Alternate 240Z rear brakes...?

A

acotyk

New member
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.
 
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.
 
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
 
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.
 
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.
 
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!
 
LLoughman said:
Seems that acotyk has a point. Can someone explain the performance advantage of acotyk’s recommendation?
Click to expand...

The ITAC and/or CRB doesn't have to explain the performance advantage of acotyk's recommendation. As I'm sure you are aware the GCR reads:
"To maintain the stock basis of Improved Touring.....No interchange of parts between assemblies is permitted, and all parts of an assembly shall be as originally produced for that assembly"
​
Their answer is pretty well spelled out in the introductory rules for Improved Touring.

Unfortunately the rear drums being no longer available forces the Z driver to make some choices. Race the car with available steel drums and accept the lower performance, or quit racing the car in Improved Touring.

I'll be cutting some holes in my backing plates and getting some air on those shoes and drums. I don't have rear brake ducting right now and race fine with the ally drums. I bet I can race fine with the steel drums using ducting.
 
LLoughman said:
... If you were a lawyer, you could retire on arguing for/against inconsistent decisions by a governing body!
Click to expand...

LMAO. Jeff's a lawyer.

...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. ...
Click to expand...
Please DO ask that the GM exception be removed. It got poked into the ITCS long before recent efforts to be consistent on this and other issues, so it's time has come and gone.

EDIT - a little more history on the ITCS... The entire IT category suffered from a wicked case of benign neglect between its inception in the mid '80s and about 10 years ago. A lot of things have been fixed since then but this rear brake exception isn't one.

K
 
I suspect the drums are cast iron, not steel. Using iron instead of aluminum is not a safety issue. Sure it will run hotter, but iron will take it where aluminum will not. Aluminum is very rarely used in brakes, and for good reason.

If you really want to talk safety I move we ban the stock drums.
 
L --

No problem on the info. I wish more detail was listed with the decisions in Fastrack.

I run steel drums (came stock so I have to) on the TR8 and I delaminate shoes and burn up wheel cylinders occasionally. I have on the list of things to do (as does Ron) to run ducting to the rear brakes. We have a very brake intensive track here (CMP -- I'll put it up against any track in the US for being hard on brakes) and we survive.

So, I think there are ways around this other than allowing alternate rear brakes. As you can see, the one time this was done (incorrectly) for the Olds, it opened a can of worms that could really do damage to the core philosophy of IT. It is critical, in my view, that we toe the line and not allow "safety" or "NLA" issues to cause us to allow alternate parts. If we start with that, THAT is the path to production and/or AS, etc.

If you write a request to have the Olds rear brake/hub allowance rescinded, I will support that 100%.

If you have any other questions, let me know, and thanks again for the polite and considered post. It is appreciated.

Jeff

LLoughman said:
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!
Click to expand...
 
LLoughman said:
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,
Click to expand...

OK, so steel drums are bad b/c of less heat dissipation. Nevermind that I'm sure you could have custom shoes whipped up that would work at the higher heat but I follow your train of thought.

Most of the braking (energy to heat transfer) is done by the front of the car
Click to expand...

Uhhhh... so how much heat can the rear be making? :shrug:

Christian, who races a car with rear drums and will beat the "horses for courses" drum some other time.
 
GKR_17 said:
I suspect the drums are cast iron, not steel. Using iron instead of aluminum is not a safety issue. Sure it will run hotter, but iron will take it where aluminum will not. Aluminum is very rarely used in brakes, and for good reason.

If you really want to talk safety I move we ban the stock drums.
Click to expand...

Yep, I think you're right on the cast iron. Been awhile since I looked though.

Now on the "ally drums" I'm pretty sure that is an ally drum, with fins cast in it, with a steel insert. Carbotechs can handle the heat and I was just talking with those guys a few weeks ago and they have a compound for shoes that can handle even more heat than the previous versions.

I'm not a Z historian but are these ally legal in the first place??? My 260Z shop manual doesn't show drawings of finned drums, but of round drums with no fins. Were the fins added by NIMSO for performance reasons and were they listed as an alternative part number by Datsun/Nissan?

I'm with you though. I'd like to ban the blasted things for selfish "don't want to ever work on a drum brake again" reasons, but I am logical enough to know that isn't something to pursue. Funny how one of my prime motivators for getting a new IT car is to get something that doesn't have drum brakes and carbs.
 
Last edited:
finned drums.....

Every 240 I've ever pulled apart, had fins.......

Now I have seen 3 vented rotors as well....vented rotor caps that is.....

Didn't realize the olds came with drums.... I Need a letter penned Jeff...

David
 
Ron Earp said:
I'm with you though. I'd like to ban the blasted things for selfish "don't want to ever work on a drum brake again" reasons, but I am logical enough to know that isn't something to pursue.
Click to expand...

I was really kidding, but was trying to say that if safety is the arguement then make them run the iron drums. I vote a big no to the disc swap. Not sure how to handle the Olds, I'd rather it get pulled than be a precident further creep.
 
Ron Earp said:
Yep, I think you're right on the cast iron. Been awhile since I looked though.

Now on the "ally drums" I'm pretty sure that is an ally drum, with fins cast in it, with a steel insert. ................

I'm not a Z historian but are these ally legal in the first place??? My 260Z shop manual doesn't show drawings of finned drums, but of round drums with no fins. Were the fins added by NIMSO for performance reasons and were they listed as an alternative part number by Datsun/Nissan?

...............
Click to expand...

They were all finned Ron. Aluminum drum with steel insert. They can be re-sleeved if you will. Not cheap but it can be done. I think JohnC at Betamotorsports was looking into that for one of his customers. Also, the new aftermarket's are cast and are without fins.

My drum backing plates are vented and there was evidence of a rear ducting system being attached to the rear control arms at one time. One of the previous owners of my car ran it in enduros on the west coast.

While I agree it would be nice to do away with the drums, as a Z racer I wll argue that it is against the class philosophy and an allowance should not be made. Like Jeff, I have another Z waiting in the wings that actually has discs all the way around :)

BTW, I will try to get a picture or two up for the Nissan fans. I have a buddy that has a Nissan IMSA GTP in his shop. Pretty neat car.....
 
"My drum backing plates are vented and there was evidence of a rear ducting system being attached to the rear control arms at one time. One of the previous owners of my car ran it in enduros on the west coast."



It was always my understanding that the cast drums were preferred on z's for enduros anyways. I don't know from personal experience, and have no idea if it's true, but the internet lore was always use the alloy drums for auto-x and sprint races, and the cast for the long races because they dealt with extended periods at high temp better.
 
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