Hey-

I talked to my Uncle this weekend who was a huge autocross guy in the 70's (owned a Lotus Super Seven). He said that he was able to shift gears without using the clutch, because the gears were synchronized, and that this helped his lap times. He said this is possible in the S2000, as the gears are also synchro'd. He said that it is alright to do, as long as you know HOW to do it (i.e.-not grinding by modulating gas between throws).

Is this possible? I know this cannot be recommended, or the clutch would not be there. I have heard of "dog box" transmissions that are effectively manual transmissions without the clutch. I want to know if our car is capable of what my Uncle's Super Seven was capable of (changing gears regularly without damage).

thanks

John

 

I don't know.
I do know you can upshift a motorcycle by throttle on put pressure on the shifter relax the throttle 25% 'snick' it goes right in to 2nd gear. It is recomended by racers. Screw it up and I would imagine you will have little bits of gear teeth in your transmission oil in pretty short order. It works great on a Motorcycle but you really need to focus.
I adopted a bit of a blend.
Throttle on.... pressure on shifter and roll off the throttle and ease the clutch in just a tad. You know you got it right when it sounds like 'snick'
Happy oil change

 

yeah, that is kinda what I am talking about.

I am still getting used to it, but I can shift now from 3-4, 4-5, and 5-6 w/out using the clutch. You just ease off the throttle, and gently push the shifter into place. My Uncle told me you can almost make instantaneous shifts if you get good enough at modulating the throttle. I want to know if this will shread the transmission or screw up the synchro.

 

Not particularly recommended for the S2000 tranny. That's actually more something you do with unsynchronized transmissions.

 

my buddy has old ass golf GTI and he does it all the time but not recommanded on s2k or any nice cars like it.

 

I would not recommend this unless you plan on replacing/rebuilding your tranny.

If you shift perfectly every time you will not harm your synchros or gears. However, every time it is not a perfect shift, the synchros are trying to match the engine speed to the transmission speed. So the synchros try to speed up or slow down the engine or the car (via the transmission and rear end). Either of these scenarios is asking a lot for brass rings a couple of inches in diameter. The crunch you hear is the synchro and gear protesting.

I did this a lot on the first car I owned. Eventually the synchros gave out. When I drained the transmission oil it looked like gold fleck paint from the ground up synchro rings.

The S tranny is a mechanical wonder, but won't take a lot of abuse and it is expensive to repair. If you want to practice clutchless shifting, use your uncle's car.

BTW, modern cars have decel valves or software to reduce emissions, so your clutchless shift may be slower than using the clutch.

 

Motorcycle trannies shift easily without the clutch because they are straight cut gears, sorta like a "dog box" tranny if you will. I don't reccomend it in a street car with a known delicate transmission/synchros. It's just not worth it to save .1 second per shift or whatever small number it amounts to.

 

Clutchless shifting is not recommended on bikes either. You won't end up with gear teeth in your transmission oil but you will end up with bent shifter forks and worn dogs/windows in the gears that will no longer hold engagement (it'll keep dropping out of gear).

I'm currently in the process of rebuilding the transmission on a bike that has suffered such abuse.

The secret to changing clutchless in the S2k (or any other car for that matter) is rev / speed matching.

For example, the S2k runs approx 12.5mph per 1000 rpm in 4th. Therefore all you need to do is to acelerate up to 50mph in 3rd, push the lever to neutral and rev the engine to 4000 rpm, and then slot it in to 4th.

It works, but is not easy and frankly, what's the point? You certainly won't get a faster shift out of it unless you practice for hours and hours and hours (and more hours) and even then you will be slower 90% of the time.

 

If you don't mind about 15 minutes of reading, this easy-to-understand article explains exactly what is going on in your manual transmission and makes all this easier to understand:
http://auto.howstuffworks.com/transmission.htm