Alfa Romeo Owners Club of Australia Forum

Technical => 160 Series (90, 75, 164 Sedans) => Topic started by: Southern75 on April 15, 2006, 04:49:02 PM

Title: Brakes on 75
Post by: Southern75 on April 15, 2006, 04:49:02 PM
Im interested in doing a brake upgrade to my 75, while many people boo hoo the idea saying than the standard brakes are good .... well... i think otherwise.

I have always had what i consider to be a soggy pedal and i have changed pads, discs, fluid, all cylinders have been rebuilt etc.

While the brakes work ok, they seem to lack bite and feel, what i would like to do is change calipers to something with more pad area, and maybe if really keen run larger diameter rotors.

I'm not doing track work with this car so i don't want to spend uber dollars to do the AP calipers (or similar) thing but i would like o get the best possible result without doing something really crazy.

Any suggestions?
Title: Re: Brakes on 75
Post by: Sam on April 15, 2006, 11:53:56 PM
Hi Matthew,

I'm thinking of doing the same thing. I have an Alfetta Sedan, I'm restoring a 79 GTV and my son has a 1990 3ltr 75.

I believe a cheap upgrade is to use Volvo 244/5 series callipers. These bolt straight on.
I bought 3 sets for $25 each from the wreckers. I cleaned them up and gave them a light sand blast.
I tried to use them on the Alfetta but they were a fraction too wide and hit the spokes on my Simmons wheels.
I want to find a way of making them work but they are a low priority for me at the moment. The bolt holes line up between the Alfetta & 75 & Volvo 245.
I got one from a non-vented Volvo 245 and 2 sets from a vented model. These later ones are for the GTV and 75 as they are vented.
I've heard of people putting Holden or Ford Rotors and Volvo Calipers, on Alfas. They are all easily sourced.

Also - I notice that the rotor on my Alfetta is a little smaller then the Volvo (in diameter) so I will probable need to go to a larger rotor too.
One more thing - they must be Girling callipers, not the ATE ones.

I'll let you know how I go. In the meantime, I know for fact that other members have done this also, so perhaps you should keep trying for a response from others.

Title: Re: Brakes on 75
Post by: Southern75 on April 18, 2006, 04:13:19 PM
I know the holden caliper thing is something that is done but that's something i don't want to do for a number of reasons.

1. I feel kinda guilty replacing a fixed two piston caliper that is relatively attractive with a sliding single piston caliper that looks ugly.
2. They aint an improvement ... if they are its negligably
3. the swept area is bigger but the depth of the pad is much less, so when you calculate the contact area you only end up with about 1 cm more surface area ... not enough i reckon

The volvo thing i have heard is not as easy as you say, i hear you have to change to 164 discs and do some machining work... i may be wrong though
Title: Re: Brakes on 75
Post by: Sam on April 18, 2006, 10:21:20 PM
Hi Matt,

the person to speak to about Volvo calipers is Bruno from Marenallo Motors.
He's done it many times and currently has them on his blue Spider.
I actually tried them on the w/e and found they bolt straight on , except that the standard rotor is too small - by about 10 - 15 mm, and they need a small washer/spacer between the caliper and where it bolts on.
 I'm told that the 116 Gulietta upright is the one to use, because its smaller. They ran 14" wheels.
 I've heard you can bolt these straight on then all else just comes together. There is a girl in the SA Alfa club who runs her Gulietta in sprints. She has this setup. You can try the forums at This is where I found out about her and others.

Title: Re: Brakes on 75
Post by: Southern75 on April 20, 2006, 04:48:52 PM
There are differences in the upright if i can remember ... i used to have a guilietta (for about a week or so until i got bored of it) its brakes were very different.

I will see if i can contact him and get some advice ... however i think i can use toyota hilux 4x4 4 piston calipers ... while i bit on the heavy side, heaps of pad area and the right stud spacing and look about the right size.

