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I drove manual car for a long time but never tried to switch gears without clutch.

Question: given that clutch-less shift is executed properly, does it take a toll on transmission in any way? For example: does clutch-less shifting reduce life of synchros?

MeIr
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It is straightforward to do this without any wear to your synchromesh, but it takes a lot of practice, especially when downshifting as you need to match revs accurately. Learning to heel and toe correctly will help you a lot here!

You should never need to race the engine, as you should be using the same rev range as you would normally driving the car!

Rory Alsop
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    It's also worth noting that's even harder to pull this off without spousal rolling of eyes (at best). Proper heel and toe-ing is not a procedure optimized for passenger comfort. – Bob Cross Dec 19 '12 at 14:44
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    hahaha - very true. But the cheering from the kids in their Recaro baby seats always made up for the eye rolling :-) – Rory Alsop Dec 19 '12 at 14:51
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    You will need to blip the throttle on the downshift though, to get the engine up to the right rev range for the lower gear. – Nick C Dec 19 '12 at 15:03
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    Hence the toe part of heel and toe, Nick – Rory Alsop Dec 19 '12 at 15:06
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Question: given that clutch-less shift is executed properly, does it take a toll on transmission in any way?

See Rory's answer: it is possible to do properly without wear. It is difficult to do properly every time.

For example: does clutch-less shifting reduce life of synchros?

While you are learning shift clutch-free, yes, you will beat the hell out of the synchros.

My advice is to learn how to properly heel-and-toe using the clutch (and actually double clutching). Become an expert at using the clutch properly and then decide whether clutchless shifting is for you.

Full disclosure: I never shift without the clutch. I don't drive a dog box in competition and don't see a good reason not to use one of the pedals available to me. I've worn through the floor mat in two places trying to become better at heel and toe-ing, though.

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Bob Cross
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I had an old T5 I could shift beautifully without the clutch but the motor had to be screaming (somewhere between 4 and 5 grand). At normal operating speeds the transition just wasn't fast enough and the gears would grind.

I've never seen a tranny that would tolerate clutchless shifting under regular conditions without some major gear crunching.

plainclothes
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    4-5k is normal operating speeds for many engines ;) That's nicely in the power band on mine (redline is 7k, and it's gutless below 2k5) – Nick C Dec 19 '12 at 15:05
  • Mine was a V8 so those pistons were hanging on for dear life at 5 and hoping not to meet the valves! – plainclothes Dec 19 '12 at 17:07