jamie077366 Posted April 15, 2012 Share Posted April 15, 2012 Hi every one, sorry if this is a boring topic. When i bought my v8 manta it had volvo calipers and 246mm 2.2 calton discs. The discs must of warped 'cus i get massive judder at track days so i need to replace them. There's around a 10mm space between discs and calipers so i thought i could replace with audi 257mm discs. Would there be any machiening etc for this coversion? Any would be appiciated. many thanks, Jamie. Quote Link to comment Share on other sites More sharing options...
monzta Posted April 16, 2012 Share Posted April 16, 2012 You need to make sure you have the right offset on the discs.. But why not use a set of Carlton GSi 288mm discs ? Those babies can really stop a car There is very little machining needed on the discs (redrill) and regarding offset on the hub. Quote Link to comment Share on other sites More sharing options...
opelman Posted April 16, 2012 Share Posted April 16, 2012 Hi, I also use my manta on track days and use audi 256mm grooved discs. I know from experience why your brakes are juddering, it is gassing from the pads, ie. as the pads heat up they produce gas and this forms a layer between the surfaces. It will only take a few corners before the discs have overheated. The solution is either use cross drilled or grooved discs that allow the gas to escape. I use Nitrac grooved discs with yellow stuff pads and have never again experienced any juddering or fade, it is however important to bed the pads in correctly and takes quite a while. Hope this helps. Quote Link to comment Share on other sites More sharing options...
Kevin Abbott Posted April 16, 2012 Share Posted April 16, 2012 Without seeing the Audi discs and trying them unless they are exactly the same offset and bore you will have to have machining done. You will have to have the manta disc pcd put on anyway? The biggest I got under volvo 4 pots were 284mm and fitted great. XR4x4 discs with manta disc pcd drilled in Using small discs with a lot of clamping pressure from 4 pistons just locks the wheels so it makes your brakes worse Quote Link to comment Share on other sites More sharing options...
opelman Posted April 16, 2012 Share Posted April 16, 2012 Yes, some machining is required, the PCD 4x100 will need doing and the centre bore opening up, apart from this the offset is ok. The model they are from is an Audi 80 2.0 16v vented disc made between 91-95. I run R888's on the track and once they are up to temperature there is no problem with locking up. Quote Link to comment Share on other sites More sharing options...
mantasrme Posted April 17, 2012 Share Posted April 17, 2012 The audi discs offset is 56 or 56.5mm depending on which reference book you look, standard manta is 55.5. But that lines up within tollerance of the gap in the astra caliper carrier, not sure of the volvo calipers but a 1mm spacer would re-align the caliper if need be. They need the centre bore opening up on the lathe from 67.5mm to 73mm to fit the manta hub and then 4 new mounting holes at 92mm not the 100 that the wheel bolts are at on the front of the hub. If you want larger discs then 2wd sierra cosworth 283mm discs have an offset of 55mm and centre bore of around 63mm, they fit nicely with the early caibra v6/turbo cavalier 4x4 calipers which ran 284mm discs. Ive yet to try them with the later caliper which ran 288mm discs but i think they might have just a smidge of overhang. The carlton GSi discs list as 296mm (in all my reference books) and have an offset over 58mm which would mean moving the caliper 3mm inboard to allign it on the manta upright Again not tried that one and to be honest don't plan to when the cossie/calibra setup is only 6mm smaller radius and a tried and tested one that all lines up Quote Link to comment Share on other sites More sharing options...
opelman Posted April 17, 2012 Share Posted April 17, 2012 The centre bore on the cosworth 283mm discs is larger than the manta hub ? did you have centering rings made up ? I was also wondering about the brake pedal travel as i assume the V6 caliper has a greater piston displacement ? Quote Link to comment Share on other sites More sharing options...
mantasrme Posted April 17, 2012 Share Posted April 17, 2012 The centre bore on the cosworth 283mm discs is larger than the manta hub ? did you have centering rings made up ? I was also wondering about the brake pedal travel as i assume the V6 caliper has a greater piston displacement ? No the Cossie is 63mm centre bore the manta is 73mm. When I first ran them many years ago the pedal travel wasn't bad but they were too powerful when the rear had drums on a standard setup mastercylinder. Have since changed to a bias pedal box so no longer an issue. I've also fitted them to a car with rear discs and sierra rear calipers, that needed a larger master cylinder from a monza to get the pedal travel back as much bigger pistons front and rear made for much too far a pedal travel. Quote Link to comment Share on other sites More sharing options...
jamie077366 Posted April 17, 2012 Author Share Posted April 17, 2012 Thanks every one, thats been so help full, basicaly i'v just pasted your info regarding audi discs to were i'm buying them from and there gonna sort all out for me. That's saved so much hassle! So, any one take there manta to track days around lincolnshire area? I'v been to cadwell few times, would be good to meet up? Quote Link to comment Share on other sites More sharing options...
Kevin Abbott Posted April 17, 2012 Share Posted April 17, 2012 Glad to help, now join the club Quote Link to comment Share on other sites More sharing options...
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