Converting rear inboard brakes to outboards???

[gtv6sv]

Another question, what's involved in doing this conversion? Is it quite common practice? Highly recommended? Approximate costs?

[Stephen Aarons]

Its very doable, and looks great when done.
I got mine done at Monza Motors is Bayswater

[Duk]

Its very doable, and looks great when done.
I got mine done at Monza Motors is Bayswater

Road legal?

[gtv6sv]

I hope it's road legal!

[deano]

Having done 50,000 kms in a car with them I would say that if its a road car or if its registered I'd leave standard.

- Annoying without a handbrake. Almost as annoying as having no cup holders
- Better brake feel and bite and bias when I put the standard calipers back on compared to the outboards
- Worth every cent in terms of not having to adjust the rear calipers again. Heaps easier to bleed.
- Better in terms of performance, pad selection, wear, looks but unless you have a pedal box its hard to get them working right, I ended up with two wilwood bias valves in the car. One under bonnet and one in car.

Better off spending money on the fronts.

Cheers
Dean

[gtv6sv]

Definitely some valuable information there deano, my car will be a road car so from what your saying probably would be best to leave as a standard set up

[Duk]

Having done 50,000 kms in a car with them I would say that if its a road car or if its registered I'd leave standard.

- Annoying without a handbrake. Almost as annoying as having no cup holders
- Better brake feel and bite and bias when I put the standard calipers back on compared to the outboards
- Worth every cent in terms of not having to adjust the rear calipers again. Heaps easier to bleed.
- Better in terms of performance, pad selection, wear, looks but unless you have a pedal box its hard to get them working right, I ended up with two wilwood bias valves in the car. One under bonnet and one in car.

Better off spending money on the fronts.

Cheers
Dean

Some good points Dean.
After living with a (non Alfa Romeo ) car for nearly 2 years, that has a fully functional hand brake, I thought would be a good idea for anyone who wanted to go down the outboard brake path, would be to use the hand brake drum mechanisms from a regular car like a Commodore/Falcon/Nissan/and maybe even a Magna, with some custom made drums where the original brakes were mounted. That way you should be able to achieve a totally dependable hand brake set up for the car and awesome performing, easy to service (when you actually have to) rear brakes.

With extra rubber on the road and much more effective front brakes, the value of bigger/badder/better rear brakes would come into their own. At what point that is the case, would be hard to judge.
And it has been mentioned more than a few times on other forums, that brake heat gets pumped into the transaxle and increases the TA's oil temperature. Obviously not going to be an issue on a road car, but definitely something to consider if taking a stout car to the track.

[Duk]

I thought I'd add this for some relatively comparable examples.

Alfa Romeo GTV-6.
Weight: 1210kg.
Power: 118kw/160hp
Front Brakes: 2 piston caliper, 265 vented disc.
Rear Brakes: 2piston caliper, 250mm solid disc.
Wheel Base: 2400mm
Wheels/Tyres: HELP!

Alfa Romeo 75 3 Litre.
Weight: Upto 1300kg (a bit generic).
Power: 138kw/188hp (141kw/192hp Potenziata).
Front Brakes: 2 piston caliper, 265mm vented disc.
Rear Brakes: 2piston caliper, 250mm solid disc.
Wheel Base: 2410mm
Wheels/Tyres: HELP!

R32 Skyline GTS-t.
Weight: 1280kgs.
Power: 158kw/212hp.
Front Brakes: 4 piston caliper, 280mm vented disc.
Rear Brakes: 2 piston caliper, 297mm vented disc.
Wheel Base: 2615mm.
Wheels/Tyres: Couldn't find exact information, but they did have 16x7 rims and at a guess, 205, 50 tyres.

***Something that is unavailable without having them to measure, is the surface area of the brake pads for each car.
Everyone knows how small the pads are in the Alfa's brakes. The Skyline's front pads are much bigger than the pads used in the front brakes of the Alfa's, probably close to twice the surface area. The Skylines rear brakes use pads that are, at a guess, a bit smaller than the front pads used in the Alfa.***

So the GTV-6 is relatively light and reasonably powered. But the 75 in its heaviest form weighs a (rather generic) 1300kgs, which is heavier than the Skyline. The 75 Potenziata gets pretty close to the Skyline's power output, but when you compare the brake specs, the Skyline has it all over the 75.
Interestingly, the 2 Alfa's should have better weight distribution numbers than the Nissan, but the Nissan sports much bigger rear brakes. The Nissan is also has a longer wheel base than either car, which would give less forward weight transfer under braking.
The Skyline also has the largest diameter and widest tyres here, which makes its comparison to the fattest version of the 75 even more interesting.

[deano]

All I can add is the standard pot has 205 55 15s.

I put 205 45 16 cheese cutters off a 156 on it cause I had them with good tyres. Plan is to also put a set of rx7 I have sitting in the shed with 225-45-16. One of my dions is now the jap stud pattern, I need to work out what sort of front brakes to put on it before the front gets done.

I think there are so many areas to spend money on 75s (for example making it keep up with hectic habib in his Ve ss in a straight line) that I ccouldn't bring myself to do the rears until it was almost the last thing to do. The value proposition just isn't there for me being a road car that i don't plan to take on track and if it was a race car that had a proper set up, then yes I'd do it as part of modifying the the dion at the same time because I'd already be spending a lot there.

The front brakes are way more important in my opinion so I've gotta work out what to do there. Done the volvos before but Getting a set of ds3000 into them isn't that straightforward.

I'm leaning towards the lc 100/200 calipers for this road car - heard on good authority that they are great with the only draw back the weight. should be easier to get some rotors too once it's jap stud pattern. I'm guessing there will be some master cyl work.

Cheers
Dean

[Duk]

Dean, have a look at this: http://www.davebarton.com/volvo240bigbrakes.html
Series 4/5 RX7 Turbo 4 piston caliper conversion for an Ovlov is quite straight forward. So appart from rotor hat offset, should be quite straight forward, actually hydraulically easier, for the Alfa.

***Edit: http://www.dvs.net.au/240.html ***

[Mick A]

Another question, what's involved in doing this conversion? Is it quite common practice? Highly recommended? Approximate costs?

We have done this conversion many times at Monza Motors. If you want a rough idea of labour costs and materials feel free to give us a call during business hours.

We don't do this upgrade for road cars, race cars only.

Cheers

Mick

[Mick A]

My apologies, I've just read a little more through the thread and I see your's is a road car.

You are best to just leave the brakes as they are in that case, no great advantage in performance to be had driving on the road with this setup.