I decide to do a search cos yous lot, except for notenoughtime, are useless! Mind you I recon that n-e-t is wrong! EBC have curved slots and holes. They could be StopTech, but the slots to holes ratio is wrong. They are probably Tarox, which is not unacceptable. But, I have some reservations. Tarox, unlike Brembo and ATE, do not specify the type of cast iron used. They state that the castings are from the UK, which in real terms means sod all! NOW! When I searched for 'Performance Discs' I got hundreds of companies offering different slot and hole configurations. Some of these companies cannot possibly have control over the casting process. SO BEWARE. Because I believe that there are vast amounts of Chinese and Indian cast rubbish, out there, being slotted and drilled by idiots with a CNC machine!
I think some small tuners had their own made, dubsport used Zimmerman discs and had them grooved/drilled and possibly anodised
People didn't bother Dave as you couldn't be bothered to take the wheel off so we could see things properly lol ( love you old man ) You are right about the vast majority of groved and drilled discs being cnc'd by any Tom Dick or Harry . Many of us are aware that cnc'd discs are not up to your standards as holes and groves need to be moulded into the discs in the casting process to keep the disc integrally strong .
When I had a track prepped 944 Turbo we in PCGB found Zimmerman discs warped and the holes cracked. I understand that unless holes are cast in at the start then post cast drilling cuts the metal grain and promotes cracking around the holes. Porsche cast in the holes so the metal grain is continuous (I am told) I now only use grooved discs as I have found holes get full of almost welded on residue very quickly on a track car and the gaseous layer as the resin burns off is not properly dissipated. Grooves seem best to me but I will admit I am a somewhat amateur expert on this and only from my personal experiences and I use Brembo discs.
aye tried a good few drilled and slotted over the years now i don't bother i tend to go for ate who are the one of the oem supplers or get vw ones from tps as both are coated to stop them rusting as much saves me painting them with hi temp paint if you still want slotted ate power discs are good bit pricey though ebc do not bad discs as well though their pads are not that good black diamond is another one i had they cracked along the grooves after a very short time
that's a very good point about the holes clogging up most of the ones i had rusted over closing the hole over that brembo ones look good very similar to the ate power disc less the coating
Back in early 1987 the Audi test drivers complained about the brakes on the 90 20V and S2. I can confirm that they were awful. They really spoilt what is a supercar: My 90 20V Q. They 'graunched' and destroyed pads rapidly. I had Mintex make special pads and they were no better. So I got C&R to get hold of Brembo 'Group N' discs, high carbon alloyed cast iron, and cross drilled them myself. Cross drilling is not permitted in Group N. MAX did not exist at that time. The result, with Brembo pads, was amazing. Cast iron of all forms is purely granular in structure. Basic cast iron which has not been heat treated to refine the grains is very coarse in structure. Cross drill this and big bits will break off. Basic cast iron which has been heat treated will have smaller grains. Cross drill this and smaller bits will break off. Heat treated high carbon alloyed cast iron has a very homogenous structure with small grains and strong inter-grain bonds. Cross drill this, and chamfer the holes, and no bits will break off. Grooves are there to permit the gases generated to bleed away. Gases between the pad and disc reduce braking effect. Cross drilling is to permit the brake pad dust to escape. Dust between pad and disc reduces braking effect. The MAX design is better as the gases can vent to the outside of the disc and thus carry some dust with them. But some dust will tend to remain in the grooves. These from some of my other threads. The thing is. ATE and Brembo really do know how to make the best cast iron discs. Now, the reason I looked at the Brembo Max discs is because they are made from high carbon alloyed cast iron. And so are ATE Power discs. But it turns out that ATE also make some standard discs of high grade iron! The standard ones for the Mk4 Anni are so! A1 fronts have a different part number. New rear discs are needed. I know that Brembo/AP have homologated the MAX/XTREME as Group 'N' discs rear discs for the MK2, etc. So. I made a search, but the Mk4 rears are not available. But. The Audi A1 fronts are almost identical, and are available in AP XTREME type. Why VW and Audi should use two different discs that are as near as damn it the same I can't understand? For those who did not know, Brembo/AP have homologated some XTREME/MAX Group N rear discs. They are for Mk2s and, what I believe may be Mk3, and later models, with solid rear discs.
We love your technical research of no use to me but interesting none the less , keep your rants up please .
No research was undertaken. It's all acquired knowledge from Bradford, and working in the laboratories at Laycocks, coupled with 49 years of engineering experience. We cast our own, iron and aluminium, and forged all of our own parts. Our only bought outs, besides basic raw materials, were friction components from Mintex, nuts and bolts, Loctite, Solenoid valves, etc.
I have been accused of being a 'scaremonger', so I really should not post these images. But. If I did not then I would be failing in my duty to inform other people of my 'research' findings. This time it is pure research Mike. Brembo admit, now they own AP, that they are the best. But even AP products can fail! BREMBO GT. AP ATE ZIMMERMANN STANDARD RS4
