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Brake upgrade FAQ


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does anyone have part numbers for the different calippers cause it seems evry post i read gives different model years for the donnor vehicle.

 

what i want to know:

 

1-part numbers with each model: s12, s12w and both sw+8s

2- does it come from a pick-up or 4-runner (some peapole refer to a "4x4 pick-up", some, "4-runner" and some, "only 4x4".). It gets confusing after reading all posts.

3-does it come from a 6cyl. or 4cyl.

 

Then we could get all the info in a "toyota calippers FAQ tread" and sticky it in the "Brakes FAQ".

 

 

I recently upgraded my front calipers thanks in large part to this site. The NAPA part numbers were 2426648 & 2426649. I don't remember what was stamped on them though.

 

Napa advised they would work on the following Toyota's:

84-85 4 Runner 4WD

79-85 Pickup 4WD

 

The junkyard I purchsed my cores from revised the year range on the 4-Runner to:

84-88

 

I have no idea on the engine though.

 

My mechanic installed them on my stock (I assume) 240z rotor and that it was bolt on with the exception of cutting the dust shield. He also said there was plenty of room for a thicker rotor.

 

Hope this helps.

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  • 4 weeks later...
  • 1 month later...
Guest bobbyparks

Believe it or not, I just took the front brakes off my car for the first time since I got it. (actually, I think I put new pads on it right after I got it... 7 years ago.) Mainly to see how the dust shields were attached and remove them. I noticed that the inner wheel bearing seats against the dust shields. Did you guys keep the center part of the shield and trim it off? or remove it completely?

Also, can you get that cloth seal, or whatever it is behind the dust shield? I've never seen anything like it before.

 

I can't believe how good my brakes look, after 25,000 miles, dozens of autocrosses, and a couple of open track events.

 

They overheated at the opentrack events, even with the ducts, but the pads have so much material, they almost look new. The rotors are also in great shape... I'm tempted to just throw it back together, and hope they'll stay cooler and not fade as bad without the shields...

 

Naw, I'll probably upgrade the pads at least, and put on some braided lines.

I also run synthetic brake fluid.

 

I'd like to upgrade to the 12.19 wilwoods, but don't need the hassle... maybe this winter. Besides, I can't find anyone who can get them.

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  • 2 months later...

Sorry to drag up an old thread but it is related.

 

I'm thinking about the upgrade to front Hilux calipers. Can I install a 79-81 zx master cylinder to a 1970 brake booster without any issues?

 

The reason I ask is because I have already got the original brake master and booster refurbished and wouldn't mind saving a few dollars.

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  • 4 months later...
i have all of the parts for front and rear disc brake conversions mentioned above. now, how do i go about hooking up the rear emergency brake cables on my 74 260 2+2 to the 280zx callipers? i don't see anything related to this in the thread. sorry if i missed it.

This is a very old post, but the question is still a good one. You can use a small bracket to hook the e-brake cable to the caliper. Modern Motorsports does this with their 240SX brake kit. The other option is to adapt in a different cable. I used a 240SX ebrake cable, and it had the proper clevis for 280ZX brake calipers. I had to mount the cable to the bottom of the car and hook it up to the handle, which was really easy to do. It did require removal of the rear bell crank and attaching the cable directly to the ebrake handle. Total cost was about $10 and installation was really easy.

 

Sorry to drag up an old thread but it is related.

 

I'm thinking about the upgrade to front Hilux calipers. Can I install a 79-81 zx master cylinder to a 1970 brake booster without any issues?

 

The reason I ask is because I have already got the original brake master and booster refurbished and wouldn't mind saving a few dollars.

You can install the master easily, it just bolts right up. The only thing that you would need to do is adjust the pin length in the booster. I ran this combo on my car for years.

 

Believe it or not' date=' I just took the front brakes off my car for the first time since I got it. (actually, I think I put new pads on it right after I got it... 7 years ago.) Mainly to see how the dust shields were attached and remove them. I noticed that the inner wheel bearing seats against the dust shields. Did you guys keep the center part of the shield and trim it off? or remove it completely?

Also, can you get that cloth seal, or whatever it is behind the dust shield? I've never seen anything like it before.[/quote']

Most racing organizations don't allow dust shields, so most racers just remove them completely. The inner wheel bearing grease seal seats on the spindle, not the shield, so there is no danger of leaks from removing the shield. Your long lived brakes are the exception to the rule, the brakes are adequate for track use but usually require bleeding between sessions and adjustment, etc.

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  • 4 weeks later...
Guest 280ZForce
And, for you drag racers and autocrossers, the stock Z brakes are lighter then anything else you can put on the car!

Sorry John, gonna have to disagree with you on this 1...

 

I just recently bought the front Wilwood 4-piston setup from Arizona Z Car.

