Questions about front & rear brake upgrades for '73 240Z

[Chuck_V]

Just bought a '73 240 that needs some attention. I'm upgrading the brakes all the way around rather than repairing the OEM parts. Can someone confirm the following will work/fill in the missing info for this brake conversion? I already read the FAQ but still have some questions.

 

Front brakes:

'84 300ZX vented rotors

'89-'95 Toyota 4WD/'89-'91 4Runner calipers (will be marked S12W)

Rotor spacers from SilverMineMotors

 

Rear:

'79-'83 Maxima caliper brackets

'82-'83 280ZX rotors & calipers

~OR~

 

ModernMotorsports caliper brackets

'89-'94 240SX rear calipers <--- Can I run Z32 calipers instead of the 240SX calipers?

'83-'84 300ZX rear rotors <--- Are these the correct rotors for the ModernMotorsports caliper brackets?

 

Master Cylinder:

'79-'81 280ZX (must be dual reservoir version)

Some type of aftermarket proportioning valve

[Miles]

The 280zx MC is NLA. Go to the brake section and read the first post about the Wilwood 1 inch MC as a replacement.

 

The kit from Modern Motorsports is ok, but people are complaining that service is slow. See post "Has anybody heard from Ross lately" in the FAQ section and then decide.

 

I have the MM Toyota front and 240SX set up on my 240Z. It is not all that great. Adding Porterfield R4S pads and a 280Z booster helped, but still not that great.

 

You should spend some time reading in the brake section the pros and cons of various "brake upgrades".

 

 

You might be better off refreshing your stock brakes and using Porterfield R4S pads and shoes. Several people have told me that stock brakes with a 280Z booster works well.

 

A proportion valve is not needed with the Toyota front and 240SX set up. The 240SX rears can't keep up with the Toyota fronts. It is an unbalanced combination. Most people complain that they have to run the proportion valve wide open to the rear brakes and rears are still not balanced. So the proportion valve is not needed. There are many discussions in the brake section about this problem. Read every post on the Toyota/240SX subject and then decide.

Edited July 10, 2012 by Miles

[RebekahsZ]

Consider keeping it stock and installing ceramic pads. The stock system is fine and you'll be driving around with a smile on your face in no time!

[Midnight-280Z]

I agree with Miles and RebekahsZ...Refreshing would be a better idea than doing the "upgrade" notice the quote....it may end up more trouble than it seems just to get everything working in sync. That's my opinion. I had the MM front brake upgrade (S12W Calipers) and bought the MM rear upgrade as well (never installed it). When I had the front upgrade I had to pump the brakes, first pump doesn't bite hard enough...second/third pump usually does it... If you're driving hard, it can become a dangerous factor. Because of this reason, I never drove within a certain distance of cars in front me (you never know when **** may happen). I never got around to installing the rears as I decided to go another route (FC3S calipers & 12.2" rotors all around, no after market proportioning valve or master cylinder upgarde...maybe in the future I will).

 

Anyways...

 

For the front upgrade you listed, MM also sells an adapter as well

For the rears, it's a 1984-1985 300ZX (Brembo Part #25139). Not sure if you can run the Z32 calipers..You'll need the 240SX calipers and hangers, not just the caliper.

[Hybrid240z]

Miles is right about the unbalanced issue when running the Toyo front setup you mentioned together with the 240SX rear setup. I have read there may be the same issue when running the 280ZX rear setup too. From info posted so far, the Silvermine stage 4 rear kit is the one to run with the Toyo front setup to end up with a brake system that can be balanced using an adjustable proportioning valve.

[bjhines]

I Completely disagree with everything said so far. Modern cars are proof enough that the antique 240Z brakes design is ineffective. I consider the stock brakes DANGEROUS in hard driving situations. I have run an example of most possible upgrades ON TRACK!!!! Some of you guys answering this thread are probably fine boulevard cruising to show and shines with the stock brakes....

