8 Speed Zf

[senna_T]

That is a good point, but when you look at it we are talking about going to a 12 speed. The only reason you would do this is if the engine doesn't have a wide range of torque (or alot at all) and requires a gearbox to keep the RPM in the torque band. A car with alot of torque, say 500Nm+, wouldn't need 12 gears, let alone 8 IMO. The Bugatti Veyron has a 7 speed gearbox, but that is becasue it needs to accelerate to 400+kph and beat the aero. If it didn't have to get to 400, I think they would've gone with a 6spd. or even a tough as nails 5spd.

[tab]

The veyron is the exception to the rule though, the amount of power that puts out you really only need one gear!

Eight-speed would be perfect on a european autobahn, can’t really see the point in a local vehicle though.

But then some probably said the same 10 years ago about six-speeds while we were all pottering around in three-speeds!

[dule]

If it was fitted to a local car it would probably have a similar top gear ration as the 6 speed box so at 110 it would sit in top gear, I think the amount of gear changes would almost be funny but if the box offers better fuel economy, less power loss, smother/quicker shifting and doesn't cost much more, then what the hell 8 speed it is.

[dule]

Actually ford V8's would even benefit from it as their torque ban isn't as thick as the turbo's and according to the reviews they need a rev or two be in the happy zone.

[Kimberley Scott]

Bring it on, Daewoos could do with an 8 speed box, all those low powered cars would drive much better. Set up and tune a 4 Lt turbo engine to match an 8 speeed box, would mean throttle response everywhere, not pause drop back two gears make alot of noise rev only to realise that its running out of usable revs and change up again.

Make it so it down changes like a manual driver would and it would be farking brilliant, may even drive one myself (nah only kidding).

Scotty

[Lawsy]

I'm in a hurry and can't go into detail, but the 8 speeder will shift so fast and smooth that you'll barely notice. And get this, it will be locking and unlocking the torque converter every time...

That 12 speeder will be faster again, if they bother (its 3 planet sets with 3 over drives).

The thing is, the over drives these days are nearly as strong as the rest of the gearset, so meh....

Oh, and btw, unless you're on full boost, an engine won't produce its flat as a table torque curve. So the gearbox will try and get the engine in the torque peak for the applied amount of throttle. That is absolutely the most important thing for economy. Since for a given amount of throttle, an engine is most efficient at its torque peak. With 5% throttle, this could be 1200 rpm, with 50%, it could be 2000 - 3000 with 3psi of boost, whatever, but the idea is, the more gears, the easier it is to literally sit the motor right on the torque peak all of the time. This could improve fuel consumption 10% on its own.