 

I weighed all parts on a digital scale: stock vs Wilwood setup.

 

I know it's not much of a difference in weight, but the Wilwood setup actually comes in weighing 2 lb 10 oz lighter per side! or 5 lb 4 oz total savings! And this was using used stock rotors that I'm sure have been turned down plenty of times as well that have been used for 30 years and with new OEM replacement pads.

 

Here's the breakdown of what was weighed - FRONT BRAKES ONLY:

 

Picture19.png

 

280z hubs were not weighed in factor, due to the fact that you use them for both setups. so no weight differences there.

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I found some usefull information from vwvortex.com about the downside of "big brake kits" that being the added weight of said kit effects the unsprung weight of the car. This guy has some calculations that prove that those effects are minimal. I copied the page but here is the link.

http://forums.vwvortex.com/zerothread?id=2536336

 

 

Over the last few years on the Vortex there have been a multitude of posts arguing about the benefits and disadvantages of big brake kits. The most popular “disadvantage” is that a larger diameter rotor means it has a bigger rotational inertia, or moment of inertia. What this means in laymen’s terms is that a, say, because a 12” rotor is bigger, it “saps” more power from your engine than, say, a stock 9.4” set up. This is indeed true. However, how big a factor is it? I was doing some project work on this kind of thing so I decided to diverge a little and do something that might show me and those of you who are interested something pretty interesting. If you couldn't be bothered with the technical explanation, scroll down to "conclusion". I sort of rushed through this stuff, so if there are calculation errors, please don't kill me, I'm just trying to help, educate and illustrate smile.gif

 

The basic equation to calculate the moment of Inertia of a solid (as opposed to “floating” disc and assumed to be a constant-thickness disc) is:

sxnkon.jpg

Where m is the mass of your disc, and d is the diameter of your disc.

To interpret this, it means that the moment of Inertia increases with the square of diameter. This looks like a really scary thing! But again, we ask, what does it actually mean?

More useful than the simple moment of Inertia equation for demonstration is the Kinetic Energy (KE) which is required to rotate this disc to a specific speed, due to moment of Inertia. This is given by:

sxnmud.jpg

where is angular velocity of the disc, ie. how quickly it is required to spin at a given point. What this means is that the energy required to rotate the disc at that velocity is a factor of the square of velocity, and the square of diameter, as before.

What we will assume:

Car weighs 1100kg

Car has 16” wheels which aren’t coming into the equation

Car is on a flat road

9.4” rotor weighs around 3kg

Decent 12” rotor weighs around 5kg (this is pretty conservative)

 

If we take a test subject, let’s say a 12” non-floating rotor weighing in at 5kg, we calculate:

I = 0.0581kg/m^2

And the energy at a car velocity of 100km/h (62mph) is

KE = 412.175 joules

Since the measure of energy that the engine puts out is simplified to be the energy your car has at a particular speed thanks to the energy the engine transferred, we can actually go and find out exactly how big a difference this EXTREMELY SUPER SIZED OVERKILL TRUCKLOAD MOTHER DISC WILL MAKE!

The graph below shows the ratio of the Kinetic Energy required to reach a vehicle speed of 100km/h starting from 0. The speed of the car signifies the energy that the engine was able to produce from burning fuel (simplified version of Kinetic Energy of the car).

sxnnh1.jpg

Interpreting this, the curve shows that most of the energy that is ever used to accelerate the rotors is used at the lower speed band, and as you get progressively fast, the rotors rotate quicker and are thus are not as “difficult” to rotate.

sxnp50.jpg

CONCLUSION

What the data and the graph shows is that most of the energy that is ever used to accelerate the rotors is used at the lower speed band, and as you get progressively fast, the rotors rotate quicker and are thus are not as “difficult” to rotate.

I’ve shown all the rotor energies in the table just for the hell of it – so you can see how the energy required by the rotor goes up exponentially with speed. In this table for TIME SPLITS (not the same as the above graph), the various energies for rotors and energies of the car at various speeds, the ratio of required rotor energy compared to energy from the engine, is the same at all speed splits. This percentage is 0.007494%. That isn’t a hell of a lot!!! So finally there is some evidence that even big brakes aren’t such big factors in “power loss” from the engine! Woot!

A typical 9.4” rotor would have a ratio % value of around 0.00276%. Calculating a percentage ratio of these two ratios, we land up seeing that from changing from a 9.4” rotor to a slightly heavier 12” rotor, you are increasing your energy “wastage” from the engine by 36.78% compared to the original value.

While this may seem sort of high, you have to understand that everything in tuning is a trade-off. I’ve highlighted the negative side-effect of going to bigger brakes, and in my opinion, 36.78% increase is really not much, because you’re looking at heat capacity improvements of up to like 120%.