 

The rear drums will lock and are hard to modulate to unlock. The entire system is dangerously inconsistent under hard driving. The rear drums will heat expand so much that you have to partially set the handbrake to take up the slack until they cool off for a lap or more. There is a damn good reason that drivers of my skill level and experience would NEVER CHOOSE to use the stock brakes, we are forced to use stock brakes under some rules and that is a HUGE handicap for our cars.

 

Midnight-280Z; You FUBARED the install is why. """""""" When I had the front upgrade I had to pump the brakes, first pump doesn't bite hard enough...second/third pump usually does it..."""""""""""""

Edited July 11, 2012 by bjhines

[Miles]

Perhaps he is not going race or drive his car hard. Is the car stock? Does he plan on more power or a V8 swap? At face value, the car appears stock at this time. Let's see what his plans are.

 

Chuck, what are your plans for the car? Daily driver? Street performance? Racing? Occaisional track day?

 

 

[bjhines]

Consider that most people think a 240Z has good brakes. What they fail to realize is that the 240Z weighs less than anything they have ever driven and even shitty brakes can stop a 240Z HARD! Once you learn to drive the car hard, the brakes are the most obtrusive issue.

 

On a racetrack, the stock brakes are a constant source of problems for all who are FORCED to use them.

[OldAndyAndTheSea]

I've got the stock master cylinder, stock calipers in the front with slotted and drilled rotors and a nice set of ceramic pads with a fresh set of shoes/drums in the back.

 

Those brakes will pull the eyes out of your head if you get on them too hard.

 

Obviously drums are not ideal if you plan to race your car, but if you daily the car, like I do, the stock system is definitely sufficient.

[bjhines]

I drive a BMW M3 that weighs 600# more than the 240Z and it will rip your head off after your eyes pop out. It will REDEFINE your ideas of proper braking even with all that extra weight.!

 

A stock 240Z is light.. That is the ONLY factor that makes the stock brakes even remotely adequate. Even then they don't stop as well as a lot of newer cars that weigh considerably more.

 

For a stock 240Z; A braking event from 110mph to 50mph in 200ft will cause significant fade the first run. It only gets worse after that. Brake management is a nagging issue the whole time out on track. I can see a few situations on mountain roads that would induce that kind of fade, especially after heat builds up and surprises the driver at the wrong time. That is an example that I have encountered on public roads with a stock 240Z.

 

Modern friction compounds can work at temperatures that will destroy seals, warp and crack the rotors, blow off the grease caps and push out hub seals. I did it and suffered failure of the next weakest links with little overall improvement in lap times.

Edited July 11, 2012 by bjhines

[Miles]

I did the MM set six years ago. I was hoping the MM Toyota front/240SX rear swap would perform eye poping stops like your BMW. It has been a very disappointing "upgrade".

 

 

My only point is that, I and others here, and at other Z car sites, have expressed second thoughts after completing the MM Toyota/240Sx swap. The main complaint is that the MM set up is not balanced. I won't recommend something that I know has not performed well. If someone has achieved eye popping stops and balanced braking with the MM set up I would be interested in knowing what they did so I can fix mine.

 

There are other brake upgrades available.

 

 

Chuck, I suggest that you look at the brake FAQs and the Brake section before you modify your brake system. There are many options each with its own set of pros and cons.

[Chuck_V]

Miles, can you clarify what you mean by the Toyota/240SX setup not being "balanced"? Are the front or rears locking? Is one of them not providing any stopping power?

 

Thanks for the responses so far. I'm continuing to do my research before purchasing anything. The car will be used for street drivin and autocrossing. Coilovers, upgraded brakes, larger wheels/tires (no flares), and a nice set of seats/harnesses. Power wise I'm only looking to make sure everything is running as well as it can for now. More power later down the road.

