[CamaroCracka]

I bought a pair of ZL1-1LE front rotors but the hats don't work on GenVs. I used a different hat for my set up, so now I have this set for sale. These hats measure 8.5 in dia and are not the same size as regular Gen5 ZL1 hats. These are for the 390mm rotors. $75 OBO

[Dlynch1130]

What setup are you putting together and what rotors did you end up using?

[Vtor_ZL1]

Good deal on rotor hats - those look very clean.

[CamaroCracka]

Originally Posted by Dlynch1130

What setup are you putting together and what rotors did you end up using?

I got a set of ZL1/1LE calipers off here and found a set of front Gen6 394mm rotors on eBay. The hats looked similar to the GenV ZL1 so I gave it a shot and found they needed 10mm of spacing to work with the Gen6 caliper on a GenV. In my quest for a solution I came across a thread on LS1tech where a guy was trying to put Vette rotors on a GenIV and had the same 10mm problem. His solution was a 2013 ZR1 hat off a carbon rotor, so I found a guy selling used ZR1 hats on eBay and the spacing turned out to be perfect. The downside is the ZR1 had 12mm studs so I had to drill the hats with a 16mm bit to match the holes on the Gen6 hat. The ZR1 hat is also about 2mm smaller than the Gen6 hat, but I believe there is plenty of meat left even for tracking. For the GenV guys interested in doing this, the 394mm rotor uses a hat that is ~8.5" while the GenV ZL1 hat is ~9'". That means that not only is the 394mm rotor larger overall, but the swept area of the pad also reaches a quarter inch further into the center of the wheel. I know that is a long answer, but I wanted to cover other questions people may have. The pads I used were Gen6 pads from RockAuto. Trackpads will obviously have to come from somewhere else.

One of the best things about this is it still fits an 18" drag skinnie over these brakes, just barely, but they fit.

Pics of the mounted caliper and rotor below.

The cleanest solution would have been spending the 1400 on the Girodisc Z28 iron conversion rotors and I will probably go that route on the next round.

[Dlynch1130]

CamaroCracka:

Thank you for the detailed explanation and working out what mods are needed to make this solution work. I have been thinking of doing something similar but using the Gen5 ZL1 rotor hats on the Gen6 ZL1 rotor ring. There are several for sale on eBay at the moment, so I plan to buy a set and see if they will work as well. (The Gen5 ZL1 rotor is 2mm thinner at 34mm than the Gen6 Z1 rotor at 36mm, so we will see how that impacts the fitment.) To cover myself, I found the seller on eBay who has the ZR1 rotor hats and purchased a set. Thank you for that steer.

I agree on the high cost of the Girodisc Z28 rotors at $1,400 a pair. Still attractive though with the front Z28 carbon ceramic rotors at $1,100 each on Amazon and the rears at least $1,750 each.

Did you buy new hardware or did you use what came on the Gen6 rotors?

Finally, in my searching, I saw that DBA USA is selling replacement rings for the Gen6 ZL1 hats. The one I was looking at is on eBay for $899 for two rings (part # DBA 53916.1S), so that and a matching set of DBA USA rotors for the rear would be a nice setup in between using the GM rotors front and rear and the full Girodisc rotor setup.

Thank you again for the great write up and insights!

[CamaroCracka]

I used new hardware from KNS Brakes which amounted to new nuts and bolts for the hat and you reuse the inserts etc. The hardware is a bit different using an allen key and 7mm vs the stock Etorx and 8mm. BTW, the pic was with the old hardware and just used for fitment purposes.

Either DBA or Giro had Z28 hats they mill for $1400. That made no sense to me. I actually considered trying to get my machinist to mill some or even flipping the Gen6 hat over and using some thick washers to get the spacing correct. If you flip the hat over it moves the rotor in relation to the hub in about 12mm. I'm not sure how much movement you might get out of flipping a ZL1 or ZR1 hat, and of course any bevels that were on the back are now on the front which is not ideal.

[Dlynch1130]

I watched the KNS video on the assembly of the 2-piece rotors and see their recommendation to use new bolts and nuts when re-assembling the rotor. I also took another look at the Gen5 ZL1 rotor hat and it looks very similar to the Gen6 hat. However, as you have pointed out, the Z28 hat looks identical to the ZR1 hat, so I plan to follow the same path you have followed with the ZR1 hats, reusing the anti-rattle clips and bobbins and buying new bolts and nuts from KNS. Thanks again for the time you invested laying out how this all works.