Alternate 240Z rear brakes...?

[acotyk]

For discussion:

I posted this request to the comp Board, Ref Letter #279:

Sent: Sunday, November 29, 2009 11:17 AM
To: Club Racing Board

Subject: Request for competition change - ITCS

Gentlemen,

Respectfully request your consideration of the attached
change to the ITCS. Reference (2009) GCR, page 349.

This request is being made due to NLA (No Longer Available)
status of the rear brake drums for these vehicles. Reference the
following from one of the primary suppliers of Nissan and Nissan Comp
parts in the US:

(Inserted link to Nissan Comp website where Datsun rear brake drums are shown as NLA)

What I requested was:

"Alternate Brakes are allowed (R) 258 or 269 Solid Disc and calipers from 280-ZX."

For all of the Datsun's with drum rear brakes.

This was the Comp Board's answer:

2.

ITS – #279 Request for alternate rear brake assembly

This request is not within the IT philosophy.

For Reference, this is what was historically allowed for the Old Calais/Achieve/Pontiac Grand Am:

"Alternate rear bearing, flange, and disc brakes from (General Motors) Saturn are allowed. 16" wheel not allowed"

Does anyone know the history of this change that allowed the Olds/Pontiac's to change from rear drums to disc brakes?

I honestly felt that there would be no competitive advantage to this, only that the rear drums are out of production and that with the use of a stock Maxima rear bracket, the 280ZX discs fit the 240/260/280Z's.

Appreciate any comments and other viewpoints. What philosophy did this not follow? How was this different from the Olds allowable alternate?

Thanks!

A.

[Z3_GoCar]

If you search you may find the latest thread that brought the reason for this exception up. If I remember correctly it was less than 8 months ago. This exception followed the cars from Showroom Stock, where it was given. I'm sure it was a safety issue related to the rear bearings more than switching from drums to discs.

[Knestis]

I've been arguing for eliminating that GM exception for EVER, seems like. There should be no spec line exceptions. Anything that makes things easier provides a competitive advantage. I'd argue that the fact that you requested it is proof prima facie that it's an advantage. You wouldn't ask for it if it wasn't.

K

[Ron Earp]

The drums are still available. Now, I know that Brembo quit making the aluminum drum, but the steel one is available from numerous aftermarket suppliers, or at least it was last October when I checked.

We had the drums NLA discussion a few months back but I'm too lazy to dredge it up again.

Bottom line is that you can get drums that work (maybe not optimal, they weigh 11 lbs versus 6 lbs for the ally), and a change is against the core IT philosophy.

[JeffYoung]

I'm on the ITAC; we recommended to the CRB that they turn down this request. The reasons are:

1. Ron Earp is a racing buddy of mine; I work on and drive his 260z, and I also know several Z racers very well (Steve Parrish, David Spillman, Jay Miller, Mike Mackaman, etc.). The drums are still available, you can occasionally find an alum one on ebay etc. Steel drums are still available at your local parts counter. Plus, i think there is some discussion about having new ally ones machined.

2. IT class philosophy -- perhaps the strongest one we have -- is that we don't make line item exceptions for IT cars for parts that are NLA, or unsafe, etc. You choose your car and the warts that go with it (and I'm certainly in that boat with an ITS TR8). At some point, some cars naturally age out of IT due to lack of parts (I think RX2/3 rear brake parts are totally gone). At that point, you go vintage or build a newer IT car (I have a 300zx sitting in a shed waiting for the day the 8 can't run anymore).

3. As Kirk indicated that exception for the Calais/etc. is an anamoly. I'm not sure why it is there and it frankly should be removed. It is the ONLY exception like that and totallly contrary to class philosophy.

[LLoughman]

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!

[CPLUCKER]

earlier this spring I talked about doing some re-built drums

I finally got them from my machine shop source, he machined new steel rings, machined the ould rings out of the drums and pressed them in with .006 of interference.

I am going to test them this weekend at gobblins Go and make
sure they work o.k.

is there still an interest in the drums ?

I was going to see if we could get together and make a batch of maybe 5 sets for th inital production run

I will get the final run price from my buddy

Thanks
Chris Plucker

[240zdave]

I might be interested, depending on price.