Automotive Technology

I would not be concerned about how a sports car got up to speed. What is needed is absolute control on the down shift for cornering. This is where the driver approaching a turn needs to be in the appropriate gear to come out of the corner, especially on a double apex corner. Feathering the clutch for braking and immediate power after the apex will keep the weight transfer/power vector/traction coefficient more effective than drifting or relying on the vagaries of an automatic transmission. The front wheels turning ability must not be overpowered by the brakes. In other words, it could get hairy without precise control. And cornering ability is what wins a race more than suitably matched power plants within a given racing class.

So yup, it's all in the transmission.

For track use I agree with some of what you say, but power to weight is important, as is weight distribution.

Getting up to speed, or more exactly, exit speed from a turn, is what wins races.

As far as a sports car for the street, well, just about anything goes I imagine. Many so called sports cars are sold with automatic transmissions already and buyers often times are more concerned about self image. So, I would argue that the transmission is only a concern for a fraction of the total sales made in the US.

There are a small segment of purists, such as myself, that look very skeptically upon technology in a "sports" car. However, many buyers want stigma or brand recognition and are less concerned about what is under the hood or inside the transmission.

You're right about power to weight but it all goes thru the transmission. If you hang around the drivers and pit crews the talk is as much about gear ratios, suspensions, and cornering techniques as it is about tweaking the engines within a given class. And the class is largely defined by the power to weight ratio. So for me that ratio is a given. Formula V's do not compete with Formula B's for that reason. And FV's often put on a better show.

I guess I am a purist in that respect, as I have no use for the 'image' provided by such as the "Vette' which can't handle worth a darn. I'd rather drive a truck.

Given the high torque and low CG of a hybrid I have no doubt they have the possibility of cornering and accelerating as well as IC cars of a similar weight. But you can't feather an automatic, which is were traction control comes into cornering ability. The transition between braking, deceleration, and power needs to be smooth and precise in order to take advantage of the ≥ .12% gain in traction afforded by this technique. Having to shift, or having an automatic shift in the corner will break this traction advantage. One moment of slack in the drive train at a critical point in the turn and you're off the road.

This is a discussion often heard around the burn barrel among flagmobbers and rally enthusiasts, passing a bottle of 'Jack' before hitting the tents for the next days race. The only other type of transmission given any possibility is the belt drive variable with but two gear ranges. The jury is still out on that, but I've heard there is a new class just for it.

Well, the only reason you have a box with so many gears is to keep the engine rpm at its ideal torque band. This is the Achilles heel of the internal combustion engine.

With an electric motor shifting is superfluous if top speed is under 100 to 120 mph given the broad torque band of an electric motor. Unfortunately, electric cars just don't have the power to perform competitively above those speeds nor the ability to go the distance.

If you want to talk about modern transmissions, then transmissions like Porsche's PDK, which I have personally driven, are a totally new ball game on the track. The downside is once again weight, which is exactly why the 2010 GT3 is not going to have a PDK. Although, Ferrari appears successful at integrating theirs into their street and track cars.

Obviously, F1 has taken full advantage of the electronic transmission. As far as performance goes, this is the future.

Which brings us back to hybrid technology's place in the sports car domain. I don't see transmissions as being the road block for successful integration of hybrid technology into sports cars. The bigger problem is space and weight and keeping enough power to weight to make the car fun.

You might find this article interesting in regrads to Honda hybrids and manual transmissions.

I recall the Brabham automatic transmission cars that happened along when engine power got so great it could spin the wheels at any speed due to torque amplification. It also led to mandated reductions in power, weight etc.

As for electric cars, you can have 4 wheel drive cars and a joystick to vary the power to each wheel(this can be automated to a degree to back off at spin edge). They even tried wheels that shifted their vertical axis. car controls could approach game controllers with more variable. Electric cars will have endurance limits. battery changes at high speed during pit stops, etc, like gassing up in pit stops.

Possibilities endless = a sport can be made..

My first response to this, much like the guy who posted before me, was why do we need gears? the only reason we have them now is to keep the IC engine within its efficency range. If an electric motor can produce the same torque over its entire rpm range then why even have gears?

The answer lies in power consumption. Obvesouly a motor is going to take more current per second when its at its maximum rpm compared to if it is turning slowly.
this could be the key to getting electric cars to run longer. If one were to put a "rev limiter" on the electric motor one can ensure that the motor never eats up more than a certain amount of power.

I am a hardcore American LeMans fan and every car I have ever owned has had a manual transmission. However an electric motor reacts differently to fluctuations in fuel (aka current) than the IC engine. It might serve the car manufacturer better to keep the motors in an open loop setup, where no energy is transfered to the motor under no throttle and let the driver account for the drop in rpm's just like in an IC engine, rather than have the motors close loop where the same amount of engergy is used weather your on or off the throttle.

i see no problem having only two gears, one for street which is good for 0-70 mph, and one for highway which is good for 50mph - 200mph...

subscribed...

I know Tesla Motors had quite a bit of problems with their two-speed transmission and eventually had to lock it in a single gear, but that can be solved. There is alot of discussion about manual control of longitudinal traction (feathering brakes and clutch), and the purists are going to hate this, but what makes us think that we can react faster than automated control systems that can optimize these factors in a turn at several tens of thousands of cycles a second? Entering a corner at the right speed using an automated "turn" controller still exceeds my trust, but managing traction through and out of a turn with an automated controller is not only feasible, it already exists.