300zx master cylinder?

[NismoGreg]

I own a '93 fastback and the brakes have always been ****ty. I heard that you can swap a 300zx master cylinder but I dont know if it fits right in or if you have to do some mods to get it to work

[180fan]

The lines will match up, but you'll need to cut up your s13 master for that plug that fits into one of the lines for the z master.

http://importnut.net/300zxbrakeswap.htm

that should run you through it

[Hijacker]

46010-30P21 Z32 17/16ths Master Cylinder

That's the part number for the proper master cylinder that will bolt right in. No cutting, or pressing. A little known fact is that Nissan uses Nabco and Tokico to make their hydrolics. The nabco part is a direct upgrade and uses the proper flare fitting that the 240 uses. If you nab the tokico part, you'll have to deal with either making a bubble flare fitting on the brake line or going through the hassle that Al went through in 180Fan's link.

I wouldn't suggest doing the master cylinder if you are retaining your stock brakes. The proportioning valve is designed for 12 pistons worth of brakes, not 4. I would go through and bleed your system, and upgrade your pads. I feel that the stock 240 brakes are really good. I'm only upgrading because I managed to land a few components for cheap

[crzycav86]

The z32 master cylinder won't make your "****ty" brakes better. It'll just give you a stiff pedal, and make it harder to push. If you want to stop faster, push the pedal harder. That's basically all you'll be doing with that mc on stock brakes anyway.

[gabossie]

If you want to stop faster, get better rubber. Bigger brakes are just for less fade after continual use.

[Soulja]

You can also install a 86 s12 200sx Master cylinder. 15/16, no worries about fittings. Also costs about $25 for a new one at advance auto or autozone.

[gabossie]

If you upgrade the master cylinder without upgrading the brakes, the result will only be a stiffer pedal, it will do nothing to help you stop faster (technically neither does upgrading the brakes). If you do upgrade the brakes, the S12 MC would be a minimal improvement gaining only 1/16" bore over stock.

[crzycav86]

Well, bigger brakes DO help you stop faster, if you can't lock up your tires with the stock brakes..

[Hijacker]

The diameter of the master cylinder determines both how much brake force you'll get for a given pedal effort, and how much pedal movement there will be. The stock 7/8-inch master cylinder has a piston area of 0.60 square inches, so 100 pounds of force shoving on the piston from the combined effort of your foot, the pedal lever ratio and the brake booster, will make 167 psi (100 lb/0.60 in2) of fluid pressure with which to squeeze the calipers. Moving to a 1-inch master cylinder gets you 0.79 square inches, which makes only 127 psi from the same 100 pounds of footwork.

Since we had complained that the brakes felt touchy and overboosted, this reduction in pressure would be exactly what we needed. We also complained that there was too much pedal movement. The bigger master cylinder helps here, too. A 7/8-inch cylinder moving 0.1 inches pumps .060 cubic inches of fluid to the brakes. A 1-inch cylinder would pump .079 cubic inches. That means it would take less pedal movement to move the brake pads the fraction of an inch from their resting position to the rotors

...

Going with the larger 17/16" bore cylinder, this would increase pedal effort by 65 percent. (The 0.99-square inch bore would make 101 psi at 100 pounds of pedal force, or need 165 pounds to make the same 167 psi the stock cylinder made at 100 pounds.) Since the bigger cylinder pumps 65 percent more fluid for the same stroke, it would also significantly reduce pedal slop.

Modified by tenkawa_akito at 12:20 AM 9/17/2004
Modified by tenkawa_akito at 12:23 AM 9/17/2004

[crzycav86]

the biggest issue with upgrading the brake MC is that you will be pushing too much fluid to the stock calipers. now, by pushing more fluid will cause the brakes to lock up earlier. also, you won't obtain a stiffer pedal.

Well, it will lock up earlier, but it will take more effort to make them lock up. It will make the pedal stiffer, thus it takes more effort to lock them up.

I don't see how that relates to my quote in the previous post though.

[Hijacker]

honestly, i don't know why i wrote that anymore. i think i was drinking a bit that night ^_^ edited to correct it