|C5 Brake System Upgrade
by Bart A. Lane #W1379
A fifth generation Corvette has more performance than the typical driver could ever use. Of course, Corvette drivers are not typical drivers. As fantastic as the new Corvette is, I get great joy from altering every aspect of the car mechanically to a superior level. I try to do this without sacrifice, which is the difficult part. Every Corvette I have ever owned has left my possession a far different beast than its reception. For the first time, made possible by the power of a home PC, I have kept records of all changes to my car. I am putting this together in the hopes that some of my experiences will assist others that chose similar modifications for their own vehicle. People will say you are crazy for messing around with a $40k plus automobile but they don't understand. At least nobody I knew did, until I took him or them for a ride.
Even though I did not follow this precise order, I am going to make these reports in this order. Brakes, suspension, engine, and other. First and foremost, you've got to have stopping power. This is the number one determining factor in racing and this is the number one determining factor in safety on the street. If your brakes can't handle your engine and suspension upgrades then you have nothing more than a ticking time bomb on your hands. Fortunately, the C5 brakes are pretty darn powerful to begin with so you don't need a lot in this area. We will talk about these in this installment. The second most important factor in racing and safety on the street is the suspension. Again, the Corvette group has blessed us with a miracle of modern day suspension design and application. The C5 handles better than almost any other vehicle on the road today thank to the stiffness of its structure most of all. There is little to do, if anything to the suspension so the second installment will talk to the owners of base suspensions who want to upgrade to the Chevrolet option of Z51, the performance factory suspension. Finally, after your brakes and suspension can handle the power you will be able to focus on increasing engine output. GM has built a wonderful drive-train but it can be improved upon. When fuel mileage, emissions, and sound levels are not your chief concern, as they are the governmentally mandated GM, then there is much you can do to make your C5 faster without ever pulling the heads from the block. In the third installment I am going to discuss letting your LS-1 engine breathe better for more power and then focus on bettering the stock ignition and fuel system. Furthermore, the engine section will include a massive cooling upgrade and complete, bumper to bumper, lubrication switch over to Redline racing synthetics. I will also help those with automatic transmissions try to recoup some of the losses this gearbox forces you to endure along with changing the rear-end gears for the final drive. In the last issue I will discuss little things to make your C5 look better and feel better, add ons that aren't tacky but have functional benefit. The sound system will also be seen here.
On to some braking news. The C5 brakes are great. Need to stop from 70 in a big hurry to avoid a flipped over semi? No problem, the Corvette will oblige. There are two issues with Corvette brakes and they have been around with every Corvette I have ever known; fading after repeated braking and rotor warpage. The goal of my brake upgrades was not to decrease stopping distance so much as it was to provide good stopping in fast, repeated applications. Before, after three 60mph hard stops my pedal would fade badly. Now, I can't get my brake pedal to fade even if I want to. There are many ways to upgrade your brakes and many companies that will help you with your product selection. You can go the extreme route and spend close to $10,000 and get a full floating rotor set up with six piston calipers in front and 4 piston calipers in the back along with a 1" internal diameter master cylinder. The kind of brakes that can put you through the windshield. This level of braking, while essential for real racing applications, is too harsh for the street. Racing brakes are practically impossible to stop smoothly and are not effective until the heat ranges rise into temps that would melt street brakes. We don't keep our brakes that hot just driving around. Doug Rippie offers a nice option, using stock calipers on larger rotors. He supplies the rotors, new mounting brackets and Carbon Metallic pads. The only problem with this set up is that you need 18" wheels on the front. This can get expensive fast. At this time, I know of no aftermarket rotor/caliper combo that fits under the factory front wheel. This kind of narrows your choices a bit. As I stated before, thankfully the stock hardware is up to the task with a little help.
What you need to work on your brakes- A functioning knowledge and mechanical skill to remove and safely reinstall your braking system, every aspect of it from the master to the rotors. This is a serious, serious safety item here folks. If you don't know brakes then don't try this. Get a shop or a skilled friend to help you. You don't want to mess around with your brakes if you are in the dark or somebody could wind up hurt or worse. You want a good set of tools with large sockets and wrenches. Some of the bolts are fairly large so keep a socket set up to 24mm on hand. One of the things I can not stress enough is to purchase a GM factory repair manual. You can get these from a number of sources and they are essential. I am telling you now, don't take one bolt off of your car unless you have a GM service manual for your model opened up on the work bench.
Making the stock system last longer is just common sense really- cooling the hardware you can't change and getting equipment that works at higher temps for the hardware you can switch out. I selected the following equipment for my upgrade;
1.) Motul racing fluid. Performance brake fluid is a very good idea because it raises the boiling point which allows you to make more stops. Motul is a great value at $10 a bottle compared to $90 a bottle for Castrol racing fluid (Although the Castrol is the very best.) Motul fluid can handle just about anything you will throw at it. I got mine from DRM (Doug Rippie Motorsports, http://www.dougrippie.com ) even though it is not listed on their site a tech there recommended it. Motul is fully compatible with all aspects of Corvette brakes and ABS components. I got the DOT 4 Racing Fluid 600 with a 585 degree boiling point.
