Does anybody know what i need to do to fit some Porsche calipers onto my mk3 What discs do i need and which calipers, and whats the score with fitting them to the VW my rims are 8 x 16" Porsche D90 if this helps cheers
There are variety of porsche calipers used on dubs Good starting point is Seat Leon cupra r discs at 225mm i think and make brackets to take calipers of your choice. Some porsche rears are good choice to use up front on dubs
cheers mate, think cupra r ones are bigger than that?? any idea if anybody makes the brackets to purchase?
That will be 325mm hehehe sorry typo Yea there are people over on ed38 forum so have a search, or ebay. Sorry i'v no links
I use 996 fronts with a 305mm (4stud disc) on my mk2 with 7" D90s with 20mm adaptors. (mk2) You dont state whether yours is 4 or 5 stud. If 4 stud then you will be best off using the Seat Ibiza Cupra 305mm disc. They are a tight squeeze! If 5 stud then probably use the 312mm mk4 type disc but you may have clearance issues to the weights on the inside of the wheels. Regarding brackets there are a few guys on ebay and the other forums who will sell you a pair for decentmoney - or buy a pair of OE Audi RS2 carriers, about 140 a pair last time I looked, - these need shimming to centre them in the caliper when using the 305mm disc - the 312 is more akin to the 'shallow offset 288 type disc so not sure you may need to shim less or more, cant think which way it will be! Hope this helps.
Boxster rear calipers are used on the front. There was alot of info on ED38 but they seem to delete past threads. A guy called superlativelycharged IIRC has done it on his VR
the area of the pistons on boxter rears is less than stock 288 calipers, so not really worth it, stick to front calipers
^^^^you beat me to it! Assuming the OP is fitting the brakes for performance benefits and not aesthetical ones, then fronts are the way to go.
So you are saying because piston area is smaller, caliper cant apply same or more pressure? Wrong. In fact due to smaller area it will apply more pressure then stock caliper but pedal feel may be a bit sharper due to mismatch between piston area size and size of master cylinder . And greater pad area with better and more evenly applied force will offer better performance then stock caliper.
not true, show me your maths elucidate bought some for his A3 a few years back and some quick sums showed they were pointless, like austin princess calipers, look good but don't stack up in reality. the casting etc is stiffer than the OEM sliding 1 pots but the 1 pot offers more clamping force. use the boxster front calipers.
There is no need for maths for my point regarding pressure generated. Smaller piston will generate more pressure then larger one for same displacement of master cylinder. Size of caliper piston is largely dictated by size of brake pad so it can apply force evenly at the back of pad That is why multi piston calipers can have smaller overall cylinders area but they are spread to apply force over larger pad area which leads to stronger brakes and less fade as they can absorb more heat and dispate it better. So porsche has those calipers on the back for looks only instead of single piston caliper like lets say mk2 front? Dont think so
Pressure = force/area Force=Pressure*Area Therefore for the same pressure produced by the driver at the master cylinder, the bigger area at the caliper end = more force applied to pad.
that's why there's the need for maths, not for vague theorys. The 4 pots are a superior design from many aspects, but in this case because of the reduced clamping force they are inferior at stopping the car compared with the 288 calipers. the small pistons are because they are on the BACK with much bigger pistons in the front calipers that have a much bigger cross sectional area. think what mk2-4 golfs have on the back, now you wouldn't put them on the front would you
a quick google "oe front caliper has a piston area of 2205 and the Boxster front caliper, which is the one ecs use in their kit, and Neuspeed too, is 2274, so bigger than oe, and thats why that caliper works. But the 996/Boxster S rear caliper has significantly smaller pistons, so has less area and so less available braking force. IIRC the Boxster front caliper has 36 and 40mm pistons and the 996 rear has 28 and 30mm. So it is obvious that the 996 rear is the wrong caliper." the standard mk3 gti has 54mm pistons
so area for 54mm pistons = 2290 area for Boxster rears = 616+706=1322. man you really don't want those
True But even tho mk2 caliper have slightly bigger piston area which in theory will generate more force will this lead to better brakes when taken into consideration smaller pad and inferiour sliding arrangment? Dont think so. This is where i was trying to make a point of bennefit of having much larger pad area with more evenly applied force accross whole of the pad on both pads at same time unlike sliding caliper with unevenly applied force over smaller pad area preventing pad flex Plenty of reading material out there explaining this very argument
Prof, i get what you mean with cylinder size But please read up how much of that force is transfered to the pads and discs in sliding caliper with certain pad area and the losses due to design And then in a multi piston caliper
