a dumb question

[IALuder]

ok on a different board (preludepower.com) this guy went and made me out ot be a retard and said that 18 inch rims are better for handling then 16s. becuase theres less of a sidewall. i claim that 16 or small are better becuase it lowers your center force of gravity. plus you put more tire down being that low. hint better traction.

who is right?

[GT40FIED]

That would depend greatly on your choice of tire. Generally, 18s would handle better (though they will still look ridiculous). The lower center of gravity provided by 16s vs. 18s isn't a whole lot...really no more than an inch given that both cars have the same suspension. My professional opinion...it's a stupid thing to bitch over.

[IALuder]

true it is. i understand that.

but i was under the impression that 18s arent the ideal race rim size. which that is why.

[AzCivic]

most likely because they are heavy. alot of times the center of gravity doesnt even change, since as the tire gets skinnier the rim gets bigger, so for the most part it evens out.

[CD5Passion]

Originally posted by AzCivic
most likely because they are heavy. alot of times the center of gravity doesnt even change, since as the tire gets skinnier the rim gets bigger, so for the most part it evens out.

that is the reason right there, they are heavier. that and more power is needed to turn a larger wheel compared to a smaller one.

[ChrisCantSkate]

but as far as handling, the 18 with a smaller sidewall should handle better. there is a night and day difference between how my 17's handled and how my 15's do. and thers only a 10mm difference in tire width. (195 vs. 205) the rim weight wont effect handling, it will effect acceleration from a stop.

[Racing Rice]

A lot of it depends on the car they are on as well. Most small cars suspension systems are not designed to work with tall 18 inch wheels and tires. Bigger cars its probably not as much of an issue.

How many professional race civics, integra, preludes, and the like do you see on street tracks or SCCA courses with 18 inch wheels? Probably not many. Most of them run between 14s and 16s to stay away from the added weight and extra rotational mass among other reasons. With quality tires and proper suspension tuning, handling has never been an issue for them.

There are a ton of factors that determan better handling besides the size of the rims and tires. Tire compound, is more important then size.

[JDMFantasy2k]

Originally posted by Racing Rice

How many professional race civics, integra, preludes, and the like do you see on street tracks or SCCA courses with 18 inch wheels? Probably not many. Most of them run between 14s and 16s to stay away from the added weight and extra rotational mass among other reasons. With quality tires and proper suspension tuning, handling has never been an issue for them.

There are a ton of factors that determan better handling besides the size of the rims and tires. Tire compound, is more important then size.

my thoughts exactly, many of those cars run 15's with tires that have decent sidewalls. Although they flex, they're really grippy and all the handling components are designed to work with that setup. Also, less rotating mass.

[CD5Passion]

rotational mass was that word I was trying to get out but couldn't get to mind
so see that isn't a stupid question Ben

[KwikR6]

If a car has 18's on it..on the track...it's made for it...generally speaking though..an 18 will be wider then a 15 or 14 wheel...generally speaking...so then you also have more rubber on the ground as well with a wider rim.

[Racing Rice]

Originally posted by KwikR6
If a car has 18's on it..on the track...it's made for it...generally speaking though..an 18 will be wider then a 15 or 14 wheel...generally speaking...so then you also have more rubber on the ground as well with a wider rim.

So generally speaking, what cars run 18s on the generally speaking track?

[KwikR6]

Originally posted by Racing Rice
So generally speaking, what cars run 18s on the generally speaking track?

Generally speaking...you can lick my generally speaking nuts! bwahahahahaha jk man

[CD5Passion]

wow that was golden

well with the track, in most cases if you see a car with 18's it's most likely going to be something like a supra, 350z, or maybe a skyline, at least that's what I've seen

[mylittlecivic]

That is a real dumb f**kin question. j/k

[GT40FIED]

Rotational mass will increase, sure...but not too much if you can keep the aspect ratio close to original with low profile tires. Say you've got a 195/55/16 tire on there now and you switch to a 215/35/18...it's not going to change a whole lot in terms of power required to get moving. It WILL throw off your speedo...which is a bitch. And everyone talking about track specific cars and 16s is forgetting two things. First being that most competition compound tires only come in 16" and maybe 17" sizes. Second, those tires are really only designed to last you one or two race sessions (read: they're sticky as fuck). Honestly...more than tire size, I would think reducing unsprung weight would be my first concern.

[esthirteen]

Bigger rims are going to make you go slower. In my opinion, smaller rims, maybe 16 or possibly 17 will be better then 18's. Maybe a 17 with 40 profile. Or even a 16 with 45 profile. Plus the rotational mass which is said up there^. What you using the car for? Drag, autocross, or just street?

[IALuder]

im running autocross or SCCA.

[esthirteen]

I would say that if your doing that to go with a size 16 rim. 205 or 215 will be good. Also, your cars suspension has alot to do with the handling. Too low is bad, too high is bad. What you running for suspension?

[IALuder]

koni yellows, GC coilovers. im also running 16" rota subzeros with Toyo T1Ss'. im also working on getting bushings and a bigger rear sway bar.

[esthirteen]

That sounds good. I think it will do better then with 18's. What tires and sizes?

[IALuder]

205/45/R16