[RebekahsZ]

Wow-this turned into a bit of a pissing contest.....sorry Chuck. My point was this: of your car is on the rack all the time, it doesn't need very good brakes. There are a very small number of guys operating at the level that bj is and they are awesome. Awesome fabricators, drivers and machinists. I want to learn as much as I can from those guys but I am quickly learning that I am not in their class and most guys on this forum are not. I honestly hope that everybody who finds a rust free z-car does a brake up-grade because I know that a great number of those cars will never get back out of the garage until the owner dies and his children sell a dusty old barn-find to me for pennies on the dollar. Brake upgrades ensure me a constant supply of decent sheet metal well into the future. I like 'em.

[Miles]

As you are aware that most of the braking is done by the front brakes which is desirable because you want the brakes biased toward the front so they will lock before the rear brakes in a hard stop. A rear wheel locking first will act like a rudder and cause the car to skid and slide. Assuming that the brakes are set up properly and maintained you should be able brake hard and lock the front front brakes just before the rears lock.

 

In my experience with the MM set up, it is like the fronts are doing 95% of the braking and the rears are doing only about 5% of the braking. That is, the set up is not efficient or balanced. I have never been able to lock up the rear brakes - not even come close. As you will read in the brake section people have tried different pad combinations, bigger boosters etc. to improve the Toyota/240SX setup without much improvement. I have tried most of the "fixes", but didn't see any sinificant improvement. Although, using Porterfield R4S pads did improve braking a little.

 

The rear brake setup that better matches the Toyota vented front brake swap is the kit supplied by Silver Mine Motors. It uses large late model Mustang calipers and rotors, but is very expensive. Look in the vendors section. Silver Mine Motors also sells a front vented Toyota kit that is like the kit that MM sells. Again the problem with MM is that people are complaining that Ross is slow to respond with their orders or respond to questions.

 

If you are going to race the car you might want to consider the Arizona Z front and rear brake kits. Arizona Z also sells complete coil over kits. Arizona Z equipment is all designed and manufactured new for Z cars.

 

I am planning on replacing my Toyota/240SX set up with the Arizona Z front and rear kits.

 

 

 

 

[Miles]

Here is a thread on stock vs ugrades.

 

 

 

http://forums.hybridz.org/index.php/topic/95402-stock-brakes-vs-upgrades/page__p__897529__hl__bjhines__fromsearch__1?do=findComment&comment=897529

[duragg]

I drive a BMW M3 that weighs 600# more than the 240Z and it will rip your head off after your eyes pop out. It will REDEFINE your ideas of proper braking even with all that extra weight.!

 

 

 

M3 brakes...

 

A guy pulled out in front of me driving an M3 and I slammed on the brakes so hard, but I was still going to hit him.

So I put all my remaining energy to that pedal with full adrenalin it about ripped my head off and stopped instantly.

 

Wow. Impressive for sure.

Sorry for TJacking.

[bjhines]

One of the things that leads to disappointing results from upgrades is the lack of ability to tune the modified brake system. No one here has stated which compounds they are using. Friction compounds come in so many flavors that it will make your eyes pop out(lol!!!). Biasing is part of the job. This depends on the dynamics of the car as well as the brakes. I tried several compounds front and rear before I arrived at the best combo for my car. I have a shelf full of slightly used brake pads to fit the common upgrades that did not work well.

[Chuck_V]

Ok, so what I'm finding is that for the weight of the car, the Toyota S12W calipers are more than enough, and the difference in piston area between the S12W front calipers and 240SX rear calipers is too big to properly adjust the bias front/rear. That leaves the following options (assuming I'm not leaving it stock):

 

Option 1:

Tilton dual master cylinders (allowing different size MC for front and rear calipers)

Toyota front/240SX rear calipers

300ZX 289mm rotors

 

Option 2:

Toyota S12W front calipers

Z32 rear calipers on ModernMotorsports 240SX caliper brackets <---- IS THIS POSSIBLE?

