tire weight

[8000RPM]

if two same cars have the same size tires, but on one of the cars the tires are 24lbs and the other has 22lbs, how will that affect the acceleration of both cars. I remember that I red something about that long time ago, but can't find the article anymore.
and if only the rear pair are heavier and the fronts are the same on both cars, will that affect anything?

 

[LauraSVT]

if two same cars have the same size tires, but on one of the cars the tires are 24lbs and the other has 22lbs, how will that affect the acceleration of both cars. I remember that I red something about that long time ago, but can't find the article anymore.
and if only the rear pair are heavier and the fronts are the same on both cars, will that affect anything?

As a general rule, weight always affects acceleration. That said, however, the small amounts in this scenario should have minimal impact, particularly if the weight in question is on the rear wheels.

 

[fornetti14]

Grassroots Motorsports magazine tested brakes on a dyno once to see the affect of rotating weight on HP.

#1 was a larger mass but smaller rotor size

#2 was a smaller mass but a larger rotor size

#2 dyno'd 2-3 HP less at the wheels due to the fact that even through it was lighter overall, the larger rotor's rotating mass was near the outer edge and that extra weight rotating far from the center pulled down HP.

 

[GrandMasterKhan]

for every 1 lb you add to the rotational mass you can expect it to be equal to adding 4lbs to the car.

(ie 1lb of unsprung mass = 4lbs of sprung mass in terms of handling)

so a total of 4lbs would be like adding 16lbs to the car. not that much but thats 16lbs of weight the engine much push directly. So it IS something you could feel when behind the wheel.


Weight on the non drive wheels would only affect handling. not acceleration.

 

[catfish]

one other factor that would slightly mitigate that though, is the additional friction caused by the extra weight. So you could in theory launch a little bit harder w/o spinning the tires. I doubt it would fully offset the extra rotating mass though.