Guest scca Posted November 27, 2000 Share Posted November 27, 2000 you should get together with MikeD he's in Tx (ft worth? - i think) as well and building a ZX. he has all the 5 lug stuff and big brakes.. and i dont think 14" will fit under a 17" rim. be really close but i wouldnt want to buy the rotors to then find they dont fit. ------------------ Mike mike@fonebooth.com http://www.fonebooth.com/brakes.html raceparts and brake upgrades. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 27, 2000 Share Posted November 27, 2000 14inch rotors? For the street? You're only going to be able to use as much braking as the tires can hold - 14inches is a hell of a lot of leverage on those brakes. Are you sure you need that much braking? I've got 13inch brakes on the front of my Mustang, a car that weights about 3500lbs, and it stops well enough that I've had people slide past me on the shoulder to avoid hitting me (shiver). When I hit the brakes in that thing I really do have to watch the rearview and let up in order to not get hit by cars with lesser brakes. The Z weighs less and shouldn't need as much brake IMO. Mike, what size are your Outlaw brakes? 12inches? Quote Link to comment Share on other sites More sharing options...
Guest scca Posted November 27, 2000 Share Posted November 27, 2000 yep i agree.........you need 10" rims with sticky tires to make the 14" rotors work.thats bigger brakes than they use on TRANS-AM cars..... the oulaw stuff is 12.19"x1.25" so effectvely larger than the cobra R rotors. i have one of them on the bench right now... i was going to try to modify one and use it but they are $75 ea new and will take more mods than the one i use now to make work....i was hoping to find something for less $$ and the same overall results..... i can use up to 14" rotors in the calipers. FYI bumping the rotors to 13.5" from the 12.2 i use will increase the price from $850 to $1000. ( i dont have the caliper brackets to make it a bolt on either) ------------------ Mike mike@fonebooth.com http://www.fonebooth.com/brakes.html raceparts and brake upgrades. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2000 Share Posted November 27, 2000 First off, please read my post (too close for comfort) in the I'm Telling You section to see why I'm getting new brakes. I have a 1982 280ZX NA 2+2. I want to get all new brakes, a 5 lug upgrade, and new rubber all at the same time. I want 275 wide tires up front and 315 in the back if at all possible (V8 is on the way). If I'm using 17" rims, will 14" rotors fit under them? I'm looking at the Baer Alcon 4 piston calipers with 13-14" rotors. I don't want any questions asked by my car when I hit the brakes. What do I need to do to my suspension (specifics if possible) to fit these tires under the car (with fender flares)? Also, how big do the flares need to be, how wide to the rims need to be, and what does the offset need to be? I want 17 x 9.5" rims, 5 lug, front and rear. If any of you can help me get the whole setup finished (quickly if possible, last night scared me bad), it'd be a great help. If you feel that something I haven't mentioned is worth doing at the same time as this, please add that too. I'm not sure what all is involved in the whole process and what is needed to truly revamp the entire stock suspension and brake systems. [This message has been edited by SamH (edited November 26, 2000).] Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 27, 2000 Share Posted November 27, 2000 I have to agree. The car weighs maybe 3000 lbs. There won't be much if any need for more than 12" brakes, and that's probably overkill. Unless you're really doing endurance racing, I can't see where more than 11.25" would really be called for, especially if you used curved vane rotors and ducting. Bigger brakes (of the same design) mean more unsprung weight (bad for suspension dynamics) and rotary inertia (more difficult to accelerate), and you don't really want that either. It's all about balance. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com - Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2000 Share Posted November 27, 2000 quote: Originally posted by pparaska: Bigger brakes (of the same design) mean more unsprung weight (bad for suspension dynamics) and rotary inertia (more difficult to accelerate), and you don't really want that either. I was wondering about that as well, wouldn't a large rotating mass (big brake rotor) have a real gyroscopic effect at speed? Meaning heavier turn in at the steering wheel? Just curious. Lone Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 27, 2000 Share Posted November 27, 2000 Figure a wheel and tire is about 2x the diameter and weight of a large brake rotor, so the wheel/tire has roughly 2*4 times the inertia, or 8x the rotational inertia of a rotor. You'll also notice that the coriolis force is at a 90 degree angle, so it is transmitted through the suspension and you don't even feel it in the steering wheel. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted November 28, 2000 Share Posted November 28, 2000 Hadn't thought of the added weight. Just go with the 11+inch rotors - the difference will be awesome I'm sure. I've got the Toyota stuff - the crappy solid rotor too - and I think it stops darned well. However I've also got one of Mike's kits just waiting for me to get started turning wrenches. Hope to get more room in the garage soon and get started before it gets too freaking cold out there. For the cost - go with the smaller rotors, it'll be all you need. I just wish I'd sprung for the pretty Outlaw stuff Guess maybe I'll paint the calipers or maybe polish them perhaps. