Nightpager Brake upgrade supra 323mm disk walkthrough for z20 soarer

[oldcorollas]

grinding will often reach red hot in the local area = maybe around 6-800deg or higher. can easily reach 1-200 or more after you have been grinding for a while

lathe will be much cooler, especially if they use coolant (but even if they don't... you don't often see sparks coming off lathes)
brakign event will not get the hubs anywhere near that hot.. even race brakes would be struggling, and that it would be the disc, not the hub at those temps. hub = even a few hundred deg = bye bye grease/bearings

are the hubs cast iron or cast steel?

one issue is the localised heating of the small area just outside the studs.
other issue is removing of more (or less) material than is needed, in what is a fairly important area.. ie wheel studs. from the pic, there does not seem to be a huge amoutn of material outside the studs.

i mean, you can surface grind brakes and flywheels with an angle grinder, and do a fairly good job... but do a poor job and there is a big chance of helping cracks start.
on the hub is not as big a deal, but as they say, one dodgy thing leads to another and we, as a club, should be generally encouraging safe practices, rather than dodgy ones.

he might do it ok, but there are less mechanically apt people out there that might fark it up royally while doing it his "safe" way (especially if they use angle grinder , plus issue of grit in bearings etc etc )
plus, if gumby takes a hub to a machinist, at least the machinist has the chance to say "no really, it's gonna be too thin if you take that much off", whereas a benchgrinder man at home may not realise at all...

[oldcorollas]

tbh, i think if you went slowly and carefully, and kept the hub cool while grinding, the metal itself might be ok. but i would still not recommend it.

there is also the issue of how you are going hold it safely while bench grinding...don't wanna be wearing gloves...

i just would have thought lathe would be a no-brainer?

[GU11TY]

i dont mind using a lathe. i can easily get that stuff done because there is a brake shop 2 streets away from my work
i was just doing a write up to help people. i aint doin this write up for my benefit.
as i said on the first your YOU DONT HAVE TO GRIND YOURS DOWN THIS WAY but i was doin a way which was fairly easy and anyone could do
lots of people have just spent alot of money buying a big brake upgrade and then now have extra costs to fit them which they aint happy with. i dont mind spending the extra cash but like i said, doing a way anyone could do

and as its on the grinder its gettin hardly any heat in it at all. its spinning slowly and i only hold it on for short periods of time.
if it doesnt work out i guess we will see in afew wks but like lots of people have said. its 2.5mm and it will be centered on the hub centre and on the studs.

[CrUZida]

while the process is not ideal, i dont feel it is unsafe. grinding can theoretically achieve the same finish as a lathe, if not better.

Can you explain your thoughts behind this statement please Brett? (just the bit in bold)

[TERRA Operative]

If one can spend $1000+ on a brake upgrade, I'm sure an extra $50 to get things machined correctly isn't going to break the bank.

If it is going to be a financial burden, then one needs to either rethink the modification or forgo a few maccas meals to save a few more $$$

[oldcorollas]

but but... $50 is like 4 or 5 big mac meals!

[TERRA Operative]

Gotta stop eating like a king and fall back to the good old Mi Goreng.....

[greywolf]

Or one whale burger !

I think this one should be put to the moderators of this section as to whether or not the write up stays. This pretty much goes to the heart of the rep system, and why it was made so only those who write up in the technical sections can obtain additional rep. So new users who are looking for technical advice can steer clear of bad advice/practices.

The shortcuts, and the longer,more expensive but 'safer' method of using the correct tools and methods of modification both have their place in our community. Both have their pros and cons, and that needs to be be discussed in maybe a calmer and less confrontational manner. If we go blasting everyone who comes up with a 'dodgy fix', then we lose the ability to better educate those people about better practice and give them a choice about how they proceed in the future.

[SillyCarS]

i think there is some serious over reaction here. while the process is not ideal, i dont feel it is unsafe. grinding can theoretically achieve the same finish as a lathe, if not better.

my thoughts
1. removal of 2.5mm is not going to affect strength.
2. the radius that the material is removed is not going to affect balance by fuck all. ive seen factory hubs that are cast with ~1-2mm of runout.
3. i highly doubt the temperature that grinding induces is much higher than a repeated, hard braking event.
4. grinding temperatures will be very localised and for short periods. i wouldnt expect temperatures to be higher than that from a similar metal removal process (Lathe)
5. oldcorollas can comment on the required temperatures and times required to degrade the material's strength. i think ive read around 800degrees with a slow cool-down. is the whole hub really going to reach this temperature?
6. as someone already said, the disc is located by the centre spigot so the outside shape isnt really important.

im not trying to defend anyone but this is my opinion

agree

think of some of the pioneers in motorsport, how balanced was their shit?

[CrUZida]

think of some of the pioneers in motorsport, how balanced was their shit?

So the OP is a pioneer now is he?

[SillyCarS]

come again?

[CrUZida]

You directly compared what the OP did to what the pioneers of motorsport did back in their heyday.

As this was quite a ridiculous thing to do, I decided to take the piss.

[SillyCarS]

OP? im not following mate

i dont even know whos taking the piss anymore

a 360 at 120km/hr.. now that rediculous.

http://www.youtube.com/watch?v=3KqmfYXbNTo&NR=1

[oldcorollas]

original poster.....

you know that "balancing" has been possible since the steam ages....
i'm pretty sure those pioneers of motorsport, often being far more engineer than anyone here.. (you know.. designing and building their own cars and engines), would have paid attention to balancing, especially sicne the early tyres were not particularly happy with wobbles (or anything really)

[Luisito]

This thread should just be deleted(no offence guilty), the community of lolmods if afflicted by this instead of helping out fellow enthusiast like a community its a my dicks bigger that your dick ill prove it by shitting on your chest scenario......, lol i got neg reped for commenting earlier why? meh .