Quicker upshifts with SRM off?

the_student · 11-20-2010, 01:07 PM

Quote:

Originally Posted by optiontrader

I never felt the need to turn off SRM (note: NOT VDC!

) , but decided to do so when I was driving home from work.

I noticed the rpms don't "hang" as long as when SRM is engaged while upshifting. It seemed easier to snick off faster gear changes.

Before, with SRM on, there was a long enough pause that I could take a sip of coffee while accelerating from a stoplight.

Anyone else notice this? Or am I a victim of psycho-somatic button pressing in a Z?

I know what you mean. But, I think what you felt about faster gear changes may be related to the timing of getting back on the gas pedal when you shift after the gear change. When I drive with SRM off for a while and then turn it back on, I have to get on the gas pedal a little later to get the same smooth shift otherwise it feels like i slip the clutch a bit or it gets jerky.

So it makes sense that you do feel the RPMs hang and its related to the timing issue again. With SRM on, as the revs decrease, it slows down (just before the correct RPM) and stops at the specific rpm you need for the next gear. With SRM off, the revs would just continue to drop and won't have to slow down and stop, and instead of the SRM controlling the RPM, you as the driver would have to match the revs for the upshift. So you have to get on the gas a little bit earlier, which makes you feel like you can get those faster shifts.

I hope I make sense and hopefully I've articulated what I'm thinking correctly.

Anyway, the timing isn't as vast as you make it out to be. It's more like a fraction of a second. Unless, you are just letting the revs stay on the RPM for the next gear without engaging it...haha and that is definitely not recommended.

NiZZZmo370 · 11-20-2010, 05:52 PM

Quote:

Originally Posted by the_student

I know what you mean. But, I think what you felt about faster gear changes may be related to the timing of getting back on the gas pedal when you shift after the gear change. When I drive with SRM off for a while and then turn it back on, I have to get on the gas pedal a little later to get the same smooth shift otherwise it feels like i slip the clutch a bit or it gets jerky.

So it makes sense that you do feel the RPMs hang and its related to the timing issue again. With SRM on, as the revs decrease, it slows down (just before the correct RPM) and stops at the specific rpm you need for the next gear. With SRM off, the revs would just continue to drop and won't have to slow down and stop, and instead of the SRM controlling the RPM, you as the driver would have to match the revs for the upshift. So you have to get on the gas a little bit earlier, which makes you feel like you can get those faster shifts.

I hope I make sense and hopefully I've articulated what I'm thinking correctly.

Anyway, the timing isn't as vast as you make it out to be. It's more like a fraction of a second. Unless, you are just letting the revs stay on the RPM for the next gear without engaging it...haha and that is definitely not recommended.

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