Why are BMW and Nissan going to a double clutch

nickwfd92 · 02-04-2009, 01:22 AM

Ok so last night I was at the Philly auto show, and I got to see the ZR1

and touch same. You could not sit in it though. I was walking around BMW and sat in the M3(really uncomfortable) the sales rep was talking to someone and said that it now has a double clutch. He said that it means faster shifting.
I also heard the girl in Nissan for the new GTR say that that had a double clutch.
I was just wondering what the benefits would be and if there were some if a double clutch would be developed for the vette.

SearayC5 · 02-04-2009, 01:37 AM

I've driven the new M3 DCT (Double Clutch Transmission) and the regular six speed. The upshifts are a hell of a lot faster than any human could make a shift. There is a down side though. I'm sure you've heard about the deboccle with no more launch control on the GTR, well the M3 does not come with launch control. This means that the six speed can get off the line much quicker. The computer slips the clutch nice and easy until you're going. There is a clutch for the even gears and a one for the odd gears. So this means that the car anticipates which gear you are going to next based on learned trends. If you make an unpredictable shift it shifts like the old SMG tranny.

I love the vettes but you gotta love the 8400 rpm rev limit in the M3!

Wethingtonvette8093 · 02-04-2009, 01:42 AM

Yeah the new double clutch is fast, but I liked the old SMG in my old M3

nickwfd92 · 02-04-2009, 01:42 AM

thanks for the imput, yeah I saw the 8k rev limit.

karateboi87 · 02-04-2009, 02:07 AM

I remember a magazine did an article on different transmissions. the dual-clutch seems to be the way to go.

It's efficient like a manual, but it doesn't lose power between shifts (especially helpful for FI cars). I think the downsides are supposedly weight and cost. As someone said, these dual clutch shifts VERY fast. Actually, I even remember the magazine article talking about mercedes-benz using a new automatic which can supposedly shift in like 10 milliseconds. I don't remember the details but it doesn't have a torque converter, but still is an automatic?

Wasn't dual-clutch a possibility for C7 but was abandoned because of cost as a good portion of GM's research fund is now put to "fuel economy" and "hybrids" like volt?

I also heard the new porsche 911's dual clutch is amazing.