n.m.racer

Ive been reading a lot on the forum about how people can swap their stock f-body front brake set-up with a few factors by using...
1. CTS-V calipers
2. 06+ Z06 Rotors
3. New Brake Lines
4. Wheel Spacers with Longer Studs or Appropriate Offset 18" Wheel

But there has not been any progress on using this caliper set-up with a smaller rotor.. therefore the ability to run a smaller wheel.

My 2cents on this swap is that it looks unappealing. I understand the braking capabilties for the price and I totally agree, and if I tracked the car at high speeds I would personally consider this set-up but running a 14"rotor in front and a baby in the back isnt as visual appealing for me, and especailly what one would assume as uneven braking front to rear. I daily drive my car, experience brake fade on longer trips, and Ive always had issues with LS1 Calipers.

The reasons I am against the current swap are for a few reasons...
1. I dont like 18's on the front of F-Bodys
2. I dont want to add more overall weight to the wheel assembly.

I do like...
1. The abilty to run overshelf pads
2. The strong need of 2pistons on BOTH sides of the rotors.

Im not ragging on anyone who has done the swap because everyone who has done it are truely pioneers of fabricating an affordable brake enhancement.

But for the people (like me) that do not want to swap wheels and run factory brakets and look for a true "Caliper Only" Replacement I may have a suggestion.

I do not have all my measurements and information gathered but by just looking at the caliper I may have figured something out. But with 2 fabrication techniques to the caliper, it might be possible to run the run caliper on a stock setup. Since I want to run the 12 inch F-Body Rotor Not C5 that weighs a ridiculous amount... Since I am taking 2 inches off rotor diameter, Making 1 inch of the radius...

1. Why not drill a hole 1inch from the center of the original mounting hole towards the body of the caliper? That would allow for the pad contact area to be where the rotor needs it to be.

but then there will be allignment issues since the rotor will not be center since the caliper mounting braket is thinner at that point.

2. Since the washer tricked centered the caliper over the rotor, why not get a heavy peice of aluminum the appropriate width needed to center the caliper over rotor and tig weld the peice to the body of the caliper for strength.


*Safety is the only concern about this modification.* The durablity of the mounting could be a concern by many and thats why I would like expert's opinions on this modification. If it sounds like a good idea I am about to try this but everyone should please join in with their opinions

tbird31

iTrader: (22)

Remember these are my opinions.

First and formost, it's a nice idea, but people that pay the money for the calipers are going to want to upgrade to a bigger rotor. To be completely honest, over 90% of the people that do this upgrade are doing it for appearance purposes only. The reason I know this is true is because the stock LS1 brakes with a premium upgraded rotor, such as the Baer 2 piece ones, and a set of Hawk ceramic pads will stop our cars FAR better then anyone is EVER going to need.

Secondly, from a safety stand point, drilling holes on the back side of the caliper to mount it closer to the center of the wheel to be able to use a 12" rotor would completely KILL the load and force analysis that the designers have calculated. Being an engineering student myself, if you calculate a force to act upon an object at a certain distance from the center it creates a moment. The reason the back side of the calipers are reinforced the way they are is because the designers at GM have calculated it to be so.

Finally, if you're wanting better braking capability I'd honestly upgrade to the Z51 calipers and put them on your stock brackets and like I said run a premium pad and rotor.

I would honestly suggest against doing what you've suggested. You might be able to do it, but the benefits of taking the time to modify the setup to the way you'd want it wouldn't be worth it at all.

n.m.racer

Your opinions sound nothing but the truth for me lol. I completely agree that the stock brakes with pads and and a good rotor perform good, thats definately not a lie, but im just not a fan of our calipers. Ive rebuilt mine twice and I always have a piston seize problem.

You hit the nail on the head when everyone wants to upgrade rotors. But it doesnt make sense to me to add more weight to the wheel rotation mass therefore needing more power to compensate for the new brakes.... which that leads to changing the whole balance of the car. My power adders are meant to make my car faster, not to get it back to where it was. A fast car needs to take advantage of every area, not over-power one section. Im just not a big fan of huge rotors...

