I have 13.0x1.11" rotors and 300ZX 4 piston aluminum calipers sitting in my living room. I'm going to take pics and start test fitting them to get the dimensions I need for the bracket tomorrow. SS lines and unstreetable pads being ordered in the next 2 days too. Speed Bleeders sitting in my trunk.

You guys should see these rotorsthey are huge. For reference the Brembo GT kit which costs $2600 has 12.9" rotors... mine are .1" bigger I'm really excited right now.

 

Sounds like a ton of fun. Cant wait to see pics.

 

holy **** those rotors are huge. your car will stop on a dime after you get those on. keep us informerd on how the project goes.

 

sweeeeeeet hook up the pics, how much did it run you? is there any weight difference between these rotors and stock? does it do anything to help in that respect?

 

I'm sure these rotors might be a little heavier considering their size and I'm sure that with the 4 piston calipers and these rotors it will greatly improve his stopping distance.

 

Will these fit under the Kosei 15 inch Racing rims though? Or are you swapping the 300zx rotors in when you go to the track?

Please keep me informed on this Neal. I am VERY interested to so the least.....

 

Make me a set Nealoc!

 

how much did you pay, man those things must be monsters

 

VR4 setup??

 

wow 13" rotors will fit behind the 15" kosei's or do you plan to swap them out for track days....

 

getting the bracket will be the hard part..

 

I thought the 300zx TT 4 piston claipers were direct bolton

 

not with 13in rotors

 

Ya I would like to know how much it cost, what special things you need to do to get these to fit. Don't you have to get special SS line? Where did you get speed bleeders?

 

VR4's are 12.5". Those are the one's I am in the process of makin brackets for . Those cobra rotors sound pretty badass tho, lemme know how that goes.

 

I believe that's true if you just replace the calipers. If you use bigger rotors and increase the hub to caliper distance, you can improve braking. I believe that's why AEM makes a kit that moves the Honda caliper out more(with bigger dia rotors) but uses the same caliper

 

That is correct Jeff. When you increase the hub to caliper distance, you are increasing the leverage of your caliper and surface area your brake pads have to sweep. Going with MAXIN's post, the rotor, being a bigger area, will have better heat retention (distribute heat better throughout itself wihtout creating hotspots and "gassing" the pads). With less fade, a brake setup of 13" with take less stopping distance from say 110mph then a brake setup of 11". For braking at slow speeds, either brake setup will be closely matched until repeated attempts are made. So to say bigger brakes won't decrease stopping distances is not an entirely true statement, no offense MAXIN.

Note: This reply just has to do with using same style calipers and just using different rotor sizes w/o getting into the argument of leverage. That's a whole nother can of worms.

 

A longer moment arm as KMax said will decrease stopping distance as there is more torque applied to decelerate the vehicle. That combined with much more agressive pads (I will have a set of pads for the track that will not be at all usable on the street) will help decrease stopping distances, most likely to the point that my T1-Ss will be the limiting factor. The increase in surface area will help dissipate heat.

These will NOT fit under 15" wheels. I'll be pulling off the 13" rotors and brackets and putting on the 300ZX rotors.

One problem I forsee with the cobra rotors is that they seem to be offset to the outside of the car a little further than the 300ZX rotors are, and thus will move the caliper a few mm further outward, necessitating even larger spacers. I have yet to test fit them but that's how it looks to me. I might not be able to find long enough studs at the local parts store and I may end up having to go with the 60mm Nismo studs that are $8 a piece

 

Neal, you using the 10mm plate steel?

 

Yeah, depending on your wheel offset, that maybe a problem. With all my measurments and CAD mock-ups, I know the VR4 rotors sit 15mm outward (helps with the whole having to grind the control arm thing with the stock 3Z's, too late now lol). They should just fit under my TSW Revo's with no spacers though, kinda like they do now. Pretty tight but worth it if ya ask me. I might look into the cobra rotors now, you got me interested.

 

Are the rotors 2 piece?

 

Neither are. Neal is using stock Brembo 13" 03 Mustang Cobra rotors (from what I gather) and I am using stock Porterfield 12.5" 98 Mitsubishi VR4 rotors.

 

I just got my rotors. I was foolin' around with putting a loaded 300z calipers on the rotor. It doesn't look like the whole pad can sit on the rotor(ie.. some of the pad sticks over the top of the rotor). It's really a small amount but something to note anyway. Another thing is the rotor surface is HUGE. The 300z pads look tiny on them! Neal, you finally get the Z caliper on? Any info on those brackets?

 

Yes Neal, I am interested in what you got.

Jeff, couldn't you just mill down the "inside" radius of the caliper and move the caliper father down on the rotor? Then, when you get this, design the bracket for it????

 

Hey Neal, quick question about the brackets. I know you've mentioned that they are flat, hence the ability to use Cobra rotors. How are you getting them cut? I'm only asking because at our shop, we've been getting bored of the usual floormats and dash kits and have been doing a lot of flanges lately for turbos and headers. I'm assuming that your bracket is similar. If you need any help getting more brackets made, I'd be happy to help. Sounds like a cool project. And I'm not trying to muscle in on your market or anything if you plan on selling them. I just don't know what method you're using now, and how much it's costing you, so I thought maybe we could save you some money or make them more precise.

A while back, we had some brackets custom made to convert Porsche 911 calipers to VW/Audi's. They were 3D milled, at one of our subcontractors. After seeing how much design time it took to CAD everything out, I gave up on making brackets for my 300ZX rotors. But it's cool to see that you've figured out a way to make them flat and much easier.

