i have 17 in rims now with 215/45 tires but theyr too heavy. i wanted to get some lighter rims maybe some 15" or 16". i want performance and handling. so what are the advantages and disadvantages or every size. please reply if you know, if you're just guessing, then dont. i just want to get the right knowledge.

 

the diameter of the wheel has nothing to do with the weight.

its the material they are made of has alot to do with the weight. for example gram lights and work wheels are very light but cost a grip..

your suspension has to be adjusted properly in a perfect world to work with your tire and wheel size choice.

example.. if you ran tires with higher profile they also absorb impact from the road, now you have to take that into consideration when adjusting rear and front damper rates, psi levels off-set etc. its not straight forward bro. a pro racer will go through tons of tires and suspension setup before he finds what he wants

more info can be found here

http://www.discountedwheelwarehouse....tion_links.cfm

http://www.discounttire.com/dtcs/infoHome.dos

https://www.rsracing.com/tech-wheel.html

 

think about packing more meat/width on wheels if you are going for better handling, but you are right, loosing the rotational mass of 17" wheels and going down to a lower size will help acceleration and braking. imo the ideal wheel/tire size is 15x8 +20 with 245/50 tires

 

right but thats for the person who is worried about their 1320 time lol...

like Pontiac say's "Wider is better"

 

+1 Airman Jackson

 

reduced rotating mass allows for higher entry speeds and better exits

 

understood. but all 17" wheels don't weigh the same as you know and bigger wheels are used by higher hp cars to help offset the loss of traction. like i told him wheels and tires are another beast by it self.

im well aware that 17" wheel on a CRX for example shouldn't really be there lol

 

+1 Airman Jackson
(CRX with 17''s = wtf!!! 13-15s only)

 

wider is better for a number of reasons, one of which is better traction.

+1 more for airman because not all wheels weigh the same even if they are the same size. so while you'r right about rotational mass light 17" wheels are better than 15" because of the added contact area.

 

heavy rims = rotating mass

bigger rims to a point can have advantages.

hence why race cars dont run 13" rims and some series mandate wheel sizes @ 19" like the BTCC.

wider is better to a point for tarmac racing.

bigger wheels also means your motor has to work harder to turn them.

http://www.newton.dep.anl.gov/askasc...9/eng99334.htm

 

i believe there was a section in BMI that tested the effects of have a larger sized diameter rim. i believe handling can increase a slight bit. they did several tests including:

-ran stock STI with 17s & 18s on the touge and 18s had noticably better time.

-ran s2k with 2001 16s, then ran 2006 17s and 17s had better time and better impression with the drivers.

what does that prove? HANDLING is one fo those small advantages by running larger diameter wheels.

 

what wheels do you have? how much do they weigh? whats the width and offset?

my new wheels are a good bit heavier than they were before but they outperform the hell out of my old ones..theres a lot more involved than just weight..

 

Thats a little too generalized. Depending on the wheel, weight, width, and tire size, it could go either way. There is always a point where a larger diameter wheel will reduce performance. Its really quite dependant on what size tire you want to run and what profile. For example on my STI, I am moving from a 18x8.5 to a 17x9, and I garuntee I will ahve better handling on my 17" setup as it will be better matched sizing and lighter. Generally, once you get below a 50 profile tire, going bigger wheel and lower profile is not a given that handling will improve.

To figure out what setup will work best for you, you would need to know what rolling diameter you want to stick to, how wide and what type of tire you want to run, how wide a wheel you CAN run with that tire and that car, and what kind of driving you will be setting it up for. Auto-x would be different than high speed road course which owuld also be different than backroads. Even the weight of the car can factor in.

IMO, for most grip setups on a 240, 17s are typically going to yeild the best results. There are some cases where 18s or 16s may work better.

 

I am building a all-around handler biased towards road courses. I have 17X8s in the front wrapped in 235/45/17 Proxes4s and 17X9 245/40/17s on the rear. Once the fronts wear, I will be dropping down to 225 in the front as the 235 is juuusstt a bit too heavy.

While the car now has PHENOMINAL grip and near perfect feedback, it is markedly slower due to the wider contact patch (increase in rolling resistance) combined with the diameter increase. The engine works noticeably harder to move the car and my fuel mileage has plummeted. I estimate that I will need to find about 15 - 20HP to overcome the width increase.

Not that I am really complaining, the car sticks to EVERYTHING and I havent chosen coilovers or what I am doing to the engine. It's a problem that will disappear soon.

 

- haha there is sum goon running around here named 240***** that thinks he is gonna drift a 240 with 28's.