chilli Posted July 26, 2005 Share Posted July 26, 2005 Hi all, I’d like to do the seemingly obligatory front brake upgrade from j-spec to uk spec at some point. My car is a 96, I understand that the discs may already be the same as the uk spec ones if it originally came with 17” wheels, is this definitely true? If I measure them they should be 320mm in diameter I take it? Does anyone know how much extra clearance I’m going to need between the new uk spec 4 pot callipers and the wheels, compared to the old j-spec 2 pot ones? If it turns out I need spacers, is this generally considered ok, or a nono? Any idea’s where to get them. For the callipers, I’m thinking of waiting until some second hand ones come along, as I believe they are a reasonable £ new. For the discs, I don’t mind buying new ones, although if good condition second hand ones come along then I’d obviously use those. Anyone know of a good disc manufacturer (EBC etc) that make a good disc upgrade (ones that don’t rust would be nice), or is the standard spec part as good as any? Sorry if this is a repost, I have searched and not been able to find all the info needed, cheers! Quote Link to comment Share on other sites More sharing options...
cashpoint Posted July 26, 2005 Share Posted July 26, 2005 From what i've seen the jspec disk are smaller than the UK spec ones. As the upgrade is new disks and calipers. Have a look on the traders sites for disks. You shouldn't need spacers but there usally regarded as a bad idea. Quote Link to comment Share on other sites More sharing options...
SimonB Posted July 26, 2005 Share Posted July 26, 2005 My car is a 96, I understand that the discs may already be the same as the uk spec ones if it originally came with 17” wheels, is this definitely true? If I measure them they should be 320mm in diameter I take it? If it's an RZ it will definitely have the big brakes, otherwise it may have. Have a look at the calipers, they are quite different - you should be able to find photos of both types on here. Front discs are 323mm vs 295 I think for the smaller ones. Anyone know of a good disc manufacturer (EBC etc) that make a good disc upgrade (ones that don’t rust would be nice), or is the standard spec part as good as any? Standard ones are fine. I've switched to DBA slotted discs now as I managed to warp the standard ones, but you are unlikely to do this unless you're doing trackdays with big braking zones. Quote Link to comment Share on other sites More sharing options...
chilli Posted July 26, 2005 Author Share Posted July 26, 2005 ok cheers, yes its a jap spec RZ-S, sounds like I need to locate those pics then to check for the differences in the callipers and get measuring for the discs too!!! Will any of the model/chassis number tell me whats fitted I wonder, guess just looking at the pics will tell me... I take it discs and callipers can't be mixed... Quote Link to comment Share on other sites More sharing options...
colsoop Posted July 26, 2005 Share Posted July 26, 2005 If you have a digital camera take a pic and post it up and someone will tell you if they are jap or uk Quote Link to comment Share on other sites More sharing options...
chilli Posted July 26, 2005 Author Share Posted July 26, 2005 nice one, will try and do that tonight Quote Link to comment Share on other sites More sharing options...
Jake Posted July 26, 2005 Share Posted July 26, 2005 My '93 RZ and my '98 RZ-S both came with j-spec brakes Quote Link to comment Share on other sites More sharing options...
colsoop Posted July 26, 2005 Share Posted July 26, 2005 nice one, will try and do that tonight Try not to use a camera phone Quote Link to comment Share on other sites More sharing options...
SteveR Posted July 26, 2005 Share Posted July 26, 2005 Isn't it a bad idea to only upgrade the fronts?? (not as bad as only upgrading the rears tho!) Won't the brake balance be totally out? Quote Link to comment Share on other sites More sharing options...
Jake Posted July 26, 2005 Share Posted July 26, 2005 Only theoretcally. In practice it's great. Quote Link to comment Share on other sites More sharing options...
chilli Posted July 26, 2005 Author Share Posted July 26, 2005 Has anyone got a handy close up pic of a uk brake install? I think I can tell from memory if they are different (and my dig camera is pants and probably has no batteries lol) Quote Link to comment Share on other sites More sharing options...
