wondersparrow Posted March 17, 2009 Share Posted March 17, 2009 Good day everyone, After many hours of searching, I havent found anything that will help me out with this. I am reviving an old 240z roadcourse racer, and in the process I upgraded to the AZC 6 piston front/4 piston rear willwood setup with the 12.2" disks. Everyone says to upgrade to the 280zx master cyl, but they seem to be really pricey. So pricey in fact that I have somewhat foolishly sold myself on getting a new triple master cylinder setup. The research I have made has led me to eye these guys http://www.tiltonracing.com/content.php?page=list2&id=13&m=b . Of course with remote reservoirs to make life simple. The main question I have is "how does one choose the master cylinder size?". What size master cylinder should be used for the clutch? Of course the bigger part of that is what size should be used for the front/rear. Which pedals? The 5.5:1 or 6.2:1? I am sure there is a program or a spreadsheet out there that would get me close. I just cant seem to find one. I have looked into the calipers and the front calipers have 2x 41.1mm and 4x 28.4mm pistons, and the rear calipers have 4x 35.1mm pistons. As I don't have scales handy (and the car is in pieces) I have decided to assume a weight of 2450 and a 53/47 weight distribution (unless someone has some suggestions there). I have a proportioning valve already and I will get a balance bar adjuster. I have read a couple of convincing threads regarding using both to get the brakes tuned just right. Thanks in advance for any help anyone can give me. I have registered for the school in Calgary on May 2, so I really need this ready by then. Brent p.s. Does anyone have advice on bedding and tuning the brakes before I get to the track. This thing is nowhere near street legal and it would be nice to at least be close so that I am not fiddling with the brakes for the whole school. Quote Link to comment Share on other sites More sharing options...
tube80z Posted March 17, 2009 Share Posted March 17, 2009 This is an online version of a spreadsheet that will help with brake calcs, http://www.jakelatham.com/radical/info/brake_calculators.shtml. I would recommend the 6.2:1 pedals to reduce effort. If you give more info on your car we can probably give better examples for weight and balance. With regards to bedding most of the newer pads are much easier than they have been in the past. If you can't drive it on the street you'll need a session to slowly bring them up to temp and then let them cool. Another option is to tow the car with a tow bar and bed the brakes that way. Seen a few people do that in a pinch. Cary Quote Link to comment Share on other sites More sharing options...
Mayolives Posted March 17, 2009 Share Posted March 17, 2009 Check out this thread from a few weeks ago. http://forums.hybridz.org/showthread.php?t=136153&highlight=wilwood There is a bunch a good information in it. I'm using the AZ set up like yours and I posted what works for me in that thread. Quote Link to comment Share on other sites More sharing options...
jerryb Posted March 17, 2009 Share Posted March 17, 2009 I dont understand what you mean by Pricey...... It should not run more than $150 on ebay..... that all I paid for a new one. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 17, 2009 Share Posted March 17, 2009 Not to be too obvious, but I sell a bracket that lets you mount two Tilton MCs to the stock brake pedal and keep the stock pedal box unchanged. Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted March 17, 2009 Author Share Posted March 17, 2009 well, one of the reasons I decided to go this way is one of the previous owners must have thought himself a fabricator and made his own pedals. The clutch literally has a block of wood for the pedal surface and its held on by electrical tape. I just decided to bite that one in the butt and replace it all. This car has been quite challenging because it has been around so long. It was raced in the late 70's and from what I have found so far, it had at least 6 owners before me. Very little is/was stock (except for the drums at the back), and nothing is documented. There have been more than a few times that I replaced something just so that I knew what was actually used. John, I had a look at your bracket a few days ago. It certainly looks like quality stuff, but I don't think it would help me much. Cary, I think that may be exactly what I was looking for, thanks! Mayolives, I read that whole thread a couple of times. Maybe I missed it, but I could not find anywhere which calipers were used on the front of that car, and the rears appeared to be ones from an sx. I did e-mail Tilton as well. I just dont always trust technical sales teams I like to double check everything myself. Thanks! Brent Quote Link to comment Share on other sites More sharing options...
Montezuma Posted March 17, 2009 Share Posted March 17, 2009 Not to be too obvious, but I sell a bracket that lets you mount two Tilton MCs to the stock brake pedal and keep the stock pedal box unchanged. We purchased one and like it very much, it saves a lot of headaches. Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted March 17, 2009 Share Posted March 17, 2009 -Brent, Every car is different having different brakes, wheels, weights, etc. therefore your going to have to choose a pair of master cylinders that work for you. Give Tilton a call and talk to their tech support guy (I think it's only one guy and he's good). Your going to need a bit of info on hand to give the Tilton rep. All rotor diameters All caliper types and piston sizes Car's center of gravity static weight on each corner pedal ratio friction coefficient of brake pads That's all I remember off the top of my head, but i'm sure you can give them a call and ask what info they're going to need. Quote Link to comment Share on other sites More sharing options...
