jeffbrig

Actually, resistance when downshifting into 1st usually suggests that the synchros are worn. The numeric gap between 1st and 2nd is significantly larger than any other sequential gear pair in the transmission, that's why you find it difficult to engage the clutch smoothly. To downshift at higher speeds, double clutching is suggested to take the load off the syncros. Double clutching means you shift to neutral, release the clutch, and blip the throttle to the approximate rpms you would be at in 1st gear at your current spead, then clutch in and move to 1st. This accelerates the layshaft to the proper speed to mesh with 1st gear so that the syncronizers don't have to do all the work. I (and I expect xviper and many others) do this anytime I aggressively downshift to 1st.

da_illist_onE

[QUOTE]Originally posted by jeffbrig
Actually, resistance when downshifting into 1st usually suggests that the synchros are worn.

jeffbrig

Revmatching alone makes the clutch engagement smoother, but does nothing to help the transmission make mesh the gears together. When the clutch is in, the input shaft is disconnected from the engine, so rev matching has no effect on its speed. The synchros take all the load, and the wear. The throttle blip with the clutch out matches the input shaft (layshaft) speed with the speed that 1st gear is turning (connected to the output shaft), so when you push the stick into 1st, there's little or no load on the synchros to match the speeds.

So, to answer the question, YES, the clutch must be released in double clutching.

xviper

Jeffbrig is pretty much correct in what he's said, however, I'd like to make slight ammendment to one thing.
You will get resistance to shifting into 1st even when the car is brand new. In fact, the newer it is the more resistant there will be to a 1st gear downshift "on the roll". This is attributed to the 1st gear blocker ring. It's almost like a "safety" to prevent inadvertent downshift at too high a road speed. You will notice that as the tranny breaks in and wears a bit that the speed at which you can put the car into 1st without much resistance gets higher and higher.
If you use the tranny's characteristics (blocker ring) to gauge when you can go into 1st, you will have no problem. Don't "force" the stick too hard. The tranny will "let you in" when it's ready. Just remember to let the clutch out easy or learn to rev match so you don't jerk when you connect up the driveline again.
As Jeff indicated, you can easily defeat the blocker ring and shift into 1st at relatively high roads speeds (for 1st) if you double clutch, rev match. However, I would not recommend this if you are not used to driving stick or have a poor understanding of the relationship between road speed to engine speed to gear position.

da_illist_onE

[QUOTE]Originally posted by jeffbrig
Revmatching alone makes the clutch engagement smoother, but does nothing to help the transmission make mesh the gears together.

jeffbrig

xviper, good point on the blocker ring. I didn't even think about that.