Rear Z Drums

[Ron Earp]

Z fellows, I don't think my rear drums do much braking and I want to learn how to get them to do some braking.

My wheel cylinders and drums are in good order. I use stock shoes (might bemy problem). When I check my brakes I'm getting plenty of fluid back there and my brake proportioning valve that can restrict rear fluid is fully open. When I go to service my brakes I do have some shoe wear, but not much. Sure, there is dust back there, but my drums are blue and cracking to pieces, far from it. I've been running the same set of shoes for like a year.

Do I need to use Carbotech shoes? I'm adjusting my brakes out as far as possible either manually when I service my rears, or by using the parking brake. I can tell slight differences when I get them adjusted out, but I still don't feel like I'm getting a lot of braking back there. Definitely can't lock them up, or at least, the fronts are far and away locked up long before the backs think about it.

Any pointers?

[Parrish57]

I tried for a long time to use Pep Boys shoes but they were always either ineffective, glazed over, or crumbled under pressure. I went to the Carbotech rears and stepped up my brake program a TON. They don't last very long but that's racin' life. If you want to play, you got to pay.....

[jrvisual]

I am the Regional distributor for Airotech brakes. They are nearly as effective as improperly adjusted stock shoes and offer 100% weight savings over Carbotechs or any other shoes. Reduce that all important unsprung weight.:D

One change in driving technique is required for use. To apply the Airotech brakes one must release the clutch and let the engine engage on each downshift.

Airotechs are only $300 a set and come with a lifetime warranty. They are guaranteed to never wear and will also extend the life of your drums.:023:

[spawpoet]

Steve, How long do the carbotechs last if your using you rear brakes enough? We've had better results in auto-x with the carbotech shoes as well. Also what do they run new? I got mine from somebody who just wanted to get rid of a couple of sets.

chris

[spawpoet]

Jeff that had me rolling on the floor, but now has me asking how tight is too tight on the adjustment? Just figured out Sat. that I've been using Airotech shoes on my right side the last two events. I thought if anything I had been a little tight on my last adjustment, but I was a good bit loose on the right and them drum came right off. Left side seemed fine, and the drum took a little finagling to get off like i thought they should.

chris

[Parrish57]

I am the Regional distributor for Airotech brakes. They are nearly as effective as improperly adjusted stock shoes and offer 100% weight savings over Carbotechs or any other shoes. Reduce that all important unsprung weight.:D

One change in driving technique is required for use. To apply the Airotech brakes one must release the clutch and let the engine engage on each downshift.

Airotechs are only $300 a set and come with a lifetime warranty. They are guaranteed to never wear and will also extend the life of your drums.:023:

Sign me up!! 100% weight savings! I'll buy 3 sets....

[Parrish57]

Steve, How long do the carbotechs last if your using you rear brakes enough? We've had better results in auto-x with the carbotech shoes as well. Also what do they run new? I got mine from somebody who just wanted to get rid of a couple of sets.

chris

I'm told that I probably adjust them too tight but I prefer being able to stop. Mine last about 3 races (depending on the length of course) and they are about $125 per set. I've said this a few times today but here goes: If you want to play you've got to pay!

[jrvisual]

Steve,

I don't want to rip you off. ;) Unless you have 3 cars, I won't sell you three sets. They are guarantee to never wear out.

Just sent the $300 to my paypal account and remove your old shoes and you will be good to go.:D

[jrvisual]

http://www.ctbrakes.com/pads/nissan.html

I don't see the rear shoes on the carbotech site. Where do you get them?

[Parrish57]

Just call them on the 800 number.... They'll fix your wagon!

