New 4 piston calipers= lotsa fun

[Jeff G 78]

I happen to drive an '89 Toy 4x4 (vented S12W caliper) as my DD, so when I needed new calipers, I did a bench test fit on a 14x6 zero offset Enkei rim I had laying around. I used an old Z hub/rotor and spaced the caliper so it was centered over the rotor. Surprisingly, I had plenty of clearance to the 14" rim. I took several pictures that I could post later if needed.

I currently have the stock 2 piston/solid rotor/drum brakes on my Z with the braided SS lines and a proper bleed and the pedal feel is great. The SS lines are a must.

[=Enigma=]

Based on my reading the ZX master (15/16") is recommended when going to the S12W or converting from drum to disc in the rear and cergtainly when doing both. You might be able to get away with the original MC (7/8) when using only the S12 caliper. My pedal is nice and firm with very little travel. We'll see how it does once I get it back on the road.

[70 Cam Guy]

I happen to drive an '89 Toy 4x4 (vented S12W caliper) as my DD, so when I needed new calipers, I did a bench test fit on a 14x6 zero offset Enkei rim I had laying around. I used an old Z hub/rotor and spaced the caliper so it was centered over the rotor. Surprisingly, I had plenty of clearance to the 14" rim. I took several pictures that I could post later if needed.

I currently have the stock 2 piston/solid rotor/drum brakes on my Z with the braided SS lines and a proper bleed and the pedal feel is great. The SS lines are a must.

Cool, thanks for the input! A popular upgrade that I did on my truck brakes was to buy the dual diaphragm brake booster from, I believe, the V6 4Runner, and T100 trucks. Some of the pickups had them too I think but I can't remember, it's been a while since I did the swap

I, too, have the Earl's SS lines with the stock brakes. I completely flushed the old fluid when I installed my new brake master and wheel cylinder, and the pedal is very firm. I am actually very happy with the brakes at this point. I have all the parts, and spare struts now to do my coilovers and I can't wait to see what it'll do with some fresh springs and struts

[Inf]

I'm kind of curious how this changes things for street driving...

Yesterday I was involved in an 11 car pileup on the freeway, and through some miracle myself and my Z came out unscathed. When it all came to a stop, I was completely penned in by totaled and moderately damaged cars, and I actually came to rest 2 inches away from the concrete wall on the side of the freeway. I'll have to post the pics later, it was quite an amazing stroke of luck that I wasn't crushed between the other much larger vehicles out there.

Anyway, I had no trouble locking up the brakes with the stock setup. I know, I know, locking them up is bad and extends the stopping distance, etc, but what can I say? It all happens so fast, much too fast to THINK, and easing your foot off the brake pedal when there is a wall of cars coming at you at 70mph goes against all your instincts. I followed my own skid marks back a good 50-75 yards at least while we were waiting for help to arrive.

Wont this brake upgrade just make it possible to lock the brakes up with less pressure on the brake pedal? I'm a little confused now, as I now feel that there is no shortage of one-shot braking power with the stock setup.

[Jeff G 78]

Wont this brake upgrade just make it possible to lock the brakes up with less pressure on the brake pedal? I'm a little confused now, as I now feel that there is no shortage of one-shot braking power with the stock setup.

The key to the vented rotor brake upgrade is thermal capacity. The stock brakes have plenty of power to lock the stock tires. Once you put the car on a track, the thermal requirements go way up and the stock brakes eventually reach their design limit. The vented rotor setup can dissipate much more heat and therefor run longer and more consistantly before boiling the fluid, warping the rotors, and breaking down the linings. The four pot calipers allow for more even clamp load on the rotors and apply additional clamping force. Once the tires are upgraded beyond what was available in the 1970s, the brakes can be used harder without lockup. The key is to be able to modulate the clamping force. Brakes that are very binary are worse than ones that can be easily modulated. Having more clamping power along with linings that are progressive will allow for much better brakes than stock.

As for the rears, the drums work great. Most people change them for appearance and ease of service. Discs do not require adjustments like drums, but the overall braking is no better.

[texasz]

I believe that they recommend 79-81 280zx master cylinder.....I just ordered 2 from (believe it or not) REDAT. Nissan no longer offers it and you want to make sure you get one made in Japan(Napco or Tokico). 15/16 is what you're looking for I think.

I'm sorry to hear that you are doing business with REDAT from Houston...I truely hope you have a better experience that I and others have had (there's a thread on here somewhere about him).