DIY 11.75x1.25' Rotor BBBK
 

"Bigger Big Brake Kit" hehe.....After a rather eventful situation involving brake fade I dove into upgrading my brake setup to a larger rotor. I've been running the mini cooper rotor with Dynapro calipers for a quite a while (thanks Rallas!) and they have done well but the 400 whp LS swap seemed to have exceeded their thermal capacity. I also setup a force fed brake duct with a few blower fans for good measure. I had a wire come loose and that was all that it took to cause the brakes to fade. If the fans are all that was separating me from brake fade that wasn't going to cut it. Since the min rotors were 11.56x.81" stepping up to a 11.75x.81" rotor wasn't going to do a whole lot for me. Enter the off the shelf gold standard for most circle track cars, the 11.75x1.25" rotor.
https://cimg9.ibsrv.net/gimg/www.mia...864f32e6b6.jpg
https://cimg2.ibsrv.net/gimg/www.mia...e6172be384.jpg

So I've been itching to use this bad boy to help design parts, it's so call to see parts leap out of CAD and into something I can mock up on the car.
https://cimg8.ibsrv.net/gimg/www.mia...561d05a093.png
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https://cimg0.ibsrv.net/gimg/www.mia...1265ae445a.jpg
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https://cimg3.ibsrv.net/gimg/www.mia...6690967530.jpg
https://cimg6.ibsrv.net/gimg/www.mia...ebb1467f8a.jpg
https://cimg2.ibsrv.net/gimg/www.mia...fc956173cc.jpg




Since most brake kits have the rotor up against the ball joint already the only way to add a wider rotor is to go out towards the wheels. A test fit shows that 10" Longblows clear pretty good, 9.5" Freeforms clear even better surprisingly and 9" 6UL's will need a 5-10mm spacer.
https://cimg2.ibsrv.net/gimg/www.mia...b993110dd4.jpg
https://cimg0.ibsrv.net/gimg/www.mia...a49f1616d5.jpg
https://cimg1.ibsrv.net/gimg/www.mia...65791555f8.jpg

Next step after a few tweaks to the design is to order up a few hats and brackets in real live aluminum and they're ready for testing on track next spring.

I see Emilio just mentioned making a kit based on the 1.25" rotor but I was already pretty far down the rabbit hole of developing my own DIY setup so I figured I'd share it anyway.

this is so cool... i was dumbstruck when emile showed me a pic...

wish i didn't drive my car to the track!

Don't let street driving your car stop you, I drive DTC60'S on the street all the time, other than the dust they do fine

I guess I'll join the fun and share mine too. Stoptech C43 with 20mm 7420 pad on 11.75x1.25" :)


https://cimg0.ibsrv.net/gimg/www.mia...e2b1230902.jpg

Ohh you fancy, I've got plans to upgrade the calipers eventually but wheel clearance is a concern once you're 1.25" care to share your wheel hub face to caliper distance as a rough measure of clearance?

My calipers are mounted on a friend's car right now and I don't have accurate enough CAD for the C43 to pull that number out of CAD. So far the 15x9.5 Freeform and 15x10 Dekagram are the only wheels confirmed to fit with no spacer, but those were the wheels I designed the kit around and I haven't tested much else. The drop center on the barrel is the biggest issue, lots of clearance to the spokes.

*heavy breathing*

So this project took a hard right at baller street. I figured out the adapter kit I had found would not work with my Dynapro's to widen them to 1.25" so I was going to need another set of calipers. One thing led to another and these AFCO's popped back into my mind. I had looked at these years ago but never had the means to take on a project such as this, low and behold they were on sale for $120 normally between $150-180. Dimensionally these look almost identical to the superlite. There is some concern these calipers are getting phased out, they disappeared off of AFCO's website in this configuration. Hopefully it's just a supply issue or a newer version is getting released.
https://cimg3.ibsrv.net/gimg/www.mia...ad8b908a6f.jpg
https://cimg4.ibsrv.net/gimg/www.mia...f3b2b33dec.jpg
https://cimg5.ibsrv.net/gimg/www.mia...d2a169af77.jpg




These use the superlite 7420 pad shape which is the main reason for the change, with .800" pad thickness compared to .490" for the dynapro it should do wonders for spreading the heat around and prolonging pad life.
https://cimg4.ibsrv.net/gimg/www.mia...e1a0c104c5.jpg
https://cimg7.ibsrv.net/gimg/www.mia...d0950ec73a.jpg

