Auto-x'ers,
Im going to try to make my first auto-x (in the 4S) this weekend. I've been trying to learn more about the specifics of the viscous clutch, but have not been so successful.

It does seem however, that you could "drop" the clutch around 4K or so, get a little chirp from the rears before the fronts kick in and sling-shot you forward.

Any help / experience is greatly appreciated!

 

How you launch depends on how the start is laid out. Many events have 20-30 feet from the start gate untill you hit the timing lights, some even have a real sharp turn just before the lights to keep you from dumping the clutch on the start. If it is a drag race start then wind it up to 5k and just ease off and let her rip. Just don't rip so hard that you get axel hop. I usually just do a medium start and rip after I get rolling.

 

sounds good. So assuming a straight start - get the clutch out quick and once rolling drop the hammer.
Thanks!

 

That's it. Once rolling get it into second and keep it there.

 

just to expand a bit on whats already posted, I hear alot about people asking about launch technique, and every autocross course I've driven has at least a 45° turn before the lights, and at a minimum 30°-40° if the starter lets you work the angle on it. I always just leave like I'm leaving a stoplight fast, but keep my foot in it. Bring revs up to about 2000 as the clutch is coming out and feed more gas till the right foot is on the floor or you need to lift for the corner. After that, find where you can shift to second smoothly without losing time (when you lift for the 1st corner is usually a good spot). I don't like high rpm clutch dumps because its so hard on parts, and if you don't end up doing it just right you either break axles, transmissions, or glaze clutches.

Think about it this way, if you need to lift before the starting lights, you launched too hard.

 

Its your first autocross and you are worried about your launch? well then...

Seriously though, if you like your car, clutch, motor, driveline and tires then be easy at the start. As others have mentioned, there are often gates soon after the start, so there isn't much to be gained by an aggressive launch.

Have fun and enjoy yourself. What I would suggest is to walk the course at least 3 times.. more if you can. It will look VERY different in your car at 40mph than it does walking it at 2mph. Knowing ahead of time where the course goes, and staying on it, is infinately more important than how you launch at the start.

 

Just to update my original post...

I was able to take the car to an event two weeks ago... what a car! Unfortunately I was late to the sign-up coming straight from working an all-night shift, so I was only able to walk the course once... but it was such a great time nonetheless.

As suggested here: I revved up to about 3500, got the clutch out rapidly, and once it was fully out, floored it. With the PSM off, the car was terrific (plus I had a LOT more confidence getting the tail WAY OUT when there were just cones to come in contact with). I could really feel the AWD system pull me out of tight corners... sometimes with too much understeer...

Anyway - great great fun. For anyone reading this who has yet to try an Auto-X event - just get out there! Its awesome.

 

and
you'll PO the person parked behind you waiting her turn when you spray her car with pebbles if you launch too hard.

craig

 

[QUOTE=Malakas;5822126]
As suggested here: I revved up to about 3500, got the clutch out rapidly, and once it was fully out, floored it.
QUOTE]

I do a normal rolling start (less drivetrain shock) then go WOT. It might cost a bit a time but much less wear and tear.


Especially those running slicks or DOT-r tires.