Drum and Toyota 4x4 front brake questions.

[Oiluj]

FWIW, I like my Toyota 4x4 brakes & 13/16" master cylinder combo.

I have no quantitative evidence that they truly stop any shorter, but my brakes do have a firmer pedal compared to the stock brakes._I did replace my proportioning valve, but only because mine was shot.

My Z is primarily a street car.__However, during a "fun run" autocross and also after brisk driving on curvy roads, I've not observed any brake balance, over-heating or fading issues reported above.

I have a buddy who routinely tracks his car.__He did two autocross runs and thought the Z's front/rear brake balance was OK, but said I needed stickier tires and more negative camber.

[pbarcher]

Julio,

I'm glad that you're happy with your setup, but just for fun try this. Use your brakes moderately hard on a cool day, and then stop and touch the rear drums if your wheels allow access. If they're not hot, it would suggest that they are not contributing much. All cars depend primarily on the front brakes, but the rears are important too.

Just a thought.

Peter

[Oiluj]

Have done that and the rear brakes do get warm, but not too hot to touch.

[tlorber]

One other thing about the rear brakes; I know the ratcheting mechanism is supposed to tighten the rears when the e brake is pulled. I'm not overly confident about this. Before going on a long run, I jack up the rear axle and manually tighten the rears via the holes in the drums until there is just a slight drag. This way I know the rears are engaging, and the feel in the pedal is noticeable.

[Oiluj]

One other thing about the rear brakes; I know the ratcheting mechanism is supposed to tighten the rears when the e brake is pulled. I'm not overly confident about this. Before going on a long run, I jack up the rear axle and manually tighten the rears via the holes in the drums until there is just a slight drag. This way I know the rears are engaging, and the feel in the pedal is noticeable.

Yep. I do that once a year, usually mid-April after the rains subside. It does make a difference in rear brake engagement / pedal feel.

This year the rain hasn't even started so I'll need a new trigger point. Think it's going to be a dry summer....

[grannyknot]

Just for anyone interested here is the original aluminum drum on the left and new cast iron on the right,

Aluminum drums are 4lbs a pc. cast Iron are 12lbs. Not happy about that but the old ones were 4mm over the max dia. so it's no wonder I could never get them to lock up.

[Oiluj]

16 additional lbs. isn't that much, especially in terms of the reclaimed braking force the new drums should provide.

Heck, I add almost that much extra weight to the car as compared to when I drove my first 240Z.

[Captain_Zeros]

except that 16 pounds is unsprung

[Oiluj]

except that 16 pounds is unsprung

Very true, but unless you seriously autoX or track your car, I doubt you'd really notice any difference.__ Also, stiffer springs and better shocks can help to somewhat offset the added unsprung weight penalty.

For most of our "weekend" or daily driver cars, the impact of cast iron brake drums isn't going to be an issue.__From my perspective, it's more about keeping our cars on the road.

Heck, I don't "jump & rebound" like I used to either, but I still get around just fine!

There are companies like Whitepost Restorations that will turn and re-sleeve your aluminum drums with brass linings, keeping them lighter than the cast iron alternative.

http://www.whitepost.com/brake.html

They do great work, but it won't be inexpensive. I suspect re-sleeved drums might not be acceptable for a track car, but they work fine for street use or light autoX.

An observation:__ I always find it interesting that when we talk of "upgrades" like larger front brakes, larger wheels and wider tires, no one ever mentions the added unsprung weight. This only seems to come-up when talking about cast iron brake drums.__Why is that?

Same can be said about adding A/C and powerful stereo systems with amplifiers and heavy sub-woofer systems. Both of these can easily add 50 lbs to a car, but nobody ever mentions that in terms of impact on performance.

Just my 2 cents...