The caliper bracket get's very simple as well, flat plate with some funky dimensions to sneak the 3.5" lug pattern between the OEM lugs. The casting does need cleaned up with a flap wheel to make it all work.
https://cimg6.ibsrv.net/gimg/www.mia...d609351ebf.jpg

While I was acting like I was made of money I stumbled upon these very ingenious floating rotors. They are designed to work with a common 8 on 7" rotor hat so they could be used with any commonly available BBK's. Works out to around $150 per rotor with hardware, friction rings are $110.
http://www.colemanracing.com/Floatin...ors-P6384.aspx
https://cimg5.ibsrv.net/gimg/www.mia...c47b4755bf.jpg
https://cimg6.ibsrv.net/gimg/www.mia...22c4b03622.jpg


Wheel clearance gets pretty bad, but all the wheels I'm interested in still fit. 10" Jongbloeds just clear at the spokes. 9.5" Freeforms still have a mile of clearance. 9" 6UL's even with a 15mm spacer touch the barrel where it necks down.
https://cimg3.ibsrv.net/gimg/www.mia...d4fcb85fea.jpg

Quite a few changes but I think it's really going to help out with heat tolerance and do wonders for pad life, granted the pads are twice the volume but I think I'll see more than twice the life out of them since I won't be throwing away pads with 25% of the pad material still attached.

We keep having the same ideas. I called AFCO last week... All of their calipers are discontinued except for what's currently on the website. What Speedway has in stock is basically all that's left.


https://cimg6.ibsrv.net/gimg/www.mia...4e25737793.jpg

Well fuck..... Looks like there is a wilwood lug mount superlite that's identical and there's a $175 version of it as well. Powder coat is more expensive

I'm not a wilwood fan but I ordered a superlite at the same time as the afco to compare them side by side. I'm keeping the Afco and returning the Superlite. The Afco has four M10 screws holding the halves together and proper M10 bleeder screws. The Superlite has 5/16" (8mm) screws and the shitty wilwood NPT bleeders.

Also a surprise: the Afco has metric pistons. I knew Stoptech manufactured these calipers for Afco but the metric pistons and hardware still surprised me. I bet Stoptech piston seals will work. It's a bummer that Afco discontinued these.

Heard stoptech went bankrupt so that would explain why these are getting discontinued.

Thanks for the encouragement here. Converted my tse bbk to 1.25 rotors. Added .120 arp washers between the caliper and bracket and faced the tse hat .320. Clears 15x10 6ul by a mile.

not sure if this setup would fit on a factory knuckle. Copy at your own risk.

https://cimg9.ibsrv.net/gimg/www.mia...b4bf4ce03.jpeg
https://cimg0.ibsrv.net/gimg/www.mia...e7518d880.jpeg
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I have an 11.75x1.25 kit ready to go, but after delaying over and over for 4+ months, the machine shop finally sent me a bunch of garbage that I wouldn't even give away to my worst enemy. Had to send the parts back and start all over with a new machine shop. Should have new parts ready to ship in 2-3 weeks.

This is making me feel like upgrading from my trackspeed kit suddenly.

you might want that disc (rotor) on the oposite side;)

Rich.

Weird flex.

Multiple wheels already confirmed to fit the 1.25" rotor without spacers right here in this thread. Tons of off-the-shelf friction ring options available in lightweight or heavy duty, floating or fixed, cheap or expensive. No custom single-source rotors required.

... And DIY not required if you know where to look.

This is super interesting. Our modeling and testing showed absolutely no way to fit the Superlite + 1.25" rotor inside a Gen4 15x10 6UL, which was our target wheel, since we knew that the 6UL had probably the least brake clearance of the three main 15x10s.

@Twibs415 That's the caliper that came with the TSE Superlite kit, correct? Dumb question, but have you actually confirmed it fits around the 1.25" rotor with new 20mm thick pads installed? According to Wilwood's specs, it won't. Because of this, we went to a larger Superlite caliper (meant for wider rotors) which is why we had to do the 1.1" friction ring to get it to fit. Spent a *lot* of time going around and around to fit a 1.25" friction ring, finally settled on the custom ring we are now offering.

Wider caliper. No way to fit otherwise. 20mm pads.