Also, all the calculations have been done assuming the 12” is of one-piece construction, and weighs 2kg more than the 9.4”. 1.9..16vTurbo weighed his 12” AP’s and the floating rotor was actually lighter than the 9.4” stock rotor!! This brings that 36.78% down quite a margin, and it also reduces your unsprung weight which is great news for cornering performance.

Also, while I have used the term "big brake kit" in this article quite loosely, in automotive aftermarket brake systems, 12" isn't that big and is certainly the maximum diameter I would suggest for a Mk2. I saw an Audi A4 running around with some 14" Wilwoods, and the energy sapping of that size rotor is really going to be bad.

While wheels haven't featured in this, I think I'll do a similar article on energy that wheels require sometime in the future. A lot of people say that the upgrade to bigger brakes means needing bigger wheels and THAT is the big deficit, and I don't agree, because of the mechanics of them, they aren't as influential on inertia as one might think... But that, ladies and gentlemen, is a story for another day... Hope you enjoy, and it isn't too technical :/

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  • 1 year later...

I'm bringing this one back from the dead (again). I have a whole pile of spare parts lying around in my garage, including a set of s12w calipers, and it seems like a good idea to put them on. I really don't need the whole kit from modern-motorsports and $130 seems a bit steep for a couple of spacers, so does anybody know the dimensions (thickness, inner diameter, and outer diameter) of a pair of spacers so I can just make some myself? I'd really appreciate it if anybody has some measurements to work off of.

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  • 1 month later...
This is a very old post, but the question is still a good one. You can use a small bracket to hook the e-brake cable to the caliper. Modern Motorsports does this with their 240SX brake kit. The other option is to adapt in a different cable. I used a 240SX ebrake cable, and it had the proper clevis for 280ZX brake calipers. I had to mount the cable to the bottom of the car and hook it up to the handle, which was really easy to do. It did require removal of the rear bell crank and attaching the cable directly to the ebrake handle. Total cost was about $10 and installation was really easy.

 

 

You can install the master easily, it just bolts right up. The only thing that you would need to do is adjust the pin length in the booster. I ran this combo on my car for years.

 

 

Most racing organizations don't allow dust shields, so most racers just remove them completely. The inner wheel bearing grease seal seats on the spindle, not the shield, so there is no danger of leaks from removing the shield. Your long lived brakes are the exception to the rule, the brakes are adequate for track use but usually require bleeding between sessions and adjustment, etc.

 

Hey guys. I have an 1981 zx master and booster. My original 1972 240z booster's diaphram just went out. Can I swap on both the booster and the master from the zx? Its a two resivoir master but, the booster looks much larger.

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  • 1 year later...

ZX/Maxima swap: The rear wheel drive Maxima (79-83?) had a rear disk brake bracket which could be used on the rear of a first gen Z and would allow the 82-83 280ZX rear rotor and caliper to bolt directly on. This was a very popular setup, but the caliper brackets have become increasingly hard to find.

 

I just wanted to make an update. This Information is in accurate. With 82-83 280zx caliper and rotors and 79-83 Maxima brackets there is a quarter inch of the pad that does not contact the rotor. I tried 240sx calipers to fix the issue but they will not work.

 

On another note. With these brackets, 85 300zx rotors with z32 tt calipers will fit. You will run into wheel clearance issues as the calipers stick out to far and will contact the spokes of the wheels. I could see using a different type of wheel or wheels spacers fixing this issue.

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  • 7 months later...

What year 240sx brake cable did you use?

 

This is a very old post, but the question is still a good one. You can use a small bracket to hook the e-brake cable to the caliper. Modern Motorsports does this with their 240SX brake kit. The other option is to adapt in a different cable. I used a 240SX ebrake cable, and it had the proper clevis for 280ZX brake calipers. I had to mount the cable to the bottom of the car and hook it up to the handle, which was really easy to do. It did require removal of the rear bell crank and attaching the cable directly to the ebrake handle. Total cost was about $10 and installation was really easy.

 

 

You can install the master easily, it just bolts right up. The only thing that you would need to do is adjust the pin length in the booster. I ran this combo on my car for years.

 

 

Most racing organizations don't allow dust shields, so most racers just remove them completely. The inner wheel bearing grease seal seats on the spindle, not the shield, so there is no danger of leaks from removing the shield. Your long lived brakes are the exception to the rule, the brakes are adequate for track use but usually require bleeding between sessions and adjustment, etc.

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  • 4 weeks later...

Well one thing I can tell you is I have never seen a Toyota caliper used for a Z upgrade that has a 90 degree fluid line connection. Everyone I have seen threads directly into the caliper.

 

This is what you are looking for

 

http://forums.hybridz.org/index.php/topic/39435-help-what-brake-options-are-available-for-s30-z-cars/

Edited by rags
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