is it bad shifting with out the cluch
As long as you match your rpm's well and dont grind, nothing wrong with it. Its especially helpful on big trucks. Once on a 200 mile trip, I only used the clutch to take off at light, otherwise i never touched it
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it does harm the syncros, regardless of whether people say it is not harmful or not. you are never going to get the speed to match just right all of the time but for temporary purposes it does and will work, i just wouldn't make a habit out of it.
Originally Posted by Karack
it does harm the syncros, regardless of whether people say it is not harmful or not. you are never going to get the speed to match just right all of the time but for temporary purposes it does and will work, i just wouldn't make a habit out of it.
It's called floating the gears. The reason it is harder to do in a car compared to big trucks is because trucks are turning lower rpm and you have less of an rpm range to work with.
Interestinly enough, my neighbor has a 71 bigblock 4spd Camaro with the M-22 ( The greatest of all 4spds btw!) . Try as I might, I could not shift that thing with the clutch, but floating the gears was a breeze and the only way I can drive it. Guess I've been a truck driver to long.
I do notice that I sometimes float the gears in the RX7 when I am not thinking about it. Just comes second nature I guess. But for the most part, I use the clutch.
Later,
Bill
Interestinly enough, my neighbor has a 71 bigblock 4spd Camaro with the M-22 ( The greatest of all 4spds btw!) . Try as I might, I could not shift that thing with the clutch, but floating the gears was a breeze and the only way I can drive it. Guess I've been a truck driver to long.
I do notice that I sometimes float the gears in the RX7 when I am not thinking about it. Just comes second nature I guess. But for the most part, I use the clutch.
Later,
Bill
you do it in big trucks because you shift those cat motors at 1.6k and the next gear is at 1.4k
when you do it in a rx7, where you shift at 3 and derop to 1.5k, you have alot more room for error, add that to the lighter built transmission, its going to see problems.
the clutch is there for a reason, u know. rather than the synchros having to spin the clutch faster or slower, it now has to do that, and the heavy counterweight and the whole motor when you shift.
btw, m-22 is garbage, like the m20 and m21. it has stronger gears, yes, but the problem with muncie is the casing that deform under high hp, and ears breaking off, which causes it to deform even more. the toploader and hemi 4 spd at the same era is a much better transmission.
when you do it in a rx7, where you shift at 3 and derop to 1.5k, you have alot more room for error, add that to the lighter built transmission, its going to see problems.
the clutch is there for a reason, u know. rather than the synchros having to spin the clutch faster or slower, it now has to do that, and the heavy counterweight and the whole motor when you shift.
btw, m-22 is garbage, like the m20 and m21. it has stronger gears, yes, but the problem with muncie is the casing that deform under high hp, and ears breaking off, which causes it to deform even more. the toploader and hemi 4 spd at the same era is a much better transmission.
karak is right, no matter what you are going to prematurely wear out the dog teeth on the syncronizer rings. They are made of brass for that reason, they wear so the gears and other parts do not wear as quickly. You can do it, but you will need to rebuild that tranny eventually, it's all a matter of your wallet size
. Now, if you were to get a sequential, non syncronizing tranny, then you can speed shift it all day long, also it would have straight cut gears and in general just be really badass.... 
Dave.
. Now, if you were to get a sequential, non syncronizing tranny, then you can speed shift it all day long, also it would have straight cut gears and in general just be really badass.... 
Dave.
Joined: Apr 2006
Posts: 615
Likes: 0
From: South Flo-rida..south jersey originally
i drive tractor trailers for a living, and every driver i ment never uses a clutch only for first..they say for trucks it helps tranny last longer which is true,,it's all about rpm's even with a car if you shift at the right rpm you dont need a clutch nor will it cause problems..but at the wrong rpm you start hearing grinds..i never use my clutch in my tractor trailer, but in my seven always..
^+2 exactly, the trannys do last longer in big trucks because they are designed that way....I have my Class A Combo CDL...so iv'e seen this one before
the reason you don't use clutch in a tractor/trailer situation is because #1. the clutch cant handle that much torque, strain, and weight through every gear #2. you WILL snap drivelines if u catch that clutch too hard... #3. clutch brakes wear out if you are on and off the clutch too much tractor/trailers and rx-7's are totally different, lets not lump them together 
Rx-7's are not designed to be shifted without a clutch, that is why synchronizer rings (dog teeth) are in the transmision in the first place. If they wanted you to shift without it, they would have had straight cut synchroless trannys from the factory to allow the gears to catch up in speed, and allow a smooth transition. They designed these cars to be driven by everyday people, not race car drivers, truck drivers, etc.. hope that clears it up...I guess all I'm saying is..you can shift without it all you want, but your longevity and condition of your transmission will decrease...
Dave.
the reason you don't use clutch in a tractor/trailer situation is because #1. the clutch cant handle that much torque, strain, and weight through every gear #2. you WILL snap drivelines if u catch that clutch too hard... #3. clutch brakes wear out if you are on and off the clutch too much tractor/trailers and rx-7's are totally different, lets not lump them together 
Rx-7's are not designed to be shifted without a clutch, that is why synchronizer rings (dog teeth) are in the transmision in the first place. If they wanted you to shift without it, they would have had straight cut synchroless trannys from the factory to allow the gears to catch up in speed, and allow a smooth transition. They designed these cars to be driven by everyday people, not race car drivers, truck drivers, etc.. hope that clears it up...I guess all I'm saying is..you can shift without it all you want, but your longevity and condition of your transmission will decrease...
Dave.
Originally Posted by rjpbboi
Why do it, the clutch pedal is there for a reason
Joined: Dec 2003
Posts: 6,598
Likes: 10
From: Temple, Texas (Central)
There was a rally driver back in the day that shifted this way for better control of the gas and brake pedals. As one journalist put it "his transmissions usually lasted all the way through the race."
I've done this a few times when I had a broken toe on my left foot an dit hurt to shift. This was in my daily beater, though. I would never do it my 7.
I've done this a few times when I had a broken toe on my left foot an dit hurt to shift. This was in my daily beater, though. I would never do it my 7.
I do it all the time in my 7, ends up much smoother than when I use the clutch, especially on downshifts. I'm sure it's much easyer on the rest of the drivetrain. But then again, I learned to drive on a crashbox, old habits are hard to break. I was really suprised at how well this car responds to clutchless shifting, the car really seem to like it, so long as you do it right.
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