In theory they work, but there is just as much downfall as there is benefits.
If the stock 12 does the job good, why does everyone think a bigger will do better. All I want is an even brake distribution against the rotor. The "pinch 1 side" method doesnt cut it for me. Id be happier if my 2 piston calipers had only 1 on each side of the rotor.

So how are the z51 calipers set-up. Are you just talking about c5 calipers because ive tried those and wasnt much more impressed.( I had them loaded with Doug Rippie Stainless Pistons too...)

qwk93ta

iTrader: (13)

I would like to put just c5 calipers on front so I can still run 15" skinnies at the track. I am trying to figure out if I can do this. As my car gets faster I want to make sure I can stop at the end of the 1/4 mile.

slammed68

iTrader: (1)

larger(diameter) rotors are much more effective than smaller rotors. the larger rotor has a greater leverage over the smaller rotor. just the same way a longer wrench takes off a nut with less effort than a shorter wrench. so yes the larger rotors have a great benefit, but it doesnt seem like you are really in need of the performance larger brakes offer. in that case do exactly what tbird31 said and get a good set of pads and rotors and upgrade the calipers to the z51.

Striker

iTrader: (1)

In order nto run the Z51 caliper, what do you have to modify on our current setup?

Foxxtron

iTrader: (1)

This is NOT anywhere how big brakes work. The only place where leverage physics apply is with the use of the brake pedal over it's respective hydraulics and then onto the pistons which then actuate the pads over the surface.

The physics of flywheel and moment of inertia is what disc brakes deal with. Having larger front rotors with more mass along it's outer diameter will increase the MOI, therefore actually contributing to longer brake distances. Also, having larger discs on one end whilst leaving the other end alone can and will affect brake balance.

If anyone likes to read about this, start by reading the late Carrol Smith's topics on braking and suspension. Also, look at the StopTech website's technical white papers.

n.m.racer

Thank You for putting this into scientific specs for everyone. I wish more people would understand how good of a rotor diameter gm gave us from the factory.

Just think of nascar, i dont really like to... but think of the speeds they reach, and think of the size of their wheels... They still rock 15inch wheels and I think I'm safe to say they couldnt fit a 14" rotor or even 13" at that matter. If their cars are going 200mph+ and running consecutive hot laps and still brake great, what would be the need for a bigger rotor.

Another example, Ive run good quality pads and rotors on my car, and also stock set-up too. Without data I cannot really prove anything but my overall conclusion is the upgrades just allow some parts to run cooler(rotors) or hotter(pads) but ive never felt tremendous increase in performance.

I know locking brakes isnt a good thing, but after 5 years of thrashing on brakes I have never noticed 1 single wheel lock. If two pistons cant get a 12" rotor to lock there is a problem, and it is not the diameter of the rotor. There is not enough strength in our LS1, or C5 calipers. Abs only kicks on when I hit a bump or pothole... thats it. My car has never slid due to pure braking power.

If NASCAR uses 12" rotors and high performance calipers, and can brake far more outstanding than most aftermarket kits, (granted the cars are completely different) why cant we just simply upgrade calipers. I just want even pressure excerted onto my rotor. I dont want to wobble it against a pad and push the rotor against it. I want to clamp the rotor. I almost gurantee if there was a 4 piston caliper with correct piston measurements and resevoirs for fluid, that set-up would far outshine alot of big brake kits.

But where would profit be if you couldnt retain customers by FORCING them to run only their pads, rotors, hats etc... I know what my braking problem is and I want a solution. throwing 3g's minimum starting investment at something that will be obsolete in 15 years doesnt sound reassuring to me. Im not putting the sponsors down since they offer great products that make our cars perform better, but we dont need all of the glam of having huge brakes.

I would to buy a reasonably priced caliper ($200-250 a piece)that somehow used over the counter pads that I do not want to specially order. If they offered that I would be more than glad to run the set-up. The only thing I am finding is the CTS-V Caliper.

Why cant I just modify the spindle so that why I do not alter the geometrics of the caliper. drill 2 holes 1" further down? 2 spindles from a junkyard be $50tops? That still be cheaper than going out and buying a current big brake kit.

Foxxtron

iTrader: (1)

I apologise for not responding to this sooner, however a question that should be asked is...