tube80z Posted March 17, 2009 Share Posted March 17, 2009 -Give Tilton a call and talk to their tech support guy (I think it's only one guy and he's good). Your going to need a bit of info on hand to give the Tilton rep. All rotor diameters All caliper types and piston sizes Car's center of gravity static weight on each corner pedal ratio friction coefficient of brake pads And if you have all that you can use the link above to do the work yourself. And better yet you can see what different sizes will do. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 17, 2009 Share Posted March 17, 2009 I think you forgot your link Cary, but if it is intended to be a link to Tom Holt's brake worksheet, that worksheet isn't correct. I can't remember what exactly is wrong with it but it was something pretty blatant, like rotor size didn't change the results. Quote Link to comment Share on other sites More sharing options...
tube80z Posted March 17, 2009 Share Posted March 17, 2009 I think you forgot your link Cary, but if it is intended to be a link to Tom Holt's brake worksheet, that worksheet isn't correct. I can't remember what exactly is wrong with it but it was something pretty blatant, like rotor size didn't change the results. It was farther up in the post, http://www.jakelatham.com/radical/info/brake_calculators.shtml I used this one to sort the brakes on my old car and when loaded with good data helped me sort some balance bar issues I was having. Quote Link to comment Share on other sites More sharing options...
jerryb Posted March 17, 2009 Share Posted March 17, 2009 Very obvious John...but its all good. BTW, I still plan on getting one! Not to be too obvious, but I sell a bracket that lets you mount two Tilton MCs to the stock brake pedal and keep the stock pedal box unchanged. Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted March 18, 2009 Author Share Posted March 18, 2009 hmmm, oddly enough, both the rep at tilton and my calculations imply I should start with a 13/16" front and a 1-1/8" rear. That seems odd to me, but those 4 piston rears really are overkill (hehe, makes the 6 piston fronts seem tame). I'll probably go with that and see where I end up. Back to one of the original questions... What size should I use for the clutch? Does anyone know what the stock one is? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 18, 2009 Share Posted March 18, 2009 Stock is 5/8 I think. It says right on it. You should use a stock size unless you're not running a Z clutch. It's not just the size of the master that matters, it's the size of the slave. Too much master volume will hyperextend the slave. Can't recall if it would fall out or if there is a snap ring in there. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted March 18, 2009 Share Posted March 18, 2009 i went with the wilwood dual pedal set with the tripple master cylinders, i had dual 1 inchers for the brakes and a 3/4 inch one for the clutch, i paid $200 for the entire thing new, down to the last bolt, the DIY brake line kit from speedway motors is $100 plus another $30 for the adapter fitting and say another $20 for the tool to make them, theres only $350 for a brake system you will almost not have to worry about, I'm sorry john, but i cannot justify spending $500 for a kit when i can buy everything i need brand new from wilwood and tilton for less then half of that, the only reason i could see your kit being an advantage is if the rules said "stock pedal" (not to hijack the thread or anything ) Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted March 18, 2009 Author Share Posted March 18, 2009 Ak sweet, I haven't yet taken apart all the stock pedals/master cylinders yet. I'll double check to see what the clutch master says on it, thanks Jon. Hoov, How did you get the master cyls and pedals for that price, that seems really low. The pedals alone seem to be more than that. Has anyone used anything like these http://www.tiltonracing.com/content.php?page=list2&id=8&m=b ?? It really would be nice to have a good gas pedal to go with everything, but it looks like I would have to change out to a cable. It could prove to be a little tricky with triple carbs. Quote Link to comment Share on other sites More sharing options...
EMWHYR0HEN Posted March 18, 2009 Share Posted March 18, 2009 For a straight bolt on dual MC kit John's price is great. If you got a quote to custom install 2 masters you'd be surprised how much that would be. Not to mention John's kit is proven to perform, and he does fantastic work. If I had the money, and I didnt have the time I'd totally buy it. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 18, 2009 Share Posted March 18, 2009 Ak sweet, I haven't yet taken apart all the stock pedals/master cylinders yet. I'll double check to see what the clutch master says on it, thanks Jon. Hoov, How did you get the master cyls and pedals for that price, that seems really low. The pedals alone seem to be more than that. Has anyone used anything like these http://www.tiltonracing.com/content.php?page=list2&id=8&m=b ?? It really would be nice to have a good gas pedal to go with everything, but it looks like I would have to change out to a cable. It could prove to be a little tricky with triple carbs. Putting a cable on triples is EASY. Just need to modify the stock pedal and then I ran the cable directly from the firewall to a clevis that I made from a piece of angle aluminum that bolted to the middle carb. Actually my clevis was a bit on the hokey side, but it would be really easy to do a nicer job than I did. Others have left the bell crank on the firewall side and run a cable off that. Either way it's really not hard to do and I think it's a lot smoother and better than linkage. Mine was certainly better than the early SU linkage. Quote Link to comment Share on other sites More sharing options...
wondersparrow Posted March 18, 2009 Author Share Posted March 18, 2009 hmmm, the triple sets are quite pricey, but it would be pretty sweet to have a nice uniform pedal set. I have 5 weeks to get this thing ready for the school, I am trying to be careful to not bite off more than I can chew. Luckily I don't have to have the body fully done for the school. Floor mount is kindof attractive (if it fits, the z feels tight for me as is) as you dont have to manufacture some sort of mount for it. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 18, 2009 Share Posted March 18, 2009 Have you ever driven a car with floor mounted pedals? I wouldn't use them unless it was absolutely necessary. YMMV. Quote Link to comment Share on other sites More sharing options...
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