Wilwood brake sizes - Lateral-g Forums

Panteracer · #1 07-31-2015, 11:34 AM

Looking at upsizing things with my brakes
Looks like my 6 piston Wilwoods with 12.88 rotors has
the same Caliper as the 14".. hub is the same
also.. just change to 14" and tweak the mount maybe

How much do I really gain??? 14" vs 12.88.. cooling surface
for the rotor.. the Caliper is the same, pad size the same
Maybe for track conditions... I guess grabbing farther out
diameter takes less effort

any thoughts

Bob

MtotheIKEo · #2 07-31-2015, 02:03 PM

Larger rotor has more thermal mass and can generate more brake torque grabbing the rotor farther from the centerline. Unless you are overheating your current brakes or are unable to lock them up, you may not gain much by upsizing.

Panteracer · #3 07-31-2015, 02:36 PM

Thanks.. brakes are ok.. only autocrossed so far
Worried about when I try to track the car
wanted to upsize the fronts and get at least a 4 piston
out back so was looking at moving the fronts to the rears

After looking at the upgrade can just change the front rotors
and buy new for the rears

Bob

RdHuggr68 · #4 07-31-2015, 09:14 PM

Check out page 2 of the brake section entitled "Which brakes shall I buy" Ron Sutton hI know there is a way to as a post that really makes it easy to understand. Once I read it I contacted Ron and purchased my brake system from him.

**GregWeld** · #5 08-01-2015, 10:45 AM

Quote:

Originally Posted by Panteracer

Thanks.. brakes are ok.. only autocrossed so far
Worried about when I try to track the car
wanted to upsize the fronts and get at least a 4 piston
out back so was looking at moving the fronts to the rears

After looking at the upgrade can just change the front rotors
and buy new for the rears

Bob

I think your old Mustang has Wilwood 2 piston front and single piston rears... just like my Mustang used to have. Sutton upgraded me to 6 piston front - 4 piston rears on the Spec 37 rotors.... and it's just a WOW (or should it be WHOA) difference. Night and day. I had to learn to shorten the braking zone quite a bit! The rotors also got larger diameter...

There IS a reason for bigger brakes! They work better! LOL

RdHuggr68 · #6 08-01-2015, 08:32 PM

Greg, I have the same brake package from Ron, 14" Spec 37 rotors on all 4's 6 piston front 4 rear,but they are still in the box. Glad to hear they work great. What master cylinder and size bore are you using? Are you running power brakes also?
I bought a Wilwood master cylinder 7/8" bore with no power brakes.
Kevin

**GregWeld** · #7 08-02-2015, 09:08 AM

Quote:

Originally Posted by RdHuggr68

Greg, I have the same brake package from Ron, 14" Spec 37 rotors on all 4's 6 piston front 4 rear,but they are still in the box. Glad to hear they work great. What master cylinder and size bore are you using? Are you running power brakes also?
I bought a Wilwood master cylinder 7/8" bore with no power brakes.
Kevin

Kevin -- same master you listed. You'll very happy with your new brake package. For the race car - the only thing we've done is to switch to a lower CF REAR brake pad in an effort to balance the brakes. We're using a relatively "soft" pad set up - which was my discussion with Ron. I'd rather buy pads than rotors... so to save the rotor wear we went softer. They work great and I think they come "in" better.
One of the things we continue to work on is having the car come in early. We only get to run 9 to 10 laps or so per session. No reason to waste 2 of them getting things up to temp so they work. I now know that a lot of people go to an ever higher CF (harder) brake pad in a failed attempt to get more stopping power - and while that might work on real race cars that are out there for far longer periods - running far higher MPH etc... it doesn't really work very well for our short stint amateur hour drivers (me).

Panteracer · #8 08-03-2015, 10:31 AM

Greg,
What brake pad do you run?
I recently switched to bp 20s from bp 10s on the Pantera
and it made a big difference.. I can go so much deeper
but the pads do wear quicker so I need to keep an eye on
them... the other thing is the Pantera is 500 lbs lighter
than the Firebird so I getting away with using 12.88 rotors
both ends.. 6 piston grand nationals and 4 pistons out back
with good results.. Will be doing 14" both ends of the bird
and maybe 6 pistons both ends also

You also give up at least a lap to get the tires to warm up each session

Bob

**Sieg** · #9 08-03-2015, 01:48 PM

Bigger rotors create a substantial weight percentage increase at each corner that your shocks need to cope with, then there's the additional rotational mass. A big heavy flywheel on a dirt bike is something you can related too!

Ever been to a historic Trans Am race and noticed the lap times they run vs the spec brakes they have to run? They scrub speed pretty good considering.

Caliper clamping force trumps rotor size IMO.

More isn't always better.

Panteracer · #10 08-03-2015, 03:38 PM

Sieg,
I understand your comments on the weight.. problem is the
car is too heavy so I know I need more braking
to stop the thing.. I know it would not last on
a race track the way it is.. trying to make it best
of all worlds.. been trimming weight on it here and there..
maybe lost 200 plus pounds on it so far

I already have 6 pistons up front.. will look at the weight
gains of a 12.88 rotor vs the 14" ... Having anything better
than the single piston 11" brakes out back will be better...
Its kinda like too much stagger from front to back on tires now

Bob