Whats the difference between grooved and drilled discs and just grooved discs?? is 1 better than the other? Which would be better for me as i dont do any track days but i do enjoy driving with a smile on my face?

 

Drilled ones crack....................

 

When pads get hot they give off a gas , and the gas gets stuck between the discs and pads and pushes the pads off the discs causing brake fade , you can combat this by having drilled or grooved discs as its somewhere for the gases to go.

A grooved disc will also deglaze the pads if they glaze over from overheating , and the grooves are somewhere for the gases to go so keeping the pad on the disc , again similar with a drilled disc , the problem with a drilled disc , is you are drilling through the grain structure of the discs which causes a weak point in the disc which then leads to cracking , this doesn't happen with grooved only discs.

I am offering deals on grooved discs for all model Impreza's , either check out my group buys , or email me ian@godspeedbrakes.co.uk or phone 01656 723060

Cheers Ian

 

Even plain discs can crack:



What is most suitable will be down to your driving style and what pads you choose. We supply drilled and grooved discs together with Kevlar pads and have never had a problem. If you choose a more aggressive compound we may recommend grooved only, but with the Kevlar pads being just one stage up from OEM we have no issues supplying drilled and grooved brake discs with Kevlar pads.

They do look nice and work well: https://www.scoobynet.com/showpost.p...93&postcount=1

We also supply grooved only (as well as plain).



AZTEC PERFORMANCE ONLINE STORE - WHOLESALE PRICES DIRECT TO THE PUBLIC

Give me a call if you need any advice 01462 488244

 

Yes plain discs can crack , but your picture is taken from a web site selling lorry discs , and they say its down to faulty calipers ect which I agree with , so its not relevent to your reasoning about drilled discs not cracking.

http://www.juratek.com/UserFiles/Fil...%20English.pdf

If you drive a car hard , and do track days you will get heat crazing , small cracks in the surface of the discs , this is normal and acceptable for the use , if you drill a disc it will end up cracking through the holes then right accross the width of the disc , you are producing a weak spot where the discs are drilled , grooving a disc does not produce a weak spot , which is why they are the chosen discs of just about all forms of motorsport.

I have been machining discs for around 18 years , back in the day , I was the person who came up with the idea of grooviing and drilling a disc , so have been there and got the tee shirt ! but as fast road pads have come on , the heat ranges have increased , this then brought about the problems of drilled discs cracking.

I am not saying this to be agumentative , I am saying this as proven facts over many years of making and machining discs

Cheers Ian