xA6x, xZ1x, xX7x + others FRONT AND REAR Brake Upgrade

[CrUZida]

I'd pretty much decided to adapt the stock calipers to the Z32 disc.
They are the same width, so fitment is no issue.

If anyone wants to buy the brackets I made (as seen in the pics) PM me.

If you guys want I can finish designing the brackets properly, and make them available for sale.

[Stefan]

[finally got approved so can post!]

I'm interested in a kit for the rear, if you develop it.

Are you still leaning towards using the stock calipers? If so, would I be able to grab some measurements to I can compare them to the solid disc rear calipers I have?

[CrUZida]

No!
No longer using the stock calipers.
I'm going to use a Skyline master cyl or brake bias valve, what ever they use for bias.

The Z32 rear calipers are going on.



Which kit would you want? stock calipers + z32 discs, or all z32?

[Draven]

matter of curiosity... why did you end up going for skyline rears (thus necessitating new mast cyl, bias valve etc) over the bigger stock calipers, which work with the stock m/c ?

apart from the fact that GTR stuff will be a bolt up for when you're rich.

[CrUZida]

For the bling!

Nah, plus, on the engineering report, it will be all Skyline on the brake system part of it, should make it easier.

[Stefan]

Which one do I want? Whichever is better My prefference is for Skyline gear all round, just have to find some for the rears now.

If upgrading both front & rears, I don't see bias being a problem with the stock toyota bias valve...

I deliberately got different offset rims front & back (+22 fronts, +12 rears) to compensate for the r32 fronts with stock rears. Turns out that I could have got +22s all round after all and made things a lot easier! Guess I'll be getting some bonus rear track unless choose not to use the 6mm spacer (The way the kit will work, is the 6mm optional and all other parts would be the same?).

[Yian]

Peewee,

Got my hands on front z32 calipers for cheap. You still have some adaptors/rings for these to go onto z32 discs eh?

Yian

[wilbo666]

I was under them impression that braking bias would also be effected by the diameter of the disk being used. This might not really have an effect when on the front as the fronts should lock before the rears, but I suspect the upgrade on the rear will have an effect on the bias, even if the stock caliper is used due to the larger rear disk?.

Wether the effect is large enough to upset the bias enough to give rear lockup before fronts I don't know. I would imagine that someone, somewhere, once upon a time created calculations to simulate bias given the input variables...?

btw, kit looks awesome dude

Cheers
Wilbo

[Draven]

Guess I'll be getting some bonus rear track unless choose not to use the 6mm spacer (The way the kit will work, is the 6mm optional and all other parts would be the same?).

this is a BIG question for me too - I can only afford to have a small increase in track on the rear, if at all.

[CrUZida]

Got my hands on front z32 calipers for cheap. You still have some adaptors/rings for these to go onto z32 discs eh?

If you mean for the front, yeah, I gots some.
Shoot me a PM

If upgrading both front & rears, I don't see bias being a problem with the stock toyota bias valve...

Did you read the above posts?
The Z32 pistons are 27% smaller, so they need ~27% less fluid to work.
Stock bias valve = rear locky locky.

I deliberately got different offset rims front & back (+22 fronts, +12 rears) to compensate for the r32 fronts with stock rears. Turns out that I could have got +22s all round after all and made things a lot easier! Guess I'll be getting some bonus rear track unless choose not to use the 6mm spacer (The way the kit will work, is the 6mm optional and all other parts would be the same?).

Check with Frank, I think he has enough room to fit an extra 6mm track per side in the rear, and still clear.

Can it be done without it, probably, but you'll need to bend the dust cover to fit it.
And it will still increase track ~2mm per side, as the disc is thicker.
The spacer will be slightly different, but easy to do.

And Stefan, I have a spare set of rear calipers if you want them.
$150 incl post.

[Stefan]

Yes, yes, read whole thread. But amount of fluid req'd for rear calipers isn't the whole story - apart from the fact that the rear caliper is biting onto a bigger disk, we aren't just upgrading the rears. We also happen to have a big front upgrade which is a VAST improvement over stock. Just upgrading the fronts with stock bias would mean more front braking; just upgrading rears would mean more rear braking; upgrading both I imagine would put it back in the ballpark.

Oh, there's oodles of room in the rear of non-flared xA6xs, I was just talking about ease of having same wheels all round (rotating tyres, cheaper/easier to buy set of 4x +22s than different pair as +12 are much rarer, funnyness with spare tyre yadda yadda), and the handling considerations of increasing the rear track a little. But the handling is prob non-issue or improvement.

If the spacer is infront of the hubs rather than behind, does that mean more stress on wheel bearins etc (same adverse side effects as fiting wheel spacers?) Or am I missing something?

I'll PM you re: calipers.

[CrUZida]

Yeah, Wilbo brought that to my attention the other week (disc size vs piston size thingo)
I'm not going to worry about it. I'm going with Z32 calipers all round, and Z32/Skyline bias, whatever I manage to get hold of.

Feel free to do some calcs and post up the results.


As for the spacer, there is only one place it can go.
Between the hub and the wheel.
Which side of the disc its on doesn't matter.
You were missing something.

[Stefan]

I realsie the spacer can't go anywhere else... let me rephrase that:

Given that the spacer has to go between the hub and the wheel, isn't that just as bad as using a wheel spacer (which puts stress on bearings etc etc and that most engineers won't approve).

[CrUZida]

Ok, I see now. (you did say 'spacer behind the hubs' which doesn't make sense)

That's why I'm going to +35/+32 all around.
Therefore I'll have +27/+24 offset weight on the hubs, which is the same offset as the factory 5.5" rims.

Your +12's will go down to +4, which is only 4mm more than factory rims.

I don't see that being a problem.

[Stefan]

Ok, I see now. (you did say 'spacer behind the hubs' which doesn't make sense)

That's why I'm going to +35/+32 all around.
Therefore I'll have +27/+24 offset weight on the hubs, which is the same offset as the factory 5.5" rims.

Your +12's will go down to +4, which is only 4mm more than factory rims.

I don't see that being a problem.

My rims are 16x7.5", not x7". IIRC that puts the outside edge in about the same place as the outside of stock 7" +8s.... so adding another 8mm will be making the outside edge sit another 8mm out, not 4. But... that's still not that much, you're right.

May be a silly question, but will most brake places bond additional material onto drum shoes, or will they look at you funny and go, "huh?"?