Ok so my car is a 2011 Grand Sport, I've been tracking my car for a few months now, I've upgraded a few things, one at a time between each race. Sway bars, shocks, break pads #10 Hawks. Break lines, fluid, Intake, exhaust and roll cage with seats. I run stock tires on stock rims, super sports. I have stock rotors and my second time in a row I have got small stress cracks in the front rotors. Not major yet, hairline I would say, the first time I got them (stress cracks) I replaced the rotors, then the next time out it Happened again with brand new rotors. I've heard to not get drilled, just slotted, and I'm ok with that, but is there a specific brand and or modle that can handle the abuse I'm giving them? I know none will last forever with aggressive pads, but there's got to be something that lasts more than a day. Any help would be appreciated!

Also, how long would be safe to continue to use my rotors with hairline fractures? Should I replace immediately or would they be good for another track day or two? If I can find some rotors that can take more punishment I'll replace them right away, but if I have to get another set of OEMs I would like to ride them out longer.

 

I've had good results with kns dba blanks. Cheap and effective.

 

Build a brake cooling kit from Lambert. This makes a huge difference. I just completed mine yesterday and have about 200 bucks in it.




Then add Racing Brake rotors. Whatever rotors you get, do not get rotors that are drilled, that is where the stress fractures primarily initiate from. Problems solved.

 

How do you know it makes a huge difference?

 

Not from personal experience. But I'll be back on the track with them after Summer passes in TX.

The brake specialists I spoke to all said that better brakes would not help until I reduced the heat. When I tried to buy 2 piece rotors the guys at Zip were frank and said "deal with the heat first then re-access." And if you think about it, the problems the OP and myself have had with the brakes are all related to excessive heat. And of course we should all start with the easy less expensive things first. Adding a $3.5K aftermarket brake kit isn't in the cards for me personally. It's not a race car. It's a street car I enjoy tracking from time to time.

I already have high quality aftermarket rotors, and full Z06 brakes (calipers and rotors) on my Z51. And of course I turn off all nannies, run good race pads, run fresh Motul fluid and ss brake lines and I can completely kill my brakes in just 2-3 laps and then I have to cut back to driving at around 75% to manage brake temps.

 

Get some dba rotors than get a pad that is not as hard on rotors such as Carbotech. part of your issue is the harshness of the pads and yes I would definitely add cooling ducts. I would look into Carbotech XP12 front and XP10 rear for brake pads.

Carbotech™ XP10™

When Carbotech™ unleashed the XP10™ to the general public it immediately gathered multiple regional, divisional, and national championships. The XP10™ has a very strong initial bite with a coefficient of friction and rotor friendliness unmatched in the industry. Fade resistance is in excess of 1475°F (801°C). XP10™ still maintains the highly praised release, excellent modulation and rotor friendliness that have made all Carbotech™ compounds so successful. Carbotech™ XP10™ is not recommended as a daily-driven street pad due to possible elevated levels of dust and noise.


Carbotech™ XP12™

Another highly successful XP™ series compound with an excellent initial bite, torque and fade resistance over and above the XP10™ compound. XP12™ has temperature range of 250°F to 1850°F+ (121°C to 1010°C+). The XP12™ has that excellent Carbotech™ release and modulation that has made all other Carbotech™ compounds so successful. The XP12™ is more rotor aggressive than XP10™, but compared to the competition the XP12™ is still very rotor friendly. XP12™ is NOT recommended for use as a daily driven street pad due to possible elevated levels of dust and noise.

 

I have the "Grand Sport" which is the exact same car as the Z06 ( besides engin and chassis material) I know I have ducted rear breaks and I'm pretty sure the front is as well. I also have the big break kit, it comes stock in GS and Z06.

 

I'm looking at getting DBA 2 piece rotors, and have Hawk 10 or 12 pads, can't remember which ones. Are you saying the Carbotech are less harmful than Hawks? These are not Hawk Bkue, they are Red I believe. Their newer stuff.

 

All Carbotech compounds are a lot more rotor friendly than Hawk and a lot less corrosive.

 

Do the carbotechs stop as good as the Hawks? And how is the noise on them/squealing noise?

 

You do not have brake spindle ducts stock.

 

Ok thanks, do you have directions and or a kit on how I can add the ducting?

 

http://www.lapponline.com/index.php?...cPath=89_90_99

 

Some clarification is in order, because you guys are talking past each other....

- A big brake kit (BBK) is how people refer to aftermarket setups like StopTech, Wilwood, etc. While the Z06/GS brakes are different and use larger rotors than the base cars, it's not a BBK per se'
- The GS like the Z06 has front and rear brake ducts
- The GS and the Z06 do not have front spindle ducts as mentioned above. LG, DRM, Lambert, and others sell spindle kits, all with pluses and minuses

Regarding the OP original question. Hairline fractures are no big deal. Replace the rotors when the fractures extend to the edge of the rotor.

