Talk:Lotus 56

Racing car template

I've had a stab at a template for racing cars (see template:Racing car) to summarise the usual data. I've used the F1 templates as a starting point and applied it to the Brabham BT46 article. If anyone's got an interest in this, please have a look at the template and modify or suggest changes as appropriate. After a few people have had a go at it and we have something we're happy with we could start to use it more widely. Note that it's not meant to be specific to F1, by the way. Cheers. 4u1e 09:37, 2 July 2006 (UTC)

No clutch?

Sorry, but that doesn't make much sense. No clutch works fine for an electric motor powered car, but it makes no sense for a turbine powered car. A turbine runs at like 5-10,000 RPM. You can't start it out from 0 RPM and just put fuel into it and run it up to revs, it needs to be spinning all the time. if you had a car without a clutch, you could air start it with a hose from an air compressor, but you could never, ever stop it once it was going, or you'd kill the engine and be helpless until someone came along to start you again. I mean, maybe, just possibly, you could throttle the engine back far enough that the flame would be maintained and enough air flow would continue though the engine to keep the first stage turbines powering the compressor running, but NOT so much air flow that you couldn't stop the power extraction turbine dead in the casing against the force of the gas stream. As long as the brakes on the car were strong enough, it would feel something like using the brakes in a car with an auto transmission with a slightly stuck open throttle.

That's the only way I can imagine a turbine car without some sort of clutch mechanism could work, basically with the power extraction turbine acting as if it was a centrifugal clutch, and "ignoring" low gas flow levels, only picking up real torque when as flow increases after a certain point. In fact, it would be roughly functioning as a fluid coupling, except using hot gasses as a working fluid instead of hydraulic fluid. But it still seems like it would make a lot more sense to just fit a clutch, or some equivalent such as a torque convertor, for a number of reasons.

64.223.163.142 (talk) 00:53, 13 February 2021 (UTC)

I would also add that "no gearbox" doesn't seem likely either, unless the output shaft of the turbine drives the rear differential directly, without any sort of gearing at all. Much more typical is a single-speed gearbox, as seen in the STP Turbine car, and most electric motored vehicles. Just because it doesn't have multiple gear ranges doesn't mean it has no gearbox. What is described in this article is an absolutely direct-drive turbine-powered car, with a turbine shaft bolted directly to the differential, no gearing, no form of disconnection possible: whatever speeds the wheels are turning, whether stationary or 200mph, the extraction turbine is spinning at the same speed (allowing for the differential gear ratio of course). And vice versa. I can't think what the benefits of this would be, besides the weight savings of the deleted clutch and gearbox. Starting would likely be much slower (even assuming what I described above is possible), but I suppose that would matter much less in a rolling start race, or a race where victory is found from running nonstop at a steady pace, like at Lemans. And above a certain engine speed, the turbine is probably so much more effective that rolling acceleration is roughly on par with piston engine motors. Altough you'd still have to learn how to drive a car without lifting on and off the accelerator for every corner, since turbines have much slower reaction times from piston engines. You'd have to learn to brake the car against the engine, which is still trying to drive it ahead. Which is another reason why a clutch would seem so crucial in such a car. Even if you could brake against bot momentum and the force of the engine, how much brake effectiveness would that cost? And how much more heat would you be putting into the brakes? Not to mention that much of the heat would be wasted fuel energy. I suppose one could design a turbine in which the fuel flow could be cut rapidly, and the output speed is independent of the speed the gas generator core is spinning, so you could decelerate and accelerate the car without waiting for the actual engine to change speed (or more importantly, for the engine to spool up again afterwards).

64.223.163.142 (talk) 01:37, 13 February 2021 (UTC)