Paging the people what know

Why do you feel the need for grooved discs on a 406?! It's not exactly a trackday tool is it? Unless you've got an M3/M5 and are using it for fast road/track hooning, you'd never notice the difference. Standard discs and good quality (Pagid or similar) pads are all you need I'd think. Disc warping has nothing to do with whether they are drilled/grooved or standard. for the record, we've had 4 406s as pool cars for the last few years and they've been *spanked* mercilessly. all have over 80k and only one has had more than one full set of discs replaced so far. YMMV.

JB

Because I'm looking at increasing the power of it and normally it's a good idea to fettle the brakes at the same time...

I'd twigged that. My understanding is that grooved discs = sharper brakes. And obviously more opportunity for gas to get away from the pad in the event of them overheating horribly, which I assume they must be doing to warp disks. OTOH I've got no idea what actually warps disks - I've had discs glowing and not had them warp on me...

They're fairly well known for warping discs - this one's got warped discs, a bloke I know had 4 sets go warped when he had one as a company car...

Machine being the correct term of course. How easy is it to find an engineering shop willing to do such a job ?

Or wouldn't you rather buy grooved discs from another supplier.

For example ?

I could get it done fairly easily as a mate of my dad's is an engineer, so it's a different kettle of fish to "You want us to do *what* to your car brakes? So you can come back and sue us once you're dead?"..

Good thinking batman.

Nah, just fit some OEM Kia ones. I hear they work a treat.

ITYF that the 406 3.0 Coupé had huge Brembos on from the factory.

Besides, 406 discs, IME, aren't bad.

Having said that, I've not warped a set of discs since about 1992.

I wouldn't risk it personally, try explaining to your insurance company how you've cut grooves into the discs. I can't see grooved discs helping the warping problem as they're not doing anything to reduce the heat that causes the warping. Bigger discs is the way to do for better brakes, would discs and Brembo calipers from the V6 model fit?

A straight forward swap iirc but he'll also need the Coupe wheels as getting wheels that clear the calipers is a bit of a bastard.

The reason one piece disks warp is because the outside edge gets much hotter than the bit with the bell or bolt holes is. Metal at the outside tries to expand more than the cooler middle and cant without warping..

Those that race and stock bikes use floating discs. The bit that has the pads on is seperate and attaches to the cooler centre only by loose rivets. Now it can be massively thinner as it does not have to stand extreme warping forces caused by the edge being hotter and expanding compared to the cooler centre

Thats the expensive racing solution. Many bikers and club racers from years ago (before floating discs) figured out that straight radial cuts "read hacksaw cuts" from the edge to say 2/3rds of the swept face allowed the outside edge to safely expand without the diferential expansion warping and cracking the disk. It also has the same effect as grooved disks and removes water or gasses at faster rates. And to further prevent cracking at the end of the cut a 6mm hole should be drilled at the end of each cut. Knowing this its sensible to have say 12 cuts with 6 at 1/3rd swept area and six at

2/3rds. Then the holes clear gas across the pad width. Warping and cracking and fade caused by gasses released from hot pads and improved wet performance all for the price of a hacksaw and drill bit. .Its safe and very effective. Actually better and more effective on non floating disks than grooves or holes or both because it adresses the diferential expansion and disk warping/cracking as well.

Pretty useless for a streetcar and the grooves will eat brake-pads.

If you want something that works (= extra stopping power or less warping), fit bigger disks and mount the caliper with a spacer (or fit the calipers and disks of a bigger Pug-model, they might fit)

You might have the change the rims too and check the brakeslines if they allow the extra distance. Some better pedalfeel and stopping power can be found changing the aging rubber lines by braided teflon hoses (Goodridge or the likes) and while you're at it: remplace the brakefluid.

The make of the disks (Brembo, Pug or whatever) is insignificant if the disks are of identical dimensions. On my former 405 the disks bought at Peugeot were at 200 UKP/disk while disks without make (but for the 405) were at 120 UKP per paire. We couldn't feel nor measure any differance.

If it is looks you're after: find some diskdrilling pattern on internet and drill your disks. Replace them every 10 kmiles. Same goes for grooves.

With grooves and/or holes the disks get a sense of direction, so drill/fit them accordingly.

On brakes you can either spend a lot of money or you can spend elbow grease, all up to you.

Tom De Moor

Helped loads on the GT4 when mixed with Ceramic pads. Pads worked better and didn't get eaten as much as with standard pads. More stopping, less fading, harder braking and less dust. And you could get the ABS to finally kick in.

Vented grooved discs on front, bigger solid grooved discs to the rear (standard is plain vented to the front, larger solid to the rear), Akebono ceramic pads, braided brake hoses all round, dot 5.1 fluid.

Time to think about doing something to the front of the Aero as the rear pads and discs have been done as part of the service while I was getting the HG done. Brembo grooved and redstuff ceramic, or Ferodo 2500 should do.

test...

Am I getting out?

"Burgerman" gurgled happily, sounding much like they were saying:

Yup. Both of your Anglia posts did, too.