Harrison Front Brakes

[Modena]

I got me AP 6-spot calipers from Part Box (uk) for cheap, 330x32 2-piece rotors and Aussie Mike brackets.....perfect.

[Gav]

I would definitely opt for 6 piston callipers if I had my time again.

I have AP 4 pots on the front of mine, they work really well but the pads wear quite unevenly when they are flogged to death.

IMHO 6's are a must if you are contemplating doing a bit of track work.

[sambo]

Modena/Gav, how big are the rotors with that AP setup?

Does anyone know what's required to fit VE or VF front brakes to VZ spindles? I read somewhere that the rotor is offset slightly with VE/VF.

Edit: this looks like a good explanation: http://www.ls1.com.au/forum/showthre...g-Bracket-kits

[Aussie Mike]

Ben's rotors are 2 piece DBAs (A very nice rotor). 330mm diameter and 32mm thick.

Gav are you still using my old 330mm x 28mm one piece rotors on yours or did you replace them or wear them out?

I managed to squeeze 343mm rotors into my 17" wheels but it's a bit to tight in my opinion. There's not really enough clearance for wheel balancing weights. 330mm rotors are a good fit in a 17" rim

Cheers

[sambo]

Whoops, missed "330x32" in Ben's post, thanks. Love the black and yellow too, just hope I finish better than 9th!

[Gav]

I am still using the one piece that I stole from you Mike.
They machined up ok in the end.
I don't think I'll get another go with them though.

[sambo]

How did you guys go with clearance between the callipers and wheel spokes?

I've had an email exchange with the guy who offers a 4 piston Brembo kit to suit 17" wheels (see thread below) but he says I need a minimum of +35mm offset on my wheels.

4 piston CTS-V Brembos with stock 17s - LS1GTO.com Forums

I have 4-7/8" backspace on my 17x8s which converts to roughly +10mm positive offset. Too much dish!

[Gav]

Mine fit fine with the 17's but I don't have Halibrands.

[Modena]

I don't have wheels yet
But in discussions with Dragway and measurements taken, looks like it will be fine.

[DaveW]

Mines pretty much same as Ben's,
AP5570 6 pots from Part Box in UK, DB5000 2 piece discs 330x32, and my own designed mount on a VZ knuckle.


The rears are AP5147 4 pots also from Part Box on a 328x26 DB4000 Ford Territory discs on my own custom mount to the VE rear Knuckle.


Having measured Dragway and Team 3 17", i'm confident of them fitting with about 6mm clearance on the front and about 9mm on the rears.

[sambo]

Terrific, thanks Dave. How far do the front callipers protrude out from the bolt up face? The hats on your rotors look a lot deeper than the VZ factory discs, so I'm guessing the calliper is located further inboard using your custom bracket?

[DaveW]

The front calipers protrude about 7mm from the hat face. the rears about 24mm
If the pic i tried to load doesnt show hear, i stuck front and rear pics on photo page
This is based on a Dragway Cobra 10 Spoke Wheel



Second try, looks like this pic wont load, i dont know why, but some of my pics dont have the right link to show

Yeah thanks Sambo, (next post), it worked

[sambo]

Dave, it looks like you're copying (valid) HTML straight from a webpage but the forum uses a different notation for image tags. Just click the image icon in the toolbar (mountains on yellow background) and paste the image URL into the popup, leaving out the img & src tags, etc.

Found another thread with good info - DBA 2 piece rotors/Calipers

[DaveW]

Ok, that worked, thanks Sambo

[sambo]

Thanks Dave, that's great - looks like I have a solid option. Also browsed your blog, talk about attention to detail with the build! Sensational.

[sambo]

Originally Posted by Gav

I have AP 4 pots on the front of mine, they work really well but the pads wear quite unevenly when they are flogged to death.

Gav, assuming you have the CP5200 4 pots on the front with 330mm rotors, what do you have on the rear? Howard from Race Brakes seemed to think the 4 pots would be plenty on a Cobra doing track sprints and that's the way I'm heading.

Also do you have the smaller piston leading and not the other way around? I was confused initially, until I realised the "leading" piston is the rear-most one as the rotor spins when driving forward. See diagram below.

http://www.apracing.com/Drawings/cp5200_1cd.pdf

[Aussie Mike]

The leading edge of the pad takes the brunt of the punishment. The smaller piston near the leading edge means less pressure at that point and the larger at the trailing edge means more pressure there reducing the tendency for the pad to wear into a taper.

[sambo]

That was my thinking too Mike - just wondering whether Gav's issue with uneven pad wear is due to the calipers being upside down as a result of moving the bleed nipple to the top.

[Aussie Mike]

From what I've seen I think even with the differential bores you still get some pad taper. The piston layout reduces it but doesn't eliminate it.

Having the calipers mounted backwards leads to severe pad taper.

Cheers

[sambo]

Mike I was reading elsewhere that you helped out with a billet bracket for someone's AP front calipers - does that bracket suit the VZ knuckle? I'm undecided on CP5200 (4 pot) or CP5570 (6 pot) but the mounting centres and offset appear to be the same.