What is your suspension like? By what you describe, it appears you may also have a suspension issue, which can indeed contribute to premature brake wear as well as higher brake temperatures.

AFA "off the shelve" pads are concerned as long as a caliper has been designed around a specific FMSI shape, there is little to no concern with finding pads. Brembo's, Alcons, AP Racing (currently under Brembo ownership), PBR's, Akebono's, Performance Friction as well as Wilwood and Stoptech kits are designed around a specfici FMSI standard as it's extremely expensive and highly impractical to design a "non-standard" pad that's solely unique to a brake manufacturer's specific caliper design. With that stated, the general presumption that somehow an "aftermarket, new brand" will only fit "their own pads sourced from them" is almost always a false presumption.

With concerns to a "solid dual-piston" in either monobloc or two-piece design being "ultimately superiour under all conditions" compared to the single-sided piston calipers is highly debatable. Even though I myself prefer using a dual-sided piston solid caliper, the real problem with the stock calipers are mostly that they're either in need of a rebuild (as you notice doesn't always fix a "problem"), sticking slide pins (usually a result of overlooked or neglected maintenance) or even worse, possibly spread (increasingly becoming common with neglected brake maintenance). Even worse, much of these "spread calipers" are beginning to reveal themselves in "rebuilt parts" from Auto stors. These are the downsides of the OE calipers for the 1998-2002 F-bodies. This is nearly non-existant with the "C5" calipers due some slightly better designs of the caliper.

One interesting thing I'll mention is that I've noticed recently that a 'mitchntx', a long time road racer with lots of experience, is using stock dimension rotors with stock abutment brackets fitted with a C5 caliper over it. IIRC, he stated in one of his posts that he races a nearly 3800 lbs. GVW F-body for over 30 minutes with this setup, and his temps are good and his brakes suffer from extremely little fade (some fade can be expected since it is 'door-to-door' road racing, which results in lots of hard random braking over a long duration). In short, he stated "big brakes not needed."

Just clearing some more air from the smoke of false assumptions around here. No flame or insult intended.

ramairjohn2000

iTrader: (3)

I am running my stock calipers never rebuilt with Baer rotors all around and hawk pads and have track raced it at pocono and am extremely happy with the setup lasts almost 20 minutes hot lapping with little fade and overheating. I dont think bigger rotors are necessary. just my 2 cents

Iyyob

A few questions, how many races do nascars keep there brakes for ? How long is a nascar race ? How often do they need to come to a complete stop on a dime and not just a slow down and let the pit crew try to stop them with bumpers/hands ? Think of some of those things before you make those compaireisons. Thoose cars are not made to handel great and they don't there made to zoom zoom. A better compaireson would be auto-X/GT where they do more then turn left. Does a 12 inch rotor dissapate heat as fast as a 14 inch ? Energy is lost threw heat. To stop we transfer our foward energy to our brakes and rotors. Then try to loose that foward motion by friction (caliper/rotor) that creates heat. Were playing the heat game guys to make it and get rid of it as fast as we can. I won't say a stock sized blanks are bad they serve a purpose, just not as good as one with suspension/handeling otherwise we would be seeing better stopping time with upgraded 12inch setup and there would be no need and no market for the 'big brake' field. Many may not need the bigger and the 12 will do fine. Somthing else you may want to look into is the rear cts-v setup mabe you can better fit those on the stock sized rotor. Where there's a will there's a way. Where there's $ there's a faster way lol goodluck guys

n.m.racer

True about nascar and I really dont like to compare their cars to much because i am not a fan of that kind of racing.... but they do put out decent times at watkins glen and infineon...

Ill check into the rear cts-v calipers and see if they are worth it. If they are dual sided and possibly a decent sized piston, then it could be beneficial, espiaclly if the rear rotor is around 12" or 13".

Ive never done any autocross or road course in my T/A because its an auto, and i grew up grabbing gears. Im just not comfortable without a clutch. But that still doesnt mean i drive fast around corners. Its my daily driver, trip car, street/strip, and show car all in one. If i get bored i might try an autocross event seeing id probably never get out of second gear anyways... but not with the way my car is braking Id say its probably a no.