 

Option 3:

Toyota S12W front calipers

280ZX rear caliper (43mm piston vs 240sx caliper which is only 34mm)

280ZX rotors (258mm) <---- IS IT POSSIBLE TO USE 300ZX rotors (289mm) WITH THE 280ZX CALIPERS?

 

Option 4:

Some type of smaller front brake caliper upgrade, is order to minimize the difference between front/rear caliper strength and allow for proper bias. <---- IS THERE A BOLT-ON ROTOR/CALIPER COMBO THAT IS LESS POWERFUL THAN THE S12W CALIPERS?

 

 

ONE MORE QUESTION! What can you guys tell me about the S12+8 calipers VS. the S12W? I'm reading that the S12W is more powerful and has larger pistons. Since the S12W calipers seem to powerful to correctly match with the rear disc conversion, would I be better off using S12+8 calipers?

Edited July 11, 2012 by Chuck_V

[h4nsm0l3m4n]

Option 2:

Toyota S12W front calipers

Z32 rear calipers on ModernMotorsports 240SX caliper brackets <---- IS THIS POSSIBLE?

The Z32 calipers are of a quite different design from 240sx. Also the rotors on the z32 are different from the 240sx (different diameter and vented design). Because of this I would say that it wouldnt work without a bit of screwing around to make it work. At that point youre just better off fabricating your own brake brackets. Z32 brakes also have a drum e-brake setup. I think it will be very difficult to get these to work on a Z.

 

Option 3:

Toyota S12W front calipers

280ZX rear caliper (43mm piston vs 240sx caliper which is only 34mm)

280ZX rotors (258mm) <---- IS IT POSSIBLE TO USE 300ZX rotors (289mm) WITH THE 280ZX CALIPERS?

Maybe. If youre using the typical brackets used with a 280zx setup it wont work. The rotor is too large to fit. Fitting the 280zx calipers on the MM 240sx brackets MAY work but I have not seen it done so I cant say for sure.

 

Option 4:

Some type of smaller front brake caliper upgrade, is order to minimize the difference between front/rear caliper strength and allow for proper bias. <---- IS THERE A BOLT-ON ROTOR/CALIPER COMBO THAT IS LESS POWERFUL THAN THE S12W CALIPERS?

 

ONE MORE QUESTION! What can you guys tell me about the S12+8 calipers VS. the S12W? I'm reading that the S12W is more powerful and has larger pistons. Since the S12W calipers seem to powerful to correctly match with the rear disc conversion, would I be better off using S12+8 calipers?

 

Easiest option is the s12+8 calipers. They would probably balance out the brake bias a bit better. However, S12W calipers can take Z32 brake pads without hardly any modification. It works out really nice since there is plenty of aftermarket compounds available. I'm pretty sure S12+8 and S12W use different pads so this will not be the case. As such brake pad selection may be a bit more limited with s12+8 calipers.

 

You can also modify the strut assembly to accept 280zx front calipers. This is not a bolt on procedure so its not as easy.

 

The brake bias issue is not something insurmountable. I run s12W calipers up front, 280zx calipers in rear and feel like I was able to get pretty good brake bias. I had to try a couple different brake pad compounds but eventually found something I felt was a good compromise. It was just a matter of experimentation.

Edited July 11, 2012 by h4nsm0l3m4n

[Chuck_V]

OK, here is what I think would be a good compromise:

 

S12-8 front calipers

300ZX vented rotors

 

 

'82-'83 280ZX rotors & rear calipers (43mm piston vs 34mm for 240SX)

'79-'83 Maxima caliper brackets

 

 

If my math is correct, the stock 240Z front calipers have a total of 9156.24 mm² piston area.

 

The S12-8 calipers have a total of 9393.12 mm² piston area (that's 236.88 mm² more than stock, which seems like a reasonable upgrade to me).

 

The huge S12W have a total piston area of 11611.72 mm² (that's 2455.48 mm² more than stock, and I think way too much to be able to achieve proper bias front/rear).

Edited July 11, 2012 by Chuck_V