Wheel Fitment Templates: Why they're important!10.26.2012
Today I had a customer call me with a wheel fitment issue on our Competition Brake Systems for the FT86. I had spoken to him a couple weeks back, when he was trying to decide which wheel to run with our brake package. At the time we had discussed the possibility of running an Enkei RPF1 17x9 +45. I told him that we were running the Enkei RPF1 17x8 +45, and they cleared by half an inch. However, that didn't necessarily mean that the wider wheels would fit, even with the same offsets. If you run the numbers on one of the popular wheel offset calculators, it suggests you'll actually gain clearance on both the inner and outer half of the wheel. However, many manufacturers change a number of design features on a given model of wheel depending on width (Volk is notorious for doing so).
The Enkei's in question are unfortunately one of those wheels. The top picture below is the 17x8, and the picture below that is the 17x9. See any differences? The spoke designs on the two wheels are quite different. On the 17x8, the spokes sit further outside of the barrel and offer more clearance. On the 17x9, they curve inward into the barrel, dramatically reducing brake clearance.
I just wanted to use this as a good example of why you can't necessarily make assumptions about brake clearance just by running the numbers. Testing the wheel fitment templates on an actual wheel are the only foolproof way of verifying clearance. Hopefully that will save some blood, sweat, and tears down the road for some of you.
Above: Sprint FT86 Competition System fitment template clears 17x8" Enkei RPF1 no problem
Above: Sprint FT86 Competition System fitment template will not clear 17x9" Enkei RPF1's, because of the different spoke design.
Sprint vs. Endurance System Wheel Clearance
Another note...since our Endurance System for the FT86 uses a larger diameter disc, the caliper is located further out from the wheel hub. That means that even though it is a 'bigger' brake system, it will actually have superior clearance on some 17" wheels vs. the Sprint System.
Below is the Endurance fitment template in the 17x9 RPF1. Notice how it has superior clearance vs. the Sprint template pictured above.
of the story...always check wheel fitment on the actual wheel you
intend to run! Also, even though our Endurance System is bigger, it may
have superior clearance on a wheel you're considering.
Everything fortunately worked out for our customer, as he's just going to exchange his wheels with the 17x8's. A big thanks to Uncle Fester for snapping some pics for us in the name of science and proper brake clearance for all!
Finally...just to reiterate on the Enkei RPF1's:
17x8 +45 Plenty of clearance on both our Sprint and Endurance packages without a spacer.
17x9 +45 Will NOT clear either of our Competition Brake Systems without a spacer.
Check your wheel fitment with these links:
FT86 Endurance Compeition System Wheel Fitment Template