JeffYoung, thanks for sharing the insights on the logic behind this decision. I have been a long time follower of the IT forum and now think it’s time to give some feedback. Having run an ITS 240Z since 1997, about a year ago I noticed the standard aluminum rear drum was no longer available. While true you can find the steel version, there is a performance difference. As mentioned earlier there is an almost 50% weight penalty in rotating mass and the steel drums offer less heat dissipation (steel vs aluminum and cooling fins). Since I have experienced a rear shoe delaminating more than once, I will wait until some other fool runs the steel drums at Blackhawk (brake hawk) or Road America before I risk my fait at one of those venues with steel drums. If anyone has experience with the steel drum configuration at one of these tracks (and can run 1:22 at Blackhawk) please respond. Since we now have a known performance change running the 240Z without the available aluminum drums, what will be done to resolve this issue? Seems that acotyk has a point. Can someone explain the performance advantage of acotyk’s recommendation? Most of the braking (energy to heat transfer) is done by the front of the car and on all the Z cars this is done with a 2 piston caliper on a solid disk rotor up front. By the way using old parts like ebay aluminum drums is one of the reasons for a pedal to the floor failure that I had over the years and should be avoided at all cost.

As for the GM issue with the Olds/GA if JeffYoung’s comments are correct, than a safety issue as mentioned by Z3_GoCar does not make sense. If I recall correctly, the rule that allowed these GM cars to not only change from rear drum to disk but the bearings as well came long after their ITS classification. The argument here is simple, there is already precedence set to allow drum to disk conversions in ITS. I will be posting a notice to the comp board to either revoke the GM disk as stated in their reply to acotyk or to allow the drum to disk swap for the Z car or any other drum brake car. The board needs to be consistent on this “core philosophy” and in this case there is no sing of it.

Thank you acotyk for bringing up this issue.

JeffYoung or any of you other Z drivers, if you know of someone making the aluminum drums please post. By the way doesn’t a custom machined part by a non-oem type manufacturer for brake parts go against the “core philosophy”? Seems like a vintage concept.

If you were a lawyer, you could retire on arguing for/against inconsistent decisions by a governing body!