2.) Doug Rippie bias spring. A bias spring will divert a little more braking pressure to the rear of the car. What this does is it keeps the car level during hard braking because each end is carrying closer to 50% of the stop. A level car handles much better than a diving car. On the C5 there is no reason not to do this because it is very simple as compared to the C4 which required the taking apart of the master cylinder. For $13 you cant make a better braking modification for the money. A magazine test reported five feet off of the 60-0 stopping distances.
3.) Also from Doug Rippie I purchased the braided steel brake hoses. Rubber hoses flex, expand, and crack. Braided steel does none of this. Every time you step on your pedal fluid pressure builds up in the hoses and lines. The hoses expand just a bit and make your pedal feel softer. I put braided steel hoses in every car that I or my family drives, I believe in them that much. $130
4.) From Mallett Cars ( http://www.mallettcars.com ) I purchased a set of their performance silver street pads. In the past I have always used a set from Carbon Metallic usually purchased from DRM. But these pads were not available when I was putting my parts together, they are now. My only option at the time were the pads from Mallett. $280 for the full set, front and rear. Would I go with the Mallett pads again over the Carbon Metallics given the choice? To be honest, no. I like just about everything with the Carbon Metallics more than the street Mallett pads. They seem to stop better with less downfalls. I will discuss these later and you will see, while I didn't much care for the pads, I have much praise for Mallett Cars as a company and most of their other products.
5.) New factory rotors - cross drilled. Factory rotors were my only choice to fit under a 17" front wheel. Thats OK, the factory rotors are big and are up to the task. There have been many complaints of warping rotors and an equal number of explanations. Farther down I will share my views on the warpage and its cause. I had the rotors cross drilled by a company in California called Porterfield Enterprises. ( http://www.porterfieldbrakes.com ) I had to UPS them the rotors and pay for return shipping and the cost was $50 per rotor. Expensive, I know, but they did a wonderful job and they look great through my BBS wheels. Cooling is everything and the stock rotors have directional, internal vanes that force the air through the rotor. With holes drilled more air can move and thus, more cooling. Also, it allows air to be pumped into the hot brake pads and allows a place for built up gas under the pad to escape. Porsche, Ferrari, Lamborghini, and Lotus all use drilled rotors on their brakes. The best feeling brake pedal I have ever felt was in a late model 911. And people, Im here to tell you, drilled brake rotors look kick ass and thats the main reason I got them. I wanted other Corvette enthusiasts to know that my brakes werent stock. Oh yes, at Porterfield you can get a bit better price on the Motul racing fluid and Performance Frictions Z rated Carbon Metallic pads than you can many other places. This is also a good place to get Redline synthetic lubricants.
6.) Stainless steel piston inserts from Doug Rippie. Again, an item that does better when hot as opposed to its aluminum, stock counterpart. 90 bucks. Installing them basically requires that you rebuild your calipers so make sure you get a GM rebuild kit before you start. I used a new set of GM calipers anyway so I didnt feel I needed the kit.
OK, added up that is about $750 For about the price of one car payment you can have a very effective braking system that can take repeated poundings. That is quite the bargain. Labor of course is up to you to provide or pay for. Doing it yourself is more fun though and makes you friends with your car. (Or enemies, depending on your temperament.)
Thats it on the parts and you are pretty much done opening your wallet. Time to get your knuckles bloody. I have been a professional mechanic for much of my adult life. Thankfully, for my body, I dont have to do this any more but I learned much and retained almost everything I learned over the years. I have done it all, from putting in a clutch while under a car in a mud field while the rain poured down on a cold day to having a car fall of jack stands while I was under it because a lube boy started the car. (Thanks to God because the car stopped within ½" of crushing my face and had to be lifted up to get my head out from under it.) I have messed around in both the worst and best shop conditions. I didnt want to screw around with my C5 so I bought a professional hoist that lifts the entire car into the air. I got it from Auto Lifters of America ( no web page, Wichita, Kansas Phone # (316) 630-0011) and it took two months to get. Myself and two friends put it up in an evening and let me tell you, it makes life in the garage wonderful. It really is the only way to go. If you have the room then I highly recommend you look into it. I got a 7,000 lb. Hoist as a Christmas special for $2000 which included delivery.
