A question on my BBK for Willow

Messages
3,756
Location
CA
My 13" 4 pot Wilwoods are going to be here soon, ordered specifically for my upcoming trip to the track. I got to wondering, with just the front being upgraded, I'm assuming the total piston area is the same or less as the stock front brakes and my braking balance won't be upset??? Just getting worried that I may end up with worse one stop braking performance. I'm thinking with ABS, braking balance may not be as important but I'm thinking of pulling the fuse since the ABS in my car is very conservative. For those wondering why I didn't go with a rear kit, besides the fact that 65% of the weight is on the front, the rear kit is nearly double the cost of what the front kit is due to the e-brake arrangement and I flat out can't afford them....really can't afford the fronts either but if I skip lunch for the next 2 months I should break even... \:\( So cliffs notes: Will upgrading fronts only kill my braking balance or does the manufacturer usually keep this in mind so that the upgraded brakes have the same leverage as the stock brakes they're replacing?
 
Messages
433
Location
Melbourne, Australia
It depends on how much more piston area, pad material and braking leverage is with the new BBK. I am assuming the BBK is larger than the existing OEM brake. Is it a multi-piston setup? Brake bias isn't just about upsetting the ABS. It's also about weight transfer during braking and cornering, which may upset the balance of the car. Another thought, if you do have large piston area with the new calipers, will you master cylinder have sufficient volume to cope? If it doesn't, you will end up with a low pedal before the brake bites hard.
 
Messages
1,385
Location
Houston, TX
It's also about fluid volume, you may have to change proportioning valves or master cylinder bore size if you go with one of the Wilwood rear kits...just give them a call, their tech dept is top-notch.
 
Messages
11,247
Location
PA
I understand the question perfectly. I believe that the F->R transfer of "stopping power" in turns is governed by the tires...more as the slip angle increases and probally proportional to the apparent loss of "even" braking as you come off center. So, strait braking, you see no apparrent "difference" in the F->R transfer....the car stops strait. Offset from center, you can only brake so hard anyway, until you break grip, thus the oversize fronts become less effective (apparently) and the rear tire grip itself is more of a limiting factor than the braking power is. Kind of hard to explain. You could always pop from a adjustable bias controller, even one adjustable from the cockpit.
 
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