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 28, 2000 Share Posted November 28, 2000 Thanks so much for the replies. Must've gotten caught up in the hype about the bigger rotors. I do want Baer brakes, they look awesome and have a great reputation. The Alcon systems come with 13" rotors and bigger tho, so I still think they'll be bit big (a lot?). I don't want to ever have to upgrade the brakes again for any reason, cosmetic or performance. I hate paying twice for the same thing. So now that I need brakes, I think I will do the whole job the way I want the first time. Side note...future plans call for some wicked abuse of the car at the track. I'm trying to build it to take a beating and still be reliable. At this point, most of all I need to know what I will need to do to the suspension to make it a proper match for the rubber and brakes. The wheels I found are 17 x 9.5" with 285/40R17 tires. Brakes are still being planned. Does anyone know a definate way to get this to fit? I will use fender flares, but what about the inside? Also, any preferences on struts or other components? Thank you for all the replies. I definately learned much about practicality from them...may step down even more on the brakes, we'll see how that part turns out. [This message has been edited by SamH (edited November 27, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 28, 2000 Share Posted November 28, 2000 9.5 inch wheels all around? You'll need big flares! Figure wheels and tires will run you close to $2k easily, brakes another $k easily when it's all said and done. I'd put that $3k into the engine transplant and see where you stand there. Such large wheels are unecessary if people would just spend a few $ more on better tires in more reasonable sizes as well..... ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted November 28, 2000 Share Posted November 28, 2000 I thought about putting my money into my engine first. I was planning on going V8 before doing any other upgrades. My mind was changed as I went sideways at 50mph on the Beltway. I got another car today so the Z is off the road for a while. This gives me time to really think this through better and I'll choose carefully before making my final decision on what to do. All in all, I may do may engine (V8) swap and the suspension and maybe even the body before I put this thing back on the road. Of all things, while I'm whooping up on people, I want to be absolutely sure my contraption is safe. What good is a killer race if you're what gets killed in the end? Doesn't sound like a fun road to go down. I don't expect to put the Z back out and around other than around the neighborhood until Spring Break or maybe even the summer. Take time to do things right the first time, fewer troubles down the road. As I get fully into the overhaul, I'll be back for more help. I've ordered the JTR book and I'll sit this one through. Won't let impatience get in the way of a good job as it obviously wants to. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted November 28, 2000 Share Posted November 28, 2000 Sam, I think you are wise to worry about brakes/suspension before putting gobs of power in the car. Or you could do it all at once. But putting a big powerful engine in a car that doesn't have the brakes or suspension upgraded to handle it safely is asking for trouble. The stock Z brakes are dicey at the best of times, certainly not made for hot laps... ------------------ "Gimme Fuel, Gimme Fire, Gimme that which I desire" -Metallica Drax240z 1972 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html http://members.home.net/drax77/newpage.html Quote Link to comment Share on other sites More sharing options...
Mikelly Posted November 28, 2000 Share Posted November 28, 2000 A couple of things come to mind... 1st, lets all remember that a rotor acts on leverage, and some think that if you use a larger lever, you can worry less about heat, which is the true culpret in poor brake performance. One look at the BSR 240Z from 1972 will show that larger brakes don't really mean better brakes. The data I have from that car shows 10.9 inch rotors up front and 10.5 inch rotors in the rear with the proper balance, large tires (on 14 and 10 inch rims and appropriatley fitting tires) and the proper ducting. That car was a series champion for several years. Even into the ealry 80s the ZX teams ran smaller diameter brakes on their road racers. The key is keeping the rotor and caliper assembly cool, and keeping the fluid from boiling. My advice is to run the Toyota V6 4X4 caliper, vented veined rotors, kelvar pads, Ford Heavy duty fluid (Recommended by BAER) and brake ducts with the proper duct hat to the spindle. Run that combo up front and you won't need to do the rears except for looks, and the brakes will work exceptionally well. If you simply must have rear discs but you don't need an e-brake setup, SCCA sells some nice rear brake options.. Now, as to the comment about wheels: I currently have a nice set of 15X8 wheels I am being forced to sell... Why? Because of lack of selection in a wide enough tire for my car. 500+ HP requires some serious width and the widest true performance tire (In a Z or higher rating) is 225... That is woefully to small for my current powerplant. You could go to 16s but the selection there is not a lot better. 17s add a flare of "Boy Racer" to them, but the only real reason I'm going that route is that every tire maker has a hi performance tire in a wide range of sizes and widths. So 17s for me.. As for flares, I'd say you will need them. Mike ------------------ "I will not be a spectator in the sport of life!" mjk [This message has been edited by Mikelly (edited November 28, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest scca Posted November 28, 2000 Share Posted November 28, 2000 my .o2....... on the brakes front you should be looking at wilwood or outlaw.if i was to go beyond these i would opt for Brembos......$$$$$ real alcons are huge $$ i dont know how good the baer alcon is.. did alcon buy baer or vise versa?????? if you go to 13" rotors by the timeyou make custom hats and all the fronts alone will run you $1500. IMO you will need rear disks 90% for looks. i think drums look dumb esp. behind a 17" rim.. and i think a 9.5 MAY fit a unflared ZX you will need coilovers but are probalby better off with 8.5" all around. ------------------ Mike mike@fonebooth.com http://www.fonebooth.com/brakes.html raceparts and brake upgrades. Quote Link to comment Share on other sites More sharing options...
