Lightened Yaris

[HTM Yaris]

Tom: for track and autox I take out the rear "junk" so that I can utilize oversteer . In the mountains I leave everything in so that I can utilize understeer . I don't want my tail to be in the opposing lane !

Jason: First of all , I really admire what you have done with the Yaris

But it is really unfair to compare your fully track prepped Yaris with a street driven Yaris . I mean your Yaris looks like it has the correct weight reduction measures ( in all 3 planes ) . I mean really , those Goodyear ( which have extra stiff sidewalls BTW )slicks are enough to keep any vehicle from tipping over Not to mention I feel you have a custom suspension among other things . Try this , put your stock Goodyears on and put your glass back in or up ( not sure if you removed/replaced your glass ) . I feel certain that the stock tires will roll onto the sidewall then the wheels will dig in to the tarmac , then loopedy loop , you will make some body shop happy

Light is might . That is correct to a point . To the point that safety is compromised .
The OP doesn't have a roll cage to stiffen the Yaris up after the reduction in weight . Nor does he have 10.5" slicks with a custom suspension . Nor does he have the driving experience(Yaris) in a panic/performance situation like Jason does .

In no way am I saying that weight reduction shouldn't be done . I'm just trying to point out the potential pitfalls . Another pitfall I forgot to mention is that the Yaris will be more likely to hydroplane with weight reduction . I can't speak for anybody else , but I would not want to be hydroplaning on the downside of a 12% grade Not saying that will happen , but the potential will be increased with weight reduction .

[Jason@SportsCar]

Originally Posted by HTM Yaris

But it is really unfair to compare your fully track prepped Yaris with a street driven Yaris . I mean your Yaris looks like it has the correct weight reduction measures ( in all 3 planes ) . I mean really , those Goodyear ( which have extra stiff sidewalls BTW )slicks are enough to keep any vehicle from tipping over Not to mention I feel you have a custom suspension among other things . Try this , put your stock Goodyears on and put your glass back in or up ( not sure if you removed/replaced your glass ) . I feel certain that the stock tires will roll onto the sidewall then the wheels will dig in to the tarmac , then loopedy loop , you will make some body shop happy

Light is might . That is correct to a point . To the point that safety is compromised .
The OP doesn't have a roll cage to stiffen the Yaris up after the reduction in weight . Nor does he have 10.5" slicks with a custom suspension . Nor does he have the driving experience(Yaris) in a panic/performance situation like Jason does .

In no way am I saying that weight reduction shouldn't be done . I'm just trying to point out the potential pitfalls . Another pitfall I forgot to mention is that the Yaris will be more likely to hydroplane with weight reduction . I can't speak for anybody else , but I would not want to be hydroplaning on the downside of a 12% grade Not saying that will happen , but the potential will be increased with weight reduction .

I would guess you have not drive on a slick... The tires are trying to pull the car over, not stick it to the ground. I have had it on two wheels at least once per race this season - more than once without clipping the curbs, just by grip alone. Street tires will not generate enough traction to pull the car over unless you hit something. As far as sidewall stiffness, that is largely offset by the fact we roll out with 19psi in the slicks, they roll on to the sidewall by design. A great way to pick up MPG is extra tire pressure, a few extra psi can help.

Less weight builds traction, as the tires are not have to work as hard to hold the weight up. More weight on a tire does not make it work more efficiently. At the initial moment of inertia the extra grip will help to prevent wheel spin, but once the car has moved even a fraction of an inch the weight is hurting efficiency.

Worrying about the effect of the trivial amount of weight you could remove and keep the car civilized for the street is a waste of energy.

If you want to use a hydroplaning example keep in mind that the inertia of the heavier car will carry it longer than the lighter car, and it will take longer to recover. You want to prevent hydroplaning, use a better tire.

Manufacturers are going to alternative lightweight materials for a many reasons... It helps fuel economy for one. Another is safety. Look at the numbers, a full size van does not fair better than a lightweight compact when it comes to occupant safety.

No one should be suggesting removal of any safety equipment, or any devices that compromise the structure of the car, but there are things that can be removed without a dangerous downside.