other models brakes fit?

kinkyllama · Post by **kinkyllama** » Thu Apr 06, 2006 6:17 pm

Audacityracing wrote:what are the cars in question?

The Nubira is closest. Followed by lanos, and astra, then the saab. But this is just the rotors.. I dont know if any of those cars calipers fit, I know the saabs does.. or most likly does, according to Chris

Audacity Racing · Post by **Audacity Racing** » Thu Apr 06, 2006 6:22 pm

i meant, why don't you look at cars that have the same 114.3 pattern...

drilling new holes in a brake rotor is dangerous. i know it works... but the hat becomes extremely weak if you take a 5 lug and convert it to 4

kinkyllama · Post by **kinkyllama** » Thu Apr 06, 2006 6:42 pm

Audacityracing wrote:i meant, why don't you look at cars that have the same 114.3 pattern...

drilling new holes in a brake rotor is dangerous. i know it works... but the hat becomes extremely weak if you take a 5 lug and convert it to 4

How so? I mean.. there doesnt seam to be much stress on the rotor itself besides the braking itself which I wouldnt think effect the hub that much.

I'd think making custom calipers would be more dangerous and harder. Although if I can find rotors w/ a 4x114.3 pattern that are 288mm (the same as the saab rotors) I can just use the rotor with 4x114 pattern with the saab caliper

kinkyllama · Post by **kinkyllama** » Thu Apr 06, 2006 7:11 pm

I think the saab 9-3 rotors I found actually already have a 4x114.3 bolt pattern. Alot of the listings list the rotors both for 9-3 and 900. The 9-3 has a 5lug and some of the 900s have 4x114.3

*edit.. yess.. both the 9-3 and 900 brake rotors have the same part # which means the rotors already have a 4x114.3. All I'd need is to get a hubcentric ring

kinkyllama · Post by **kinkyllama** » Thu Apr 06, 2006 7:58 pm

kinkyllama wrote:I think the saab 9-3 rotors I found actually already have a 4x114.3 bolt pattern. Alot of the listings list the rotors both for 9-3 and 900. The 9-3 has a 5lug and some of the 900s have 4x114.3

*edit.. yess.. both the 9-3 and 900 brake rotors have the same part # which means the rotors already have a 4x114.3. All I'd need is to get a hubcentric ring

What do you think about the strength of the hat since it comes drilled wiht a couple different bolt patterns?

Also could I or should i trade out the entire brakes with the Saabs.. like the master cylinder and all. Im guessing since its bigger brakes and the master cylinder and other things might be more beefed up. Plus I can get stainless steel lines and all

DomWoo · Post by **DomWoo** » Thu Apr 06, 2006 11:38 pm

you have to remember its pretty damn thick.. i dont think it would weakin it much at all and when the wheel pressed against it, it would be solid

kinkyllama · Post by **kinkyllama** » Thu Apr 06, 2006 11:48 pm

DomWoo wrote:you have to remember its pretty damn thick.. i dont think it would weakin it much at all and when the wheel pressed against it, it would be solid

Thats what I was thinking. Like on wheels the stress is moved onto the hubcentric ring.. since i need one to make the rotor fit that takes even more stress off the rotor itself

Audacity Racing · Post by **Audacity Racing** » Fri Apr 07, 2006 1:22 am

problem is this....

holes that are cast into the metal have a uniform metal shape underneath. if you go back and drill holes, you rip apart the metal structure. all of the force when braking a car is placed on the lugs. if the holes around the lugs are weak... then you can get hat failure. since you have a track car... i would in no way do that, and as a scrutineer for the SCCA ... if i saw it on a track car i wouldn't allow it to run.

let's do some finite element analysis

standard rotor from a saab 900...

with the new drilled holes

notice the red circle indicating a HUGE amount of metal deformation (the whole is slanted from force). if this were to happen... you would risk sheering a stud off or maybe never getting the rotor off because of compression against the stud or even (worst case scenario) have balance issues and have the front suspension shake itself to death.

if i would have done these forces at 100mph to 0mph the metal literally folds the extra holes shut and the rotor changes shape. the stress isn't much... but it's applied as such to move the metal in a bad way

kinkyllama · Post by **kinkyllama** » Fri Apr 07, 2006 3:17 am

ahh, Alright I understand.

But I found out the rotors already have a 4x114.3 from factory.

DomWoo · Post by **DomWoo** » Fri Apr 07, 2006 4:25 am

sence its that one hole would it be easy to weld and redrill to only one hole?

Audacity Racing · Post by **Audacity Racing** » Fri Apr 07, 2006 4:26 am

look again... i count 4 holes with metal deformation... two of them are on your studs... which means you'd run a risk of sheering a stud at higher speeds (like the track speeds kinky would see)

kinkyllama · Post by **kinkyllama** » Fri Apr 07, 2006 2:36 pm

Audacityracing wrote:look again... i count 4 holes with metal deformation... two of them are on your studs... which means you'd run a risk of sheering a stud at higher speeds (like the track speeds kinky would see)

lol, for the third time... but this is the way the rotor comes from factory, with both 5 and 4bolt patterns.. one of which matchs my car. Is this still a risk?

Audacity Racing · Post by **Audacity Racing** » Fri Apr 07, 2006 2:37 pm

yeah, the argument made was that the rotors that have the 5 and get drilled to 4 is dangerous.

kinkyllama · Post by **kinkyllama** » Fri Apr 07, 2006 2:40 pm

Audacityracing wrote:yeah, the argument made was that the rotors that have the 5 and get drilled to 4 is dangerous.

Thats how they come factory stock on the saab 9-3, 9-5, and 900 (II).

ant0ny · Post by **ant0ny** » Thu Apr 27, 2006 9:42 am

Check your rotor suppliers... In Australia I can buy rotors with no holes drilled from DBA.. then just drill my own.

To drill holes I normally just get the original rotor off you car.. make a spigot the same size all the centre hole of the rotor.. if you have a new rotor that has a smaller centre hole machine it to the same as the old rotor.. if the hole is larger you will have to make an adaptor to make the centre the same size.

Using the spigot to line up the centre hole you can drill or mill (this is better) the stud pattern.