Quote:
Originally Posted by APEX Race Parts
The guys in the Engineering department are telling me that we are just weeks away from being able to launch a community Group Buy for all of the new 17" & 18" wheel solutions we have in the works.
With that said, the widest fitments we currently have designed for this release are 17x9.5" and 18x9.5". For 17" wheels, the widest compounds we see track enthusiasts and racers using are 255/40-17's. In 18's, we see both 255/35-18 and 265/35-18. All of these compounds are well supported by a 9.5" wheel to promote good wear and handling characteristics, and weight is kept to a minimum. As you guys know, with the right aftermarket coilovers and negative camber specs, 9.5" wheels are a relatively easy fit.
Edit: I'd love to hear from the guys requesting 10" wheels in regards to what the perceived value is.
If the demand is there we can certainly add it to the lineup, but I believe wheels this wide only make sense for high HP cars with flares or widebody kits looking to run 275mm or wider compounds. 
- Ryan |
I'll be the first to say this is absolutely GREAT news. I'll be first in line for the group buy. *dreams of Bronze SM-10 in 17x9.5*
As far as the 10 inch wheel setup goes, I'll give a shot. In the Miata world, there's been a ton of data that suggests that a 245/40/15 tire on a 10 inch wheel is significantly faster than a 245/40/15 on a 9 inch wheel, even in low power setups where an increase in rotational mass (and aero footprint) would have an otherwise negative effect. The consensus is that with a wider wheel, you can artificially stiffen up the sidewall of a tire (to an extent). This allows the user to reduce tire pressures more without encountering tire rollover.
Decreasing tire pressure has a couple benefits, the most obvious being an increase in area. Since pressure = load/area, a decrease in pressure while the load remains the same, nets a higher area. Additionally, as tire pressure increases, it's resistance to frictional shearing decreases. For that reason, it's beneficial to reduce the pressure to promote elastic deformation over the road instead of shearing.
That's the science from what I understand. Admittedly, I'm not a vehicle dynamics engineer but that's what I picked up. Obviously the question is whether the .5" increase is worth extra fitment hassle (maybe it won't fit under stock fenders), and for you guys the question is "is there enough crazy track guys to justify making 17x10's?" That one I don't know the answer to
