Brake upgrade FAQ

[JMortensen]

Brake FAQ - Hopefully this will be of some use to everyone.

 

What to do about Z brakes?

 

The stock Z brakes are adequate for street driving, autox, and drag racing.

The stock Z brakes are adequate for street driving, autox, and drag racing.

This is not a joke. Even with a V8 or turbo pushing lots of hp;

The stock Z brakes are adequate for street driving, autox, and drag racing.

 

This is especially true if you upgrade the pads to suit your driving. KVR, Porterfield, Hawk, and others make proven pads and shoes for aggressive driving in Z's.

 

If properly maintained and if cooling ducts are added, the stock brakes can even be used for road racing. The faster you get the more intense the maintenance will be to keep them race ready. Bleeding between sessions and adjusting shoes between sessions are common practice. Turning the drums to precisely the same ID is also a good idea for a road raced Z. Stock brakes are lighter than just about anything that you'll put on the car as an upgrade, so autoxers and drag racers looking to put their car on a diet should consider the weight penalty of an upgrade.

 

OK now that's out of the way. So lets look at some braking upgrade options for Z cars.

 

FRONT BRAKES

 

The 4 piston caliper: The Toyota 4 wheel drive pickup trucks from about 79-85 will bolt directly onto the Z strut and will work just fine with the stock non vented rotor. This upgrade will require the minor step of trimming the backing plate to make room for the new larger caliper. It is also recommended that the larger 79-81 280ZX master cylinder be used, since the 4 piston calipers displace quite a bit more fluid. Although the master cylinder isn't absolutely necessary, the pedal throw is a bit long without it. Fits most 14" rims.

 

The VENTED 4 piston caliper: This is the same as above, but uses an '84 300ZX vented rotor and a different caliper from a 89-95 4wd pickup or 4/89-91 4 Runner. This caliper is an S12W and is stamped as such. These parts do not just bolt on unfortunately. A spacer is needed between the rotor and the hub to line the rotor up with the caliper correctly. This spacer is available from http://www.modern-motorsports.com and is a different thickness for 240 and 280 hubs (260s as usual have 240 hubs in the early part of the year and 280 hubs in the latter part). This is a substantial upgrade from the solid rotor 4 piston caliper upgrade because the vented rotor can shed a lot more heat than the solid rotor. Fits most 14" rims.

 

The 300ZX rotor/280ZX caliper mod: blueovalz came up with this one, and I grabbed most of this info off of the zhome.com website, so check me for accuracy Terry. Use an 84-86 NA (which is a vented 4 lug) 300ZX rotor along with a 280ZX front caliper. It is a floating caliper, so there is less potential for interference with wheels than a 4 piston caliper. The Z strut is threaded, and the ZX caliper is threaded. Solution: drill out the threads in the strut with a 15/32" drill bit and slide the bolt through to attach to the caliper. The caliper also needs to be spaced out to center over the rotor. A simple washer of a thickness around .160" (may vary) should get the caliper centered with early hubs. Later 280 style hubs are thicker and place the hub too far inboard, requiring the rotor mounting surface on the back of the hub to be turned down. The outside diameter of the 300ZX rotor is a bit too large as it comes from the factory, so the rotor also needs to be turned down about 1/4" total to fit inside the rotor. From there it all just bolts together. The bad part about this mod is that the rotor is a wear item, and this machining needs to be done every time they are replaced. A different more difficult solution is to cut the caliper mounting ears off the strut, position the caliper correctly on the full size rotor, then weld the ears back on. This will add 1/8" to the length of the ears and then the off the shelf rotor will work, but obviously this is a pretty advanced modification and only those who are very experienced with fabrication should even consider it.

