Our project Z06 needed some new brakes. We opted for a set of Ferodo DS2500 pads. While we installed them live on camera, David Zeckhausen of Zeckhausen racing joined us to discuss brake technology. You can watch the whole thing below.
Our project Z06 needed some new brakes. We opted for a set of Ferodo DS2500 pads. While we installed them live on camera, David Zeckhausen of Zeckhausen racing joined us to discuss brake technology. You can watch the whole thing below.
Ferodo...............don't go to a track with no runoff.
I raced a '99 model in '99. It had an alarming tendency to go into Ice Mode: hard pedal, no brakes. We had several nasty moments as a result. Hopefully the track-oriented ZO6 models were better. Keep an eye out for this, and maybe consider going to non-ABS and a bias adjuster, real race car style (well, old school, anyway). Seems street ABS systems of the 80's and 90's were not quite smart enough for race tracks, and could cause trouble. I won many races with them, but the threat always lurked in the backgound, and when it reared it's ugly head, caused several of my worst crashes.
The Chevrolet engineer's have admitted that the ABS in the C5 was never design for or even optimized for use on a road course. The ABS system in the C6 is an improvement in that regard. I have always had good luck with Carbotech and Hawk pads - never used Ferodo pads.
Not sure about the these two brake mods in regards to the rules in your class, but...
You can upgrade to the stiffer C6 base front calipers. Its legal in several classes of road racing with no points penalites. The 2-piston sliding C6 calipers are less likely to spread, which has always been the problem with the C5 units. They are direct bolt-on, no need to change the caliper mounting brackets, rotors or pads. Also DRM offers replacement stainless steel pistons for the 2-piston sliding C5 & C6 front calipers that help keep heat out of the fluid. Granted that may or may not be all that critical for autocross use.
Also now that you have 18" front rims, at least for autocross or track duty, you can also upgrade the front rotors from the C5 / C6 base 12.8" [325mm] front rotor to the slightly larger diameter (and heavier) 13.4" [340mm] front rotors from the C6 Z51 package. All you need is the C6 Z51 caliper mounting brackets - again you use the same calipers and pads.
Of course once you start doing some track event, then there are always the Wilwood kits for upgrading the fronts as well as using the C6 Z06 front brake duct extensions. Don't worry about upgrading the rear brakes, there is no need to until you are running a dedicated track car with some serious aero and lots of rear down force.
Thankfully I've not had any issues with ice mode in the Z at all. Not having used Ferodo pads before, I was not really sure what to expect, but so far I'm impressed with their abilities as an autocross pad that can also be street driven with nearly no downside. The release in particular is very good. They make trail braking and sub-threshold braking really, really intuitive.
Buuuuut... I'd definitely be a little wary of them on a road course–especially in a lapping situation. They do seem a bit prone to fade, although they don't seem to lose effectiveness, just bite.
Ultimately I think we'd like to go to a two-piece rotor to save some weight while increasing the size. I really liked what we did with the Mustang—substituting a complete setup with calipers and rotors in the front and just going with a lightweight, larger diameter rotor in the rear. Fora dedicated road race car i might want a little more rear capacity, but for a car like this that will see mostly time trials and shorter sessions for its track action, i think that would be a nice upgrade and not overkill.
2-pcs rotors are of course a great way to save weight. I have used both Baer units as well as custom hats from TCE with Coleman rings. There are lots of choices out there, if the budget allows.
Those ferodo pads are a decent dual duty pad but for a car as fast as the Z06, I wouldn't run them on a track....
If you are going to start doing time trials or spending extended sessions out on the track, then I would highly recommend those C6 Z06 front brake extensions GM #15829066 & 15829067. They are dirt cheap at less than $40 for the pair. Also I would recommend that you upgrade at least the front bearing hubs to the SFK X-tracker units. They are not cheap (best price out there is about $350 each), but as noted here they last on the track vs. OEM factory or regular replacement units.
http://www.waikatobearings.co.nz/file/skf-x-tracker-hub-units/open
Second thing would be to upgrade the front spindle/knuckles to the C6 ZR1 units GM #88965637 & 88965638. The caliper mounting ears are much thicker and stronger to reduce the chance of deflecting and bending under load or catastrophically failing on the track. The are also cast with a better alloy than the more pedestrian C5 and C6 base units. They were designed to handle the much higher loads associated with the C6; Z06, ZR1 and Z07 packages. Best price is about $240 for the pair.
