View Single Post
Old 10-16-2024, 01:54 PM   #2
JP1738
Senior Member
 
JP1738's Avatar
 
Join Date: Jan 2024
Location: Charlotte, NC
Posts: 578
Likes: 1,648
Liked 1,226 Times in 343 Posts
Default Re: ET with and without wheelie.

Not to revive this thread as it seems it got a little out of hand, but I'd like to input my 2 cents as well. Just wanted to wait until it calmed down a bit.

Obviously no two cars are the same. Between peak power, converters, power curves, gearing, weight, suspension set-up, tire size/contact patch, and a host of other variables, I believe it would be impossible to determine the right way to set up every car without testing it in the real world and seeing whether a car can wheelie, needs to wheelie, and what's faster.

I'd like to approach the subject from a more abstract, physics perspective, using one main principle. There is no such thing as a "free lunch."

The first law of thermodynamics states that energy (and matter) cannot be created or destroyed. Within a closed system, all energy put into it cannot be removed or lost. A vehicle is not a closed system by any means, but in this case, we can make a few engineering assumptions and reduce the system to a closed system, especially considering the first 60ft of a pass are at relatively low speeds so resistances such as wind and friction are not of significance.

Just think to yourself and imagine the energy it takes to lift a car off the ground with only the moment of inertia created by the rear-ends rotational acceleration on the ground, it's force being equal and opposite assuming a dead hook and perfect traction. That is a TON of energy. Now I understand there is lots of potential energy stored in the front springs of a car that help the front end off the ground along with the cars ability to drive underneath it's center of gravity as the front end goes higher and higher, further exacerbating the wheel stand.

The amount of power (or energy over time) an engine makes is finite from the starting line to the 60 ft beams along with any other increment you choose down the race track. This rotational energy can be expended in many ways: Friction loss, heat, sound, etc. but most importantly in our case, acceleration. If a car has the ability to accelerate straight forward without lifting the car off the ground at all, there is no wasted energy lifting the front end against Earth's gravitational pull. Knowing the amount of energy we have to work with is finite, any energy spent lifting the car off the ground is energy we could have used accelerating the car.

Again, each car is different, and a wheel stand may be necessary for your combination to achieve the traction it needs to keep the tire planted and accelerate. Along with whatever black magic science goes into making your converter work or whatever other excuse you may have for steadfastly insisting a wheelie is necessary or faster. From a Thermodynamics point of view it isn't and it can't be.

In conclusion, wheelies are slow, but man are they awesome. I will continue to do them, I do not care if it's slower.
__________________
Dawson Pauley
#2827 N/SA 1980 Malibu SW 2S 305/180
#2827 S/ST 1978 Mazda RX7 w/ 383 sbc/glide
JP1738 is offline   Reply With Quote
Liked