Prepparing a Yaris for FSP (Solo 2)

[Russelt3hPirate]

Originally Posted by kngrsll

yeah, that certainly true... any track time will be strictly about maintaining momentum, lol! you know, it actually takes alot more skill to pilot a car around with low power b/c it forces you to really watch your braking points and apex's rather than using brute force to wring the car around. its fun though... Russell, look for a thread about tracking the yaris, there is a guy who has already done it. he had some r compounds, springs, and an exhaust, thats it. he did really well and took pics.

anyways, it sounds like your already on the right path... even if its not just an autox car, sticking to SP is nice for simply the restrictions of it. keep us updated on anything you do to the yaris and any racing that happens and ill do the same.

and give us some info on the STi!!

yea the brakes are useless! haha (on the yaris, as in there is no point in using them you're not going fast enough to out drive the R-comps :) ).

I'll start a thread in the gallery of my STi.

[eTiMaGo]

how in the world would 10" wheels fit on a yaris??? And with such a light car, would there be enough weight on the wheels to maintain a good grip?

[03Z33]

It's doable with some pulling of the fenders, or an overfender... but I'm not sure they are needed

For autocross duty, I'd be all over a set of 13x9 Watanabes or Panasports with some sticky Avons or Hoosier A3S06's!

[eTiMaGo]

Hmm yeah with a wide body kit it could be physically done.

But what I am worried about is the downside of using really wide wheels? Isn't there a point at which the weight of the car is just not enough to ensure maximum grip on the tires?

[eclip5e]

Originally Posted by eTiMaGo

Hmm yeah with a wide body kit it could be physically done.

But what I am worried about is the downside of using really wide wheels? Isn't there a point at which the weight of the car is just not enough to ensure maximum grip on the tires?

Any non-spec size wheel will accelerate the speed at which your wheel bearings are worn, especially non-spec offset.

As for power/weight ratios, this could be a problem, but more importantly, there is a point where adding wheel/tire width no longer adds to grip levels, and only adds weight.

[the_saint]

Depending on the offset you might not need a widebody kit. I have seen a 9" wide wheel on a stock fendered Yaris/Vitz.

[Russelt3hPirate]

i was joking about the 10" wheels.

contact patch doesn't increase with tire width or wheel width, it's dependent on vehicle weight.

lateral grip will increase b/c the contact patch is now "wider" but the contact patch area isn't larger.

I dont think it'd make much sense to have more than an 8" wheel but i'm pretty sure a 15x7 will do the car plenty justice :)

[the_saint]

I'm not trying to argue anything about "wider is better"...but wouldn't a wider tire=larger contact patch area? I mean from a purely mathematical stand point.

[Russelt3hPirate]

Originally Posted by the_saint

I'm not trying to argue anything about "wider is better"...but wouldn't a wider tire=larger contact patch area? I mean from a purely mathematical stand point.

nope, contact pacth area is dependent on weight

contact patch shape is dependent on wheel and tire width

[03Z33]

I'm just going by what I see at the higher levels of "cone dodging" (autocross). You normally see the faster cars running aggressive wide tires, with very sticky compounds (slicks or DOT R's like A3S06, etc..)

There is a balance you need to achieve between the wheel width, tire width, and weight of the car. Most times, a narrower stickier tire will yield superior results to a wider tire that isn't making good use of its full contact area (and additional weight). The best way to find these things out is to go out with a tire pyrometer or some chalk and try out different setups, pressures, etc...

[Russelt3hPirate]

Originally Posted by 03Z33

Most times, a narrower stickier tire will yield superior results to a wider tire that isn't making good use of its full contact area (and additional weight).

now, i understand you like narrow tires ;)

anyway I know from personal experience that a 275 on an 8" wheel is faster around an autox couse than a 245 on an 8" wheel. (same rolling diameter too btw).

when limited by wheel size it is most beneficial to run the widest tire possible simply for the lateral grip

when limited by rubbing or fenders or anything else, it is beneficial to run the widest tire possible simply for the lateral grip

turn in and some response is sacrificed but the increase in lateral grip is worth it when you're looking at the times at the end of the day.

I plan on having a set of 15x7s for autox with some 225s, which is similar to what my buddy runs on his xA. Might actually just steal his wheels for a day. ;)

The Yaris will be a fun toy, i'm excited :)

[Russelt3hPirate]

what wheels are you getting? offset?

[03Z33]

This set is just for looks 16x8 +15 rear and +25 front (deep dish)

[Russelt3hPirate]

Originally Posted by 03Z33

This set is just for looks 16x8 +15 rear and +25 front (deep dish)

and 185s :(

is there a reason you're increasing your rear track greater than the front?

have you looked into the adverse effects of changing the vehicles scrub radius? especially on a FWD car.

my friend has some 15x7 +22mm Team Dynamics that we will be testing out.

[the_saint]

Originally Posted by Russelt3hPirate

....is there a reason you're increasing your rear track greater than the rear?

have you looked into the adverse effects of changing the vehicles scrub radius? especially on a FWD car.

Originally Posted by 03Z33

This set is just for looks 16x8 +15 rear and +25 front (deep dish)

one character

[Russelt3hPirate]

Originally Posted by the_saint

one character

??

[the_saint]

You need at least one character to make a new post...and quotes don't count.

[Russelt3hPirate]

Originally Posted by the_saint

You need at least one character to make a new post...and quotes don't count.

I was asking what point you were making.

I can read, I know what he said, i know what i said.

but what point are you trying to make?