xplaining technical issues so eloquently, great moderator.

Taking into account the "secondaries", the optimal soulution for F1 would be a tiny 60 degree V12(for ultimate balance), 30k Rpm screamer with a Williams-type Steelbelt-CVT in order to run at peak-power all the time!

Btw, now you can close this thread if you wish.

xpensive wrote:You have a way of xplaining technical issues so eloquently, great moderator.

Taking into account the "secondaries", the optimal soulution for F1 would be a tiny 60 degree V12(for ultimate balance), 30k Rpm screamer with a Williams-type Steelbelt-CVT in order to run at peak-power all the time!

Btw, now you can close this thread if you wish.

I'd say the most efficient solution would be a tiny V8 engine with twin-turbos. No need for ridiculous revs.

Honda got 16hp (depending on where you read) out of their RC116: a 50cc fourstroke twin cylinder roadrace bike from 1966, max power was at 21500 or possibly 22500rpm. 320hp/l... Too bad they didn't continue racing, I heard they were planning a 3-cylinder engine for '67, just to keep it together at even higher rpm. I wonder what that could have turned out like with another 40 years of development? Scaled up to F1-size, that could have been something ridiculously powerful.

Interesting indeed, when 320 Hp/liter at 21500 Rpm is pretty close to what today's 2.4 liter V8's did at 19k Rpm, 760 Hp?

xpensive wrote:Interesting indeed, when 320 Hp/liter at 21500 Rpm is pretty close to what today's 2.4 liter V8's did at 19k Rpm, 760 Hp?

Remember BMEP for a naturally aspirated engine doesn't really vary that much.

Scotracer wrote:

xpensive wrote:You have a way of xplaining technical issues so eloquently, great moderator.

Taking into account the "secondaries", the optimal soulution for F1 would be a tiny 60 degree V12(for ultimate balance), 30k Rpm screamer with a Williams-type Steelbelt-CVT in order to run at peak-power all the time!

Btw, now you can close this thread if you wish.

I'd say the most efficient solution would be a tiny V8 engine with twin-turbos. No need for ridiculous revs.

I like that as well, an 800 cc V8 and free boost? On Methanol perhaps?

800 cc?

Well, talking about efficiency, as Confucius said: "Dear Grasshopper, an 800 cc might be better than a middle sized 8.000 cc american engine, but, which one lasts more races?"

xpensive wrote:You have a way of xplaining technical issues so eloquently, great moderator.

Taking into account the "secondaries", the optimal soulution for F1 would be a tiny 60 degree V12(for ultimate balance), 30k Rpm screamer with a Williams-type Steelbelt-CVT in order to run at peak-power all the time!

Btw, now you can close this thread if you wish.

electrically coupled turbine. You get the revs with one or two moving parts and now up and down. And opens up the possibly for an afterburner and kers that makes sense.

Ciro Pabón wrote:800 cc?

Well, talking about efficiency, as Confucius said: "Dear Grasshopper, an 800 cc might be better than a middle sized 8.000 cc american engine, but, which one lasts more races?"

Esteemed moderator,
Considering that the 1500 cc turbos made 1300+ Hp on free boost at some 10k Rpm, an 800 cc should yield 700+ Hp, same as today. Add 25 years of technology, reliability should not be a problem either me thinks. =D>