I post on the forum every now and than but I read posts regularly, but this is my question. I am intrested in a big brake kit to fit under stock 18s for the time being and am wondeing if there is a 8 piston setup up that would fit under the 18s non-track may i remind you. If there is no 8 piston setup available yet, will their be? also will all 6 piston setups fit under our wheels?

 

Most big brake calipers will fit behind the stock rims, for both the track rims and the 18's. I have the 6 piston AP Racing BBK with the 14.25" rotors, and they fit behind my stock 18" touring rims just fine, but any rotor bigger than that will have clearance problems. It is unlikely that they will make an 8 piston setup for the Z as that would be overkill, even the 6 piston calipers are more than enough.

 

Heres a Zed with a 12 Piston Tarox kit.

 

12 pistons is alot

 

What is your reasoning behind getting an 8 or 6 piston kit for your Z? Do you just want the biggest thing you can fit under the wheels?

 

oops, i stand corrected

 

just looking for something that looks rad

 

Number of pistons will have no bearing on performance. Just so you know.

 

if it where that simple, every brake would have 1 piston

latest example that comes to mind is the new M5 gigantic 374mm brakes being outperformed by the e55 amg 360mm brakes... one has 2 pistons, the other 8

 

But it has nothing to do with the number of pistons. In the case of the M5 and E55 -- it probably has to do with tire choice and/or weight (and nothing to do with the number of pistons). I think the M5 has run-flats, and the E55 has proper max-performance tires.

Unless you change out the stock master cylinder on the Z -- you can either get 1 big piston or 6 tiny pistons (or somewhere in between). Swept area and the heat disipation abilities of the brake system will determine their fade resistance (initial cold stop abilities will be determined almost exclusively by tire grip and weight -- not the brake system). A system like Stoptech's using four mid-sized pistons will have just as much clamping force as AP's 6 piston setup which has to use smaller pistons. Remember, since the stock master cylinder is used -- the brakes still have to respond to the same amount of fluid displacement as the stock single piston brake. So more pistons -- also means smaller pistons.

That is not to say the AP system is not good -- it is very good from what I hear. But don't get fooled into thinking that 6 piston is somehow better than 4 piston (in fact -- a six-piston system may have a heavier caliper, which would make it worse than a four-piston setup). Now, single piston brakes use a sliding caliper which does have certain inherent disadvantages versus a fixed caliper system (like the track Brembros, Stoptech, AP, etc.).

 

Why would a 6-8-10-12 piston caliper necessarly be heavier? If the pistons are smaller, it could be as a matter of fact lighter and more compact around the disc. As a matter of fact, from the looks of it, the amg 8 piston calipers are more compact and lighter than the M5 2 pistons calipers (M5 is lighter BTW).

There are certain performance advantages by having more pistons, and there are probably downsides too. Tar-ox has a rich history up to formula 1 level, and produces some incredible brakes. It's not because your favorite brake manufacturer choses X pistons that anything above that is useless. I just thought you made the question awfully simple...

 

Remember though -- I am assuming you are running a stock master cylinder. Obviously, F1 cars can run any master cylinder they desire (w/in the allowed spec). I am just saying that more pistons does not equal more performance (assuming you keep the stock master cylinder).

On the Z -- the amount of fluid the master cylinder can displace is limited. So 4 piston versus 6 piston -- there will be virtually no performance advantage.

 

The master cylinder is just part of the brake system.

Number of pistons DO have an effect on brake feel, pressure distribution on the pads and total piston area (wich directly affect total pressure). For me, these are part of the perforamance equation. No need to change the master cylinder...

You're assuming the pads area is the same for any given caliper. It's not always the case.

I do agree with you tough. The number of piston by itself is pretty meaning less.