[jrvisual]

"Carbotech™ 912 Kelated Metallic™: An advance organic-metallic compound specially formulated for drum shoe applications in lighter weight race cars and/or high performance street vehicles. High friction coefficient of 0.46 to 0.48, providing excellent braking without any risk of lock-up. Very good brake modulation throughout the entire brake pedal travel range, with excellent wear characteristics, providing an outstanding value. With a price-point significantly below other compounds offering similar performance, 912 ™ is an excellent choice for the budget-minded racer or high-performance driver. Optimal recommended operating temperature range is from ambient to 650°F."

Are you using this drum specific compound?

[JeffYoung]

Porterfield has an off the shelf race compound as well, R4, that you can order on line for the same ($129) price.

[jrvisual]

I may have some new Porterfield shoes in the boxes of brake parts that I bought from the guy in VA. I'll look next weekend when I am home. I know I have new front pads, not sure about the shoes. You are welcome to try them if I have them. The more experimenting you do the less I have to do.:D

[JeffYoung]

Check the compound type. Apparently R4 is good, R4-S is not.

[irondragon]

Ron:
You have joined the Club!!
Now you know - Datsun Z-cars, at least the 240-280 series, don't have any rear brakes.
This explains why we are on the brake at the 300 marker and get passed by all the cars that don't show any lights until the 100.
Ah, but after we get out of the turn we have buckets of acceleration to pass the little pissants.
What to do about this?? Not much
Rear shoes from Carbotech, or Nismo Greenstuff if you can still get it, will help.
Diligent attention to rear brake adjustment will aslo help, a little.
If your car has a working hand brake you can use it to tighten up the rear brakes by pulling up on it a bit during the race.
But your best solution to this is to make sure your motor pulls like a steam locomotive, which it certainly can.
Best Regards Bill Miskoe Iron Dragon Racing

[JeffYoung]

After 5 laps, my car has no FRONT brakes either. No wait, we've mostly licked that one.

I am a long lost cousin of the Z, in the sense that I too am shackled with the front discs/rear drums albatross around my brake pedal. Ron and I work on each others cars, and we have both noticed the same thing. With stock compound, you can put the bias adjuster all the way back and not get much rear action (much less any lock up), stock shoes seem to last forever, and there just at much brake dirt back there.

I'm making the switch to Carbotechs or P-fields since I have to step up my program to compete with Steve's NASA fuel powered Z. Here was a suggestion I heard that seemed to me to be a BAD idea.

Put a proportioning valve in the front circuit in order to crank DOWN the front brake pressure. Hence, giving LESS front brake (bad in my view) but more rear bias (the intended result).

I say no no no no but interested in the collective wisdom of the Cult of Zness.

[Ron Earp]

. Here was a suggestion I heard that seemed to me to be a BAD idea.

Put a proportioning valve in the front circuit in order to crank DOWN the front brake pressure. Hence, giving LESS front brake (bad in my view) but more rear bias (the intended result).

I think that is a Super Bad Idea.

The result is that you've not actually increased the absolute rear brake effectiveness at all. It remains the same. What you've done is increased the relative rear brake effectiveness in relation to the front by reducing the front effectiveness. Since the fronts are doing most of the work, your stopping distances are going to increase.

I'll not be party to rigging that one up for you, but if you do it I'll video you from BEHIND going into turn 1!

Steve or anyone else, what do Carbotechs look like? Any distinguishing marks? I've got lots of shoes with the Z spares kit, I just don't know what any of them are. And, since the ones on the car seem to be made from Everlast I've not really looked at the spare shoes in any detail.

[JeffYoung]

They are a whiter/lighter material. Remember also that they expand making it a beeyotch to get the drums off.

Agree with you on the prop valve in the front line. Reducing the brakes that actually work ain't making no sense to this flyboy.

[Ron Earp]

They are a whiter/lighter material. Remember also that they expand making it a beeyotch to get the drums off.


How could it be harder? The last time you and Jeffrey had to cut the drums into tiny little pieces.

[JeffYoung]

Those were Carbotechs I think. Steve P. will post here. He's the one, and Rex I think, that told us about it. They swell on first use.

