GT-Rob

iTrader: (5)

Hey guys. Just a quick question to get your thoughts on this.


Is there a benefit to running a larger wheel on the track? For example, 17in vs 18in vs 19in? My factory wheels are 18s, however 17s would obviously be cheaper (especially for tires), and lighter, whereas 18+ would be easier to get a larger width, and a cheap way to run longer gears (if thats something desired).


Lets take gearing out of the picture, as there are pros and cons to either direction you go. Lets also take the obvious sex factor out


The only benefit I can think of off the top of my head is the ability to run a larger brake, but if I don't plan to, is there any other benefit to running an 18 over a 17?

plumpzz

iTrader: (10)

I can't imagine many reasons for not running 17's other than brake size, but 13'' rotor is more than enough for almost any case of a track car Z.

mhoward1

When thinking about rim size there are a few items to consider.

1) If you are going to compete, what sizes are allowes
2) Widths available
3) Price to replace rims
4) Availability and price of tires for that rim size
5) Scrubs available...if this is just for HDPE's and such, sharing a common size with a popular series makes getting used tires a lot easier
6) Weight

These are not in oder of importance but as they came to me. Remember that diameter does not dictate tire width, unless it's because of availability.

GT-Rob

iTrader: (5)

The plan is to compete, however the rules allow anything larger than 10in. I am allowed to go with bigger brakes, but I don't feel there is enough cost/benefit (another topic all together).

I only mention 18s getting wider as it seems to be easier to find for example 285 in an 18 more often than in a 17 (not that it doesn't exist in a 17).



Sounds good though, I think I will be shopping for 17in wheels, mostly just to keep the cost down! Thanks for the input.

scotts300

iTrader: (46)

You need to compute tire heights to see the gearing effect. 17s will typically be taller than an 18 in the same width, so they would give taller gearing (not always a positive).
17s are not necessarily lighter than 18s unless you are comparing the exact same wheel and width. 17" tires, overall, are cheaper when new, but there are a lot of 18s out on the barely-used market. What kind of tires do you think you'll run?

There isn't much selection in the larger 17" tires and they end up getting very tall. 18s come in 285/30 and 295/30, both of which are shorter in height than a 275/40/17. Like I said above, larger size tires in 17s start getting very tall and there aren't many offered.

I have never seen a 285/xx/17. I ran 17s for years in 275/40/17 and just sold all my 17" wheels (3 sets) and bought all 18s fitted with 285 and 295/30s in R6, V710, and R888.

davidv

iTrader: (2)

Don’t worry about wheel size. Find tires first. In other words if you have a good set of 17 inch tires at a reasonable price, then get some 17 inch wheels.

betamotorsports

iTrader: (1)

The performance/DOT-R tire manufacturers are currently focusing their development efforts on 18" sizes. The compound, tread patterns, belting, and sidewalls are all optimized for the 18" sizes and then adjusted to fit 17" wheels. I'm sure the performance different is slight and for 99.9% of us it doesn't mean a thing but keep in mind that 18" wheels are where the focus is on tire performance.

GT-Rob

iTrader: (5)

Interesting. I figured 17s were more common but that was just at first glance at a couple of size charts.


As for which tire, im still undecided. It will either be an R-Compound with tread as it gives me -5 points in the series I want to race, or a premium R-compound (like a BF R1 or V710 for example). Either way, I imagine I would be buying new.

The 285 was just a number I pulled out of my ... Again, haven't decided on the size as Im not sure if I want a square setup. 275 seems more common for 17s. Although I would likely lean towards something...cheaper, like a 245 all around.


In any case, my main concern was if there was some dynamic I was not seeing, that gave an advantage of running a larger wheel. I still have some research to do on the rest

betamotorsports

iTrader: (1)

There really isn't a difference that I can tell. If you're a Schumaker (not Ralph) then I'm sure there's a big difference.

kart14

Guelph eh. -5 Points must mean Solosprint Ontario. I'm planning on running Hankook RS3, 140UTQG but they don't take any negative PIPs. The setup will likely be Enkei RPF1s 17x9.5 with 255/45 R17 Hankook all round. I'm try to keep the car in GT3.

Goodluck, maybe I'll see your z at the track.

Matt B
2006 350z Silverstone
#41 GT3