So someone wanted to purchase BBK's for the occasional track use and bling factor. My question is, which BBK allows the use of 17 inch AND 15inch wheels?(winter set is 15 while summer is 17). And any recommendations?

 

There are a few BBKs that fit under 15" wheels. The Wilwood BBK specifically with 11.75x.81" rotors (12.19x.81" are standard) would work as would Texas Speedwerks BDM BBK with 11.75x1.25" rotors. That being said, all wheels are different and you should check if the calipers will clear your particular wheels, especially if you're using OEM 15" wheels for snows.

A rotor's thickness is just as important at dissipating heat as it's diameter and thus the TXWerks kit would offer better heat dissipation and resistance to fade than the Wilwoods. I believe the thicker rotor would impact pedal feel though and requires a slightly heavier left foot in day-to-day street driving although will make up for this in greater controllability.

I've been looking at a few BBK possibilities for my car and one factor that may impact your decision that I've taken into account is driving the car in inclement weather in regards to maintenance and reliability. The TXWerks and many other BBKs (e.g. DetroitTuned also use Outlaw calipers) use calipers without dust boots. The Wilwoods use dust boots which seal out snow, water, salt, road debris, etc. The TXWerks and others without dust boots, will work better in sustained high-temp track situations but in places with poor weather will probably need to have the caliper rebuilt somewhat regularly.

 

As mentioned you'll max out at about 11.75" diameter rotors for the use of 15" wheels. Actually you "might" push it to 12.0 as we do on some rally kits. Still your issues will be based in part on the diameter as well as the caliper to wheel spoke clearance, in short; the bigger the caliper or wider the rotor, the less clearance you'll have. This may lead to the necessity for both a stud conversion (or longer bolts) and wheel spacers as well.

There are a few options for you to to this so look around and see what works best for you.

 

Any particular reason why you price the 12.2 kit $100 less than the 11.75 kit? I'm just curious. Is it the difference in pads BP-10 vs BP-20 or perhaps the straight vane case rotors vs directional cast rotors?

 

Pricing is not based upon the OD, it's the pad change, rotor change, and the ss pistons provided in this set up.

One could easily build an Red, Drilled, 11.75 version of the Plus 2 kit with the dust booted calipers and street pads. Or a GT rotor shod Plus 2 kit for the $100 up charge. It's all in how the parts are mixed together to get what the customer is looking for.

Mix up some of the options and you'll see it's pretty much; pick a rotor, pick a caliper, pick your pads and the pricing is the same.