[Parrish57]

Carbotech shoes are painted green (kind of a British racing green). They also have a big price tag on them. But you guys are missing something about the Z.. The brakes are NOT the primary source of deceleration for that car. HINT: If you use the PRIMARY brakes too hard you might throw off a rocker arm..............

[Hotshoe]

Carbotech shoes are painted green (kind of a British racing green).If you use the PRIMARY brakes too hard you might throw off a rocker arm..............


Like someone I know did at CMP............lol

Do they make rear shoes that don't smoke the entire race? ..........lol

Sorry Steve............ I just had to rub it in.......

[Dave Burchfield]

I remember using Velvet Touch rears. We sent them out to be re-lined once a year whether they needed it or not. I ran my Z from 1990 to 2001 using them with no problems and they worked great. I wonder if those are still an option? I would be willing to call the shop that had them done for me to see about them. As I remember, a set of shoes cost about $40.

[mom'sZ]

Fellow Z guys: When one is seeking the knowledge of all things Z related you must climb the mountain (use the search function) and speak to the master (Katman)
I'm surpised he hasn't chimed in yet. In this thread Keith gives some hints about getting the most out of your rear brakes.
http://www.improvedtouring.com/forums/showthread.php?t=18891&highlight=brakes
Look at post #8 for some tips and #14 for adjusting the prop valve.
I swear there was another thread with more stuff but couldn't find it. Anyhow cliff notes: make sure drums and shoes are round (true) and adjusted properly. Use the ebrake to take up slack during the race.
Chris: you wanna adjust them out with a brake spoon until the wheel (jacked off the ground) becomes pretty hard to turn by hand. This will give the pedal a nice high firm feel.
I've got the Porterfield ones. Friendly folks! Jeff is right about the compound - R4 is race only (won't work so great on the street) R4-S is a street compound

[spawpoet]

"until the wheel (jacked off the ground) becomes pretty hard to turn by hand."

Thats the concrete info I was looking for. Is it safe to assume then that if you adjust them a little too tight the friction material will just wear down a bit more quickly?
How is your car coming along Andy? It was good to meet you at the regional in Feb. Tim asked in another thread, but we hope to see you at the Daytona school. For us it depends on how our initial annual tech goes this weekend. If we get the thumbs up we will be there. By the way my uncle does have two non-egr FI manifolds (n-42 I think) if you still needed one. Crossing my fingers that we will see you in two weeks.

chris

[mom'sZ]

Chris: I sent you an email on your gmail acount about Daytona. Hope to see you guys there!!

[x-ring]

Chris: you wanna adjust them out with a brake spoon until the wheel (jacked off the ground) becomes pretty hard to turn by hand. This will give the pedal a nice high firm feel.

I've got the Porterfield ones.
Don't try that with a Carobtech shoe...

[spawpoet]

Don't try that with a Carobtech shoe...


How tight with a carbotech shoe then Ty? I assume the reason not too is that with the carbotech it will render the drum permanent with the hub?

[JeffYoung]

The Carbotech shoes swell. You'll never get the drum off again if you do that.

[pballance]

You'll never get the drum off again if you do that.

Sure you will, just call the "Jeff Young Literary Society and Brake Center" and they will help you "Jeff it up" and remove that bonded drum. He and Ron are highly experienced in drum removal!
:happy204:

I have been adjusting mine like I did on my street Z, when the drum/pad are touching and I feel resistance I then back the star wheel off 1/3 to 1/2 turn. Drive the car down the street, test the brakes, and then do it again. Of course I failed to adjust mine between qualifying and race at CMP and about 6 laps into the race my pedal was all "jeffed up."

[jrvisual]

The Carbotech shoes swell. You'll never get the drum off again if you do that.

You'll never get a usable drum off. You can always get it off, it just might not be in one piece when you do.

And put a little anti-seize between the drum and hub.

