I'm certainly no expert here but there's a part of this that doesn't make sense to me. I can understand that "once the tires are spinning", there's a somewhat lessened load on the drive train when compaired to the load that exists when the tires are hooked up.

However, what kind of loading does it take to break the tires loose in the first place? I would imagine that the shock (ie: sudden peak pressure) needed to break the tires loose would be responsible for many of the drive line failures that S2000's have suffered over the years. I could be wrong on this but it makes sense to me.

Can anyone clarify?

Drive Safe,
Steve R.

 

Here's another one of my "goofy" analogies:
Imagine you are trying to push a heavy filing cabinet across a floor. Which scenario will be easier for you to achieve?
1. You lean on the cabinet and begin to push but initially not with all your might. You strain and strain and the cabinet resists movement. Even if we assume that you have "warmed up" (like a car's powertrain), you are straining all your muscles to move that cabinet and you still might "pull" something. You may eventually get the thing to start sliding but it's hard.
2. You position yourself behind the filing cabinet and on "mental cue", you suddenly and sharply bring all your might and give the cabinet terrific initial shove. This breaks the friction between the cabinet and the floor and the higher force gets the thing moving. The cabinet begins to move nicely at a good pace. You now can reduce your strength to control the movement of the cabinet across the floor.
It always take more force to "get" an object moving than it does to "keep" an object moving.

ps. Back to the case of the S2000. Due to the nature of the torque curve, if you add "gears", FI or other significant power mods, your launch rpm will thus change because of the way in which the torque is then delivered.

 

[QUOTE]Originally posted by xviper
Here's another one of my "goofy" analogies:
Imagine you are trying to push a heavy filing cabinet across a floor.

 

Legal Bill wow - I NEVER do that. I run Khumo Victos and with those I get excellent wheel spin with just about 3 - 4 k and a slower clutch drop. Both clutch and diff are doing fine. I tried the whole launch thing a couple of times. Once it worked, the other time it didn't - that was ugly, clutch spun all the way through 1st AND 2nd and smelt the rest of the day. I don't find that on a local competition that you need to be that aggressive to be fast. Our top s2000 driver here in NY/NJ (2nd in the DC tour last week

 

Think of the trick where you "whip" off the table cloth quickly without disturbing any of the plates and silverware on the table. If you pulled with less force, you'd drag all that stuff right onto the floor.

From what I remember from physics, it's called the coeficient of friction. Once an object is moving, the friction between it and another object is reduced. In other words, it takes the most energy to break an object free from friction, then at that point, it takes very little energy to keep the object moving against friction, because the friction itself is reduced once the object is moving.

The energy needed to overcome static friction (friction acting on an object that's not moving) is much greater than the energy needed to overcome kinetic friction (friction acting on a moving object).

So, it takes a big amount of energy (higher rpms) to break the tires on your car free from friction so they are not sticking. We do NOT want the tires to stick when the clutch is released during a launch. If you launch at a lower rpm than these guys are recommending, it will not be enough to overcome the static coeficient of friction, and all of the strain will then be taken up by the car's mechanicals.

Hope this helps.

 

[QUOTE]Originally posted by vroom
Legal Bill wow - I NEVER do that.

 

[QUOTE]Originally posted by Legal Bill
Vroom, I'm amazed that you get wheel spin with a 3 to 4,000 rpm launch and a slow clutch engagment on Khumos.

 

I love this discussion, and I agree it's totally up to the owner (I, personally, will never do this to my car). That said, if you start doing launches and then end up whining here about how weak the car is, I'm gonna' come over there and slap you.

You've heard the right information now from folks who know what they're talking about. Use it at your own risk. Just don't try to BS mother Honda after you limp your car back to the dealership when something goes wrong.

 

I tried once to launch my s2. I revved to ~5500-6000 and dropped the clutch. BOG, tire grab, go. NO spin. I was shocked. Darn those sticky S-03s...

Coming from an FWD car that would spin with a 2-3k drop, needless to say I was amazed/baffled.

 

[QUOTE]Originally posted by Legal Bill