ok question: can someone explain.. how the syncros work.. like when downshifting from 6th to 4th.. when i shift to neutral.. i feel resistance trying to downshift into 4th. sometimes just downshifting one gear i feel this.. will revmatching fix this?

ok lets see if i understand this downshifting thing right.. say i'm crusing along in 6th gear.. i push down the clutch.. rev the engine up from say 4k RPM to 5k RPM then shift into 5th gear and realease the clutch. is that right?

 

Insomniak,

That's correct procedure bud.

I'm just now trying to tweek my downshifting in this car (especially 2nd to 1st)...and rev matching is a must in this car.

 

[QUOTE]Originally posted by Insomniak
[B]ok lets see if i understand this downshifting thing right.. say i'm crusing along in 6th gear.. i push down the clutch.. rev the engine up from say 4k RPM to 5k RPM then shift into 5th gear and realease the clutch. is that right?

 

Referring to a previous tread...

What is the difference?!?!?

Later

 

Wear and tear on the syncros from what I understand. Reving to 4-5k RPM with the clutch depressed isn't suppose to be a good idea.

[Edited by STL on 03-22-2001 at 03:10 PM]

 

Just to clarify.. putting the car in neutral then revving it up matches the speed of the synchros to your wheels so that when the clutch is pushed in then the transmission is shifted the synchros dont do any work in matching revs (which is what they are built to do but you can still save wear on them). Without putting the car in neutral but just revving to match speeds you still save wear on your clutch and stress on your transmission but since the synchros were not revved up in neutral on their way to the lower gear they are still doing the work of speeding the next lower gear up.

This is why its not a good idea to put your car in first going 60 even if you dont let the clutch out or putting the car in reverse while moving (I dont think this transmission has a sychronized reverse gear) becuase it still puts wear on the synchros to put it in that gear.

 

Just to be more clear, this whole double clutch thing shouldn't really take any longer than Insomniak's non-double-clutch technique...it just takes a some practice.

I myself plan to keep this car for a very long time, so I don't want my synchros wearing out in a few years! Plus once you get it down it's really cool!!

 

Double-clutching was the only way to downshift smoothly before the advent of syncromesh transmissions; right?

 

Not true, STL... the only reason to double-clutch would be to save the sychros. But it's not absolutely necessary to double-clutch, and it doesn't change any wear on the clutch.

What does a sychro do? Basically it changes the speed of next gear to be engaged to match the input shaft of the tranny (i.e. the wheels). Before you engage a gear in the tranny, it is basically free-wheeling. The synchro is like a little clutch that gets the gear spinning - it's a little brass ring that has some frictional quality to it. Once the gear is up to speed, you can engage the next gear without rev matching. In older transmissions without sychromesh, it was mandatory that you match revs, and mandatory that you double-clutch (using the engine blip to raise the speed of the tranny input shaft and get the next gear spinnin fast enough.)

This is getting confusing - suffice it to say that double-clutching is not necessary these days, and in no way reduces the wear on your clutch. It might lower the wear on the syncros a little, but the synchros work no matter what you do... So I even doubt there is a benefit there.

Single clutch downshift - recommended:
1.Depress clutch, 2.Blip throttle while selecting next lower gear, 3. Release clutch.

Double-clutch - not necessary:
1.Depress clutch, 2.Select nuetral, 3.Blip throttle, 4.Depress clutch, 5.Select next lower gear, 6. Releast clutch.

As you can see, there is a marked difference and double-clutching is un-necessary.... also keep in mind that you can downshift without the clutch at all (the synchros do all the work)

No-clutch - not recommended (hard on synchros)
1.Select nuetral, 2.Blip throttle, 3.Select next lowest gear using gentle pressure on the lever. It's best to overblip slightly and then the gear will slip in when the revs pass the optimum point on their way down from your blip. In other word you have to be appying pressure to the lever as the revs are dropping. It takes some practice, but it's very easy to do.

There are many ways to downshift, but with today's synchromesh boxes, a single-clutch heel/toe is the best method. Whew... I think I might be more confused after writing that.

 

Yes I knew it was either the clutch or the synchros. I only somewhat remember parts of a really good description I read years ago on http://www.vtec.net (back when their message boards were thriving)! It talked about all the different parts (lay-shafrt, clutch, etc.) and what they are did and when. From that (and other sources on the net) I concluded I would start double-clutching.

[QUOTE]Originally posted by Jason Saini
[B]This is getting confusing - suffice it to say that double-clutching is not necessary these days, and in no way reduces the wear on your clutch.