What is drop the clutch? is that another way of saying release it? What rpm should I start at?

 

There's a few variables to consider:

Ambient Temp, Tire Temp, Tire condition, Tire Inflation, Road Surface...

With all of those considered, I find the best launches are done between 5800rpm & 7200rpm.

In general, I launch around 6700rpm when its ~70-90 degrees out, on dry non-oily pavement.

Launching Technique:
Rev to the desired RPM (I really don't suggest anything below 5800 or you'll BOG the car, it looks reallly dumb, and you don't gain anything by launch lower than that, and even at 5800 thats what I'd consider on the LOW end for a launch).

Next, literally LEFT-FOOT the clutch. (Move your foot to the LEFT, off the clutch), letting it "POP" out... do NOT slide your foot out of the clutch, even moving your foot out REAALLLLLLYYYYY fast can screw it up (but can be done if your extreemly fast). Failure to have this rapid release will cause clutch burn (and possible glazing to the surfaces of the clutch), and an odor you'll never forget.

Just as you left-foot the clutch, stomp on the gas (floor it), and keep it floored (Except for your shift points), and you'll go like a bat out of hell.

...obviously, this is harsh on the drive train and tires, but were not really talking about that here :-)

You WILL get some wheel spin, and possibly "twist/slide" the ass a little to the side (so make sure you don't have a person or another car like 1 foot away or you'll risk slapping them).
* I should note: You actually DO want some wheel spin, otherwise you'll "BOG" (RPMs will drop below the VTECH engagement point)...thus a screwed up launch, and probably a lost race.


Keep the steering wheel straight-- pointed where you want to go... do not try to immmediatly counter-steer from the lauch (even though your ass-end might be pushed out a little, say...1.5-2 feet). The car should come in-line and go straight on its own.


Thats the basic idea...

-- Aaron

Disclaimer: Nobody should ever try anything I say :-)

 

Hey, I want a new clutch soon anyway... Might try this.

I generally dump at about 5000rpm if I don't want to risk the wheel spin (other objects too close) or 6000 if I do.

5000rpm bogs down to about 3500rpm, but 20 metres, and you're back into VTEC, so it's a slow start, but it's a much lower risk launch.

I also prefer not to side step the clutch.

 

Hmmm...

Sidestepping the clutch (moving foot out to side to release) is really unnecessary. Just bring your foot up really fast - at least I do - I'd rather have the speed of clutch engagement dictated by my foot than the clutch pedal springs.

The engine speed at launch is going to depend on all the variables Aaron mentioned. Some like to hold the engine steady at launch speed then pop the clutch, I prefer to blip the throttle up in the high rpms, enough that I know will break the tires loose, then worry about engine rpm once they're spinning, which is the key to a good launch.

The closer the wheel speed is to your actual road speed, the more available grip you'll have. You do NOT want to just mash the gas after you launch, unless you're on a really sticky surface and have to. What makes launching the S2K is that you can never, for any reason, go below 6k. A typical launch goes like this:
Car in first
Few seconds before launch, rev up to ~6k rpm, then blip the throttle from there on up to have it in a happy rpm range to break tires loose
Bring clutch up quickly and increase throttle when it's time to go
As the car starts moving forward and wheel speed/road speed get closer together, grip will increase; modulate throttle to maintain >6k rpm and minimize spinning

Goal is to have car hooked, throttle floored, and engine at >6k rpm, in a minimum amount of time from launch.

With my big heavy full-tread Victoracers at the Pro Finale, I was looking for about 7800 rpm at launch, and almost immediately flooring the gas, as the huge and immediate waves of grip quickly dropped the revs, requiring that much throttle to keep it from dropping below 6k. That huge grip caused the death of a competitor's halfshalf CV joint.

Now if the course designers had just taken out all those silly turns and extended the course another 1150 feet or so, we probably could have all come home with 13 second timeslips - it was that sticky!

Oh, and if you feel bad vibrations in the form of axle hop, LIFT! Axle hop breaks stuff in a hurry, and unless you're a F&F fool racing for pinks, it's not worth wrecking stuff.

 

You know that irony about racing for pinks?

Pink slips over here certify that your car is road worthy and meets emissions output

 

Quick launch=Z06

 

At a 5k launch, as you stated, you will drop you OUT of VTEC. I can GURANTEE you that you'll loose a pile of races with this kind of technique. Wheel spin is a MUST. The WHOLE idea here is to stay in VTEC. You'll be surprised how fast the rear end actually hooks-up.

Infact, having wheel spin reduces the drive train shock, your method is actually (possibly) more damaging.

Furthermore, you either need a side-step, or a VERY quick release of the clutch, or you'll smoke/glaze your clutch.

-- Aaron

 

I have successfully launched my S probably 7~8 times, but I am terrified that I'm going to destroy my differential. I know that there is no absolute number of launches the diff will handle, and some diffs have blown without ever launching (supposedly), but I'm curious how many times YOU have launched without your diff blowing.

BTW, I've found that lifting my foot REALLY fast produces as good of a launch as side stepping the pedal, and it seems easier to do. If I were drag racing someone, or reacting to a light tree, side stepping would give me extremely long reaction times, unless I had a really slick shoe. It's hard to slip your foot off of a pedal that is designed to NOT slip.

 

Here is a bumper cam video from an autocross with a launch that I think turned out good. I was on Kumho Victoracers. The video is of a complete run, so the file is about 17 MB.

http://www.trithese.com/ASan/movies/greg5.mpg

 

gernby, great video .