NZeder Posted April 7, 2007 Share Posted April 7, 2007 Hi all, Opinions please. I am upgrading the rear brakes on my Zed (to match the JSK hats, US Brake F88i and 12.19" x 1.25" rotors I will run on the front). I will be using a PBR Banksia park brake setup (that is a single shoe 190mm drum in hat setup). Now the donor car I got this rear brake setup from is a Ford Fairmont NL 1997 (Australian Ford) and stock they run a solid 299mm x 10.5mm rotor. Now I have found another rotor that I can use it is a 302mm x 22mm vented rotor that has the same offset and internal 190mm drum (again PBR setup so yes another Australian car). Now here is some more details on the rotors. The Zed has 4x114.3 (4x4.5" PCD/Stud pattern) and a locating spigot of 68mm. Now the Fairmont rotor is a 5x114.3 (5x4.5") with a 70.5mm center bore = machine work required for the center locating thing to be a good ID also a redrill to 4x114.3 is required (the stud holes in these rotors are large too including the 2x locating counter sung holes/screws). The vented rotor is a 5x120 stud pattern but has a 67.4mm center hole so this will only require a small turn on the lathe to take the center out to 68mm and then a redrill to 4x114.3 The vented rotor is from a new model car (release Q3 2006) so the aftermarket rotor manufactures wont have any in stock until June and will not make/sell me undrilled ones (I have tried 2 Australian manufactures so far will keep looking). I also currently don't know what size the stud holes are but this is not going to be a big concern as they will need re-drilling. However I assume one will have to share part of its space with the re-drilling. So another question would be "Is a good idea to re-drill a rotor that is GM stud pattern ie 5x120mm to the zed 4x114.3mm?" Also "Can the rotor have the holes welded up before the re-drilling? Now the plan of the car is street usage but it will see the track on driver training days, our car club track days = not a real race but this does not stop the us guys from driving our cars hard The vented rotor would mean that I would have to also get some new/different calipers - however as the hand brake/park brake/e-brake (whatever you call it in your part of the world) is an internal drum this is a non issue as any caliper could me made to fit with the right brackets. As stated I will be running 12.19x1.25" on the fronts so should I do the vented setup on the rear? Yes/No? Once I have the solution down I will let other know of the setup completely I just need know which path to take solid or vented? Quote Link to comment Share on other sites More sharing options...
blueovalz Posted April 7, 2007 Share Posted April 7, 2007 I'd say neither has a big advantage over the other for the use you describe. The liner you describe necessary for the larger bore hole (non-vented rotor) is not a big deal. And re-drilling the larger bolt pattern to a smaller 4 lug is not a big deal either (I did this on mine). The first few times I did something similar to this, I did weld up the slop on the single oblong hole (that results from the two overlapping patterns) that you spoke of, but omitted this step in subsequent conversions and have never had an issue arise from it. The heat generated by the rear brakes will obviously be less than the fronts if equal parts were being used, so the non-vented rotors would not suffer for this (IMHO) being there comparable outer diameter. I would pick which ever one is most convenient at this stage. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted April 7, 2007 Share Posted April 7, 2007 I'd go with the vented for the simple reason that it will run cooler. Since you're having to machine the rotor to work, I'd think you would want to get a rotor that lasts as long as possible. To my mind that's going to be the vented one. I've always considered rotors are a consumable item, and I would try really hard to avoid running rotors that require machining. Quote Link to comment Share on other sites More sharing options...
Savage42 Posted April 7, 2007 Share Posted April 7, 2007 I'll be running the 12.19 x .81" GT slotted rotors on the rear, to match the 12.19 x 1.25" rotors in the front. With brake pad technology, there are plenty of options where the brakes work well with cold and having MORE brakes is never a bad thing. In most cases, it's not a huge deal, but track days put everything to the test. If we make these cars fast, making them slow down really well is a good idea. Just my .46 cents. Quote Link to comment Share on other sites More sharing options...
NZeder Posted April 9, 2007 Author Share Posted April 9, 2007 Thanks guys - vented it is then - I will be off to get some rotors this coming week - once I have the installation down I will do a full right up on the conversion. Quote Link to comment Share on other sites More sharing options...
Trevor Posted April 16, 2007 Share Posted April 16, 2007 The vented rotor would mean that I would have to also get some new/different calipers - however as the hand brake/park brake/e-brake (whatever you call it in your part of the world) is an internal drum this is a non issue as any caliper could me made to fit with the right brackets. I've looked at RX7 Turbo, Z31T rear calipers for vented rotors. Also Subaru Legacy have the parking brakes on the front. All these sources have the parking brake included in the caliper, which is wider for vented rotors. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted April 16, 2007 Share Posted April 16, 2007 I'm running the Mustang Cobra setup front and rear, Although now I'm planning to change up AGAIN and buy all Jamie Taylor's stuff, and I believe his rear brakes are 13 inch wilwoods, so it's a good thing I haven't welded up those rear brackets yet, ey'? Mike Quote Link to comment Share on other sites More sharing options...
NZeder Posted April 17, 2007 Author Share Posted April 17, 2007 I have sourced some of the vented rear rotors for this setup I am working on - I will collect these when I am in Melbourne Australia on business in a few weeks - Once I get these back to New Zealand I will install and take some pics and post more info. Cheers Mike Quote Link to comment Share on other sites More sharing options...
260DET Posted April 17, 2007 Share Posted April 17, 2007 DBA will supply undrilled rotors of those they make to special order, 'those they make' because a lot of the Euro application rotors they sell are sourced from Brembo. My S30 had similar front rotors to yours, used solids on the back with never a problem, car had excellent brakes under heavy track braking from up to 180kph. From memory the solid rotors were ~300 x 15mm, know of others who use smaller than that. Can't see the point in carrying extra weight around that does not have a performance benefit, specially unsprung rotating weight. Quote Link to comment Share on other sites More sharing options...
NZeder Posted April 17, 2007 Author Share Posted April 17, 2007 Thanks Richard - did try DBA for the rotors I need and they have not even started to make them yet and they will not do undrilled orders on these currently - maybe in the future but not right now. I can do a special order but they want 50 as the quantity so have ordered the stock Commodore rotor from another vendor while I work out the complete setup. I am sure in the future DBA or PBR will sell undrilled but currently they don't (well still waiting for a reply from PBR) Quote Link to comment Share on other sites More sharing options...
NZeder Posted November 21, 2007 Author Share Posted November 21, 2007 It has been a while - work has been busy so I have not done a lot on this but here are some pics of the progress - I will be ordering some caliper in the coming weeks so I will update this post again. Rotors are Vented 305mm x 22mm with 56mm total hat height with 190mm internal park drum brake. Pics of unloaded park brake Quote Link to comment Share on other sites More sharing options...
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