17" vs. 18" Wheels

Mazda RX7 and RX8 Suspension, Intakes, Headers, Exhaust, Shocks, Springs, Sway Bars, Brake Kits, Autocross and track mods.
tuberotor
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17" vs. 18" Wheels

Post by tuberotor »

I drive a 2004 RX-8 6-speed with a few Racing Beat upgrades: Rev-i intake + ram-air, re-flash, and Rev-II catback exhaust. For a couple years now, I have wanted to order a wheel-and-tire package from Brian (RPF-1 for the wheels). What has stopped me is I have not been able to make up my mind on size. Cosmetically, I like the larger 18" wheels. However, going down to 17" would cut costs on initial purchase and re-tire expense--or is it really that big a difference over the long haul. These are the things I obsess on.

So... I have decided to let performance have a primary role. Could I get comments from people who have tried the smaller size? For aggressive, back-country driving and occasional autocross (but no full-on racing), what are the performance trade-offs between 17" and 18" wheels?

Thanks, everyone.
Jeffrey
:D
04 Titanium RX-8 6-speed
Brian
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Post by Brian »

It's a good debate. On the one hand, the RP-F1 in 17x9 is just under 16 pounds...amazingly light for that size and that means you minimize unsprung and rotational weight. It's a great choice. And on the other hand, the 18x9.5 RP-F1 gives you a little sharper initial turn-in response from your tire choice...and room for big brakes if that's in your later plans. Assuming performance is the goal, and you don't plan track work or big brakes, then I prefer to keep the weight as low as possible for the torque challenged RX8...and suggest the 17x9 with a high performance tire will make a happy driver.
Brian Goodwin
Good-Win Racing
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tuberotor
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Post by tuberotor »

Brian wrote:It's a good debate. On the one hand, the RP-F1 in 17x9 is just under 16 pounds...amazingly light for that size and that means you minimize unsprung and rotational weight. It's a great choice. And on the other hand, the 18x9.5 RP-F1 gives you a little sharper initial turn-in response from your tire choice...and room for big brakes if that's in your later plans. Assuming performance is the goal, and you don't plan track work or big brakes, then I prefer to keep the weight as low as possible for the torque challenged RX8...and suggest the 17x9 with a high performance tire will make a happy driver.
Thanks, Brian, for your well-reasoned response. OK, I think I will go that way. What do you consider the best and lightest couple of choices in tires that you carry?
04 Titanium RX-8 6-speed
Brian
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Post by Brian »

How much life do you need from the tire? This get's back to your cost questions. In general, the more fun the tire, the faster it wears. On the other hand, plenty of customers have reported they only drive about 10,000 miles a year and consider a set of tires that lasts a year reasonable. So...that's the next question.
Brian Goodwin
Good-Win Racing
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tuberotor
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Joined: Fri Sep 07, 2007 5:56 pm

Tires

Post by tuberotor »

Uh, when it comes to tires, I am not very cautious or frugal. I mainly want the stickiest, glued-into-the-corner tire I can get. I always buy Max or Extreme Summer tires and don't worry about the rain. I live in the San Luis Obispo area.

I have for about a year now had my eye on the Dunlop Z1 Star Spec tire, but I see you do not offer it. If you would like to suggest 2-3 choices at different price points (or with different handling virtues), that would be helpful.

Thanks, Brian.
Jeffrey
04 Titanium RX-8 6-speed
Brian
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Post by Brian »

Given your attraction to the Dunlop Star Spec my suggestion is either our TOYO R1R or Falken RT615. The Toyo is softer and faster (140 treadwear), but the Falken has sharper turn-in response and costs less.
Brian Goodwin
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Brian
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Post by Brian »

NEWS FLASH...NEW STR class.

Rules went up for new STR class yesterday....and we sold most of our inventory of 17x9 yesterday as a result. So, anybody wanting this wheel in the near term should order soon...because Enkei says backordered until September and we are down to 12 of the 17x9 as of this morning.

http://www.good-win-racing.com/mazda-ta ... php?t=1547
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
tuberotor
Posts: 32
Joined: Fri Sep 07, 2007 5:56 pm

tires

Post by tuberotor »

Thanks, Brian. Just a last couple questions. Of those two:

1. Which one rides better in everyday use? (Noise, harshness, etc.)

2. Which would you choose, and why, for everyday use + aggressive back-country and mounta
in driving?

Thank you so much for all your help.
Jeffrey
04 Titanium RX-8 6-speed
Brian
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Post by Brian »

The Toyo R1R will ride better and stick better, be slightly faster.

But the Falken will feel more confidence inspiring thanks to stiffer sidewall. That stiffer sidewall means less ride quality, but sharper turn-in.
Brian Goodwin
Good-Win Racing
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yarix8
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Re: 17" vs. 18" Wheels

Post by yarix8 »

Hi Brian,
I am preparing my 2005 RX8 as a track day dedicated car. I will no more drive on street again with it. I am trying to understand which wheel size is the best for me. 17" or 18"? I want maximum performance on the track...that means lightest wheels? Will Enkei RP-F1 17x8.5, 40mm offset 5x114 fits on my 8? what would you suggest?

I do not plan to go to BBK: I have Racingbrake two pieces open slots brake rotors, standard calipers, brake lines and some future racing pads which are still under investigations (any suggestions on these as well?)

Thank you very much

Y.
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