I have modified my suspension, and I am running a kinda hybrid spring kit, Eibach LS1 springs in the front, and Eibach LT1 springs in the rear. LT1 has a little stiffer rate so it doesnt sag as much under forces during turning or acceleration. I didnt have money for great shocks but I upgraded to the KYB's and I am comfortable with the ride. No control arms yet because that will probably be an investment when I am putting a tubular K-Member in. My tires arent wearing bad either for everyone that thinks its a must.... but i know I should. I Have a lot to do in the suspension department so I am not going to list everything since this post is about braking...

If anyone has good information on the rear cts-v brakes please post what you have. They might be the answer we need.

qwk93ta

iTrader: (13)

So, does anyone know if you can use C5 calipers on stock f-body rotors? If so, what mods have to be done to make it work?

KILLER-LS1

iTrader: (18)

JFYI rear calipers will not go onto the front or rear of our cars without extensive modification!!!!!!!!!!!!!!! i tried it.

also you know that stock front and rear rotors are the same size, right? the surface area is different, but they are both 12" or whatever stock is.

ill take a pic of my 14" front and 12" rears. i powdercoated all 4 calipers to match and got the rear rotors drilled to match. it looks like a 4 wheel BBK.

and to those who say its for looks. Ive tried a nice rotor and nice pad on a stock set-up. nothing compares to what it is now with the 4-piston and 14" i do a lot of high speed runs 150 and up on a reglar basis and the car can now safely brake from those speeds without heat spotting the rotors or warping them. also there is no fade at all. yes it looks great, but it stops even better.

slammed68

iTrader: (1)

The Rotor
While the rotor serves as the primary heat sink in the braking system, it is the functional responsibility of the rotor to generate a retarding torque as a function of the brake pad frictional force. This torque is related to the brake pad frictional force as follows:
r friction eff T = F × R
• where Tr = the torque generated by the rotor
• where Reff = the effective radius (effective moment arm) of the rotor (measured
from the rotor center of rotation to the center of pressure of the caliper pistons)
Because the rotor is mechanically coupled to the hub and wheel assembly, and because
the tire is assumed to be rigidly attached to the wheel, the torque will be constant
throughout the entire rotating assembly as follows:
t w r T = T = T
• where Tt = the torque found in the tire
• where Tw = the torque found in the wheel

Found on stoptechs website

Foxxtron

iTrader: (1)

Which is exactly what I'm talking about because the effective moment arm IS the MOI, which IS also a FLYWHEEL. Where the caliper is placed is where the lever is tangental to the outer diameter, UNLESS the caliper is placed towards the inner part of the diameter which it's NEVER done (if so, then why actually have a larger rotor?). The only force is more tangental at the centre is when there's engine braking.

Therefore confirming what I'm talking about bigger rotors NOT really contributing to the increased stopping distances per se but rather shifting the bias forward, and NOT being simple leverage physics. This is why it's actually ONLY necessary if the front-to-rear balance isn't good (on stock 93-97 it's way too rear biased and on 98-02's they're much more neutral). This can be confirmed when talking to Stoptech or even Brembo.

Again, not much improvement from investing in those big brakes, unless you're hitting those 1000+ F temps I've mentioned in some of my threads. If some of you search and look at mitchntx's threads as well as his youtube vids, his brake system uses Carbotech race pads, Castrol SRF brake fluid, and the fronts use a C5 caliper over an otherwise basically stock brake system. Even though he's using R-compounds, his car weighs around at 4000 lbs, and his wheels are 17" diameter and he races for more than 30 minutes and often approaches speeds of 120-130 mph before braking. If you notice from some of his vids, he actually brakes very deep into the corners and much later than his competitors. The rotors are actually $40 4th Gen F-body O'Reilly's blanks, which he replaces after one season only because he's very cautious.

If some of you also read the complete article and the technical white papers as well as doing the complete complete math for one vehicle, you'll also notice how suspension, sprung mass, weight distribution, and a whole host of other factors play a much bigger role in decreasing braking distances than messing around with the rotor diameter alone.

slammed68

iTrader: (1)

so even though a larger rotor increases torque there is no performance increase.