My rotor consumption decreased when I added the spindle ducts and hose from the factory ducts to the spindle ducts, so yes it matters and makes a difference. Lots of threads on this with pics.

I run Carbotech XP10 (F) and XP8 (R) in general although I have also used the 12/10 combo. I've tried them all and prefer Carbotech.

I'm planning to be at Willow Springs April 16th with Extreme Speed. Black GS, Toyo R888s. Perhaps I'll see you out there

 

Awesome thanks for your imput. I think I've decided to go with some DBA 4000 rotors. Slotted and change to Carbotech 12s all around. I guess the Hawks are VERRY corrosive and rotor eaters. I may also add the spindle ducts. You said they have "Cons"? What would the cons in the spindle ducting be, just added weight?

Willow is awesome, love the diner, I was on the streets last time I was there. I'm in a White GS with my Comapny logos and #24 on it. I always have my RV with a pic of my car on the back. I race with "Speed Ventures" and try to go once a month. Until it gets too hot anyway. I think end of May will be my last event till Oct, u less it's a cool summer. Will be going to Leguna Seca May 20th. That place looks awesome! Never been.

 

I'd go 12/10 on the pads. The fronts do most of the work and in my opinion 12s on the rear is spending money for the sake of it.

Regarding the spindle ducts, the pros and cons revolve around installation and cooling. For instance, the LG ducts require you to remove the hub while the Lambert kit does not. The Lambert kit does not have as straight a shot to the rotor as the LG kit....ie the LG kit gets more cool air into the center of the rotor. The Lambert kit includes heat shields for the tie rod ends, the LG kit does not.

I run with Speed Ventures on occasion, actually instruct for them from time to time so I'll keep my eyes open for you.

Have fun at Laguna!

 

Thanks again. So it seems the LG ducts are better just harder to install.

Just curious, are there any cost difference between Speed Ventures and the group you run with? Is there a reason why you chose one over the other? Are the rules and cars all the same. Speed Venturs is my first and only group I've ever raced with, I like everything about them but cur rouse about other groups, I know you can do open track days for like 10$ at some tracks with now groups, and speed ventures charges about 200$ per day. So thought maybe other groups are cheaper?

 

Your really in the wrong forum to ask about track use and brakes. Start here.

https://www.corvetteforum.com/forums...questions.html

 

Yes and no. I don't believe the LG ducts have the heat shields for the tie rod ends. The ends can be wrapped however. From an airflow perspective, I and others are of the opinion the LG design is better. Again, just opinion on my part.


ExtremeSpeed, as dates near, will lower their prices. They start at ~$150/day and will typically end up around $90 if they have slots open a week before an event. For the most part they're only at Buttonwillow, Willow Springs, and ACS. You won't see them at any of the high dollar tracks like Laguna Seca.

The BMW and PCA groups can be upwards of $400-$500 for the weekend although which track the event is at certainly plays into that because they will run at professional tracks.

Operating philosophy varies. PCA and BMW are very structured. Even in the Instructor groups, passing is limited to certain areas of the track and require a point by. From a school perspective, they are well run, in general very organized, and safe...especially for those that are trying it for the first time. I enjoy teaching for them. Fun yet relaxed and the students there really want to learn.

ExtremeSpeed I would characterize as more of the "Wild West" approach. Minimal rules, open passing in the Red (Advanced) groups. Instructing is only for the new people and tends to be lead/follow with an instructor in the right seat for the first two sessions. After that, they're turned loose. In theory there are passing zones and a point-by is required but the rules are not rigorously enforced. In the new person groups and even low intermediate, this can be un-nerving for people. At times they also get a lot of Johnny Racer types that are trying to prove the size of their manhood. You can pick these guys out by how they drive...even in true racing there are etiquette rules regarding when someone has the line, letting clearly faster cars by, etc...and these guys ignore all of that. Lots of good people/excellent drivers show up as well, but just have to be willing to accept the days and drivers can vary.

I would slot Speed Ventures as the middle ground regarding cost and rules/rule enforcement. Overall, well run (like BMW or PCA) but clearly oriented towards time trials (like ExtremeSpeed).

 

Thank you for the insite, I do feel very safe with Speed Ventires, I feel that's is run very well, the open passing starts 3 levels up, But when you get to open passing it is anywhere in the track. And I do like that they have a broad range of tracks that they go to. 90$ is half what I pay per day but I guess the extra tracks and safer atmosphere is worth it. I did run with the "Red Group" by mistake once, because there was a crash it delayed my group and I showed up to Padock on time, knit knowing there was a delay, I didn't notice I was in Red until just before they let us go, and started looking at the cars next to me and realized where I was. It was good though and did very well with them, was in the front half of the pack. Since then I noticed they check everyone's bands more befor letting them go.