 

The Arizona Z Car Wilwood: This is really a racing brake setup. Aluminum hats attach to 280 hubs (you'll need to swap out your 240 hubs for 280 hubs if you have a 240 or early 260) and then the cast iron 12.2" x 1.2" rotors bolt to the aluminum hats. A caliper bracket bolts to the strut and locates the caliper correctly over the rotor. The calipers are Wilwood Superlite 4 piston calipers. The rotors are just a tad over the weight of the original cast iron Z rotors, but are MUCH larger and can take a huge amount of heat. This upgrade does require some modification to the control arm to allow the rotor to clear the end of the arm near the ball joint. Fits some 15" rims. http://www.arizonazcar.com

 

The Arizona Z Car 13" Wilwood: Same as above but with 13" rotors and Wilwood 6 piston calipers. Requires 16" rims http://www.arizonazcar.com

 

The Modern Motorsports Extreme 13" PBR: This system uses an aluminum hat and a cast iron rotor. The PBR caliper is a stock piece from a Cobra Mustang, so brake pads are as close as the local auto parts store. The calipers have dust seals, where Wilwood calipers do not. Opinions as to the importance of the dust seals is mixed. I personally think that they are a good idea on a street car, but not absolutely necessary for someone who is looking at the brakes frequently (weekend warrior autoxer or track day type who regularly bleeds their brakes). http://www.modern-motorsports.com

 

The Mustang Cobra: This braking system uses new hubs from Modern Motorsports and a stock 1994-2004 Cobra rotor, along with a caliper bracket and a 2 piston PBR caliper. The advantage to this setup over the aluminum hat style rotor is that you can go to the corner auto parts store and buy a rotor. The disadvantage is weight. The Arizona Z Car and Modern Motorsports rotors weigh about 13 lbs assembled. The Cobra rotor is much heavier at ~25 lbs. http://www.modern-motorsports.com

 

REAR BRAKES

 

Z-Quip early 280ZX brakes: Z-Quip is no longer in business, but this kit included nothing more than a pair of caliper brackets which allowed early ZX rotors to be used with early ZX calipers on a 1st generation Z car. This wasn't much of a performance upgrade, but did make servicing the brakes quite a bit easier and looked nicer than drums as well.

 

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.

 

Modern Motorsports 240SX/300ZX: Modern Motorsports sells a caliper bracket which correctly locates a 240SX caliper over a 11" 300ZX solid rotor.

 

Arizona Z Car rear Wilwood: This is similar to their front brake kit, except the rear uses a slip on rotor. The rotor consists of an aluminum hat and a cast iron rotor which is 12.2" in diameter and .83" thick. The caliper bracket locates a Wilwood Dynalite 4 piston caliper correctly over the rotor. This system provides no ebrake functionality, so ebrake is removed entirely. It does come with a line lock which can serve as a temporary parking brake but will not work at all in the event that hydraulic pressure is lost in the brakes. Some have reported that the line locks can leak down their pressure, so watch it if you park on a hill. Might be a good idea to use a wheel chock in addition to the line lock in that event. http://www.arizonazcar.com

 

BACKING PLATES

 

Concerning backing plates and how to modify them: All of these modifications will remove the backing plates, except the non-vented Toyota 4x4 mod which only requires minor trimming with tin snips to work, and alternatively if you want to remove the backing plates you can in that instance too. The downside to removing the plates is that water will get on the rotors more easily when driving in the rain so that first stop after driving in the rain for 20 minutes won't be very good, and there is more of a possibility of a stone or a piece of trash on the road getting thrown up and caught between the rotor and the brake pad.

 

5 LUG BRAKES

 

Some people are switching to 5 lug hubs for better availability of wide rims (4 lug tend to be mostly available in FWD offsets).

 

The early 300ZX 5 lug front hubs will work on a 1st gen Z with some slight modifications and the vented Toyota brake upgrade from Modern Motorsports is available in a 5 lug version to fit.

 

Modern Motorsports and Arizona Z Car also offer aluminum 5 lug front hubs with their Extreme and Wilwood braking systems discussed above. Rear hubs can be redrilled for 5 lug, or Modern Motorsports now offers a 4340 billet stub axle in 5 lug.

 

ADJUSTABLE PROPORTIONING VALVES

 

The proportioning valve cuts the pressure to the rear brakes so that under very severe braking the front wheels lock first. Front wheels lock = car goes straight. Back wheels lock = car spins. When you change the front or rear brakes from stock you lose the ratio of front to rear brakes which the stock proportioning valve was designed for. The way to properly address this issue is to install an adjustable proportioning valve. The stock proportioning valve must be removed and the adjustable valve gets plumbed into the line that goes to the REAR brakes. Pressure can be adjusted up or down until proper brake bias is restored. Proper brake bias is when the front brakes lock BEFORE the rears. Two types are the knob style with infinite adjustment, and the lever style which usually has about 5 settings and is used by racers to cut down the amount of rear brake over a long race, since the car burns the fuel off and the rear gets lighter as the fuel level goes down. The knob style is probably a better choice for most people since it can be more finely tuned.

