Fracturing front disc

Guys I just noticed the front disc are starting to fracture.So looks like i'll be doing brakes next.So as there's a few sorts do I stick with the old style or go for drilled and grooved discs.Why do they fracture?
couldn't find no answers.

What year? are they OE disc.
DBA do a great Rotor just about to change myself to slotted and grooved but will see what others think first
maybe no good in mud and slop all the time.
Fractured disc unless its red hot and dunked in cold water I'm lost. but may have happened before.

is photo possible???

Sounds like they're getting too hot. Do you drive an auto? If not, the use of engine braking is a good way to help keep the disks cool. I've got rda dimpled and slotted rotors in mine. The drilled rotors are prone to cracking and filling up with mud.

Yeah heard that,
maybe just grooved
,worked ok on other 4x4 very well
or do they look cyrstalized

tried to take a pic but cannot see them with ipod(camera spat it the other week)they are very fine cracks,but lots of them,
tr is 93 gq I presume there the old originals. and yep its an auto

Small cracks in disc`s is common especially if the brakes are abused.
Dont worry to much about it and if the disc are with in spec just re machine them.
All so aggressive pads can cause cracking and heat spots
New disc`s need to be bedded in properly as most are very green and will warp, get heat spots and give grief if not normalized correctly
The holes in the drilled discs give the disc a larger surface area for cooling and the slots are there to try and keep the pad surface clean.

Could those who have changed from OE rotors & pads to aftermarket items comment on whether their braking performance improved & if so how & in what conditions.

Although the brakes on my heavy Patrol are adequate, they are certainly not confidence inspiring if needing to stop quickly from speed, & I have wondered if just changing rotors & pads on the front might give some worthwhile improvement.

Cuppa

Cuppa
Different material combinations give different performance also different brand combinations
It`s all experimentation,I have allways run genuine disc`s and Bendix pads.
Heat is your enemy but it can be used to your advantage if you know what temps you run at, then find a pad ,disc combo to suit.
This is all race teck, but with an infra red thermometer you can get some idea of where your at.

@ Cuppa Ron Moon has an extended GU dual cab and last I heard he was running BDA brakes with Kevlar pads
I can find out more on Monday if you like as his Patrol is quite weighty.
I had slotted only in the Troopy , they improved my braking heaps. If you have concerns ring Hopper Stoppers
in Hoppers crossing they can get anything to stop on a sixpence

I feel like my troll pulls up quite well since changing my discs and pads. I have dba rotors and qfm pads. Biggest improvement I made was rebuilding the brake calipers. It's really easy, and made a massive difference to my stopping ability