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Discussion Starter · #1 ·
2016 RS Canadian cars were automatically shipped with Forged wheels and Pilot Sport Cup 2 235/35ZR19 tires. While an excellent tire for track use, I was not impressed with the ride for a street tire, even with pressures reduced to 42F, 40R. The sidewall on the PSC2 tire is particularly stiff. And the PSC2 tires tend to wear quickly. After some research, I decided to go with a TSW Chicane 18 x 8.5 offset 43mm wheel in Matt Gunmetal and Michelin PSS 265/35ZR18 for a daily driver setup. My thanks to @zommer79 for his extensive research on fitment for a similar setup using OZ 19 x 8.5 offset 45mm and PSS 265/30ZR19.

An offset tool gave me the following:

132097d1486617331-tsw-chicane-18-x-8-5-michelin-pss-265-35zr18-capture2.jpg

The choice of 18 inch over 19 inch was prompted by several factors:

1) A taller sidewall was likely to improve the ride characteristics.
2) The PSS 265/35/ZR18 at 25.3" diameter is very close to the OEM PSC2 235/35ZR19 at 25.5".
3) The TSW Chicane 18 x 8.5 is relatively light at about 21 lbs. Overall, I managed to shed about 1.5 lbs per corner.
4) Pricing is more favorable on 18 inch setups than 19 inch.

Discount Tire Direct was very helpful in suggesting operating pressures for the tire in question; they suggested a minimum of 35 PSI, based on the load rating of 91 (1356 lbs) for the 235/35ZR19 versus 97 (1609 lbs) for the 265/35ZR18.

I came at it from a slightly different angle; the ratio of the load ratings 1356/1609 yields an 84% factor. Using OEM recommended PSI of 46 x 84% gives 38 PSI, and 42 PSI at 84% gives 35 PSI. But these numbers are close enough to DTD's suggestions.

Another interpretation is based on the comparative volume of air in the two tire sizes as a load carrying "cushion". The 235/35ZR19 has 1818 cubic inches of air, compared to 2110 cubic inches of air for the 265/35ZR18. This ratio is 81.3%.

In any event, this confirmed we should be okay to run a much lower operating pressure on a daily driver basis. Here are a few photos of the resulting setup:



















Strut looks to have at least 1/2 inch clearance:



I did a quick road test for fitment confirmation and ride improvement, using pressures of 38F and 36R. No scraping issues so far and a much better ride.

Jacob.

Update: After about 10 miles, the TPMS warning light went on. I can confirm the following procedure and tool works:

132329d1486668977-tsw-chicane-18-x-8-5-michelin-pss-265-35zr18-capture3.jpg

One additional image after a few days' use:



JacobZ06
 

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Nice write up! Where did you find the sensors for the new setup? Im looking to finish my summer set up but have been battling what the proper sensor is for the 15-17 focus wheels/tires! Any help would be appreciated
 

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Discussion Starter · #3 ·
Nice write up! Where did you find the sensors for the new setup? Im looking to finish my summer set up but have been battling what the proper sensor is for the 15-17 focus wheels/tires! Any help would be appreciated
Sensors came with the whole package, ordered from Discount Tire Direct.
 

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I have the same wheels on my ST and love them. How much clearance do the front Brembo's have with the inside of the wheel as well as the spokes? Is it really close, plenty, any shots? Ya know, incase I want to upgrade my stock ST brakes for some Brembo goodness one day!
 

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Discussion Starter · #6 ·
I have the same wheels on my ST and love them. How much clearance do the front Brembo's have with the inside of the wheel as well as the spokes? Is it really close, plenty, any shots? Ya know, incase I want to upgrade my stock ST brakes for some Brembo goodness one day!
When I looked at that I recall at least 1/4 inch and more likely 3/8 inch.
 

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Discussion Starter · #7 ·
An Update....

TSW Wheels back from paint shop. My local paint shop did not disappoint, having finished another set of wheels for me in GM Carbon Flash Metallic. These wheels bear a resemblance to factory wheels but retain a unique look.












Yet to complete: RS style center caps and possibly a silver or red lip (I am not a fan of the all black look).

Jacob
 

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That is a clean looking ride and it looks like you did your research! Nice job and I really like the shot with the smoke coming out of the exhaust.
 
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If you're trying to imply your setup is good for the track, you'd be off. A 265 on a 8.5" wheel is actually worse for handling. I would venture to guess you're focusing (no pun intended) on getting the widest tire you can get for traction, but you'd be slightly mistaken. That wide of a tire on that skinny of a wheel actually allows for much increased sidewall flex while cornering. That much flex overrules any increased traction from the wider tread. Side wall flex generates heat, which is also counterproductive. A 235 is about perfect for a 8" wheel. I'm running a 245 on my 8.5" wheel and would not want any wider. If I am wrong in making assumptions about your track comment, then I apologize and will go back in my hole;)
 

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Discussion Starter · #13 ·
This setup is simply for daily driver duty. Any track days will likely use the factory PS Cup2 with 19" forged setup.
 
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