Inisharu D

what exactly is the point in having bigger diameter of wheels when the tires gets thinner at the same time? not like your wheels' total diameter will increase so that your car will have better top speed.

RangerDan

As far as the top speed thing...not enough to matter. Big wheels are mostly for looks or rotor/caliper clearance.

I think the idea size on a Civic is 15". Whenever Ive ran anything larger it seems like they dont respond as well.

Lower profile tires to a point help in cornering becuase theres not a whole lot of sidewall flex.

However go to thin and theres no flex at all...to much of a good thing.

asmallsol

basicly what he said. There is always a happy medium. Go to big, your rotational inertia of the wheels increases. Rotational inertia is location of mass from the axis of rotation or, the Trq needed to move the object. As the I goes up, the more trq needed to make the object spin. Wheels with more mass on the outside of the rim OR have a larger diameter have a larger I (rotational inertia) take more trq to get moving (slower quarter mile times). I=1/2 MR^2 (assuming the wheel is a solid cylinder, which is the closest shape) The actual mass of the wheel is only on varible. If you keep a wheel 10lbs, and change the diameter from 13inchs to 18inchs, your I increases dramiticly.

kingSfit

like what he said ...

asmallsol

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bunz &raquo;</TD></TR><TR><TD CLASS="quote">like what he said ... </TD></TR></TABLE>

Physics Own

cxjon

another cool thing to is every pound you save in your wheel weight equals ten pounds of weight reduction in your car.

my stock wheel weighed 18lbs and my rotas weigh 11.5 that is 6.5lbs per wheel saved for a total of 260lbs of weight reduction.
6.5 x 4 x 10 = 260

xerox445

can anyone confirm that? Seems like an alot of reduction

1 point 6

Also larger wheels have smaller series tires available which is better for handling (side wall flex).

Spoon Spec EK

Better tires, wider rims, sometimes lighter.

cxjon

i saw it in a write up on hondaswap.com along with what a asmallsol said.
a few years back i raced my friends stock 98 dx hatch against a 91 stock hatch. i killed the 91 hatch everytime a few weeks later my friend pit his heavy ar 17's ov i kept losing by a car everytime we lined up. it was sad

asmallsol

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cxjon &raquo;</TD></TR><TR><TD CLASS="quote">i saw it in a write up on hondaswap.com along with what a asmallsol said.
a few years back i raced my friends stock 98 dx hatch against a 91 stock hatch. i killed the 91 hatch everytime a few weeks later my friend pit his heavy ar 17's ov i kept losing by a car everytime we lined up. it was sad</TD></TR></TABLE>

yea, he is right in theory. It all has to do with rotational inertia. What that article is kinda saying is you will see the same benifit as removing 10 lbs of sprung weight, if you reduce 1 lb or sprung weight.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 point 6 &raquo;</TD></TR><TR><TD CLASS="quote">Also larger wheels have smaller series tires available which is better for handling (side wall flex).</TD></TR></TABLE>

This is not really true. Like I said, there is a happy medium. If your theroy was right, putting 18's on your car would make you handle better. Guess what, they dont. When you get into the 25 and 30 series, you loose all sidewall flex, and then your handling goes to hell. You want your sidewall to act as a stiff shock. If the tire is so stiff that it doesn't move, then your tires can not form to the road. If they are soft, you'll get a soft ride, but your tires will experiance so much tire rollover your handling will go to hell. It is not just the size of the sidewall that makes up the sidewall stiffness. Today's preformance tires are practically bullet with the addition of kevlar in them (Potenzas s03's are one example)


In autocross's, the most compeditive cars are running 13x8's with autocross slicks on them. Hell, if you look at f1 cars, those cars have tiny *** wheels with tires that offer a decent amount of sidewall.

The only reason why cars like Leman's racers have huge wheels with tiny tires is because they are on there brakes stoping there heavy cars (compared to F1 cars) for 24 hours straight. So they have to run huge brakes. Now they cant run small wheels. So they put on huge 20+in wheels on, with tires that are about 2 series bigger then if they rapped them with a few rubber bands. But why do they handle so good? This is because, these teams have close to a million to spend in one race. They put on the stickest tires that they can find. These tires stick real good, however, in 50 or so miles, their tires are shot. They can do this because they have the money to spend 1000+ on each tire every 30 or so minutes. I think that it is safe to assume, you do not have the time nor the money to go through 6+ sets of tires between oil changes.

1 point 6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by asmallsol &raquo;</TD></TR><TR><TD CLASS="quote">

This is not really true. Like I said, there is a happy medium. If your theroy was right, putting 18's on your car would make you handle better. Guess what, they dont. When you get into the 25 and 30 series, you loose all sidewall flex, and then your handling goes to hell. You want your sidewall to act as a stiff shock. If the tire is so stiff that it doesn't move, then your tires can not form to the road. If they are soft, you'll get a soft ride, but your tires will experiance so much tire rollover your handling will go to hell. It is not just the size of the sidewall that makes up the sidewall stiffness. Today's preformance tires are practically bullet with the addition of kevlar in them (Potenzas s03's are one example)
</TD></TR></TABLE>

It is a reality, just because you run 18s doesnt mean you have to run 25 or 30 series tires. Porsche and Ferrari are 2 examples, both use 40 or 45 series tires on 18" rims.

asmallsol

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1 point 6 &raquo;</TD></TR><TR><TD CLASS="quote">It is a reality, just because you run 18s doesnt mean you have to run 25 or 30 series tires. Porsche and Ferrari are 2 examples, both use 40 or 45 series tires on 18" rims.</TD></TR></TABLE>


: Pounds head against nearest wall:

I am talking about with honda's. Yes, bigger, more powerfuls run bigger setups, but again, it is so they can fit bigger brakes, or for looks.

This is a honda board, not ferrari.


Modified by asmallsol at 8:16 AM 2/29/2004

1 point 6

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by asmallsol &raquo;</TD></TR><TR><TD CLASS="quote">


ounds head against nearest wall:

I am talking about with honda's. Yes, bigger, more powerfuls run bigger setups, but again, it is so they can fit bigger brakes, or for looks.

This is a honda board, not ferrari.</TD></TR></TABLE>

You give a general statement, you get a general answer.
Also ferrari doesnt run a larger series tire because of brakes.

cxjon

he was talking about rims not brakes..... they run biger rims to make room for bigger brakes and they run a tire with a larger side wall for better ride and handeling

JforJonathan

larger wheels look good