Well; I suspect the solution involves using that special tool known as 'the wallet'

I'm fairly sure my rotors are warped and I have questions to ask of people.

This is mainly aimed at Lower, Chilled and Dembo as I know you chaps are hardcore track users but I welcome input from anyone.

I tracked the car recently with the OEM rotors and Ferodo DS2500 pads; after only 3 laps the rotors were a nice shade of blue? Someone on here mentioned that this is an indication that the rotors have been heated beyond thier designed operating temp; Is this the case?

Beyond the track day the rotors have slowly begun to warp; I know this because they are on-off-on etc when I brake gently but with a constant pressure.

So; I'm looking at changing the Rotors and am considering the DBA 4000's; Reason here is that Chilled mentioned to me that Lower has had great success with these rotors and the Ferodo Pads.

Looking at the rotors themselves and it looks like DBA make a few variants :-

Standard
http://www.dba.com.au/view_product.php?par..._series_id=4422

6x6 Wiper Slot
http://www.dba.com.au/view_product.php?par..._series_id=4422

Cross drilled and Slotted
http://www.dba.com.au/view_product.php?par..._series_id=4422

Lower; Which are you using? Are there any issues with fitment?

And the big question; If I upgrade to these Rotors will they take the punishment and not warp? Or Is the warping simply not related to me blue-ing the OEM rotors?

All advice, pointers, knowledge etc welcome

 

You can blue disks without warping them.

Sometimes it's just a pad deposit that makes you think they're warped. To get rid of this:

Find a nice quiet stretch of road, get your brakes up to temp and do about 3-4 high speed stops, ie 70-0. You may want to move those speeds 30 mph north of that. But I couldn't comment.

If you still have the problems, if you can be arsed, you could clean the faces of the disks with aluminium oxide paper, re-bed them in. It may go away. I never bothered trying this because I'm lazy.

Otherwise the main two routes are Dixcel or DBA.

 

Are you sure your caliper isnt just sticking?

 

Blueing of the discs doesn't necessarily mean you've warped the discs, just that you've got them hit.

When you say on off, do mean they vibrate when you're braking or that they're grabby?

You want the 4000 series with wiper slots only. The holes weaken the disc, make it more likely to crack and DBA don't recommend them for heavy track use. The 4000 series have the special cooling fin design that helps stabilise the disc and make it less prone to warping and they are also heat treated which makes them harder wearing and again less prone to warp.

These are the only discs i haven't cracked or warped with the Ferodo's on the track.

No issues at all fitting them. They fit exactly the same as OEM and are proving to be very hard wearing too.

I bought mine from Clark Motorsport

http://www.clarkmotorsport.net/cart/

speak to Euan there. He's very helpful.

 

OK; There's no vibration as such but they are grabby; ie, they grab hard, then less, then hard again etc and it's clearly cyclic; ie it's predictable when it will grab a bit and then release again and this speeds up and slows down as the car does. It's becoming embarrassing tbh when slowing down gently for lights etc, the car clearly kangarooing as though I'm stabbing at the brake pedal on and off.

I'll try what you are suggesting Chilled with the firm braking; If no luck then I'll replace with DBA slotted.

I'll also have the caliper checked JD.

Thanks chaps

 

At what sort of rate? At 30mph, the front wheels are turning roughly 8 times a second (by my quick calculation), so you can see if the disk was warped you'd feel a vibration rather than a slow variation.

I found the Ferodos had so much initial bite it was sometimes hard to brake smoothly at low speed.

 

I blued my OEMs with OEM pads on my first track day. I've since fitted Redstuff ceramic pads and DBA front discs. The power is increased, as is the bite. Hopefully I'll be going to Oulton Park in November so we'll see if I've cured the heating problem!

 

That doesn't sound like warped discs. Warped discs give you a judder you can feel through the steering wheel, the brake pedal and the whole car. It feel similar to your front wheels being out of balance, but only when you brake. The harder you brake the greater the judder.

 

In my opinion OEM discs are excellent quality discs. Most people in Greek forum have done many trackdays with OEM rotos and i haven't heard having any problem with OEM discs. It may not be as good looking as drilled discs but they have superior quality. It is very difficult to wrap an OEM disc and the blue colour doesn't mean wraped disc. Most probably the pads are not combatible with OEM discs.

 

Right OK so they likley arent warped then; I've only really noticed it when going very slow and coming to a stop; maybe 10mph down to 0mph.

So it's more likley to be the pads have left some residue or something like that in which case Chilled's idea of some aggresive braking may be the solution in cleaning them up a bit.

Cheers everyone

I'll be trying the DBA 4000 slotted discs at some point further down the line then