ALFAGTV6.COM

Barry, I hope you will comment on this since you are the big brake guru.

Yesterday a semi truck delivered a nice shiny black Verde to my house. It's a customer's car, a customer who bought it sight unseen and had it sent to me for analyisis and minor upgrades (he still has not seen it). Overall the car is darn good and worth what he paid for it but there is an issue I need to resolve.

The car has some sort of 4 piston calipers on the front brakes. They bolt right on to the stock mounting points and the car has stock rotors. HOWEVER they mount in such a way that the pads only grip the outer 2/3 of the rotor. The inboard secitons of the stock rotors are unused. The tops of the pads hang over the outboard section of the rotors and don't contact anything.

My gut reaction here is that you can't have a caliper grabbing only the outboard 2/3 of the rotor. The car does stop really well, but that doesn't mean it will be ok at the track when things really heat up.

I will post pictures soon. Mats, Barry, Zamani, Nizam....what do you guys think.

Volvo 240 Girling caliper? Two circuits? T-coupling in the line?
Fit a ES30 disk and forget about it?

or a E30 325 redrilled one.

Greg,

There may be a big problem with the pistons wanting to cant or tilt in their bores with pad wear....and then stick. Pad wear will be really bad.
I remember something about that being very bad fom mopars but those had floating calipers and real big pistons.

I'd say fix it first then drive it. See if you can find rotors to fit in the calipers properly.

HTH,
Scott

Ok here are the pictures. In the first one you can see the lines I drew to show where the calipers are not grabbing.

The second picture shows the tops of the pads which are above the top of the rotors.

Here is the next picture, it's a little tough to see but trust me, the pads are way above the rotors.

Mats, I don't know what type of calipers they are, Volvo is a good guess. You think a ES30 disk will fit? The calipers work well so my thinking is that it would be better to add a bigger disk than to change the calipers back to stock.

MR2 Zig, these calipers are not the floating type, I dont' think the pads will hang up unless they get stuck at the top where they overlap the rotors. Still, it's a concern so thanks for pointing it out. Keep in mind, I drove the car, it stops well. My concern is increased brake fade because less area on the rotor is clamped. The pistons are well positioned and I don't think they will be able to tilt in the bores

I see that in the photos that there wont be the function problems that I mentioned. I thought things were worse than that.

It may be a good idea to see what rotor diameter will fit. Measure the disc to the top of the pad, add about an eighth of an inch, times 2 , plus the diameter of the rotor, and you get the latest big brake upgrade

Scott

Bigger rotors may be the best option, I am not really comfortable with the set up as is, lets see what the folks on the other side of the world say when they wake up.

Someone sunk a lot of money into this Verde. It has new rear calipers, stainless steel brake lines, 25.4mm torsion bars, stiffer rear springs, Konis, headers and a Stebro exhaust.

It also has 210 psi on each cylinder, that's the highest I have seen on an Alfa V6.

Wow that's a lot of compression. Assuming your gauge reads good, it sounds like it either has S-pistons or milled heads.

The caliper is definitely a Volvo caliper.

How easily available are SZ discs?

You can also look into E36 BMW rotors. Same rotor height and thickness I think. If I am not mistaken they are 284mm X 22mm which should work ok for your application. Minor work require to make it fit of course.

If you find a rotor that fits, but is too large (diameter) find a machinist to turn it down to size.....or send it to me, I am one

Scott

I was thinking the same thing about the compression, probably 10 or 10.5:1.

Greg,I have a car here with me now that,damn,has the identical calipers on it!
Im sure they are not,but looks the same.These are off a 70`s Maserati something.The guy also used the Maser discs,but a lot of machining to get everything working..

My suggestion would be to find a disc to fit,some modifying will obviously need to take place(Unless your the luckiest sob around.. )
You say the discs are std gtv6 atm?

Ill x ref some discs for you..

Greg,Hope some of the following will help..

Firstly,the std gtv6 disc dimentions are as follows..

Dia.--269mm
hub dia.--125mm
height--51mm (from mounting face to back of disc face.)
Thickness--22mm


Merc w124-e320-93- to 97-.
294mm
50mm
25mm

Lexus IS200,SC430,GS430
296mm
51mm
32mm

Lexus LS430
310mm
52mm
30mm

Landrover Freelander 1.8l,2.5l-2000 up.
277mm
51mm
21mm

Honda Accord(CH25 and 26),CR-V(97-)and HR-V(99-)
282mm
47mm(small spacer required)
25mm

Chevy Camaro 3.8 and 5.7 (98-)
303mm
52mm
32mm

Cadalac Seville 4.6l (99-)
303mm
52mm
32mm

BMW Z4(2003-)
300mm
52mm
22

BMW E46 1.8l
288mm
52mm
22mm


My source does not specify the "spigot hole "size..I do know BMW will work.
Some machining is obviously neccesary,and in some instances,caliper spacers might have to be made and inserted..

If you need more,let me know.

*Any idea what the spigot size for the Chevy and Caddy are?*
Might be the stick for Sally for you guys in the US.

Mmm,interesting that the forum saw the Chevy model year as a smiley..its (99-)
Ill type that as well..ninty nine dash..in case

The spigot hole for the E36s are around 72mm. JimK posted something about a metal ring he head to machine.

The E36 rotors are cheaper than alfa rotors.