bigfatpop

I'm sure this has been asked before, but I've searched high and low, and I've had no luck.

The question is whether shifting without the clutch is okay, as long as I can do it without grinding the gears. This seems easy at the correct RPM's, and even easier with the DSC turned completely off (ie 10-second trick).

Thanks in advance for your patience on this, my first post.

Jeff

w2aew

If you can master perfectly matching the RPMs to minimize wear on the sychros and potential grinds, then there's no problem with it. You'll have to slip quickly between syncro-mesh and gear mesh to avoid grinds due to RPM and speed changes during the shift.

Its easy to do on my MG, but haven't attempted it yet on the 8.

bigfatpop

It just 'pops' into place. No grinds . . . except for once into 5th gear. I just use the trick from 1st to 2nd, 3rd and then 4th. It doesn't seem to work well in 5th and 6th.

red_rx8_red_int

Also haven't attepted it on my 8, but if you can do it with no grinding then it should be OK. Search on "speed shifting" I think will get some results.

epitrochoid

the rx-8 isnt a transmission i'd like to expieriment with

wakeech

i don't see the point, why bother risking severe synchro and/or spline damage if you "oops" sometimes like you do on 5th??

Nick T

Every car I've driven recently has gone into gear without the clutch quite nicely. Hell, on my old '90 Jetta I could yank the thing in and out of gear without a problem with my foot pegged to the floor

I shift my 8 all of the time without a clutch, usually in traffic when I'm going around town - without a single problem.

wakeech

ohhhhhkay, but again, why??

loco4rx8

Why is there a clutch then? I believe it is there for a reason, to be used. But it's your transmission, so have a blast.

Jailbreak'74

If you're a perfect driver this will do no harm, if you only a great driver I would say don't chance anything, there's no point of doing that kind of damage.

OdinGuru

I've heard many people say that you can swich gears without using the cluch at exactly right RPM without any strain on the transmission. Except, given my understanding of how a transmission works, I can't figure out how that could be true with the procedure as I think it is performed. The impression I've been given is that you reach the right speed (and hold that speed though the shift?) and then shift gears quickly without disengaging the cluch. This seems like it would ALWAYS put load on the syncros as they would be responsible for changing the engine speed rather than the cluch.

Perhaps my understanding of the "no clutch" procedure is flawed. Do you let off the gas durring this procedure? How fast is the shift (as fast as you can or slowly)? Do you pause and change engine rpm while in N? The only procedure I could imagine that would work correctly would only be for upshifts (like 2->3) and would involve pausing in N to let the engine RPMs fall untill they matched the new gear, then engaging the new gear. Even this technique would still involve quite a bit of wear on the syncros unless it was PERFECTLY executed. Also you could do it at any speed as long as you wait for the engine to fall to the correct engagement RPM, so it doesn't seems to be quite the same as what other people are recomending here.

Perhaps someone who does this type of shifting regularly could elaborate on the exact procedure.

w2aew

You've got it right for an upshift. Basically you'd adjust the throttle to give a minimal gear load (not accellerating, not slowing), and slip it into neutral. Then, let up on the throttle and let the revs drop. Here, you can either "catch-it" exactly right as the revs are falling and drop into the next gear as the revs just reach the right point, or you use the throttle to get the revs right, and drop it in gear. Either way, it is somewhat of a moving target since the revs are always changing a little, and the vehicle speed is changing a little. For a downshift, you'd have to obviously increase the revs in neutral to select the next lower gear.

If you master this technique, you can shift quickly and not wear the synchros or the clutch & release bearing (obviously). Of course, you're right, if you don't get it real close, the synchros are going to be trying to push the engine around instead of just the clutch disk.

Its a good technique to know how to do, if you ever lose a release bearing or clutch linkage (ask me how I know). Never had to do it on the 8, but I am sure I could if I had to.

OdinGuru

Thanks w2aew, the procedure as you describe it makes perfect sense. Kind of like a double clutching procedure without the using the cluch than a normal shift without the clutch. However, what I don't get is why people normaly describe the technique as being executed at "one particular rpm" where it "works" (and sometime only in certain gears). Seems to me that what you and I are talking about could be executed no matter what the speed/rpm and in any gear. Any further insight on why it's described this way?

bigfatpop

I can do it @ 3500 RPM into 2nd, 3rd and 4th. I've tried 5th and 6th, but it just does not seem to work as well. Perhaps it's not great on the transmission, but I've done it all my driving life without tearing up a transmission. Thanks for all the responses!
Jeff

Nick T

My Mustang would only fall into gear at about 2k - but that was a Tremec. My friend's RSX...that would fall into gear at just about any RPM. My 8 will do it between 3-5k, depending on the gear.

