pelucidor

An uncharacteristic mistake on Wakeech's part saying that all 5 speed autos are SMT. Tut, tut .

Having driven many 5-speed autos with 'manual controls' I will say that cars like my IS300 (5 speed auto with e-shift - buttons for up/down on wheel) and G35, Acura CL, Audi A6, Chrysler 300M (gearstick with separate plane for up/down changes) are a long way from an SMT gearbox. A 'real' auto loses significant power to the torque convertor, and takes 0.5-1.0 seconds to make a shift (no matter where the manual controls are - paddles, buttons or gear lever). A clutchless manual (as in BMW M3, Ferraris, Porsches, Maseratis, MR-2) has no power loss and can shift very quickly (perhaps under 0.1 secs) - faster than a human can with a true manual. Usually they cost a lot ($2k - $10k).

The initial RX-8 auto will have paddle controls and be a regular 4 speed auto (I read somewhere because Mazda does not have a 5-speed in house (but what about 5-speed auto in Mazda 6s?), and they will not source one externally for the RX-8). One day Mazda MAY produce a clutchless manual gearbox (SMT) which will have no problems working with the higher-revving 247HP engine, but no dates have been set yet.

zoom44

i read somewhere that the 5speed auto from the mazda6 didn't fit right. but the japanes market seems to have it ( or another) as an option so now i'm at a loss to explain it.

Hercules

Exactly like your TL now. Except that the RX-8 will be slower due to the fact the engine is detuned.

justinm2

The 5 speed auto from mazda 6 doesn't fit because it's fwd, the rx8 is rwd. The Japanese market 5 speed is a manual transmission, not an automatic.

chenpin

Look here for all the info you need:

http://www.edmunds.com/news/innovati...3/article.html

JeffNY

Thanks for the info and web site guys...

gusmahler

This whole area is confusing because everyone uses different terminology (or worse, the same word to mean two different things: the Edmunds article listed above uses the word semi-automatic to mean something completely different from the way Formula 1 uses the word. I'll try to briefly summarize the differences:

Manual: uses a clutch and a gear shift selector that is manually operated by hand to change gears

Automatic: uses a torque converter to couple the engine with the transmission and the transmission automatically changes gears.

Tiptronic: This is the name Porsche uses for its system, but is sometimes generally applied to similar systems by different manufacturers. This uses a torque converter to couple the engine to the transmission. Thus, IT IS AN AUTOMATIC. The difference: there are levers, sometimes placed on or behind the steering wheel, sometimes by moving the gear selector **** to a different place. The levers allow you to change the gear of the transmission. But, make no mistake, IT IS AN AUTOMATIC TRANNY, with the associated power losses and long shift times. IMO, they are a useless gimmick.

SMT (Sequentiual Manual Transmission) or SMG (Sequential Manual Gearbox). This device uses a clutch to couple an engine with the transmission. However, there is no clutch pedal. You shift gears by pulling a lever behind the steering wheel. When you pull the lever, a computer controls the use of the clutch and the shifting of the gear. This is the system used in the Ferrari 360 and the BMW M3. The system is also used in Formula 1 cars (where it is typically called a semi-automatic transmission). The gear shifts are faster than any human can possibly do. Race drivers love it because you can't miss gears. In passenger cars, there is typically an automatic mode, where the gears are shifted automatically.

In summary, if a system uses a clutch, it is a manual. If it uses a torque converter, it is an automatic. That is how you can tell the difference, and not by the presence of buttons on the steering wheel.

As for the cars you discuss, the TL has a "Tiptronic" style shifter, but is an automatic, as are the Porsche and Audi systems you discuss.

What does this have to do with the RX-8? The RX-8 will have a manual and an automatic, but the automatic will have Tiptronic style shifting available. It appears that there are rumors of an SMT style gearbox, but it hasn't been confirmed.

Cylo

From when the RX-8 was still in concept stage:
"The transmission is a true 6-speed clutch style manual transmission. Its wing shifter system merely throws the shift lever and actuates the clutch must faster than humans can do it. The automatic option on the center console just allows a computer to send the same shift signal to the transmission that the wing shifters would have if you flipped them manually. The transmission shift system should be famial to Drag Racers and also Ferrari enthusiasts. "

source: rotarynews.com

From what I have read elsewhere, this shift system was NOT implemented.

wakeech

:p like i said, as far as i knew... i've never seen or had explained to me how a 5 or 6 speed slush box works, until Mike linked me (but that was hardly enough for me i want to know more!!)

JeffNY

Thanks for the additional input guys. It was my understanding Mazda had decided to NOT offer the auto-manual ("Tiptronic") initially. That's why I asked. But I guess they will.

>>IMO, they are a useless gimmick.<<

Gus, well, maybe my TL tranny is a "usless gimmick" (for racing 300+ HP cars)...but it can still be fun Sorta like a Pet Rock I guess. Sometimes usless gimmicks help sell things. And my usless gimmick can still blow the doors off 90% of the cars out there LOL!

I always wondered why car makers never really pursued SMTs more. They are similar to the (simpler) sequental gear boxes on motorcycles. They would seem to be so much less complicated (and smaller and lighter) and cheaper to make than a hydraulic tranny. Maybe because the electronics now available weren't ready for such applications 10 or 20 years ago?

Jeff

gusmahler

OK, useless was probably a bit harsh. For pure acceleration, a Tiptronic style automatic is useless. When you floor a car with an auto, it will shift at the redline anyway, so "manually" doing so adds no performance. If you are in a highway passing situation, flooring an automatic will will put the car in an optimum gear already. No need for a Tiptronic.

It probably helps on twisty roads, though.