BIG Brakes on a small budget

[Aussie Mike]

Hi All, Here's another big long boring post about my Cobra build.

Before I get into it and everyone starts yelling at me for getting distracted from getting the car running I have to say this is all Phil Neall's fault.

I was happily working away on my wiring loom. Phil and I were talking about big brake options for the rear of his Classic Revival which then led me to have some ideas about the brakes on the front my Classic Revival. (The rear brakes will be covered in a future installment of this automotive soap opera).

I'd been drooling over some big front discs and calipers from companies like AP, Alcon, Hi-Spec and Brembo without really having the $3K+ to buy one of these setups. To put some big brakes on the front of my car I'd have to take a different approach.

First step was to find some suitable rotors at the right price. I ended up finding a set of 330mm X 28mm HSV rotors. These are readily available and relatively cheap.

The original Jag front rotors are only 285mm X 24mm so this was a big increase as you can see from this pic.



I could have actually fitted the 343mm X 32mm HSV discs into my 17" rims but that ment a bit more machining on the calipers and reduced the options for future caliper upgrades.

Next step was to make some hubs to mount the discs to the Jag spindles. I could have machined down the original Jag hubs and used them but it wouldn't have left much of a spiggot to suport the pin drive adaptor. It would also space my wheels 10mm further out.

I bought a 6" diameter billet of 2011 T6 Aluminium which machines nicely and has good strength. $150 woth of aluminium for two hubs wasn't too bad as long as you don't make any mistakes when machining it. I machined them up to be thicker and stronger in important areas. Arround the bearings it's approx 90mm thick rather than about 80mm for the steel hub. The spiggot is 74mm right through to provide plenty of support for the pin drive adapror, The drive flange is 20mm thick and ment the use of some wheel studs with a longer shank. I believe the ones I settled on are XD Falcon. I'm still waiting for the other 7 to turn up at the auto parts shop.

The hub uses the standard Jag bearings and seals and is significantly lighter than the original steel unit.



The other good thing about this style of hub and disc is it opens tha back of the disc to let the air flow through better for cooling.



With the discs now mounted and keeping the wheels in thier original track it was time to find some suitable calipers. PBR are doing a number of after market performance brake upgrade kits. These are much the same as the factory setups used on the FPV ford and HSV Holden vehicles. They use a large 2 piston caliper which on closer inspection is almost identicle to the PBR caliper used on the VZ Commodore. It's just machined to suit a larger diameter disk and has a nice coat of red, yellow or blue paint and the appropriate logo.

I picked up a pair of brand new VZ Commodore calipers on eBay. They are a physically very big caliper with a lot of pad surface area. Almost half as much again than the standard Jag caliper.



The Jag caliper is in the fore ground. The perspective on the photo makes the PBR caliper look smaller but it's actually the same size or even a bit bigger.

The tricky part was mounting the caliper to the standard jag mounting points. Finding a position for the caliper where it will easily bolt up yet still clear everything when turning the wheel full lock and the full range of suspension movement. I ended up making adaptor brackets from some 10mm stainless steel and they turned out pretty neat and tidy.



Here's the caliper mounting



All that remains to do is fit the wheel studs when they turn up and get a pair of braided lines made to suit the new calipers.





Now I'll get back to that wiring loom.

Cheers