 

STAINLESS BRAKE LINES

 

Stainless brake lines are a very good idea and they provide much better pedal feedback. If you haven't replaced your stock 30 year old rubber brake lines, consider this cheap and effective upgrade.

 

MASTER CYLINDERS

 

The stock master cylinder is really unsuitable for any 4 piston caliper upgrade. It works marginally for the Toyota 4 piston calipers, but really increases the pedal throw. A 79-81 280ZX master is a nice upgrade and is suggested by Modern Motorsports and Arizona Z Car when using their brake kits discussed above. There are two masters in the ZX's. The early one has dual reservoirs and fits onto a Z booster. The later one has a single reservoir and has the reservoirs clocked 90º making it incompatible with the Z booster.

 

Here is the correct ZX master (79-81):

 

And here is the incorrect later master (82-83):

 

OTHER STUFF:

 

There are lots of one off setups which I didn't discuss here, as I thought they weren't common enough to warrant it. Big Red Brakes from a Porsche have been fitted to a Z, and Z32 brakes have also been used. There was also another setup sold by JSK and another by scca and these guys are no longer selling their kits, so I didn't include them. Racing master cylinders setups with dual masters also weren't included. This FAQ does not cover every situation and every possibility, just the common ones.

 

Some of the more obscure ones are covered in this thread: http://forums.hybridz.org/showthread.php?t=104735

 

LAST THING:

 

If you find an error in the above or missing info that needs to be there, please point it out. If you choose to modify or work on your own brake system, you do so at your own risk.

[quicker240]

May want to point out the difference between DOT3,4,5 Etc. and the benefits/disadvantages of each.Very good post on the most common brake choices.

 

[johnc has now posted a Brake Fluid FAQ to answer this question. Pete]

[johnc]

The stock Z brakes are adequate for street driving, autox, and drag racing.

The stock Z brakes are adequate for street driving, autox, and drag racing.

This is not a joke. Even with a V8 or turbo pushing lots of hp;

The stock Z brakes are adequate for street driving, autox, and drag racing.

 

This is especially true if you upgrade the pads to suit your driving. KVR, Porterfield, Hawk, and others make proven pads and shoes for aggressive driving in Z's.

 

And, for you drag racers and autocrossers, the stock Z brakes are lighter then anything else you can put on the car!

[clarkspeed]

Great post. I especially agree with your first paragraph. Stock high quality components with the right linings and fluid is adaquate for most all applications. I used stock based components for years for hard core autocross and open track events. I've found the only negative is they require regular "attention" to keep them fresh. It's those fat sticky tires that make you stop, and I mean eyes popping out kind of stop.

 

I now run the Arizona Wilwood kit on a GT prepared race car. They are almost overkill for a 140 mph track car. They last a long time. The stock setup could still get the job done, but I would need to freshen after 2-3 sessions and be generous with air ducting.

[Mike kZ]

I think I'll add this post too: http://forums.hybridz.org/showthread.php?t=104735

[alexideways]

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".

 

Sorry, I don't want to sound stupid or like I can't read but, I'm a french Canadian and can sometimes get mixed up with all those english Z slang.

[blueovalz]

A conversion I've had a lot of correspondence about, and positive feedback on the 300ZX front vented rotors using the 280ZX front calipers. This does not require any spacer between the hub to wheel, or hub to rotor (but will require two thin shims between the caliper and the strut mounting ears). The floater design allows this option without any fear of rubbing between the caliper and the wheels. Contrary to initial opinion, floating calipers are not a bad thing. In fact, I've had a great deal of success with them (but now they are the MkIII Supra floaters), and have yet feel the need to install the 4 piston Outlaws that I bought 6 years ago (still in the box). I even looked at the C5 calipers as well, but an aluminum floater concerns me in regards to the jaw flexing.

[tsheldon]

Ok fess up whats with the Supra Calipers??? Are they a viable alternative to the 280 zx floater ? What about weight... What rotors and hubs are you using with them ?? Inquiring minds want to know.