Mikelly Posted November 28, 2000 Share Posted November 28, 2000 Damn...there I go glossing over another post... Scratch the Toyota brake upgrade... won't work on your car. Whatever you do, see if you can get rotor ducts and plumb in some 3 inch ducting to the rotors so you can get cool air into the braking components.. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Dan Baldwin Posted November 28, 2000 Share Posted November 28, 2000 Nothing I read in your post suggests you need new big-ass brakes. For a one-time stop from 70, stock brakes, pads, and DOT3 that's been in the system for less than 10 years should offer enough braking power to lock the wheels, which it sounds like you were able to do. Big brakes will NOT increase braking force at the pavement. Max stopping power is determined by the tire/pavement coefficient of friction. With street/track pad compounds and fresh DOT3 or 4, you would probably have all the braking you'll ever need on the street (and possibly even at the track) with the stock rotors and calipers. My opinion is that you should optimize what you have first, before spending $$$ on exotica that looks cool but is rarely actually needed. Dan Baldwin '71 240Z 3.1 easily braking with big-braked M3s at the track with my solid rotors/aluminum drums Quote Link to comment Share on other sites More sharing options...
Mikelly Posted November 29, 2000 Share Posted November 29, 2000 A lot of truth in what Dan just posted. I'd research my wheel and tire options before going crazy on Baer brakes. Baer is all the rage right now in auto magazines and every car mag publication is doing a swap annually (At a minimum) with their kit. My best friend has a set of A sedan RR brakes from Baer on his Mustang... 12 inch rotors all the way around and yes they are nice... for $2400. My z with the 300zx rotors/ Toyota V6 calipers front and 280zx rear discs with KVR pads loaded at both ends, proper brake bias, and big ducts running to the rotor/ caliper assembly will brake repeatedly from 70-0 in less then 130ft, and from 60-0 in about 100ft at the 10th stop. Do yourself a favor and don't get wrapped around the hype. Sticky tires will help PREVENT lock up, since a skidding tire does nothing to slow you down... My .02 Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
pparaska Posted November 29, 2000 Share Posted November 29, 2000 Agreed. I went to the Arizona Z stuff because I got it for half the new price used. One thing to consider. The aftermarket stuff is alot lighter usually. Aluminum hats and calipers are quite light when compared to the OE stuff. I was surprised at the weight difference between my Arizona Z (Wilwood parts) solid, drilled rear disc and hat and the 280ZX rotor. The Wilwood stuff felt much lighter. But this might be splitting hairs again. Wheels and tires can get pretty heavy too as you go up in size, and that weight difference in the brakes may not be enough to worry about. Then again, adding weight in both brakes and wheels/tires is not a great thing for suspension dynamics either, as you need to offset this with stiffer shocks an possibly springs. ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com - Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 8, 2000 Share Posted December 8, 2000 Mike is right, I am using the Toyota 4X4 calipers with 300ZX rear disk 15x10 with Hoosier slicks and plenty of ducting front AND rear on my GT-2 car. When I was running ITS and using the stock 240z set up I was boiling the fluid on a regular basis. When I build the new tube chassis car I will go to aftermarket brakes like Wilwood or Brembo, but the brakes I have now have kept me in the points lead all year long. It is simple and easy to do, and only requires a spacer between the hub and the rotor to properly space the rotor back to the caliper. Krys ------------------ I may be OLD and I TRY to act like a lady, but I aint little and I aint from Pasadena and I don't drive no D--- Dodge. Quote Link to comment Share on other sites More sharing options...
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