I don't see an advantage to running a 17 either for auto-x on this car. I have the rivals left over from my bmw but I know they don't fit on the FiST. I'm not sure with our course conditions the ZII will be the one to go with, the R1R seems to be popular here in the north woods.
I have to confirm with the new street rules as well, +1 -1 is fine but I have to confirm as to how wide we can go in GS.
edit from the prelim rules :
Tires may
be excluded for, but not limited to, low volume production, extensive
availability limitations, and specialty design. Tires must meet the following
requirements to be eligible for use in Street category. No tire model
will be eligible for Solo® competition until it meets all requirements of
Section 13.3. Tire models not meeting the requirements by April 30 are
not eligible for Solo® competition until after the Solo® National Championships
of the year.
A. Specifi cations
1. Minimum UTQG Treadwear Grade of 140. (Effective 1/1/2015 -
Minimum UTQG Treadwear Grade of 200.)
draft
72 — 2014 SCCA® NATIONAL SOLO® RULES
13. STREET
2. Minimum molded tread depth of 7/32” as specifi ed by the manufacturer.
3. Listed in a current year or prior 2 years of the “Tire Guide®” and/or
the “Tread Design Guide®” (
www.tireguides.com).
4. US Department of Transportation (DOT) approval.
B. Eligibility Requirements: The following are prerequisites before a tire
can be used in competition at National Solo® events.
1. Tire availability: Tires are considered available when competitors
can take possession through retail channels. Pre-orders are not
considered available.
2. Tires must be equally available to all competitors. Tires that are
in short supply do not specifi cally violate Section 13.3. Extensive
shortages may result in the tire being placed on the exclusion list
until supply is replenished. Tire variations differing from standard
specifi cation, delivered only on a limited basis, or only to selected
competitors may not be used.
3. Tire models must have tires available in at least 4 rim diameters
and in at least 6 sizes which meet these requirements.
4. Material Change: Tires which previously met the eligiblity requirements
that undergo a signifi cant compound change, tread pattern
change, or other signifi cant redesign reset the requirement for eligibility
described in Section 13.3.B.
5. Discontinued Models: A tire model which was previously allowed
continues to be compliant until the end of the calendar year following
the year in which it fails to meet Sections 13.3.B.1, 13.3.B.2,
or 13.3.B.3. For example, if a tire model falls below the required
4 rim diameters in June 2014, the tire model retains eligibility until
12/31/2015.
6. Reintroduction: Models that were once discontinued will be considered
a new model once reintroduced and must meet all the
requirements of Section 13.3.
C. Other
1. Any tire which is OE on a car eligible for Street Category may be
used on that car in Regional Solo® events. OE tires must meet
all requirements of Section 13.3 to be eligible for National Solo®
events.
2. Tires may be shaved evenly and parallel to the axis of rotation, but
may not otherwise be siped, grooved, or modifi ed.
3. No recap and/or retread tires may be used.
4. The tire must not appear on the following list, which may be altered
at any time by the SEB upon notifi cation of membership.
No tire models are currently listed.
13.4 WHEELS
Any type wheel may be used provided it complies with the following:
draft
2014 SCCA® NATIONAL SOLO® RULES — 73
13. STREET
A. It is the same width as standard and as installed it does not have an
offset more than ±¼” (±6.35mm) from a standard wheel for the car.
The resultant change in track dimensions is allowed.
B. Wheel (rim) diameter may be increased or decreased 1” from the
standard part.
Wheel spacers are permitted provided the resultant combination complies
with the offset requirements of this section. On vehicles supplied
with an OE wheel spacer, the wheel spacer shall be considered as a
part of the wheel. Wheel studs, lug nuts, valve stems (including pressure-
relief types), and/or bolt length may be changed. Tire pressure
monitoring sensors may be removed.
So it looks like width really won't matter as long as they fit on the rims.