Redrilling brake discs

[VeeDubGTI16v]

jeez you could have used solidworks, autocad is soo last year 

[jammac]

Since it's such a popular phrase around here..

as an engineer.. the wheels hold the brake discs on anyway.. BUT 4x100->5x100 is a tricky conversion. You'll use one original hole and space out from that, but that won't give you the (and this is the 'as an engineer bit') 3xdiameter of the bolt spacing you need. You'll end up with 2 situations of a smidge over 15mm c/c, which with a 1mm oversized hole for the M14 bolts means you'll have an overlap as per the pic below

Which means at any given time in any direction under braking you'll have the rotational resistance in the disc spread over 4 bolts rather than 5. I could now spend several hours in calculations involving applied forces for shearing but why bother when 4 stud cars drive around fine without shearing hub studs?

you seem to have rather alot of time on your hands. like a true engineer huh!

[al_b]

I'm a sound engineer - does that help ? I say attach some reeds to the left over holes and with careful use of the break pedal you could probably play tunes with it.

[pro-biotic]

"perhaps the older holes could be inserted or welded."

You certainly wouldnt want to weld them (too much stress and possible deformation, its a long process anyway with the sort of materials used) and inserts wouldnt do anything but Im with you on the other points.

an insert of an interference nature would do something if you were thinking of any radial forces acting upon the edges of the bolt holes - but as we know the disc is clamped 
if an insert was skimmed over so the faces are true it would help uniformly distribute the load - only thing to watch out for is thermal expansion of dissimilar materials.

the welding point i agree with the temps would cause hardening thus internal stresses (i aint a materials kinda person) - and would distort - but a quick skim would true up the disc.

personally i reckon too much work tbh mate

[ozegti]

Amazingly, i've sorted this out 2 pages ago!! just bought the right hubs and carriers, pulled my flanges from my the VR6 hubs and away we go! Still interesting seeing who actually knows their stuff and who just say no- because it looks scary!

Cheers for a good read guys/gals!

[danny_p]

still say buy undrilled disks,  just because the companies don't advertise them dosent mean they cant be perswaded to sell them

[DarnPB]

Amazingly, i've sorted this out 2 pages ago!! just bought the right hubs and carriers, pulled my flanges from my the VR6 hubs and away we go! Still interesting seeing who actually knows their stuff and who just say no- because it looks scary!

Cheers for a good read guys/gals!

Give me a break! Does not look scary, just looks fcuking dangerous!

[JC]

 

[ozegti]

Amazingly, i've sorted this out 2 pages ago!! just bought the right hubs and carriers, pulled my flanges from my the VR6 hubs and away we go! Still interesting seeing who actually knows their stuff and who just say no- because it looks scary!

Cheers for a good read guys/gals!

Give me a break! Does not look scary, just looks fcuking dangerous!

yes, they do look F'n dangerous, but there was a set of wheels i have seen that came factory with bolt holes VERY similar to the 5x100/4x100 drill pattern. THAT was scary! What holds your wheels on?

I can understand that brake discs are clamped by the wheel, but if you take the meat of the metal from the trailing side, then you'r more at risk of doing risky damage. From the leading side (as the wheel rotates meaning the wheel stud will locate against t he undrilled part of the disc, I don't see MUCH issues with doing it that way, but I wanted to know if th ebolt holes were alligned or not. It was answered, so it's all good. But if you want to rant on and on trying to prove a point that was made ages ago.. go ahead!

I just think it's funny!

[mattneck(Beavis)]

im sure ive seen multi fitment discs before.. 

ill try and find the set at work tomorrow.. im sure there was lots of holes on a set i saw once! and no.. they werent cross drilled before somebody asks.