it dosent hurt anything as long as you dont miss, if you do, you grind the gears. so my imput dont do it unless your good at it, or unless you have to for some reason.

 

Most real race cars and motorcycles use straight cut gears, most production cars use beveled gears due to noise constraints. Have you ever noticed how loud a regular manual trans sounds in reverse? The reverse gear in your manual trans is a straight cut gear. Imagine that sound at 7000 rpms! That's why race cars make that whining sound. People won't tolerate that much noise in a modern auto. Straight cut gears can be rpm matched, and shifted easily without the clutch. Clutchless shifting will destroy a regular trans.

 

In theory if you can rev match and shift perfectly you shouldn't do damage. Like I said it has to be perfect hehe. Just use the clutch this isn't a toyota you can beat on.

 

why do it? are the couple 100 extra miles ya get out of the clutch worth tearing up your syncros? hmmm few hundred for a clutch..... or few thouand for a trans.
also the racers that are doing clutchless shifts in drag/road races have sequntial transmissons which is a compleatly different trans that I beleive use planetary gearsets and the clutch is only used for initial standing start.

 

what you're referring to is the o'neil shift, and no it's not the same as a clutchless shift perse... the clutchless shift you technically just kinda shimmy yer way in in when you have the right "feel" for your car, you know when the rpms are matched and you can do a nice smooth gear change without ever putting the clutch in. you let off the throttle and what not to accomodate

the o'neil shift is more violent... depending on the synchros a bit more, it's done when both feet are too busy with accelerating and brake at the same time and a gear change is needed.

pretty sure only automatic transmissions use planet gears... i think that's the definition of an automatic transmission or at least hte basic technology for it.

sequential shifted transmissions i think still use normal transmission gears. and at least most of them do. sequentials overcome the clutch by disconnecting the engine from the transmission via turning the engine off through ecu programming. transmissions like the smg and the ferrari boxes use a comptuer controled clutch.

but the transmissions in rally cars are different. they are both clutched and sequential which is why sometimes you hear of a sequential gear box failure and the driver has to revert back to manual. the way they pull that one off is that when they're using the sequential "mode" they don't use hte clutch and they just pull the lever, the lever actuates a pnumatic shifter which just slaps the gear in while the ecu does the appropriate things to turn off the engine.

 

If you have too much money.... do it!

 

rally racers use dog box ... wich os made for this kind of thing !

 

race cars also change out their transmission after every race... so it doesn't really matter what they do to their cars. if you can afford to change your transmission on a regular basis, then god speed.

 

this is simple, i drive tractor trailer, truck trannys do not have synchros, so we dont use the clutch, up or down shift, cars have synchros, you will destroy them, even if you can perfectly rev match...

 

you really don't use a clutch. cause when i drove 18 wheelers, i double clutched. it's not the same as a car, but you still use your clutch. but a lot of the time, you could just slip into whatever gear you needed to go into.

 

ur synchros and gearboc will last a lot longer if you PERFECTLY AND IF AND ONLY IF PERFECLY match up the rpms. even if ur off by a couple rpms, it's not gonna be good


i meant acouple hundred rpms

 

If you've got a cheeseburger in your left hand, the gearshifter in your right hand, and you're using your left knee to hold the steering wheel, then you have a perfectly good reason to shift without using the clutch.

 

umm if you trust doing that then go ahead

 

yes you could do it, but why are you doing it?? i hope you are saving your money up for a new tranny

 

it's not a good idea on a sports car...do it on a car you could give a sh_t about.....cause when you actually grind the gears.......it sucks......and you feel stupid