When downshifting, how important is it to rev the engine to higher RPM (in neutral) before letting clutch out. Properly feathered in it sounds better, of course, but I find that the S2000 tends to return to low RPM very quickly, often beating me to the punch and resulting in the rev being drivetrain-induced when the clutch is let out, and among the first few gears I often omit goosing the throttle entirely. Is that surge harmful?

 

well you can blip the throttle with just the clutch down 'rev matching' rather than reving with the clutch out in neutral 'double clutching'

 

Its not THAT important. I like to do it mainly because you dont get the immediate surge from higher rpms when downshifting.

It can also be a little better for the transmission.

 

the surge you feel is caused by the engine trying to catch up with the transmission speed(in simple terms). while this is happening, the clutch disk has to play "catch-up" and will slip until fully mated with the flywheel. that slippage will definatley wear out your clutch, and that will add up over time. you won't notice anything soon.

 

What you are describing is rev matching while downshifting. It is important to reduce clutch wear, since you are using it to force the engine to the correct speed for the next gear.

More importantly, rev matching prevents driveline shock when your engaging the clutch. If you are driving in slippery conditions or doing performance driving, this driveline shock will unbalance the car and perhaps spin the back tires. Not good for keeping the car under control.

 

how do you rev match? Can someone give examples?

 

Just push in the clutch,give a quick tap on the gas as your down shifting into a lower gear.

 

[QUOTE]Originally posted by trendy26
how do you rev match?

 

[QUOTE]Originally posted by Fongu

 

You don't have to rev-match if you don't want. I have been downshifting in my cars for years and years, including the S. Hell, your are not driving hard enough if your not downshifting and driving with the gears!

Rev-matching is nicer on your passengers, however. Since the car notceably surges if you let the clutch pedal out too quickly, your passenger usually gets leaned forward in the seat. I personaly try NOT to toss my passengers around the cabin, so I shift up and down a little different when alone.

The car (and most) can handle the downshifts, presuming you don't just pop the clutch, but rather that you do it with SOME feel. I currently have 70K+ in my OEM clutch setup, and I drive as hard (or harder) than the next guy. I do not do clutch dumps (except once), but definitely give it a workout on an almost daily basis.

Hockey