4) Braking torque: When we are talking about results in the braking department we are actually talking about braking torque - not line pressure, not clamping force and certainly not fluid displacement or fluid displacement ratio. Braking torque in pounds-feet on a single wheel is the effective disc radius in inches times clamping force times the coefficient of friction of the pad against the disc all divided by 12. The maximum braking torque on a single front wheel normally exceeds the entire torque output of a typical engine.

Only increasing the effective radius of the disc, the caliper piston area, the line pressure, or the coefficient of friction can increase brake torque. Increasing the pad area will decrease pad wear and improve the fade characteristics of the pads but it will not increase the brake torque.

im just trying to understand the concept

Foxxtron

iTrader: (1)

gotcha. Sorry if the language comes off harsh and blunt. The unfortunate matter is that this communication medium can get crazy at times and many things are misconstrued here.

You're now understanding the concepts. Bear in mind when we come to terms as "performance increase", I'll use the term more effective brake efficiency. By increasing the brake torque on one axle shifts the brake biasing towards that axle, which isn't necessarily going to make for better braking. Remember, even though it's much easier to have a slightly front-biased brake system, it may actually increase the stopping distance (of course due to other factors that I've mentioned earlier). StopTech's apparent aim is to ensure either an ever so slightly front bias, or better yet, one that is "neutral" (not quite possible considering that there are a variety of suspension parts as well as "options" and modifications which add to the sprung mass of the vehicle as well as changing it's weight management characteristics).

There can be an increase in effective brake efficiency from enlarging both rotor diameter as well as its width, however as you notice through the braking formulas we're now getting into, there's not just one way to do it, especially since there are the other factors you've now become more familiar with. When dealing with these dimensions, there's always some sort of tradeoff (as you see when you work the formulas). The idea is to find the most ideal setup without creating other inefficiencies. Again, rotor diameter IS important, but diameter alone is a terrible method to calculate the torque without concerning the where its mass is placed and effective braking torque per se is just a minor step in the whole vehicle's performance. I'm stating this whilst neglecting two other important physical properties (moment of inertia and unsprung mass which engineers sometimes struggle to manage but sometimes accept the tradeoffs).

If I can reference the bone stock setup again through using the formulas you've now looked at, the problems with the front brakes are mainly the rotors effective mass placement as well as the pad materials. In short, this is why mitchntx, Sam Strano, and a few others around here have gone through quite a bit of brake kits and upgrades, yet they notice when switching to a "quality OE blank" combined with a stock sized pad of "quality material" (in short having a good pad-to-rotor friction coefficient as well as having good elasic properties) seems to be as good as it can get for most MOT's. With regards to the OE blank dimensions, the problem lies with managing heat, because the OEM as well as "cheap, lightweight" aftermarket rotors have a problem with way too little mass along the width, specifically between the friction areas towards it's ventilation area as well as ventilation vane thickness themselves. By actually working on those areas, one can still improve the heat management characteristics of the rotor, whilst not adding too much to significantly affect the specific axle torque (which is why Sam and some others have suggested Brembo blanks in the past, but now suggest Ate's or ones of similar quality build. This is why I stress to those who are trying to "go big on both ends" really need to consider looking more at the braking dynamics of the COMPLETE vehicle, rather than just eyeballing the driveway jewlery.

AFA the heat goes, it's actually much more effective throughout the width of the rotor rather than its diameter, more specifically. If you thoroughly study the dynamics at how a proper working heat sink on lets say, the inside of a computer and compare the thermodynamics of ventilated disc brakes whilst engaged, you'll notice their thermodynamics are optimised very similarly.

I think you now see why I no longer focus completely on the diameter as well as piston count and "solid" vs. "floating", because whilst those factors are important, they're often embellished.

ChrisO

Very old i know. Did Anyone tried a ctsv caliper on a 12 inch rotor? If it would be a overhang on the brake pads. Or is a 12" to small?

Cpt.Derrek

iTrader: (13)

I'm in the process of installing cts-v brakes and I don't know why you would want to do this as most of the pad will hang off the edge and most likely won't wear right... but anyways I have a picture of mocking up the caliper on the car with the stock 12" rotor on.