Once you get the car up in the air and the wheels are off it is pretty much a typical brake job where you are replacing everything with new parts. Just follow a typical procedure for changing out the rotors, calipers, pads, and hoses and replace with all your new goodies. Don't forget; the C5 has four unique rotors that go in their own places. Each is marked so pay attention. I disconnected all rubber lines and let the braking system gravity bleed into four drip pans overnight so all the old fluid was gone by the time it came to bleed it out. That also made it much nicer to change the bias spring with no fluid dripping. Before you fill up the system you will want to locate the bronze colored aluminum block below the master cylinder. One brake line runs in and another runs out. A very simple, yet very effective brake bias system. I don't know why all cars don't use this method as there is nothing wrong with it. The instructions for the bias spring install say to do it on the car - Don't even bother because the springs are under heavy tension and you will never get the spring keeper/cap threaded again. Remove one line at the master on one line on the bias valve and secure the block firmly in a vice. Then you can simply yard out the old spring and replace it with the new and then reinstall the whole unit. If you have never changed caliper pistons before don't make the C5 your first try. This is a hard car to do because it uses multiple pistons and the old method of using compressed air to blow the dust boots over the pistons will not work. Drop them off at a brake shop before you begin any of this and they will do it for just a few bucks. They have tools for this.
Finally, you are ready to bleed the system once everything is on and everything is tight. If you want, I did, let the car gravity bleed all night with the bleeders cracked open and the reservoir filled up with your new, fancy brake fluid. Make sure you check it through the night so the master does not run empty because then you have air and have to start over again. When it is time to bleed them grab a clean buddy and have him get in the car to work the pedal. A guy whom I trusted as a mechanic told me once to never pressure bleed ABS brakes because a cup can get inverted and set off a service light and cause other problems. I have never had this proven to me but I still don't do it because flow bleeding the brakes works great, there is no chance for mishap, and is far less messy. The difference is PRESSURE BLEEDING means there is pressure on the brake pedal and in the system when you crack the bleeder. FLOW BLEEDING means that you open the bleeder and then the pressure is applied but it just squirts out the bleeder and no pressure is really built up in the system. After you bleed all four corners (in this order on a C5, RR-LR-RF-LF) make sure you get clean, bubble free fluid to all four corners and make a second pass if you want to be sure. The pedal should be firm and high right away. Clean everything up with brake cleaner and have your pedal person apply pressure while you look closely for leaks, especially look hard around both ends of each braided steel brake hose.
You are ready to drive, but not ready for heavy braking yet. You have to break the pads in, or mate the surfaces of the pads and rotors together. This is a very critical phase and decides how these pads are going to act for their entire life. What I am going to say applies for every brake pad I have ever seen with the exception of the Mallett silver street pads. I followed this break in procedure for every brake job I have ever done without problem and it made the Mallets squeal and grind like nothing you have ever heard. On most brake pads you do not want to heat them up for break in. This causes a glaze to build up and makes the pad surface very, very hard. While this is great for the pad it is not good for the rotor and you get lots of noise. So, in a typical pad install you do not want to ride your brakes for the first 500 or so miles. When you use your brakes you only want to use them when you are coming to a complete stop. Try to keep your brakes as cool as you can until they break in and then you can lay into them like Mario Andretti. I found out from Matt at Mallett cars that their pads like heat as a break in and my cool running of them caused the problem. I removed the pads and sanded the surface down a bit. I also performed an old trick for noise which is to bevel the leading edge of the pad by 45 degrees. The last thing I did was to apply a few swipes of water based (not oil based) valve grind compound to the inside and outside of each rotor. These three things will basically give you two fresh surfaces so you can try again. Matt recommended high heat for the break in and even told me to drive a mile with one foot on the brake pedal. I couldn't believe this but tried anyway and, amazingly, they are now silent. To be honest the pads stop very well, much better than stock and they finally are quiet. Mallett was great the whole time and offered to replace them whenever I said the word.
So how do I like the upgrades? It is a noticeable improvement all the way around. Money very well spent. If you want to save even more money you can use your old calipers and rotors and not bother with the drilling. Also, I don't think you will be able to tell if you don't use the stainless steel pistons. You could do all this for less than $500 and achieve basically the same thing and that is a bargain. The car stops hard and it will do this over and over and over again.
I also wanted to give my take on rotor warping. I had really bad problems with this before and many others have told me the same thing. I had the dealers turn my rotors twice and replace the rotors once. Finally, after the replacement I didn't warp them again. The dealers performed one turning for free but I paid for everything else. I was curious as to why the warpage could be so common on a performance car and I talked to some knowledgeable people to get answers. Let me tell you, I have performed several thousand brake jobs in my life, and I have put on tens of thousands of wheels. Every time I installed the wheels I used an impact gun and not once, as far as I knew, had I ever warped a set of rotors doing it this way. The chief source of warping is from improper cool down. If you heat your brakes up during some heavy driving and then just park your car the rotors will warp. Corvette drivers tend to drive harder so our brakes likely get hotter than, say, owners of Civics. When you just stop a car with very hot rotors they, of course, quit spinning all together and one side sits in contact with the pads and caliper. This acts as a heatsink and this side will cool more rapidly than the other which will cause the metal to flex and warp. Moral is, after driving hard, tool around a bit under normal loads and let your car's brakes come to a lower temperature before stopping the vehicle. Since I have adopted this policy I have not warped a C5 rotor on my car.
Thanks for reading and look for future articles on altering you entire $40,000 plus vehicle bumper to bumper!!
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