Nightpager Brake upgrade supra 323mm disk walkthrough for z20 soarer

[takai]

From my experience hubs like these are typically forged from 4140, or similar, then fully annealled and machined.........lamellar pearlite is the microstructure.

Z20 hubs are cast iron. I machined some shavings off one i have here, there is no way in hell its any form of Cromoly, and no way in hell its forged.

Oh and it took <20s on a bench grinder to get the area between the stud and the outer diameter to >450deg (max the IR thermometer i have can read).

[GU11TY]

y were u holding it on for 20 seconds at a time. like i said before just hold it on for about a few seconds at a time and there wont be a problem

[dangdang]

Over reaction by some....possibly...

You could simply file the inside section out by hand, whether done by man or machine the final result is the same.

And balance...the mass at that point of the centre section of a wheel assembly by the difference of a few mm would be negligible.

That said there is a right and a wrong way to modify parts of a motor vehicle and any one in the know will simply realise this is potentially very wrong.

Just for the bloody mindedness of a few dollars to have it done correctly and there is also the the chance that this information is passed onto those that don't grasp what can and cant be gotten away with safely THEN this info becomes problematic.

If it was my vehicle then it would be machined, this is the correct way and I would NEVER recommend anything different.

[gianttomato]

The recommendation for use of an angle grinder is dodgy as fuck. I called it out. If mods/presidents of clubs can't see why, then I'm disturbed.

The recommendation for the use of a bench grinder is equally questionable. Entering into a long winded discussion about metallurgy suggests many have missed the trees for the forest. Where is the reproducibilty/quality control? I'm sure he'll get a few right in amongst the others that are out of round or off centre.

A lathe is quick, reproducible, ensures centrality, maintains the same amount of material outboard of the stud and is cheap relative to the cost of a brake conversion.

Furthermore, it should be noted that no engineer will sign off on a machined hub.

This is a forum for modifying Toyotas. The onus is ours to do this responsibly. Questionable practices do nothing to enhance our social standing particularly when a faulty component fails and places lives at risk. The moderators have a responsibilty to delete rubbish recommendations, not to encourage them.

[TheToyman75]

GT,

Last I checked I wasn't the dodge police, and you will notice I didn't remove any of your posts. Neither myself or any Moderator is in the habit of removing content just because its not "safe practice". We don't censor peoples opinions and I'm not your mum or your work cover representative.

People reading the thread can decide for themselves how much dodge factor they want in any of the mods they do and this one is no different. Its been called out, the reasons why not to do it are there and really that's all that needs to be done.

There is always a few right ways and an ass load of wrong ways to do things and if someone suggests something that is a tad questionable then its great that it gets pointed out and then other people reading about it can make there own call and improve on the process.

Posting pics from unrelated accidents and adding useless dribble however does not add any merit to the discussion and its posts like that which were removed.

[JZA70 R]

The recommendation for use of an angle grinder is dodgy as fuck. I called it out. If mods/presidents of clubs can't see why, then I'm disturbed.

The recommendation for the use of a bench grinder is equally questionable. Entering into a long winded discussion about metallurgy suggests many have missed the trees for the forest. Where is the reproducibilty/quality control? I'm sure he'll get a few right in amongst the others that are out of round or off centre.

A lathe is quick, reproducible, ensures centrality, maintains the same amount of material outboard of the stud and is cheap relative to the cost of a brake conversion.

Furthermore, it should be noted that no engineer will sign off on a machined hub.

This is a forum for modifying Toyotas. The onus is ours to do this responsibly. Questionable practices do nothing to enhance our social standing particularly when a faulty component fails and places lives at risk. The moderators have a responsibilty to delete rubbish recommendations, not to encourage them.

I think this accurately sums up the underlying issue, and what most people are thinking and or trying to convey through their posts. Well said.

[GU11TY]

but my main concern is still how much material there is remaining around the studs after 2.5-3mm is removed, and what that does to material stress around the stud holes

ok mate measured it today and from the edge of the stud to the edge of the hub is 12.5mm so taking 2.5mm off your left with 10mm around the studs which is more then enough.

[e30-323ti]

One would think...

That the JZA80 having the same PCD would have a similar offset from the stud to the outside of the hub-flange.

But there will likely be other differences in the hub-flange to make up of the smaller OD.
Metallurgy, Thinkness etc...

[GU11TY]

first two posts updated