Aparently nissan skyline gts/gtr calipers work ... true or not.
Title: Re: Brakes on 75
Post by: jimnielsen on April 20, 2006, 05:58:34 PM
The Giulietta upright is a bit different from the 75 one.  Its caliper mounting ears are set 5mm closer to the center of the stub axle and it lacks the extra reinforcing that the 75's ones have on the mounting ears.  Either will work fine if you are going to use a totally different caliper anyway.  The Sumitomo 4 pot aluminium calpiers on the Hilux work great - but you cant really buy modern competition pads for them.  Perhaps look at the Mazda RX-7 series 4 caliper.  They are light, cheap, and easy to get competition pads for (Hawk, etc..).

Here are two pics of my car that uses the 75 upright and Mazda RX-7 calipers.  You can see the small mounting bracket used to interface the mazda part to the alfa part.  They are quite easy to make.
Title: Re: Brakes on 75
Post by: Southern75 on April 22, 2006, 12:07:59 PM
Thanks mate,

The thing about the hilux caliper is the hole spacing looks about the same so adapter plates may not be neccesary, also the car is/will be used sparingly on the track as I have a sud for the track, i just want better brakes for the street.

What's more is i have a hilux too and it takes a lot to get the brakes to fade, also i can pull it up in a shorter distance than the 75 and it weighs twice as much .... I'm interested if anyones done it

But the adapter plate idea may be an option
Title: Re: Brakes on 75
Post by: Sam on April 22, 2006, 10:21:21 PM
The reason people use the Gulietta upright is because of the difference. As mentioned by Jim, the mounting holes are set 5mm closer to the centre of the hub.. So the Volvo brakex bolt straight on and cover the standard Rotor. If you use the 75 upright, the pad will extend over the edge of the rotor.
There are quite a few people that do this conversion. Also a friend of mine brought a set of AP Racing callipers - they were identical to the Volvos !
The other thing about the Volvo Callipers is that they are twin circuit calipers, ahtough most people change them to single.
After seeing Jims Mazda brakes, I think they are a great idea. Mainly because the Volvo callipers are cast iron and are very heavy. The Mazda brakes seem to be alloy  (?) so I assume they are probably very light.

Do you  (or any one else) know if using a bracket (as per Jimís caliper) is street legal?

Title: Re: Brakes on 75
Post by: Southern75 on April 25, 2006, 06:36:18 PM
That's interesting about the uprights,

Adapter plates are legal but i think they require engineering especially in here in NSW.

I have been offered a conversion using these brakes (torndo f4's) which are very good but at 2.5k its a bit outta my budget at least for the next five years or so. (10-20 maybe?)
This includes the calipers, custom discs to fit my 16's, braided lines, residual valves, adapter plates and engineers certificate.

There has been a number of gta type alfa calipers (166,gtv,gt also) and i have seen an alfetta gt that appears to have such calipers ... has anyone done this as i don't know this guy, he isn't a club regular or anything so finding out is difficult.

I have some photos but i will need to look for them .. i'll post later in the week
Title: Re: Brakes on 75
Post by: Tristan Atkins on May 27, 2006, 06:05:47 PM
Hey Jim,
That is a very nice front setup you have there. Just a few questions, is that a modified upright to reduce the roll centre or did you raise your pickup point? Also are you front wishbones identical reproductions of the standard ones or did you alter the geometry?

I also found your Watts link article very interesting, thank-you for sharing it with us.
Title: Re: Brakes on 75
Post by: jimnielsen on May 27, 2006, 09:29:34 PM
Hi Tristan. The uprights are totally standard Alfa 75 ones. I would have used giulietta ones - as they are cheaper - but my disc rotors are set up for the greater distance from the stub axle centre that the 75 ones provide.  The only modification i have made to them is on the steering arm side that you can't really see in the pictures I have posted.  The uprights / wishbones are configured so that the bottom wishbone is parallel to the ground (at 110mm) - so all roll center adjustment is made by using the spacer on the top wishbone that you can see in the other pictures (it sits between the top of the upright and the bottom of the rod-end)  Currently this is set to a top angle of 8.5% that yeilds a roll center of +65mm.  The wishbones are not really reproductions of the standard ones. They are much more like 'generic' clubman type wishbones. I made them up from 3140 chromealloy.  Here is a picture of them on the SPAM cupboard door that I used as a Jig prior to TIG welding them!