New IS-F owner - few questions
#17
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
I found a good article that further explains this transmission. Recommended reading for those IS F owners who don't already know about the features of the transmission. Looks like the article is old (October 2007) but still relevant.
http://www.autospies.com/news/In-Det...mission-22472/
http://www.autospies.com/news/In-Det...mission-22472/
#18
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
^^^^ The above article says the IS F transmission shifts in 0.1 seconds and states that that's the fastest shift time for a street car.
That was 2007 so I went looking for the the shift time for the Porsche PDK, which is a dual-clutch manual that is operated like an automatic (no clutch pedal) or can be manually shifted with levers. I think (not sure) the PDK started showing up in Porsche street cars after 2007. I found this in a June 2008 911 review:
"Then there is the reduction in gearshift times, by up to 60 per cent. Porsche says the auto changed gears in 0.75 seconds, while PDK does it in 0.5, making 911 models 15 per cent quicker to 100km/h than their automatic forebears."
http://www.goauto.com.au/mellor/mell...25746B000BFE5E
Humm. The PDK shift is 5 times slower than IS F but I can't find a more-recent shift-time spec for the Porsche and maybe the PDKs shift faster now than they did 4 years ago.
That was 2007 so I went looking for the the shift time for the Porsche PDK, which is a dual-clutch manual that is operated like an automatic (no clutch pedal) or can be manually shifted with levers. I think (not sure) the PDK started showing up in Porsche street cars after 2007. I found this in a June 2008 911 review:
"Then there is the reduction in gearshift times, by up to 60 per cent. Porsche says the auto changed gears in 0.75 seconds, while PDK does it in 0.5, making 911 models 15 per cent quicker to 100km/h than their automatic forebears."
http://www.goauto.com.au/mellor/mell...25746B000BFE5E
Humm. The PDK shift is 5 times slower than IS F but I can't find a more-recent shift-time spec for the Porsche and maybe the PDKs shift faster now than they did 4 years ago.
#19
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
^^^^ The above article says the IS F transmission shifts in 0.1 seconds and states that that's the fastest shift time for a street car.
That was 2007 so I went looking for the the shift time for the Porsche PDK, which is a dual-clutch manual that is operated like an automatic (no clutch pedal) or can be manually shifted with levers. I think (not sure) the PDK started showing up in Porsche street cars after 2007. I found this in a June 2008 911 review:
"Then there is the reduction in gearshift times, by up to 60 per cent. Porsche says the auto changed gears in 0.75 seconds, while PDK does it in 0.5, making 911 models 15 per cent quicker to 100km/h than their automatic forebears."
http://www.goauto.com.au/mellor/mell...25746B000BFE5E
Humm. The PDK shift is 5 times slower than IS F but I can't find a more-recent shift-time spec for the Porsche and maybe the PDKs shift faster now than they did 4 years ago.
That was 2007 so I went looking for the the shift time for the Porsche PDK, which is a dual-clutch manual that is operated like an automatic (no clutch pedal) or can be manually shifted with levers. I think (not sure) the PDK started showing up in Porsche street cars after 2007. I found this in a June 2008 911 review:
"Then there is the reduction in gearshift times, by up to 60 per cent. Porsche says the auto changed gears in 0.75 seconds, while PDK does it in 0.5, making 911 models 15 per cent quicker to 100km/h than their automatic forebears."
http://www.goauto.com.au/mellor/mell...25746B000BFE5E
Humm. The PDK shift is 5 times slower than IS F but I can't find a more-recent shift-time spec for the Porsche and maybe the PDKs shift faster now than they did 4 years ago.
Interesting it's half the shift time of the LFA
It always annoys me looking back at old reviews of the IS-F where you see all the "8 gears is far too many....blah blah blah" then now days it's the norm
#20
Lexus Test Driver
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
No one has mentioned that the torque converter goes to full lock on gears 2-8 when in manual mode. This what gets you the .1 sec shifts, faster acceleration times and a better feel.
Also comparing the ISF transmission to the PDK, etc. dual clutch systems is Apples to Oranges. You can only directly compare the ISF to other torque converter based transmissions. Not single or dual clutch automated transmissions.
Also comparing the ISF transmission to the PDK, etc. dual clutch systems is Apples to Oranges. You can only directly compare the ISF to other torque converter based transmissions. Not single or dual clutch automated transmissions.
#21
![Default](https://www.clublexus.com/forums/images/icons/icon1.gif)
No one has mentioned that the torque converter goes to full lock on gears 2-8 when in manual mode. This what gets you the .1 sec shifts, faster acceleration times and a better feel.
Also comparing the ISF transmission to the PDK, etc. dual clutch systems is Apples to Oranges. You can only directly compare the ISF to other torque converter based transmissions. Not single or dual clutch automated transmissions.
Also comparing the ISF transmission to the PDK, etc. dual clutch systems is Apples to Oranges. You can only directly compare the ISF to other torque converter based transmissions. Not single or dual clutch automated transmissions.
I understand that the double-clutch transmission and torque converter types work completely differently but they both attempt to accomplish the same function (from an input / output / user-control, black-box perspective) so I thought a comparison was interesting and useful.
Thanks,
Thread
Thread Starter
Forum
Replies
Last Post