Want more traction?

[maestromaestro]

OK driver education is always tops... but here's the reason this is significant... on a stock car, not too much... when you start adding power, forward traction becomes the primary limitation, and once you start increasing the power more and more, it very significantly becomes the limitation in a very obvious way.

You can ignore that, fine, for people really looking to improve, hope they think beyond what everyone else says. Motorsports of all sorts there's usually reason to add weight in certain areas. The Fiesta ST does AX as well or better depending on the course, with a full tank of fuel... there's a reason for that. On a stock suspension car, the weight transfer and the performance curve of the tire can be optimized with a full tank compared to empty tank, so if there's only 300-600lbs of transient pressure on the contact patch of the rear tire, it's probably well on the left side of the curve... when it's off the ground it's zero lbs of course... but then is it the performance limitation? It's a problem solving excercise, what can we do within a given ruleset.

You'd think that we are arguing - we're not. My point is simple - I am not disputing the benefits of applying weight to make improvement to the vehicle chassis dynamics. But, as you yourself are pointing out, this has a very limited range of applications (I am talking about the laden bar) - for a FiST that has massive mods, notably a bigger/hybrid turbo and other associated go-fast-in-a-straight-line bits. Setting aside my statement that I don't view FiSTs as drag cars (again, to each his own as they say), 6 lbs would only manifest themselves once the driver has honed his technique and sorted out everything else on the car - in other words, only when you can 'control' for the reaction time/car behavior - you can discern the difference before and after adding buckshot/molten lead. Given that these variables are very seldom 'invariant' - this requirement further narrows the field...

[ As to the "full" tank of gas - that's ~11 gallons, which weigh 66 pounds (6 lbs per 1 gal); it also does not behave as a solid body (in a non-round tank), generating a non-trivial roll moment of inertia. So, yeah, when superimposed with the rotation of the rear of the car, it produces a synergestic effect - something that a rigid roll bar can't. ]

 

[Pablo Pistoffo]

Couldn't one get a similar effect (perhaps more) by installing an aftermarket intercooler? While it isn't as low as the two point brace, it is farther forward and has similar weight gains- I think my Whoosh V2 was around 7 pounds heavier than the stock unit.

 

[AZSP33D]

Take some ballast and move it around, it's surprisingly very effective in changing the characteristic of the car. The more you go forward of the front axle, the more you increase PMI but the more it will affect the balance forward of course. Purpose built racecars have many areas of ballast, even adjustable with motors and jackscrews. Always keep it as low as you can on a car... motorcycles are different.

 

[benvid]

Adding weight to increase vertical load doesn’t outweigh (no pun intended) the negative affects it has on longitudinal acceleration. The only way to increase vertical load and add a very small amount of weight is to use aero, but that obviously only works with more airspeed. Otherwise we could all just put 1000lbs of steel under our car to make our cars launch faster, which is obviously untrue. Now If you have a minimum weight you have to make for a racing class and you need to add weight you might as well distribute it to your advantage like what you are talking about here but otherwise this is a waste of energy.


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[benvid]

Would 6 lbs even register? This is next to nothing relative to the weight of the car. I realize that we have 60/40 split; I also appreciate that it would theoretically lower the center of gravity.

So - what would be the tangible benefit? Especially considering that the weight of the car simply would go UP, rather than being meaningfully redistributed. People buy Ti lug nuts in the pursuit of weight loss, never mind rip out the rear seat(s).

Let's say there's more traction - under what conditions would that be a net positive? The car would be heavier, so - slower even for the 1/4 mile pull (again, assuming that 6 lbs would actually lead to any discernable change).

I'm really curious here.

There is no net positive (see above)


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