Wilwood makes a six-piston forged aluminum caliper (GN3) that would work well with a nice set of 13" Baer Eradispeed rotors up front. The also make nice 4 piston billet aluminum calipers that would work nicely out back with the same Baer rotors.

Either option would require making your own caliper bracket but it would cost a LOT less than the any of the other systems (Around $2000).

(If you upgrade front and rear calipers and go with a 6 piston/4 piston setup, you had better make sure that your master cylinder has sufficient capacity for all those pistons.)

-Don

 

You are correct on a couple of accounts. However I already offer it in complete form for the truck. And with due respet you'll soon see it's a bit more than throwing together a couple of brackets....

The use of the GNIII over the base SLIII is more looks than function. The pads for the GN are much larger but piston area is only up a very small amount. Both are compatable with the stck MC.

BTW; rears are on my 'to do' list but its more likely a caliper only upgrade not a rotor package. That damn rotor is as big as it needs to be! Oh, and the cost of re doing it would make the rear rapidly surpass the cost of the front kit! Hardly a value product.

 

Brembos are a little too pricey for me.

I went with some EBC slotted and dimpled rotors with EBC kevlar pads and some super blue fluid- overall a very nice upgrade over stock and affordable (under $500)

pic of rotor

 

I completely forgot this was in the Lightning Forum. I know Tim Skelton has a link to the Wilwood Baer package that you put together.

I had forgotten about all of the work that went into new spindles (Or whatever it was. My mind is not working very well today) for the Lightning front-end. I was actually thinking of putting this on a regular F150 and was thinking of fitting it without too much work.
The larger pads help to reduce fade in repeated braking and I think that is helpful.
It was just a warning that one should be careful with a 6 piston up front AND a 4 piston out back
The cost of redoing what? The rear brakes? They really should be easier to swap out components for than the front. The components should also be cheaper. I've not really looked at it so I am probably wrong.

-Don

 

That is what I am running and was told there would the issue with the stock MC.

Todd I am running AP Racing CP5555 6 pots up front and CP5200 4 pots out back. Do you see any problem with the stock MC? I would really like to know as I am putting the truck back together.

 

There isn't necessarily a problem, you just need to be careful when going to a much larger system like that. If your brakes work and do not feel soft than you should be fine. Just make sure to keep the fluid levels up.

-Don

 

The question on the rears is not of piston size for me to do it but rather what caliper and it's mounting? The options from manufactures is or can be limited. I've not done much to look at the rear, can do it on my own 150 really, but the rotor there is very narrow. That means a caliper of proper fit.

Piston area is what the matter is for the MC. Without the numbers on your calipers it's hard to say. Keep in mind it could have 20 pistons and be less area. Also the bias of front to rear is or can be effected by this sizing. But can be countered by both pads and rotor diameter.....The stock caliper has about 6sq" if I remember right, that's huge! And most calipers come in WAY under that. So how is it any better? Rotor diameter and pads make the total torque the same or better. Not to mention 'heat management' as I call it.

Pad size vs. fade? Hmm. Good comment. but I'd put my money more on pad compound and Cf rather than the size of the pad to see fade. The larger the pad the longer the life of it, but I won't go as far as you did on that one. Just pick a pad that's right for the use and size won't matter at all.

 

Ayrton,

Care to share any details on the rear brake setup you have? Are you running a different rotor? Is the AP you have for the rear a radial mount?

I was looking at the mechanical spot calipers available from Wilwood to keep a parking brake and still allow us to use a bigger rotor. The other option I was kicking around was to use a Corvette rear caliper with integral parking brake. That would allow a .81" thick venter rotor.

Thanks, Randy

 

I am in the middle of the change over now and I had to use a pinion mount emergency brake I order to change the rear rotors. Having custom hats and rotors made up to retain the stock E brake would have been very costly. The rear calipers are the 4 pot version of the fronts and are radial mounted. My machine shop is fabing up the brackets now and I should have something to show before the end of the month.

Front
http://www.apracing.com/roadcar/cali...?family=CP5555

Rear
http://www.apracing.com/roadcar/cali...?family=CP5200

Todd do those pages help?

 

Ok, you asked so I'll give you my .02 on this set up.