Jake Posted July 26, 2005 Share Posted July 26, 2005 J-spec : http://www.sixplus.co.uk/suprabrakeswap/brake_images/brakeswap2.jpg UK Spec http://www.sixplus.co.uk/suprabrakeswap/brake_images/brakeswapc.jpg Taken from : http://www.mkivsupra.net/vbb/showthread.php?t=21534 Quote Link to comment Share on other sites More sharing options...
heckler Posted July 26, 2005 Share Posted July 26, 2005 Has anyone got a handy close up pic of a uk brake install? I think I can tell from memory if they are different (and my dig camera is pants and probably has no batteries lol) yup - except i have gold calipers... Quote Link to comment Share on other sites More sharing options...
SteveR Posted July 26, 2005 Share Posted July 26, 2005 Only theoretcally. In practice it's great. Even for hard use (e.g. track), Jake? Quote Link to comment Share on other sites More sharing options...
Jake Posted July 26, 2005 Share Posted July 26, 2005 Even for hard use (e.g. track), Jake?I'd want UK spec all round for track use but that's because the Jap ones overheat and fade badly, and surprisingly quickly. I've done some pretty hard driving on the road with UK fronts and Jap rears and never had a problem. Lots of guys run UK fronts without a problem. Quote Link to comment Share on other sites More sharing options...
SteveR Posted July 26, 2005 Share Posted July 26, 2005 Cool, thanks. I'm guessing my car (as I haven't seen it yet, I collect from Jurgen on saturday) has J-spec brakes, and if so they'll be high on my list of priorities to get sorted. Quote Link to comment Share on other sites More sharing options...
chilli Posted July 26, 2005 Author Share Posted July 26, 2005 Thanks for the pics, I'm not so sure I know what I have now lol The calipers I have do have the supra logo on them, so in that respect they look like the uk spec ones in the pic you have posted. I will check tonight. I'm hoping they are because they look damn close to the large 18" wheels I have, can't see how I'd get a larger calliper on there! I agree wth Jake, from what I've gathered, whatever you do, upgrade the fronts first to uk spec, if the braking still isnt satisfactory then do the rears too, but for the road, probably the fronts only is good enough. Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted July 26, 2005 Share Posted July 26, 2005 As someone who has done the upgrade and used the car on track, a UK front/Jap rear will work OK. I use Porterfield R4 pads and AP Racing fluid. I've never had any fade - just remeber to do a cool down lap. Quote Link to comment Share on other sites More sharing options...
SimonB Posted July 26, 2005 Share Posted July 26, 2005 My '93 RZ and my '98 RZ-S both came with j-spec brakes Yeah, pre-facelift they were optional on both, after facelift they were standard on the RZ and optional on the RZ-S. Quote Link to comment Share on other sites More sharing options...
chilli Posted July 26, 2005 Author Share Posted July 26, 2005 My fingers are crossed, will be home later to check. It's not possible to have 4 pot callipers and smaller j-spec discs is it? just checking... Quote Link to comment Share on other sites More sharing options...
Need4Speed Posted July 26, 2005 Share Posted July 26, 2005 If you've got 4 pot calipers then you've got the bigger brakes Quote Link to comment Share on other sites More sharing options...
chilli Posted July 26, 2005 Author Share Posted July 26, 2005 I've checked and alas they look like j-spec brakes for sure I think there is loads of room diameter wise, but depth wise, looks like there is only 5 or 6mm clearance at the moment, sounds like spacers would be needed doesn't it - and longer wheel studs to match... Booo, oh well, that will give me something to do one weekend! anyone know where the best place to get spacers and studs is? Quote Link to comment Share on other sites More sharing options...
Jake Posted July 26, 2005 Share Posted July 26, 2005 Yeah, pre-facelift they were optional on both, after facelift they were standard on the RZ and optional on the RZ-S.Ah I see, cheers Si. Just my luck, got the poverty model both times. Quote Link to comment Share on other sites More sharing options...
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