The r3v autocross video thread

[tinkerputzer]

Just watched them. Good visual of how to wind out first and go into second smoothly while going around a corner :up:

[Wh33lhop]

Oops. Forgot about that. Should be fixed now.

[tinkerputzer]

Videos didn't work wh33lhop but i get the idea on the shifting. I'm going to work on it for the next event. As for gearing i'd like to try a 3.46 lsd.

Nice run Gary.

[Gary Horneck]

Ran a National Corvette Club autocross today. Our site is so beat up, you figure the potholes into your line, and there's lots of gravel to contend with in the afternoon runs. Very slim margin for error on the first feature. Get too wide and there are poles and a ditch that will seriously mess you up.

[Mfever]

videos are private wh33lhop... badass course OP!

[Wh33lhop]

Great advice wh33lhop.

You are right shifting to second was mostly for convenience. I did try keeping it in first until after the first cone on one run but it seemed to make little difference. I just reviewed the run video and timed it from the start line to the second cone and both times were around 5 seconds. I'm sure with a bit more practice i can make it faster by keeping it in first longer though.

It helps if you learn to shift quickly without upsetting the car (which includes planning a line that is a bit straighter at the time of the shift). If you shift properly you can drop the clutch while getting back on the throttle immediately after--not during--the clutch engagement.

For example, two runs on the same course. First, the bad:



I get on the gas a bit too aggressively during the shift, and choose a line where I am using most of the car's traction to turn during the shift. I can stay in it and control it fine but that's not very fast.



This is much better. I've picked a line that apexes later and is straighter during the shift point (notice the wheel is at 90 degrees for that shift, whereas it's at about 180 in the previous video) and I dialed back how aggressively I got on the gas during the clutch uptake, so it just results in a small chirp instead of a wild slide.

If you learn to shift well you can pretty much wind out first on any course. It will gain you more time on some courses than others.

On a side note what's your take on gearing for autocross? It seems like 3.73's are a happy medium but i find myself wishing second was just a bit taller.

It really depends on the typical course you run. I feel relatively happy with a 4.10 and undersized tires (about a 4.27 effectively) and a 7000rpm rev limiter but most courses I run at Oakland are on the tight side. If you're regularly riding the limiter more than a few seconds per run, you may want to bump your gearing a bit.

[tinkerputzer]

I agree with 9 and 3, but it's not easy with the airbag wheel.

[I8UR911]

Hold your hands at 9 and 3 vs 10 and 2. That little bit makes a HUGE difference (think F1 steering wheels). Try not to "shuffle" your hands either. Both of these things will make you a lot smoother.

[Gary Horneck]

I like the 3.73's and a 6,800 redline. Works for 90% of our courses.

[tinkerputzer]

Great advice wh33lhop.

You are right shifting to second was mostly for convenience. I did try keeping it in first until after the first cone on one run but it seemed to make little difference. I just reviewed the run video and timed it from the start line to the second cone and both times were around 5 seconds. I'm sure with a bit more practice i can make it faster by keeping it in first longer though.

That's a good tip for judging slalom speed. These were very open slaloms, around 30 steps between each cone. I was practically at the rev-limiter in second through them. I should have tried third and a little more speed just to see how it felt.

Yeah El Toro is awesome for autocross. Nice and open and the surface provides tons of grip.

On a side note what's your take on gearing for autocross? It seems like 3.73's are a happy medium but i find myself wishing second was just a bit taller.

[Wh33lhop]

Always wind out first gear if you can--people shift early for convenience but if you can shift quickly without upsetting the car it's almost always beneficial to wind it out. Also, your steering seemed a bit slow during some of the slaloms. It's good to be smooth in general, but if you can take your time sawing at the wheel through a slalom, you're not going fast enough.

Nice course. Lots of guys drive out of norcal for pro solo down there.

[Gary Horneck]

Nice course. Makes ours look like a backyard adventure.

[tinkerputzer]

Hello rev-limiter :)



Critiques welcome.