People will always say how it's hard on the trannys...but I put 40k miles on a 1990 Jetta that started out with 110k when I got it. I shifted without the clutch exclusively for those 40k miles and the tranny never missed a beat. If done right, you're not going to hurt anything.

nightkids

so what u guys r saying is that in order 2 do this shifting technique....u have 2 have the speed and rev not going up or down then push it into N then when the rev starts dropping shift it into the next gear.....rite when the rpm starts dropping?? rite?? or no......plzzz explain more plzzzzz

Rotarian_SC

Say you are going from 2->3, your rpms in 3 are different than those in 2. Say you are going to be doing 41. for 2nd gear that is maybe 6k rpms. When you get into 3rd gear, assume a 1mph drop in speed, so you will be going 40 in 3rd, which is 4k rpms. That means that if you are going 40 then you have to have the rpms right at 4k for the shift out of neutral into 3rd without using the clutch.

xxMax Powerxx

Finding the RPM/Speed combo is easy...

When you normally shift, pay attention to what speed your traveling and what RPM you end up when you let off the clutch.

If you find that 2nd gear at 2500 is good for 20 mph, then that is all you have to "line up" to make the shift (hypothetical combo. I don't have an 8 yet and I don't know exactly what works for that car).

1) accelerate to "known" speed (20 mph)
2) Lay off or release completely the throttle.
2) Slip tranny into neutral (just yank on it).
3) apply throttle to get engine to "known" RPM (2500) and hold.
4) slide tranny into "known" gear (2nd).

Speed shifting is very common. Truckers shift that way almost exclusively. Aside from 1st gear, clutches are for the "masses" (it does take a significant amount of focus). Motorcycle racers almost exclusively use this technique when up shifting (though we don't need to messs around with neutral).

bigfatpop

What Max said. I just skip the neutral step. It just pops down (up) at the right RPM.

nightkids

hey i read this thread yesterday and started testing it on my IS300....well i got it 2 go to neutral....but i can't get it into the next gear without using the clutch......n e advise??

w2aew

The only way it works is to get the engine rpm exactly right for the gear you want to select. For example. Lets say that in your IS300, when you normally shift from 2nd to 3rd, the rpms go from 3500 in 2nd, to 2500 in 3rd. You would ease off the throttle in 2nd so that there was little or no accelleration/decelleration forces in the trans, and pull it into neutral. Then, squeeze off the throttle some more until the rpms hit 2500 at which point you will be able to select 3rd.

Of course, the rpm examples above are just that, made up examples. YOU have to be aware of the rpms necessary for each gear at any speed to make this work. After a while of driving normally with the clutch, you should get a very good feel for your shift points both entering and leaving each gear. This is a MUST before you even think about shifting without the clutch.

If you don't instinctively know what the rpm targets are, or you don't understand what I'm talking about, then don't even try it.

bigfatpop

1) Get to desired rpm
2) Slightly 'goose' the gas
3) Pop out of gear and pop into next gear.
4) Do not force anything.
5) If it does not 'pop' out of or into gear, use the clutch.
6) With practice it works on any car I've driven.

BasenjiGuy

Not necessary and not worth the potential long term wear and tear and/or damage if you mess up. When I was younger I would occasionally entertain myself by up and downshifting with out the clutch. It's an interesting technical exercise but nothing else. There's no responsible reason to do it.

Don't mistake an automobile's syncromesh transmission with a race car or motorcycle's sequential dog-clutch set up. Those transmissions can be safely shifted with out clutching. You should drive you car with the technique it was designed for - use the clutch.

bigfatpop

Great choice in dogs, BasenjiGuy. As to the clutch thingy, it's even easier with the DSC in the 'completely off' mode. It makes much less noise than the infamous clunk into first.

BasenjiGuy

bigfatpop: He's a great dog. Unfortunately, he lives with my ex-wife, two miles away from me. I see him a few times a month and we re-up with a walk, some tricks, and dog hugs.