Jump to content
HybridZ

Recommended Posts

JMortensen    235
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.

Share this post


Link to post
Share on other sites
Guest 280ZForce   
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.

Share this post


Link to post
Share on other sites
datsun40146    10

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 :/

Share this post


Link to post
Share on other sites
Jesse OBrien    12

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.

Share this post


Link to post
Share on other sites
GrenadeZ    10
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.

Share this post


Link to post
Share on other sites
Ben's Z    0

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.

Share this post


Link to post
Share on other sites
rags    138

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

Share this post


Link to post
Share on other sites

O.K. Guys I have a situation that I need to have explained to me.  I purchased 240sx calipers, and the 240sx brackets from MMS and also got the stainless steel brake lines. The two lines are different lengths and they also have two different fittings that tie into the brake lines (not talking about the banjo fittings).  Why make the different lines one having to use a reducer.  Could someone please explain this setup and reasoning. Thank you in advanced

Share this post


Link to post
Share on other sites
Namor    1

The longer of the two brake lines is for the passenger side and the shorter one is for the driver side.  

The passenger side should have a Male M10x1.0 Inverted Flare on the end

The driver side if I remember correctly is a different fitting with an adapter to be Female M10x1.0 Inverted Flare.

 

The passenger side brake line is designed to reach directly to the Tee above the diff.  It should thread directly into the Tee.  For the driver side, you will need a hardline to go from the Tee to where it will connect with the stainless steel flexible line.  

Share this post


Link to post
Share on other sites

O.K. here is a question I have that I could not find in the FAQ section. I purchased the Z31 5lug hubs from Modern-Motor Sports with +40 offset, using the 300ZX vented rotors, calipers are the Toyota S12W.  My question is what is the thickness of the spacer that is needed to push the rotor back far enough from the hub so that it will mate up with the caliper.  Tried contacting Ross at MMS but to no avail, no response.   

Share this post


Link to post
Share on other sites
EastTnZ    1

Ok I just got a brand new 79-81 280zx master cylinder from autozone as it was cheaper than finding one in a junkyard... Well the mc is stamped with 7/8 on the side and looks exactly identical to the mc already on my 76 280z.  So apparently they've done away with the 15/16 mc and said the 7/8 is sufficient for replacement mc's.

 

Has anybody run across this problem?  I would rather have a brand new or refurbished part than have to rebuild it once I pay for a used one.

 

After re reading this I may just take my refurbished toyota calipers (s12+8) and mc back and find a nice set of pads and new rotors for now.

Share this post


Link to post
Share on other sites
LanceVance    20

Possibility 1: Autozone and the like are selling the 7/8 MC as a replacement for the 15/16 unit - Unlikely

 

Possibility 2: Someone upgrading turned their 7/8 MC in for the core - Very likely!

 

Have you considered swapping your booster and MC with those found in the later ZX? Seems people have been doing that ever since the 79-81 MC supply started drying up...

Share this post


Link to post
Share on other sites
Bowtie29    0

For those of you running S130 calipers on both the front and rear, what rotors and pads are you running with them? Stock replacements? Or some sort of upgrade.

I'm looking to keep my stock brakes on my '83 280zx, but I would like to put good rotors and pads on it. Anyone have the part number for some Hawk HP pads both front and rear? Everything I find online says it fits the rear calipers. Nothing's specifically says front pads.

 

Are any of you running slotted rotors or even some of those "ABT" rotors off eBay? Are the eBay ones any good? I'll probably just put a stock replacement rotor on the rear.

 

Thanks.

Share this post


Link to post
Share on other sites
Grog    2

Can anyone verify if the maxima rear brackets/280zx brakes and rotors will fit under the 14" mini-mag wheels? I mocked mine up and it appears to fit, but would feel better about going forward with this swap by hearing from someone that already did it. I want to keep the stock alloy rims, so if this set up does not work then I will stick with the drums. thanks. 

Share this post


Link to post
Share on other sites
gijohnny23    0

I need help and apparently am too new to make a new topic. I have a 75 280 that I've swapped an 83 booster and mc to. Since I'm using the stock proportioning valve it seems the chamber for front and rear are backwards on the 83 compared to the stock is this correct? Also for the life of me I cannot get one of the lines seated into the master cylinder. When I tighten it it leaks u der pressure. This is a bran new line pre fabed from autozone. The stock was replaced for the very same reason. Any help would be greatly appreciated.

Share this post


Link to post
Share on other sites
Interceptor    0

Something I'd like to know about the boosters, since it's not covered a lot on the first post.

 

What we learn from it is : the 280ZX MC is compatible with a 240Z stock booster

 

I'm gonna change the booster with the MC on my 240, and I don't want to use a 280ZX booster, 'cause I don't want to drill the firewall of my car.

 

is it compatible with a 280Z booster or should I stick to a stock 240Z booster, cause I don't gain much from swapping a 240Z booster for a 280Z one?

 

is there anything particular to do to make those boosters fit to the 240Z body? (like drill holes)

thx!

Edited by Interceptor

Share this post


Link to post
Share on other sites
vbgambini    0

Wussup guys Im having an issue with my brakes. Ive been searching but cannot seem to find what I am looking for. Sorry if its a little long.

 

I have a 1978 280z. Went to take it out for a little drive around the block just to get it running and making sure everything still works. When I pulled out of the driveway when a few feet and my brakes were almost non existent. The pedal became very hard to push and barely stopping the car even when going 10mph. So I decided after researching that the master cylinder is probably going bad and mostly the brake booster needs to be replaced (Seemed like still original parts)

 

So I ordered a new master cylinder and brake booster from Black Dragon. Disassembled all the old parts. Mostly took out the brake booster, and left the master cylinder for now since it is still full of liquid. 

 

Received my parts from black dragon this weekend. Here are my issues.

 

Black Dragon part numbers

 

#64-162-Z brake booster

#64-103 Master Cylinder

 

1. The old nuts that went on the old master to booster, 3 of them fit but the top one. The nut cant even be screwed in. It looks like they sent me a bad part. Threads on the stud looked stripped. And even at an angle. But all other 3 nuts screwed in.

 

2. The new master I received has only 2 stud holes when the old master had 4 is that normal? So I said what the hell I will try and make it work. Ill just use the two vertical studs. So I just test fitted the new parts together out of the car, the master cylinder had to be wiggled in since the stud wasnt straight, and now when it slid in, theres a gap between the master and the brake booster. I dont recall there being some sort of spacer on the old master. I even tried the new master with the old booster, slid in perfect but still a gap. 

 

3. New brake booster looks significantly larger than OEM, Measured the rectangular indentation that fits in the firewall on the new one and the old one. The new one is larger. Will it even fit in my car?

 

Just frustrated because I wanted to get this done over the weekend and even ordered SS lines from MSA. And wanted to get it back on the road. Please if anyone can help me. Thanks.

Share this post


Link to post
Share on other sites

×