 

"Probably" but I wouldn't feel confortable milling the aluminum caliper by any amount. Especially in the area that spans both pad areas. That's pretty thin there already. It's a pretty small amount anyway. I would just maybe mill down the outside edge of the pads to avoid vibrations when the pads wear down. The other option is to use the corresponding Cobra caliper. That would ensure full pad engagement and probably bigger pads. But they are two piston. Don't know if it would be better or worse performing. I bet either caliper would work VERY good. The difference would be semantics. The Cobra caliper might even be more rim fitment friendly(width wise not diameter wise).

 

here's a pic for you guys...
http://www.ee.utulsa.edu/~mblehm/pic...s/IM000348.JPG

front: OEM 3rd/4th gen rotor (stillen crossdrilled one that had been sitting on my back porch for a year)
middle: Skyline R32 GT-R rotor... 11.8 x 1.25" rotor.

rear: Coleman 13.3" x 1.25" rotor.. hats are from another supplier. now I gotta make adapter brackets to fit (just like everyone else)



here's why I'm getting new ones...
http://www.ee.utulsa.edu/~mblehm/pic...s/IM000321.JPG

 

Hey Matt..don't think I've ever seen rotors quite like that...the last pic. You guys are really getting me interested in maybe tackling such a project...hmm. WOuld any of you that develop brackets make some to sell if one were to want to do a similar application on their car?

 

Sure once they are made, copies are easy. ESPECIALLY for the Cobra rotor project. The thing is to solve the hubcentric thing. For you and I, we have to solve TWO hubcentric problems. 1 for the rotor and one for the wheel. If my idea (from Nealoc187 works) I/we can solve both at one time. I pray the holes for the rotor lugs are the same size as the holes in the Mustang wheels! If yes, then we are good to go! If not, we are shatted and will have to run two different hubcentric rings. If you look closely on the Nissan hub, it's actually stepped. So the rotor hub's hole is actually bigger than the Nissan's wheel hub bore. Why? I have no idea. sucks though.

 

Matt, with your new Colemans I assume you cant use your current 16" correct?

I have another general question regarding fitment issues with upgraded/OEM rotors. Neal stated the 13" rotors appears to have a shorter hat which will bring the calipers more outward. Ideally I guess it's best to have a rotor with the same offset as the Max rotors.
So if your wheel doesn't have the proper offset to handle the outward movement of the caliper, besides larger wheel spacers and studs what other possible issues can/will you run into.
How about if you install a rotor that brings the caliper more inward. What fitment issues will/can you run into them, rotor to control arm clearnance? Anything else?

 

your biggest problem is rotor/control arm clearance. the skyline rotors I'm using now are very close, but don't rub.. about 1/8 at the closest.. for the 4th gens, Loren had to shave a portion of his control arm to make them fit. some of that will be offset by using a 2-piece rotor, but it all depends on the rotors themselves and how they're made. each brand is different so clearances are different, even with the same hat offest. I'd have to draw a pic or show you before it makes sense, but I'm lazy.

moving the rotors out (smaller offset on the hats) will help the control arm clearance, but you better have some BIG spoke releif on your wheels to account for it.. either that, or you can run spacers under the wheels to bump them out for clearance.

 

I kinda see what you're talking about Jeff, please let me know how this all works out...and if there's anything I can do..speaking of which...you're getting a PM from me in a few. I'm still a bit stuck on the 2 hubcentric problems..

 

Let me try to work it out first before commenting. Plus with YOUR Mustangs, you will have run a nice sized spacer to get those calipers to clear.

I just measured everything up yesterday on my Cobra rims. No clearance problems with the 17's and NO spacers required for width! Damn I'm good! Now to fab some brackets!

 

Sorry it's taking me so long to reply guys. I havent been spending much time on the net the last 3 or 4 days I have been working alot trying to get in my quota for the week so I can have the whole weekend off. I am working on my MEVI right now trying to get it functional again that's the only reason I'm on here now. I will answer all questions as best I can later tonight after I get my MEVI running and I get back to my apartment.

 

Short update. I may have found a simple solution to the Cobra rotor hubcentric problem. The Nissan hub is actually bigger than 66.1mm where the rotor fits over the hub. So finding a hubcentric ring is difficult. Also the Cobra rotor lug holes are bigger than the Nisan rotor lug holes. So instead of getting someone to machine a custom hub ring, I might have found another solution. I found a copper pipe adaptor from Hope Depot that fits exactly inside the Cobra rotor and fits nicely over the Nissan lug stud. Buy cutting the copper adpaptor to the proper length and buy using 5 to center each rotor hole, that should make the rotor sit on the hub about as hubcentric as you can get. There's not much stress on these things so copper should be okay. This particular adaptor is fairly thick anyway. Much thicker than the plain coppper straight pipe(too thin dimensionally anyway) I'm gonna cut one and see how it fits soon

 

Great idea/find Jeff!

 

**Cough**RIGGED**Cough**




j/k - so many projects, so little time

Matt, how much were the coleman rotors? those hats look familiar

 

Wait until Matt tells you how much those rotors are.

 

*only* $130 each or so for the rotors, plus the hats. not cheap, but they're of WAY better quality of metal than the OEM Skyline rotors I was using.. I tried to file just a hair off these things to clear the calipers, and ended up ruining my file in about 15 seconds. very strong metal.

And yeah, those hats should look familiar- they're hte only ones I could find that I knew would fit! I wish there was about 1/4" more offset on them, but you take what you can get. it's better than $250 each for custom hats by Coleman!

oh.. btw.. here's a shot of them on the car. they're up and running, fit great, and work even better!

http://www.ee.utulsa.edu/~mblehm/pic..._piece_rotors/
Look at the 4XX pics at the bottom for them on the car.

 

That's a good idea. Something a little stronger than copper might be better in the long run. But at least if the copper pieces start wearing out, just cut some more pieces from the tube and you're off to the races.