This winter I am upgrading loads of stuff on my mk2 16v. I have got a set of G60 spec brakes for an Ibiza Cupra coming soon, and I was wondering what people think the best option for me is with disks and pads. I was thinking Zimmerman cross drilled dsiks all round with Pagid pads. I did think about Black Dimonds with their Predator pads, but they are quite a bit more. I am also going to change the rear calipers, mainly cause I understand they can seize up over time and the hand brake gets a bit bad. Apparently mk3 and mk4 calipers fit straight on. Is one better than the other, cause they are the same price from C+R? Do they look the same? The mk4's will ultimatly be more expesive when I get the special goodridge braded hose for it. Alonge with the rest of the hose kit. If I go the mk4 route and get the special hose, can I get the 4 line brake kit for cars with rear drums? Cause I will have the rear hose sorted anyway. I assume I have to get the mk3 or 4 pads for the rear disks, but what model, GTI/VR6 pre/post 95. And does the rear disk have to be a mk2 16v one? or can I fit the slightly bigger mk3 VR6 239mm ones? I think mk3s are 5 spoke which has probably already answered that question.
Don't forget the brake fluid. You will probably notice more of a benefit by changing to DOT 5.1 than you will from slotted/drilled discs. I've got tarox g88 with pagid fr's. I've run these discs with greenstuff v4 (?) and on plain discs but for me this present combo is the best.
i have always wanted to put 256mm 16v front breaks on the rear like prash has done ! just need to get some spacers made up !
Wussel, mk4 calipers are alloy, similar design to mk3s I'd avoid drilled discs if you're going to use it on track,you'll crack them with hard use. 256mm rear brakes - Apart from looks what good will it do? mk2 rear brakes are plenty powerful enough, I wouldn't want them any better personally. Edited by: G_V_K
you know me gary,i am in it for the looks stupily low car that has to be raised to get onto stealths rollers
Anyone use the Pagid grooved discs? - They quite pricey compared to Ate/Zimmermanns, wondered if they're worth thinking about.
You can buy the 4 line hoses kit for drum brake cars as the extra two lines are for the rear callipers that you dont need since you need Mk4 ones.
Thanks for the info. So if I fit mk4 calipers, with them being alloy, the unsprung weight of the car will be lower and therefore better handling Why do they make drilled disks then if they crack with hard use on the track? How much are the Pagid groved disks? I han't seen or heard of them before. Thanks for the info about the braided hoses Jettin' I think that is the way I will go. My shopping list unless anyone says somthing bad about it: Pagid pads, Zimmerman disks (still don't know ehether to get drilled or plain) and mk4 rear calipers, with goodrige hoses and ATE SUper Blue DOT 5.1 fluid
'Cos they look like you've got Porsche discs! Even the Porsche GT3 discs crack and the holes are cast into the disc rather than drilled into it. Obviously the swept area of a drilled disc is smaller than a plain one, this results in less heat dissipation and localised hot spots which end up as <thinks of the word that means from the centre to the outside> cracks from the holes Edited by: G_V_K
I think the holes are because the holes in the disc are stress raisers (increase the stress 3 times dont they? cant remember off hand) Anyway I use the ATE power groove discs, and pagid pads and they are spot on, not had any problems, and they haul you up quick, highly recommended!
I've done 3 1/2 track days at Donny, god knows how many miles on the road and a 1300 mile trip to the 'Ring ( and 200km+ on track out there) on my Ate power discs, well pleased for the money. Anyone else disagree with this statement from Godspeed's site - The demanding driver can soon find the limits of a standard braking system. When brakes get hot the pads give off a gas, this gas then gets stuck between the pad and disc and will push the pad off of the disc stopping your brakes working. This effect is called brake fade. Fitting grooved or drilled discs dispels the gases and stops this happening. There are also further advantages of fitting performance discs: A cross drilled disc will stay cooler because the air will flow through the holes in the disc, this in turn will keep the pads cooler and they won't give off as much gas. A grooved disc will de-glaze the pads if the pads are overheated. If you combine grooving and drilling on the same disc you will get the best of both worlds - Maximum gas dispersion, maximum cooling and pad deglazing.
Some info on disc cracking Cracking: Cracking is primarily due to heat cycling that weakens the cast iron discs. The exact mechanism of this failure is disputed. Cast iron discs are formed with the excess carbon being precipitated in the form of carbon plates or flakes dispersed throughout the ferrite (iron) matrix. What is believed to happen is that when discs are operated above about 900 F, the carbon becomes more flexible or "fluid" in its shape partly due to the thermal expansion of the enclosing ferrite matrix. Then, as the disc cools relatively rapidly back below about 900 F the carbon is trapped in a changed more random shape then when it was first cast. This creates internal stress on the part and continuously transforms the disc by relieving the stress through the cracking. The cracks begin by appearing between carbon flakes. Nodular or ductile iron would resist this cracking due to the excess carbon being precipitated in a spheroidal form, but it, like other alternative materials do not have the mechanical properties needed to function ideally in a brake disc application. In discs that are cast to resist cracking through chemistry and controlled cooling at the foundry, cracking will still occur, but more slowly and take the form of heat checks on the surface. In some cases cracks will begin at the periphery of the disc and propagate inwards. In this situation, propagation can be delayed by drilling small holes at the end of the cracks (stop drilling). We do not recommend this however, because if the cracks continue to propagate unnoticed, catastrophic mechanical failure will result. Replace disc at the first sign of cracks at the outer edge of any size. A historic note, the original purpose of the curved or angled vane disc was to prevent cracks from propagating by imposing a solid vane in the path of the crack. The cooling function was secondary.
Drilled disc info Drilled or cross-drilled rotors: Disks that have been drilled through with a non-intersecting pattern of radial holes. The objects are to provide a number of paths to get rid of the boundary layer of out gassed volatiles and incandescent particles of friction material and to increase "bite" through the provision of many leading edges. The advent of carbon metallic friction materials with their increased temperatures and thermal shock characteristics ended the day of the drilled disc in professional racing. They are still seen (mainly as cosmetic items) on motorbikes and some road going sports cars. Typically in original equipment road car applications these holes are cast then finished machined to provide the best possible conditions by which to resist cracking in use. But they will crack eventually under the circumstances described in another section (see Cracking). Properly designed, drilled discs tend to operate cooler than non-drilled ventilated discs of the same design due the higher flow rates through the vents from the supplemental inlets and increased surface area in the hole. That's right, inlets, the flow is into the hole and out through the vent to the OD of the disc. If discs are to be drilled, the external edges of the holes must be chamfered (or, better yet, radiused) and should also be peened. http://www.stoptech.com/whitepapers/glossary/c.htm
Yeah exatly, and the holes in the disc are stress rasing elements which encourage the disc to crack not just from the perimiter, but from the edges of the holes aswell. So the disc in thoery would fail sooner than a normal undrilled disc (but i'd imagine the temperture variation beacuse of the holes may affect that)
