280 to 300mm disc options

[Rob7655]

Last year I fitted brembo callipers using the pms kit, I've decided to go to 300mm discs but I didn't realise I'd need a different mounting kit.

Is there any other options before I pay nearly £200 for the pms brackets?

Thanks

 

[Rob7655]

Or has anyone got a 300 mounting kit for sale?

thanks

 

[Rob7655]

 

[MLB]

Or has anyone got a 300 mounting kit for sale?

thanks

I will have to have a look but yes I think I do have a 300mm kit!

 

[Clio_fool]

Did pms machine the calipers for you? Iirc they machine a counterbore in the caliper, how much flat mounting face is left after that? Pms we're the only ones making the 280 brackets like that so any 300 bracket you find won't sit in the counterbores and you may have minimal face to face seating.

 

[Rob7655]

Hmmm, I bought the car with the calipers in the boot, the 280 kit fits no problem,

 

[Clio_fool]

Is it this kit? https://www.pure-motorsport.co.uk/brembo-280mm-brake-bracket-kit.html

 

[Rob7655]

Is it this kit? https://www.pure-motorsport.co.uk/brembo-280mm-brake-bracket-kit.html

Yes , I purchased the kit direct.

 

[Louis]

Hmmm, I bought the car with the calipers in the boot, the 280 kit fits no problem,

They must have been machined though?

 

[Clio_fool]

So your calipers would have been machined like this to fit the brackets.

Every other 280 kit the caliper mounting face is just machined down by 5mm but now you've not got much flat face to bolt the 300 brackets to.
This is the face -5mm.

And the bracket on.

And these are brackets for 300mm discs on the car.

 

[Louis]

Wonder if you could just make some turned spacer adaptors to extend them further out.

Little top hat stylee

 

[Clio_fool]

Wonder if you could just make some turned spacer adaptors to extend them further out.

Little top hat stylee

You'd need to space them out 10mm and the bores are only 11 deep so you could only do it with a big washer and then location is by the bolt and it's still sat on what's left ot the caliper mounting face.
Best thing to do is stick with 280 discs or sell the calipers and brackets and buy new for 300 discs.

 

[Rob7655]

They must have been machined though?

They must have been, thinking back the brackets were on the calipers I just had to order the bolts from pms!

 

[Rob7655]

Ohhh, thanks for explaining that! Looks like i better have a re think.

 

[MLB]

What's the reason that you want to go to 300mm discs?

I've not noticed any difference with mine on track between 300 and 280mm discs.

If anything with 280mm discs you have a greater choice of wheels that fit. 300mm was a right pain because of wheel balancing weights touching the calipers.

 

[Louis]

You'd need to space them out 10mm and the bores are only 11 deep so you could only do it with a big washer and then location is by the bolt and it's still sat on what's left ot the caliper mounting face.
Best thing to do is stick with 280 discs or sell the calipers and brackets and buy new for 300 discs

Let me draw what I'm thinking

 

[Rob7655]

So basically my callipers have had to much machined off.

 

[MLB]

Let me draw what I'm thinking

This can go wrong in so many ways.

 

[Clio_fool]

So basically my callipers have had to much machined off.

No. The pms brackets don't remove any material off the face as the bracket fits into the counterbore machined into the caliper. It's all to do with thread depth on the bracket, some noobs on Facebook made some that sit on the caliper face and the bolt screws into the bracket but you only had 5mm of thread depth which equates to 3 threads holding your brake caliper on, not good. The pms way gives more thread depth in the bracket. I fitted studs to the ones I made and had a nut on top of the caliper instead.