[Cyrus]

ive raced my friend in his integra GSR which has headers, intake, and exhaust in my 90 turbo that has only intake. Im getting a 3" turbo back exhaust and an electronic boost controller, which ill probably set around 10psi. as it is, w/ just the intake, he BARELY beats me off the line and cant beat me on top end performance. he thinks if i get 18" rims, that'll slow me down enough for him to beat me. do rims really make that much of a difference?

 

[jbsupra89t]

the only drawback i can think of for bigger rims is more weight. i myself am not that familiar with weights of wheels (in terms of stock and other brands and normal weights for 18") but also, wider tires on those 18" rims could give you better grip off the line. then again, i am NOT an expert at this stuff. anyone care to confirm and/or correct me? thanks.

-J

 

[SuprAng]

the wider your tires, the more grip you get, but more the contact is made, therefore requiring more power, as for bigger diametre, i dont see why it would matter? Nonetheless there is nowhere near a significant difference that would make you lose!

 

[vreaux728645]

Sport Compact Car did dyno a Civic with 17' wheels & compared it to a smaller (lighter) size. The result? The greater rotational mass from the cooler looking wheels resulted in a horsepower drop! The again could a Civic really stand much more of a load? Ever see one tow a boat?

 

[ChadMk3]

well if your getting bling blingin chrome 20's i can see that it might make a difference, but you can get some lightweight 18's, or ones that at least weigh the same amount as the stock MKIII rims.

c'mon, the MKIII rims are like 95% solid, if you got some 6 spoke 18's they would prolly be the same weight.



And i dont think it would matter enough for you to lose to a GSR

 

[MKIIISupraGuy]

bigger rims = overall taller gearing = slower acceleration

 

[MKNTRAXX]

bigger rims = overall taller gearing = slower acceleration

not always... that will also depend on what size tires you run.

 

[MarshmallowMike]

Don't know if this helps any...

In 7th grade we made rubberband cars from scratch, we got to choose from really small wheels all the way up to monters truck sized wheels. my and my friends cars looked somwhat the same (we were both trying to make a 64 Impala or that style car) I used somwhat small wheels and he used big monster truck ones... we raced and I killed him off the line and then coasted he went slow but eventually beat be... Dont know if that means anything but my smaller wheels with the same power went faster then the big tires.

 

[Mk threeing]

if you realy think about it,its like this:the small wheels spin faster at start ups because the wheel spins faster and needs less power(torq),--but @higher revs(same gear)it cant catch up to big ones.The big wheels must have more torq to stay with smaller wheels @start up,but it covers more ground than the smaller wheels,there for gets ahead.Its hard to put in words.read it like 10 times in a row,he he

 

[ZaZZn]

I think you guys got it all wrong.... Think as wheels as another gear just this one touches the floor.

Bigger Gears require less force to move but move much smaller distances... Ie less power to get the sucker moving

Smaller gears take MORE force to get moving but you should be able to stay in that gear longer. Now think what takes the longest... Shifting... Since you can ride the car out a little longer should be faster with smaller ones....

However, thats not considering weight.. I was toally suprised when I weighed my mk3 rims.. they are 23 pounds a peice.
I was told that 1 pound of rotational mass is equal to 10 times normal weight (car weight).... If this is true I don't know... All I know is I upgraded to

17x9's front and back with 275 40/17's and 245/40/17 on the fronts. When I go to the track we'll see if I"m slower but I doute that since I can not floor it in first and not go sideways

PZ Happy boostin

 

[NashMan]

i have the best wheels there like new prototypes

they are square littel bit rough ride but all ways make it there



hehe i have never sean some much on wheels befor half of you guys say the same thing but wrod it diffently

 

[BeatUpRx7]

Just pulled out my dynamics book so I can use the proper terminology. That way if anyone that already posted is actually educated on the subject and not just pulling terms out the ass, it might make sense to more than just one person. So here my version of the story goes...

Mass moment of inertia (I)... "is a measure of the ability of the body to resist a change in its angular motion". In this case, the the angular motion is rotation of the wheel (hopefully no one's lost yet). There's equations for a ton of different shapes, but the closest to a universal rim would be a hollow cylinder, since most of the weight is at the edges of the rim. The equation is I = mR^2, where R is the radius to the inside of the cylinder. So you can see how the Mass will change this, but the radius has a large impact on the inertia of the rim.

So basically.. If you increase the mass, it'll be harder to start rolling the rim, however it'll want to keep rolling farther. Also, increasing the diameter of the rim will have a large effect on how much power it takes to roll the rim. I don't have any equations or definitions to back the next part up, but in my opinion, the tractive forces from the tires and the power needed to overcome friction on the road is going to be much higher than that needed to spin the wheel, so most likely a change in mass and/or diameter will NOT make a huge difference. Just thought i'd toss in my info so you guys can understand and make your own decisions.

 

[Mikado]

That guy came off the line faster because his engine has less car to move. Fairly common problem for most Supra owners. The cars are built for a more refined sort of speed and performance... to go where you're going quickly and comfortably...and look damn good doing it. Or something like that. The original intent of a Supra wasn't drag racing. However, you just can't compare the engines, really. Perhaps changing wheels will slow the car a bit. He'd also have to quicken his car up as well.

Basically, unless you beat him by less than a car length, changing wheels won't make enough difference to really care about. Just up the boost a pound or two, if you're concerned.