[blueovalz]

I don't think it's anything anybody would want to copy. I had the '86 Supra rotors (12") machined to bolt onto the Z hub, and then modified the strut caliper ears to attach the Supra floaters. Nothing special, but they stop VERY well, and I've no longer found a really good reason any more to put the "better" 4 piston calipers on the car. Yes, some day I will do it anyway, but I really don't need to.

[GLSHLE]

Terry, which year 300 rotors work, I see theres a chose.

Thanks Randy

[blueovalz]

The early 4 lug ones bolt right on ('84 maybe?)

[Guest Ron]

I have not found an answer to this one. Maybe it's just not a big deal. I have read about trimming the backing plate to mount the Toyota calipers. I plan to run cooling ducts, why not just leave the backing plate off?

[JMortensen]

It is easy to trim the backing plates and they protect the rotors from getting splashed with water or rocks from lodging themselves between the pad and rotor. That said, most race cars are required not to use backing plates, and I ran my car with no backing plates for 8+ years with no problems.

[pparaska]

Jon, I was wondering if you would try to condense all of the posts in this thread into the original FAQ so we could clean up the thread and make your FAQ more comprehensive.

 

Pete

[pparaska]

Cool Thanks!

[IdahoZ]

Great post with a great deal of useful information. I have one question that I did not see answered here, maybe I just missed it. It's about the 4X4 S12 upgrade for the front brakes. Jmortensen's original post says this about the upgrade.

 

FRONT BRAKES

 

The 4 piston caliper: The Toyota 4 wheel drive pickup trucks from about 79-85 will bolt directly onto the Z strut and will work just fine with the stock non vented rotor. This upgrade will require the minor step of trimming the backing plate to make room for the new larger caliper. It is also recommended that the larger 79-81 280ZX master cylinder be used, since the 4 piston calipers displace quite a bit more fluid. Although the master cylinder isn't absolutely necessary, the pedal throw is a bit long without it. Fits most 14" rims.

 

Question - can I use the cross drilled and slotted rotors that are offered for the stock 240Z setup with the 4X4 calipers or do I need to keep the non vented rotors? I have a 1972 240Z and would like to upgrade the brakes.

 

Thanks again for this site, I never would have tried to do a Hybrid without it.

[IdahoZ]

Could you use the crossed drilled and slotted rotors that are offered for the stock 240Z setup with the 79-84 Toyota 4X4 S12 front caliper mod or do you have to use the non vented rotors with these calipers>

 

Thanks.

[pparaska]

Jon, if the above 2 posts by IdahoZ seem correct to the experts here, mind adding them in some what to the original FAQ, then we'll delete them from here. You might attribute who wrote the stuff if I'm going to delete it from the lower part of the thread.

 

Thanks,

Pete

[Zmanco]

Could you use the crossed drilled and slotted rotors that are offered for the stock 240Z setup with the 79-84 Toyota 4X4 S12 front caliper mod or do you have to use the non vented rotors with these calipers>

 

Thanks.

Having just fnished swapping the toyota 4x4 calipers, let me take a shot at answering IdahoZ's question.

 

Slotting and drilling should not change the diameter or thickness of the rotor, so the answer is yes, you should be able to use them with the '79-85 12S calipers.

 

Note: I just upgraded from the S12 calipers with stock rotors to the S12W and '84 300ZX vented rotors. I also used 300ZX pads which give a little more surface area than the Toyoto ones. Although I haven't had a chance to take it out on the track yet, I've found the brake response to be more linear than before. I'm sure some is due to new rotors and pads. If you are going to upgrade the rotors and calipers anyway, I'd recommend going this route. About the only extra expense is the spacer which I got from Modern Motorsports for about $135 shipped. To Jon's comment up top, you can get away without switching to the 15/16" master cyliinder, but the pedal becomes rather long, and it just diddn't feel right. Also, my size 12 feet were hitting the gas pedal during braking now and then. A little scary when you're still in gear!

[Guest daveyboy]

I have seen a 280z brake rear upgrade consisting of using a 85'-88' Maxima caliper bracket along with the Maxima caliper from 85'-88' and the 4 lug 300 zx rotor. Has anyone used this conversion and if so does the Maxima caliper bracket need to be macined to allow for offset or can the bracket be bolted right on without any mods?