I know next to nothing about corvettes (other than that the ls6 is legendary), but I had to say - what a wonderful episode! So much good info here in one package.
One request I have for you guys is an episode dedicated to c5 cooling. IMO it is a little difficult to find all the necessary coolers you will need, not to mention installation
The C5 from the factory is truly lacking in the proper cooling system/capacity needed at the track. Before the end of a 20-minute track session during summer you can see coolant temps at or above 220F and oil temps at or above 290F. It’s really amazingly the engineers never fitted an oil cooler of any kind to any C5 model, you would have thought at least on the Z06 but no! They remedied this on the C6. The factory radiator with a single row aluminum core with plastic end tanks that will leak - it’s not a question of if, it’s only a matter of time.
For track duty the first cooling system upgrade should be a quality 2-row all aluminum unit and a 160 degrees thermostat. The most cost effective fabricated all aluminum radiator is an ECP unit for about $280, you can spend double that by why and beware of cheap imitations that are offered for less. Another thing to keep in mind, when they switched to the LS6 intake manifold in ’01 for both the LS1 & LS6 engines they also eliminated the rear steam tube cross over. This can lead to hot spots in the rear of the cylinder heads. You can remedy this by either back dating to the ’97-01 LS1 steam tube setup and either removing the center section of tubing or trimming the ribs off the bottom of the LS6 intake manifold for clearance You can also add a rear steam tube like the GM #12605716 used on the Chevy truck LS Votech family engines and tie it into the front via some ¼” coolant tubing and a T-connector for about $50. There are also aftermarket 4-corner steam tube upgrade kits available as well.
The next up on the cooling upgrades should be a thermostatically controlled oil cooler adapter like one from Improved Racing for about $200. You can’t go wrong with a cooler from Setrab like their 13 row Series 6 unit with M22 O-ring ports for about $130 and then install it with a mount designed for it from Lingenfelter for about $40, plus another $20 for the mounting hardware. You can then piece together the needed -10AN fittings and hoses. Be sure to wrap those hoses with a heat shroud tubing wrap like something from DEI or a similar product, especially if you have long tube headers.
Speaking of the oil systems, if you have a '01-04 C5 then you have the 2-pcs bat wing oil pan. If you have a '97-00 C5 then you have the 1-pcs bat wing pan and you should consider upgrading to the later design pan design. This gives you the ability to install the Improved Racing trap door baffles in the pan for about $200 to help prevent oil starvation in the corners and during hard braking. Some prefer installation of an oil accumulator setup like those from Canton or Moroso, but space can be a premium in a C5. If you do choose to do neither than you better add one quart of oil to the sump before heading to the track. Also switching from 5w-30 to at least 0w-40 or 5w-40 for track events is smart cheap insurance for the bearings. Some even setup to 5w-50, 15w-50 or even 20w-50 for use at the track.
For extended track duty sessions then you will need to start looking into adding coolers for the T56 trany and the differential. The factory added a cooler for the TR6060 trany in the C6 that can't be adapted to the C5 T56. There are aftermarket setups available for the C5.
deaconblue said:The C5 from the factory is truly lacking in the proper cooling system/capacity needed at the track. Before the end of a 20-minute track session during summer you can see coolant temps at or above 220F and oil temps at or above 290F. It’s really amazingly the engineers never fitted an oil cooler of any kind to any C5 model, you would have thought at least on the Z06 but no! They remedied this on the C6. The factory radiator with a single row aluminum core with plastic end tanks that will leak - it’s not a question of if, it’s only a matter of time.
For track duty the first cooling system upgrade should be a quality 2-row all aluminum unit and a 160 degrees thermostat. The most cost effective fabricated all aluminum radiator is an ECP unit for about $280, you can spend double that by why and beware of cheap imitations that are offered for less. Another thing to keep in mind, when they switched to the LS6 intake manifold in ’01 for both the LS1 & LS6 engines they also eliminated the rear steam tube cross over. This can lead to hot spots in the rear of the cylinder heads. You can remedy this by either back dating to the ’97-01 LS1 steam tube setup and either removing the center section of tubing or trimming the ribs off the bottom of the LS6 intake manifold for clearance You can also add a rear steam tube like the GM #12605716 used on the Chevy truck LS Votech family engines and tie it into the front via some ¼” coolant tubing and a T-connector for about $50. There are also aftermarket 4-corner steam tube upgrade kits available as well.