First both are nearly the same sq" in size. This means that it will have a big change in the bias of the package.

They are both about 3.0sq" and I'll go out on a limb on this one and say this is way, no WAY too little piston area for the front of this truck! That's half of what you have now! Even on much larger rotors, with metal brake pads the loss of front bias is huge.

The rears sound about right, but not with the fronts! Only with calipers of much more area up front. I'm up at about 5.2 or whatever it is, and pedal feel is fine. But with your proposal the pedal will move about an inch and you'll be hard then have to push harder to make them work to generate enough psi to bite. Ok, power assit helps, but the caliper will be stresed big time at the required psi to make them work.

On the rear the problem is not the piston area but I'll wager that the nose of the caliper is going to hit the 'hat' of the drum before you get the pads at the proper radius.....

Ok, that's my take, now find out what I've left out or what is wrong with my input. I can take it.

 

Are you saying the front calipers are too small?

The CP5555 comes in the AP kit from Stillen and I purchased the 5200s to match the fronts. I will grant you that a big reason I did this was to make the “look” of the rears match the front, but I do expect some performance increase by running a thicker two piece rear rotor.

The million dollar question is do I need a different MC or even an adjustable brake bias?

 

Looking at the specs you gave me here the front piston area is nearly half what the stock truck has.

The use of this small a piston area will do a couple of things:

First the line pressure needed for them to generate the torque required will be much higher. (granted also effected by rotor dia as well as pad choice)

The high pressure used will stress the caliper greatly and given the mass of the truck you may find this is not such a good thing.

The increase in pressure to make these work will also effect the rear pressure (same MC obviously) so the rears will get 1500psi for example. Now with the fronts using less of it than needed and the rears getting maybe more than they need...what do you see the problem being?

Break it down to simple form:
Bias is 3:1 on the truck (best guess) now you take it to 1:1 Hmmm, not so good.

What to do? Well, you maaayy be able to do a MC change but why? And what a pain in the ***! Or you could do smaller pistons yet in the rear. Or you could just get properly sized front calipers! Yes a prop valve will aide in this but this is onl going to limit the rear line pressure, not really the root of the problem in my mind.

Sorry, if I'm confusing or causing grief, but I'll stand by my statement that 3sq" of piston area is just not enough for the truck and the combo you selected is poorly matched for the application. But I've been wrong before too....

 

I come up with a front piston area of 3.8” for the front and I do not know what the stock front piston is but after 3k miles on the fronts only there is a hugh difference in braking power. I am able to reach the limit of the tires much faster and after repeated stops there is little difference in brake feel.

I understand what you are saying about total piston area and on the Wilwood SL III caliper I come up with a total piston area of 4.46”. I was not able to find anything on the Brembo calipers.

 

I just made up a quicky spreadsheet on this with some very rough calculations.

The Brembo's have 4.28 sq. in. of piston area
Stock is 6.28 sq. in
AP is 3.8. sq in.

Assuming cF = .5 (for both)
Mean Effective Radius of stock rotor = 5.4
Mean Effective Radius of AP rotor = 6.3

Pad area stock = 9.8 sq. in. (from www.fordtrucks.com, 2001 Expy specs)
Pad Area AP = 11.9 sq. in. (www. apracing.com)

The line pressure required for a given about of torque on the AP system is 30% LESS than stock. Here is my math.

T=F*d

Where F=Line pressure*pad area*cF
d= Mean effective radius
Torque = desired torque

This info has nothing to do with brake bias, but unless my calcs. are WAY off, the line pressure required for the AP system should be less, and that is assuming the same pad cF. I'd venture to say that the AP pad is a bit higher than stock.

As for the front/rear bias, the stock system has twice the piston area in the front as in the back(2x2" pistons front vs. 1x2" piston in rear). When I go to fab up a rear system, I'll try to maintain this but I will definitely look at pad area and rotor size before picking a caliper.

Randy

 

WHOAAAA, hold up Randy, posted too quick.

Calculations got messed up.....

T=F*D

F=Pad area*Piston Area*cF*Line Pressure
D=MER

Redoing the numbers, line pressures are about 15% higher for the AP system assuming similar CF.

Sorry about the mixup.....

Randy