z31 brakes

[tyrannix]

on the mission for more stopping power, i have a full z32 brake swap ready to install.the only thing is my rims, the fronts will need a 12+mm spacer to clear (i like my rims)and i discovered that the z31 turbo calipers are just as beefy, but the pistons are all inboard, so almost any wheels will fit

im about to buy some rebuilt z31 fronts,im 99% sure they will bolt right on, but does anyone know if the s13-z32 brake lines will work for the z31s as well?

eidt> also, got to thinking, how much will bias be affected by this, and are the z31s the same as q45s?

anyone running z31 or q45 fronts? with or without z rears? with/without Z master cylinder

and which lines do you need for the q45 calipers, stock S lines, or the S to Z adapter lines?
Modified by tyrannix at 4:57 AM 11/6/2005

[SimpleEnigma]

The z31 brakes are not the same as the q45 or Z32 brakes. The Q45 brakes are the same as the Z32 brakes, except they take a banjo fitting like the 240sx, which is why peeps switch to them, so they dont have to go with special brake lines.

The Z31 brakes are single piston floaters, the same as ours except bigger, and they should also be a direct swap, since the z32 brakes are a direct bolt on affair for the Z31 guys.

If you want the better stopping power, i would suggest staying with the Z32 brakes, since they are a lot better than the z31 brakes.

Lots of people do just the front brake swap, since the front brakes are the ones that do the majority of the braking work. You can swap both front and back calipers if you want, though the back take a little more work if you want to retain the hand brake. there are a lot of posts on how people adapted the different hand brake setups on the calipers to work with the 240sx.

Oh, and you dont necessarily need to change the MC. for the most part, changing the MC really only affects the pedal feel, though it does have an effect on the pressure distribution between the front and rear calipers. the Z32 MC sizes vary by year and whether it was turbo or not. there is a write up on the different sizes here somewhere, you have to look for it. if you do swap to the Z32 MC you have to slightly modify it to work with the the 240sx hardlines, and that is also here somewhere. if you were to search Z32 MC or 300zx MC you would prolly find what you are looking for.

[tyrannix]

yeah, thats the thing tho, i have a full z32 swap (front rotors, calipers, rear rotors, calipers, knuckles and ebrake cable) and the front and rear S-to Z brake stainless lines (projectsilvia i think)

but the z 32 fronts are too big for my wheels. so i can get rebuilt Q calipers for $45 +shipping each, or rebuilt Z31 turbo calipers for $90 + shipping each

my choices are

A. 18mm wheel spacers

B. get wheels with more clearence

C. get front inboard mounted piston calipers ( Z31 and Q445 looking like the best choices)

i feel safer not using spacers, and i like my rims alot, so a and b are out

i can sell my Z fronts no problem...

my question was really: do Q and/or Z31 calipers use Z fittings (so i can use the stainless lines i have)

sidenote, ive read a few articles that actually tested a front only swap vs stock brakes (using teh same type pads)and the front swap only did have a faster deceleration, but because teh bias shifted so much, the actual total stop distance was something like 11 feet more for the front only swap

its like like this chart (i dont remember where i read teh article tho)

so i am doing the rear Z brakes, i just need to find a different solution for the fronts... wether the Q45 or the Z31 will do me better (ill worry about bias later)supposedly teh Z31 have more piston area, with 2 bigger pistons mounted inboard, but i need to verify this before i go buying more brakesthats why im asking if anyone has done it, i cant really find straight answers elsewhere (the archives didnt really help much)

edit> and im talking about the 88 gen turbo z31, it had 2 pistons inboard slider type

edit2> and the correct z32 MBC will go right on an s13, an s14 needs to bend the hardlines a bit

[tyrannix]

ok, just reread youso if im understanding right, the Q45 is the same caliper as teh Z32, but with the S-chasis fitting, so they can use stock linesthe Z31 is a different caliper, but uses the same fitting as the Z32

so if all that is correct, then i should go with the Z31 calipers, they use the stainless lines i have, and will let my wheels fit on

but>http://cgi.ebay.com/ebaymotors...ZWD1Vthis is a q45, it has just the 2 inboard pistons .... so the 88 z31 turbo and this q45 both look teh same (dual inboard mounted pistons) but have different fittings.. would that be a correct statement?

[SimpleEnigma]

Actually i made a mistake in my last post. I was under the impression that the Z32 calipers and the Q45 calipers were the same, but used a different style brake line fitting, however this is not true. They have similar size pad area and use similar size rotors, however, the Z32 front calipers are 4 piston fixed, whereas the Q45 calipers are just large two piston calipers.

The Q45 calipers use the same fitting as the 240sx, so you will not have to change out your stock lines, though it will be a good idea, to aid in braking performance. They will also fit under stock steelie or alloy wheels, so clearance should not be an issue.

The early Z31 used a large single piston caliper. The later Z31 turbos ('87 - '89) used a dual piston front caliper, and it should use the Z32 fitting.

So, the Z31 and Q45 calipers may be the same, however, the Z31 front calipers will most likely use the Z style fitting.

i apologize for the misinformation in my previous post.

[tyrannix]

thats cool

i deduced about the same...

unless somone else has new information to add (like which one is actually beefier, the q45 or z31) ill be looking for standard S stainless lines... that will decide which i get.. whichever is cheaper Q + new SS lines, or if i can find rebuilt Z31 cals for cheaper

[SmithSR]

The Q weighs about a third again more than the Z31 so I'll pick Q45 calipers and pads over the Z kit, although there may be more to it. Just don't overlook that fact.

If you have a full Z32 kit, do that. With all the smaller pieces in place (SS lines, really good pads, 1-1/16 MC) these brakes are fascinating.

Good luck.

[tyrannix]

i do have the full z32 kit, but again, my wheels wont clear them

im about 25/75% for spacers/different brakes

[SmithSR]

Then space them..or pick up some S14 SE alloys! or maybe Z32 wheels... both look great on the S chassis and both will clear the Z32 kit quite obviously.

This always happens when we start the domino effect of modifications. One expense leads to another. All in all, a joyful experience!!

[GhostDriver]

Dude, this should be a no-brainer. If you've already have the Z32 hardware then just bolt it up with a hubcentric spacer.

[tyrannix]

it *was* a no-brainer, thats exactly what i was doing, then found that the spacers will put me a little past flush.. i might get away with rolling my fenders (its pretty low) but i wanted to explore stealth brakes as well before i go that routebecause i also have a rear 5 lug swap, along with the full Z32 brake swap ive got half of a bunch of options to work out... spacers, 5 lug swaps, going with different fronts,

can*of*worms

and i have a set of ARP lugs to put on as well, id need to get longer ones to use a spacer (using the double-bolt type of spacer would be pointless, unless i got another set of arp hardware anyway too)

spacers will be around $200 for a full set in the size i need, but Q calipers can be done for $45+shipping (each) so around $120 for the fronts.. then again, id still need the rotors, but im planning on getting some nicer rotors for the Z32 brakes anyway

going to sleep on it again, but now, yeah, ill probably go back with just getting the spacers and call it a day