The next up on the cooling upgrades should be a thermostatically controlled oil cooler adapter like one from Improved Racing for about $200. You can’t go wrong with a cooler from Setrab like their 13 row Series 6 unit with M22 O-ring ports for about $130 and then install it with a mount designed for it from Lingenfelter for about $40. You can then piece together the needed -10AN fittings and hoses. Be sure to wrap those hoses with a heat shroud tubing wrap like something from DEI or a similar product, especially if you have long tube headers.
Speaking of the oil systems, if you have a '01-04 C5 then you have the 2-pcs bat wing oil pan. If you have a '97-00 C5 then you have the 1-pcs bat wing pan and you should consider upgrading to the later design pan design. This gives you the ability to install the Improved Racing trap door baffles in the pan for about $200 to help prevent oil starvation in the corners and during hard braking. Some prefer installation of an oil accumulator setup like those from Canton or Moroso, but space can be a premium in a C5. If you do choose to do neither than you better add one quart of oil to the sump before heading to the track. Also switching from 5w-30 to at least 0w-40 or 5w-40 for track events is smart cheap insurance for the bearings. Some even setup to 5w-50, 15w-50 or even 20w-50 for use at the track.
For extended track duty sessions then you will need to start looking into adding coolers for the T56 trany and the differential. The factory added a cooler for the TR6060 trany in the C6 that can't be adapted to the C5 T56. There are aftermarket setups available for the C5.
Great info here, thanks.
I'd heard about a lot of this stuff—like the steam tube fittments—but hadn't researched it much other than to make sure it was on our rader as we continued the project. I'll definitely be throwing this post in my notes.
Glad I can help, if only from a distance. At least you're out driving, working on and enjoying your C5 right now, mine is still hibernating in the garage for a few more weeks.
Also keep in mind that over the years I have been accused (and right so) of over building a car to say a TT level just to use it on the street and at HPDE events. In the past I have had to run cars in say ITE, just because I have over built them so that I can personally enjoy them, not because I needed to run in a specific class. Plus my friends tell me that I am always way too eager to help them spend too much on their money on their toys and projects. I suppose that's what comes from being an automotive product engineer with about 33 year experience and from hanging out at race tracks for a lot longer than that. I have always believed that if you over build the car up front, you tend to only have do any job once. Plus it tends to not leave you broken in the pits, in need of both a flatbed/trailer and a ride home. 
There's a lot of good information on the CorvetteForum (both in the C5 sections as well as the Autocrossing & Roadracing section) plus on the the LS1Tech forum too.
JG Pasterjak said:Ultimately I think we'd like to go to a two-piece rotor to save some weight while increasing the size. I really liked what we did with the Mustang—substituting a complete setup with calipers and rotors in the front and just going with a lightweight, larger diameter rotor in the rear. Fora dedicated road race car i might want a little more rear capacity, but for a car like this that will see mostly time trials and shorter sessions for its track action, i think that would be a nice upgrade and not overkill.
If you are spending your own money and not sponsorship dollars, then I would highly recommend that you talked to Ken at KNS brakes about his DBA brake rotor clearance sale. I just picked up a pair of DBA 5000 series 2-pcs front rotors (in the C6 Z51 13.4" [340mm] size) on clearance for almost 1/2 off the normal retail price. Hard to beat that kind of deal. He has other C5 & C6 sizes available as well;
https://www.corvetteforum.com/forums/c5-parts-for-sale-wanted/4109888-dba-brake-rotors-on-clearance-at-kns-brakes.html#post1596724850
randyracer said:I raced a '99 model in '99. It had an alarming tendency to go into Ice Mode: hard pedal, no brakes. We had several nasty moments as a result. Hopefully the track-oriented ZO6 models were better. Keep an eye out for this, and maybe consider going to non-ABS and a bias adjuster, real race car style (well, old school, anyway). Seems street ABS systems of the 80's and 90's were not quite smart enough for race tracks, and could cause trouble. I won many races with them, but the threat always lurked in the backgound, and when it reared it's ugly head, caused several of my worst crashes.
Some interesting reading here on the subject of the C5 ABS and "Ice Mode":
https://www.corvetteforum.com/forums/autocrossing-and-roadracing/3423347-racing-and-abs-to-fix-or-not-to-fix-that-is-the.html
https://www.corvetteforum.com/forums/autocrossing-and-roadracing/4107436-abs-failure-on-c5.html
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