AutoX question....

Joined
15 February 2003
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Fort Lauderdale
I was wondering...this weekend I was out at my first autoX event in the NSX, didn't get to race though :(

However, I watched alot of my S2K buddies race. I know that on autox, the two are closely matched, but from what I hear, the X should pull slightly ahead (and the one that was there proved this)...but my problem is this:

Most of that track, and any track, is run in 1st and 2nd gear...however, my car (and many others from what I've read) doesn't want to downshift to first if I'm going over, say 15-20mph...and sometimes below that its kinda hesitant.

Not sure if maybe I'm not rev-matching or what, but it seems like it would put a HUGE damper on my autox'ing...
 
This might be the only time on this forum that I get to say this, but the situation you describe is where my auto tranny gets to shine. In autox, my ability to drop into first almost at will, is a great advantage over a lot of 5 speeds and folks that haven't learned how to get into first easily. That couples with an almost seemless shift to 2nd to even out a lot of the differences between a manual and auto in this sport.

I guess this doesn't help you but I couldn't pass up the chance.:D
 
Without going into extensive detail here (search for past threads), it is important to remember that "rev matching" alone does nothing to help you get it into a lower gear.

Basic rev matching means that you depress the clutch, blip the throttle and shift to the lower gear (at more or less the same time), then let the clutch pedal out. The purpose of that is to bring the engine revs up to where they would be in the lower gear at the present speed. If you didn't do that then the car would nose dive, chirp the tires, wear the clutch and snap load axels etc. Very embarrassing. What it does not do is bring the transmission gears up to the speed they need to be at. The resistance you feel is from the synchronizers as they transfer your pressure and their own rotation to spin the gears up to speed via friction, sacrificing themselves in the process.

If you want to take the load off the synchros and get it into gear smoothly at speeds above ~10mph then you need to learn to double clutch. Double clutching really does mean using the clutch twice. Depress the clutch, then move the shift lever to neutral, and release the clutch. Now you blip the throttle so that the revs go slightly above where they would be if you were in the lower gear at the current seed. Next you depress the clutch a second time and as the revs start to fall you engage the lower gear and let the clutch back out. (Actually I often catch them still on the way up) By doing your rev matching in neutral with the clutch engaged (pedal out) you bring the transmission input shaft and gears up to speed along with the engine. That allows the gears to mesh smoothly without assistance from the synchros.

In real time it all happens very fast and not exactly as described above. The first press on the clutch is very quick and not necessarily as deep as a normal shift while you just flick the lever into neutral. The amount that you rev the engine is also less if you are still braking while all this is going on because your speed continues to fall.

Proper double clutching, especially under the pressure of competition, takes considerable practice, and learning often takes its toll on synchros and sometimes gears. And although it can be done very quickly, it still takes a finite amount of time and they add up in the course of an autocross run.
 
double clutching is pretty easy but i bet it gets complicated once you are under pressure and not enough experience...
 
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