Clutchless shifting
03-07-2006, 08:00 PM
#21
I had to drive home without a clutch twice. Didn't have any trouble starting it in gear cause the clutch pedal was on the floor https://ls1tech.com/forums/manual-transmission/256791-2nd-blown-slave-2-days.html. It wasn't as hard as i thought, upshifting or downshifting. It's all math, if you shift at 2000 rpm you will want to let the rpms fall to around 1400 rpm (depending what gear you're in) before you put it in the next gear. If you've had your car long enough you can do the same thing by listening to the engine rpm. The relative change in pitch will be the same no matter what rpm you shift at, that's why it "sounds right".
If you rev match perfectly, as in +-0 rpm, its not bad for the transmission at all. But the rpms won't be perfect. Instead of the synchros having to spin up the weight of the input shaft/clutch disk to the right speed, they have to spin the weight of the whole engine/car until they match. That's why it's so bad for your transmission.
If you rev match perfectly, as in +-0 rpm, its not bad for the transmission at all. But the rpms won't be perfect. Instead of the synchros having to spin up the weight of the input shaft/clutch disk to the right speed, they have to spin the weight of the whole engine/car until they match. That's why it's so bad for your transmission.
03-07-2006, 10:38 PM
#22
as was stated before, eighteen wheelers do this all the time. drivers actually are taught to do it and any driver that cant wont keep a job long. on otr trucks with twin or triple countershafts, they dont spin as high as a gasoline engine so it is ALOT easier to do, and they can handle it if a newer driver messes it up. thats how otr trucks can keep a clutch for hundreds of thousands of miles. the concept is the same in cars except for a coulple big differences. first off, we spin higher than otr trucks do. second, we have blocker rings and cones and stuff that otr trucks dont have. IMO, its a safe practice on a car once you get good at it. it saves the wear and tear on the clutch. in an M6 its puts more stress on the shifter cup bushing, but that is alot cheaper than a new clutch.
03-08-2006, 12:14 AM
#23
On The Tree
Join Date: Jan 2006
Location: bc canada
Posts: 107
Likes: 0
Received 0 Likes
on
0 Posts
yah that is an old truck drivers trick,it all started because it was supposed to save replacing clutches so often.On the big trucks it doesnt affect the trannies so much but in cars i wouldnt want to grind it too many times 
