18" tires for street/track use? .. OR stick w/17"

[glamcem]

"too many variables" ..there..I said it, does that make me one of the cool kids ?

seriously though, there are so many factors come into play when selecting the wheel size such as tire selection, power, dampers..just because it's a 17" wheel doesn't necessarily mean it will outperform an 18" wheel..

the problem with the recent magazine tests, they haven't been performed scientifically (while holding all things being equal)..

generally the wider tires will perform better to a certain extent and after that point the amount of the rubber and the added weight will be counterproductive ..

For our cars 235/40/17 or 245/40/17 or 245/35/18s are all good sizes since they're pretty close to the OEM overall diameter ..


using 18" wheels and low profile also has their advantages especially when you combine with a softer compounds since the stiffer sidewalls provide more direct feel..

I personally prefer a slightly wider rims for the 235 or 245 tires, like 9" wheels.. if I had 9.5" wheel I would opt for 255s since slightly stretched tires with more contact patch won't have the penalties of the bulging tires

[YodrOne]

if you want to save a lot of money, especially if tracking/autox'ing 17's are best bet.

I got some super cheap lightweight wheels form tirerack mounted with AD08R tires (Max summer tire) and they're we'll matched to exploit the handling limits of this car in nearly stock form. The grip is insane compared to the crappy stock tires, really night and day, and each tire is in the range of $150. You can't beat that for $$/fun.

[Alfalasy]

Originally Posted by glamcem

using 18" wheels and low profile also has their advantages especially when you combine with a softer compounds since the stiffer sidewalls provide more direct feel..

I personally prefer a slightly wider rims for the 235 or 245 tires, like 9" wheels.. if I had 9.5" wheel I would opt for 255s since slightly stretched tires with more contact patch won't have the penalties of the bulging tires

What's the ideal setup in your opinion for a turbocharged BRZ (270-300whp) used 70% on streets 30% on track days?

What if I have 9.5" 18s +40mm offset for all squared setup, tires 245 back and 225 front, plus adding 12mm spacers for all. 3.4 camber front 3.1 rear. What would you change or improve to achieve ideal blance between street and track use 70-30? What's the penalty of bulging tires?

[glamcem]

Originally Posted by Alfalasy

What's the ideal setup in your opinion for a turbocharged BRZ (270-300whp) used 70% on streets 30% on track days?

What if I have 9.5" 18s +40mm offset for all squared setup, tires 245 back and 225 front, plus adding 12mm spacers for all. 3.4 camber front 3.1 rear. What would you change or improve to achieve ideal blance between street and track use 70-30? What's the penalty of bulging tires?

since the cost of the second set of wheels and tires are relatively cheaper than many sports cars (Corvette, BMWs ..etc) I would recommend having a second set for summer/track use ..
I am not a big fan of spacers or staggered setups ..

I see some people put wider tires for the wheel size but since the size you are limited to the size of the wheels it's pretty much pointless.. say for instance, if you have an 8" wheels and tires that are designed to be worked in 8.5-9.5", you still use 8" of rubber having a wider tires doesn't give you more contact patch, in fact, it's worse since bulging is bad for reaching ideal temps, softer sidewall and lack of steering response

I think 17x9 +35mm offset (Either Enkei RPF1 or Wedsport TC105N) with 245/40/17 or 255/40/17 would be good options for the power levels.. keep in mind, if you don't have stiffer suspension you may slightly rub the tires (which is no big deal IMO but something to consider) ..keep in mind some tires run wider even at same sizes

I was using a bit more aggressive camber in front -3.2 and -2.5 in rear

[2015FRShalo]

New to everything about tires I never read up so what are some suggestions for new rims? And tires? And whatever else? Keeping the whole engine stock probably gna drop the car an inch nothing too crazy. Put a sway bar on for now till I understand the car fully and what I'm doing to it. Any links that give a break down of offset, camber etc. would be appreciated

[swarb]

Originally Posted by 2015FRShalo

New to everything about tires I never read up so what are some suggestions for new rims? And tires? And whatever else? Keeping the whole engine stock probably gna drop the car an inch nothing too crazy. Put a sway bar on for now till I understand the car fully and what I'm doing to it. Any links that give a break down of offset, camber etc. would be appreciated

Read more.

[GSpeed]

Originally Posted by 2015FRShalo

New to everything about tires I never read up so what are some suggestions for new rims? And tires? And whatever else? Keeping the whole engine stock probably gna drop the car an inch nothing too crazy. Put a sway bar on for now till I understand the car fully and what I'm doing to it. Any links that give a break down of offset, camber etc. would be appreciated

Disclaimer: I'm going to approach your question from a performance standpoint rather than an aesthetic one.

It's a good rule of thumb that smaller wheels are faster. That's not always the case, but lighter is better on racecars, and wheels are both unsprung and rotating mass. I remember hearing in a vehicle dynamics class years ago that losing a pound off of your wheel weights is roughly equivalent to losing 50 lbs off the car itself.

A "lightweight" wheel is usually regarded as something less than 1 lb per inch of diameter, i.e. a 17" wheel should weigh less than 17 lbs to be a "lightweight" wheel. A common (for good reason) lightweight wheel for these cars is the Enkei RPF1, it's an incredibly prolific wheel among the track day crowd. For the price, it's very light and strong. We just ordered a set for our car, actually.

The hot street tires right now are the BFG Rival S, the Potenza RE-71R, and the Hankook RS3, if you look at what the autocross guys are running. If you want a fast tire, I'd look there. If you've got more specific needs (wet performance, long life, etc.) you'll have to give us more information to go off of.

For more information, I'd highly recommend reading MotoIQ if you don't already. They've got a great section on handling and suspension tuning:

http://www.motoiq.com/Tech/TheUltima...nHandling.aspx

Hit me up if you've got any other questions.

Jake

[2015FRShalo]

Originally Posted by PST

Disclaimer: I'm going to approach your question from a performance standpoint rather than an aesthetic one.

It's a good rule of thumb that smaller wheels are faster. That's not always the case, but lighter is better on racecars, and wheels are both unsprung and rotating mass. I remember hearing in a vehicle dynamics class years ago that losing a pound off of your wheel weights is roughly equivalent to losing 50 lbs off the car itself.

A "lightweight" wheel is usually regarded as something less than 1 lb per inch of diameter, i.e. a 17" wheel should weigh less than 17 lbs to be a "lightweight" wheel. A common (for good reason) lightweight wheel for these cars is the Enkei RPF1, it's an incredibly prolific wheel among the track day crowd. For the price, it's very light and strong. We just ordered a set for our car, actually.

The hot street tires right now are the BFG Rival S, the Potenza RE-71R, and the Hankook RS3, if you look at what the autocross guys are running. If you want a fast tire, I'd look there. If you've got more specific needs (wet performance, long life, etc.) you'll have to give us more information to go off of.

For more information, I'd highly recommend reading MotoIQ if you don't already. They've got a great section on handling and suspension tuning:

http://www.motoiq.com/Tech/TheUltima...nHandling.aspx

Hit me up if you've got any other questions.

Jake

Thank you Jake I appreciate the help!