[x-ring]

How tight with a carbotech shoe then Ty? I assume the reason not too is that with the carbotech it will render the drum permanent with the hub?

Permanent with the drum, that would be the reason. I don't think you need to ask me how I know, even after Katman warned me. :eek:

Pb got it right on the adjustment, you can always go a little tighter next session if it is too loose this time. If you start out too tight make sure you have a big soft head hammer in your tool box along with a die grinder and a whiz-wheel.

[Ron Earp]

Excellent information, thanks for all the tips and the links to the other threads.

I called Carbotech and ordered three sets of shoes, but they won't make it here in time for Roebling. Does anyone have a spare set of shoes I they'd be willing to send me that I could get from you before Roebling to put on? I could then send you a new set in about 2-3 weeks when mine come in. I could make is simple by emailing you a UPS label, all you'd have to do is print it out and tape it to a package.

Carbotech is backlogged pretty good. I bought a lot of front pads a month or so ago so if anyone is short pads I could advance you a set of those if you have some on order and can't get them in time.

Best,
Ron

[spawpoet]

We may Ron, but I won't know for a few days as I won't be in the shop. I'll email you if we have an extra set, but it might not be til Friday.

[spawpoet]

Permanent with the drum, that would be the reason. I don't think you need to ask me how I know, even after Katman warned me. :eek:

Pb got it right on the adjustment, you can always go a little tighter next session if it is too loose this time. If you start out too tight make sure you have a big soft head hammer in your tool box along with a die grinder and a whiz-wheel.


Thanks Ty. This should help us avoid the issue in the future.

[dspillrat]

I gotta couple extra sets Ron.....

Wait, You need brakes at savannah??:eclipsee_steering:

I'll bring a bout wore out set Ron. Should last the weekend. I got a old set I'll be running.

David Spillman

[kthomas]

I gotta couple extra sets Ron.....

Wait, You need brakes at savannah??:eclipsee_steering:
David Spillman

Not since you blew up that V8 Z there and took a ride with Chet, eh?

[Ron Earp]

Thanks guys, Steve called my cell and I'm going to borrow a set of his shoes while my new ones come in from Carbotech. I know Roebling isn't much for brakes, but I've got new fronts and might as well have new rears to bed in on the test day. Maybe they last longer that way - I for sure as hell know putting them on new and racing them hard seems to make them have short lifespan. Killed a new set of Carbotechs at CMP like that....

[dspillrat]

Not since you blew up that V8 Z there and took a ride with Chet, eh?


Yep,
Was eye opening experience for sure!! Really helped me understand the difference in from what I thought was fast driving.......:eclipsee_steering:

David spillman.

[Mike Mackaman]

I have had pretty good luck adjusting until I get a little drag when turning the drum. The thing that you are missing on the front brake bias deal is that you will then push down harder on the pedal. Once you reach the same pressure to the fronts you had before, the pressure to the rears is higher. As the apex comes screaming at you, pushing down harder becomes increasingly easier, and more natural. This is all theory, you won't find this on my car. One thought though, some pads have higher and lower friction coefficients than others. If you have a really grippy front pad, you will lock the fronts before the rears are doing a lot. If you get a less grippy pad, then you will need to back off the rears.

I like the Hawk blues in front and carbotek celated in the rear. I like the Carbotek pads better, but the friction is too high and it messed up my rear braking, like I go fast enough to worry about that!

Mike

[Ron Earp]

Hey Mike,

I ended up putting some Carbotechs on the rear and love them, with the Carbotechs on the fronts I was used to. Braking got much "flatter" since the rears are finally doing some work. Quite pleased with them for sure.

You coming to the Monster Memorial?

Ron

[Mike Mackaman]

No, unfortunately my nephew was inconsiderate enough to graduate from high school on a race weekend. I am going to have to have a talk with that boy! I will be in the Greater Cleveland Metro Area this weekend doing the family thing. Weather is great, wish I was there!

Mike