I've read a lot on here about people wanting to stray away from cross drilled rotors because of cracking and less friction surface. I have also read that the z51 rotors were cast with the vanes in the same direction which raises concerns for cooling on trackday outings. However, are these drawbacks outweighed by the fact that the z51 rotor is .6in larger?

I've searched which is how I came up with the above info. But I'm hoping someone with some experience could help me split hairs and decide on which rotors to use?

 

The C6 Z06 brakes with the backwards veins have been proven to overheat one side during track use. Now, if you had coleman racing build you proper left and right rotors, you very well might like the Z51 brakes.

What do you intend to do with them? Track, autocross, street only? And, any idea what pads you might run with them? All of this will impact the answers you get and we'll try to help you with anything you're not sure of.

 

Thanks for the reply! The car is a daily driven, full interior 01SS with the added weight of a 9 inch and twin turbo system (~+75lbs), on Nitto 555r 285/40/17s. Street manners are important but the car will be used for Solo II events with some road racing the local road course a few times a year. The car most likely be getting Koni SAs and springs. It will drop no more than an inch. I planned on a 550/180 spring rate but that is based on what I've read here. I'm fully open to suggestion here!

As far as pads, I was planning on following the crowd for some Hawk pads but I am fully open to suggestion here too . I will be making my own brackets and using f-body calipers unless there is a more compelling reason to go with C5 units.

For driving style, I will use every bit of brakes I have to run into a corner hot to pass and whatever is appropriate for the best lap time otherwise. But I'm pretty mild mannered on the street.

I didn't know Coleman built rotors. I wonder how much that would cost lol

 

Ok, with extra weight in the nose (Turbo's and plumbing), I'd run more front spring rate than that. I run 600/150's in my daily driver without extra weight in the front. I'd probably consider 600 in lb a minimum and possibly 650 or 700. In most cases I've seen, the 180's are a bit stiff for autocross (well, 200's have proven to be too stiff and hard to balance the car with the 600-ish in lb front springs, running more front spring could help that). I'd suggest starting with a 150 and either a 19mm or a 21mm rear sway bar (or a 22mm hollow strano bar). You'll have to tune the rear to taste. With that much power, you might want to try less bar to help settle the power oversteer that you might be dealing with. And most importantly, get a 35mm front sway bar. It will do more for the car than many of the other things combined. You might try the Strano springs (600/150) and not a huge drop, but they may be a bit lower than you'd like.

I'd probably run a Carbotech XP8 or XP10 front pad, or one of the other Hawk compounds (not the HPS/HP+) like an HT10. You'll need more brakes for that monster than you might expect. Also, with the brackets, it's easy to get the spacing right and bolt the stuff to the car so it fits, it's much more difficult to design something rigid enough to not flex and taper pads. I know of one major brand brake company who's kit has exactly this problem under track use. The bracket twists and the pads wear with a diagonal taper (think of mounting the caliper 20 degrees from square with the rotor so that the rotor runs diagonally through the pads and they wear accordingly). If you screw this part up, you might only get one shot at it, so I'll warn you to be careful. Do not copy some of the products out there thinking "it must work ok or they wouldn't sell them". There are a few products that border on dangerous in my personal opinion. Those are made of material that is too thin and likely to cause problems (again, my opinion).

With that said, in the interest of full disclosure I'll state that I do manufacture and sell C5 conversion brackets that are built to the level of overkill (as are some others out there). Some might call me biased, but I do not want to see you get yourself hurt, even if you don't buy them from me, be careful what you build or buy.

I think Coleman builds 13" rotors for about $135 each. Not cheap, but it's a heavy duty rotor of excellent quality (think real race rotors more than OEM stuff). They are probably a good idea for your use.

 

That's a lot of good info and I appreciate it! I'm interested in your conversion brackets. PM me some info if you have a chance. I had planned to machine mine from billet 4340 then harden and temper them. These will be similar to the LGM style brackets. I think they should be able to hold the caliper square. They will mount to the stock mounting locations. I'm a little leery of mounting adapter brackets to the hub bolts. That mount was never designed to see torsional loads caused by braking. Have you seen any issues moving braking loads to that point?

I had planned to make my own swaybars also using 4340 bent and quenched in chilled oil and tempered slightly to make it a bit less brittle. I had planned on a 1.5 inch front bar and a 7/8ths inch rear bar both hollow with .250/.120 walls. Does that sound excessive? But I haven't found a good source for the steel so a commercial option might be easier.

Thanks especially for the advice on spring rate. I had wondered if a higher front spring rate would be required but I was a little surprised at the rear rate. What are the stock rates you find on an 01ss? Do you think a 650/160 with 1.5 and .875 swaybars will keep the car neutral and stable with the Koni SAs?


As you can see, I love fabricating stuff.

Anyway, all the way back to the brakes, so some custom 13.4in rotors, blanks preferably would, would work best. I've found brembo 12.8 blanks for around 100 bucks, I'm wondering if that .6in is worth the additional cost?

Again thanks for the info!

 

if you go with the Z51... dont get the regular C6 abutment brackets.. you need the Z51 abutments... rotors can be had from gmpartsdirect and are 127 shipped each..

there is a company (im not allowed to say who because of the gay non sponser link removal crap) but they are a brake company, specializing in GM conversions.. they have EVERYTHING you need.. and are very reasonably priced.. PM me if you want their website..

 

Trackbird - will your brackets work with a C6 Z51 caliper and a 13" rotor? Will the LG motorsports brackets work with them?

I've read conflicting threads about which brackets will hold what ...

 

its not the bracket to spindle.. its the abutment bracket.. you need the Z51 abutment bracket (or caliper carrier).. and it will work.. the abutment carrier on the Z51 pushes the caliper out farther for use with the 13.4 rotors... C5 rotors are 12.9

 

the trackbrackets, i believe will work for c6z06 setup as well.

 

Yes, my kit will work with the C6 Z06 and C6 Z51 stuff. LG's kit will not work with those brakes. The reason is that the bolt hole sizes are different between the C5 and C6 stuff (they are both the same) and the LS1 F-body parts. My kit (and any others built to use all C5 parts) will fit the C6 parts use the same mounting locations and bolt holes. The LG kit uses the LS1 F-body style PAB which has smaller bolt holes and that's why the C5/C6 stuff won't work with that kit as a direct bolt on.

 

Thank you for the information, I'll be sure to order the piece that will work for my application. ( Your brackets, that is =P )