Well I did my first auto-x a few weeks ago and had a great time. Over the course of four runs I went from 49.xx seconds to 43.xx seconds....the the tsm champ who did first was 40.xx. I was pleased for my first event.

Now to my question. there was one corner after a short straight....a very hard left hander. coming out of it I was in second, actually was in second the whole course. but the rpms were very low (only in that 1 corner) and had to wait what for the rpms to come up. They probably dropped to 2600 or so. so i was wondering how does the evo trans do 2-1st downshifts while rolling. I have never tried this before. I know in my past car (wrx) it just wasn't happening and a bad thing. So is it safe, or is there another solution. Thanks

 

I have not tried it either but did you try left foot braking? Just an idea.....

 

most of the autox events i've been in,i always stay in 2nd.there are times were i'm like "i should try to downshift into 1st".a guy here who downshifts into 1st.he says something like "clutch in,rev,clutch,shift" i'm still confused

 

You certainly can downshift to 1st. I've done it in autoX with no special tricks, just clutch in, shift to 1st, clutch out. You can rev match (give throttle while clutching) to keep the car from lurching when you clutch out; that's a good idea but the transmission and clutch should handle an occasional non-rev-matched downshift as long as you ease the clutch out.

But frankly, I don't think it's necessary most of the time. In autoX, the car is very temperamental in 1st gear. Unless you're accelerating in a perfectly straight line, you'll probably find 2nd gear to be the better choice. It's hard to put the power down in 1st gear except when going straight ahead.

Just about every time that I've tried a section in both 1st and in 2nd, it's been the case that 2nd gear worked better.

 

The situation you've just described is pretty much the ONLY time you'll ever have to perform a "double-clutch" downshift. If you try to force the car from 2nd into 1st, you'll find it's REALLY hard to do (most cars have a first-gear lockout) and if you DO manage it, you'll be putting a lot of wear on your synchros. The double-clutch downshift basically bypasses the synchros and lets you manually synchronize the gears.

What you do is:

1) clutch in
2) shift out of 2nd and into neutral
3) release the clutch fully
4) clutch in again
5) blip the throttle
6) shift from neutral into 1st
7) clutch out

Emre

 

Kool, thanks for the info. The next auto x is memorial day....we'll see if i can be a little more competitive for the Subys this time ;-)

 

Well, I agree with J Brennen. 99% of the time the Evo will be faster without shifting. The trick with the car (and many other turbo cars) is to recognize when you are going to be off boost and make sure that you get on the power earlier. This is where left foot braking can be beneficial.

As far as making the downshift to 1st. It is certainly doable and double clutching will help. Practice on the street at slow speeds when there's plenty of room. When you get to the point where there is no jerkiness then you can think about doing it at an autox.

My rule of thumb for any up or downshift during an autox is that I had better be able to save 1 full second in acceleration or speed cause the two shifts (down to first and back to second or up to 3rd and down to 2nd) are gonna throw off my cornering a bit and take some time to accomplish. Also if I don't shift I can't make a misshift.

regards,
alan

 

yeah I agree.

Most of the time if you need to downshift to first, you have made a mistake somewhere else on course.

 

I ALWAYS downshift into first while rolling with no problems, whether in an auto-x or coming up to a light on the street. No double-clutching here, just push in the clutch and push the shifter up into 1st. It may take a split second for it to go in as the syncros do their job, but no problems here.

BTW, in my last autocross, right from the start there was a tight left followed by a slolom followed by a tight right and another 90 degree left. I left it in 1st the whole time through that, never bounced off the rev limiter (7800) and it handled awesome. I was much faster through that section than the guys who were shifting to 2nd and running about 2500-3000 rpms. In this case it was wet and my speed through the turns was pretty limited. In the dry I probably would have chosen 2nd.

Coming up to the last turn (2 tight 90's = squared off 180) was a straightaway. I was about 50mph, hit the brakes, downshifted to first and powered out of the turn. I hit the rev limiter in 1st just as I crossed the finish line. I can guarantee you that it would have been slower to leave it in 2nd and try to pull out of the corner at low rpms.

EVOlutionary

 

I shift too much. And I think you'll find that all of the fastest drivers don't shift (maybe to third if it's a really fast track). They often use left foot braking and use consistant throttle to avoid these off-boast situations.

 

For the course you were describing if that left turn was the only turn where your RPMs were low, I wouldn't bother downshifting. 2600 RPMs isn't bad, so for a situation like that I'd practice on getting on the gas earlier so you're back on boost as you hit the apex of the turn. Brake early, gas early is generally the way to go with the EVO.

Cabo

 

Thanks for the input guys. I am by no means an expert. I've run 5 events so far and I still learn alot every lap out (today I learned how to get the car to rotate by playing with tire pressures). I'm currently leading my regional class, but I know I'm still way off pace at the divisional or national level.

EVOlutionary

 

Listen to the words of the wise.

 

Thats one of the first things I learned. Get into second, stay there, and keep your foot off the clutch pedal. Most courses wont require a first gear downshift.

 

I learned the opposite. I've only done 2 auto-x events now (in the last 2 weeks), and I stayed in 1st 90% of the time on the 1st one (2nd one was 100% due to being short). I was over 5k most of the time, and bouncing off the rev limiter several times with only quick shifts to 2nd in 3 places, but always followed by hard braking and a downshift to 1st while negotiating the next, tight turn.

If I stayed in 2nd the whole way, I would have done very well, as I would not have been screaming throuth the gates with instant boost at all times. To give you an idea of the course length, I ran a 38.5 (5th place), which was .9s off the FTD of 37.6. 70 of the 85 cars were above 40s. I agree that it's better not to shift a lot, but I would much prefer to be at high rpm in 1st than low rpm in 2nd, since our cars make the most HP above 6500rpm.