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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 371
Location: Bristol

PostPosted: Wed Mar 30, 2016 10:22 pm    Post subject: Reply with quote

Al,

I have been running these wheels and tyres now for a number of months, but yes I added a 20mm spacer. The plan is to modify the front wing to accommodate the new wheel / tyre position. It did not touch before, but it may well do as it is now. I have not been on the road yet, but I think that currently it will rub on things. Nothing that can't be quite easily sorted. Same with the bumper. Just some local fettling to do. It will all work out.

Jeremy,

Yep, I certainly don't target potholes, but saying that it is not too bad. Remember it is not a daily driver. The body / wheel position is not final yet, it is just where things ended up once I lowered the car off the jack.

Paul,

Don't really care what the speedo says Smile more interested in what the rev counter is saying! As regards acceleration, well, I am not sure about bigger wheels reducing acceleration - but I guess they do. The way to overcome that is more torque and power. At 170+ hp and 142 ft lbs things are heading in the right direction, but still looking forward to when the supercharged engine is fitted. 200hp+ should spin them up pretty fast Very Happy Very Happy
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paulhide
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Joined: 20 Dec 2003
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Location: Oh Beautiful Billingham

PostPosted: Wed Mar 30, 2016 10:26 pm    Post subject: Reply with quote

Will this be like the car you had at Donington all those years ago? Smile
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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 371
Location: Bristol

PostPosted: Wed Mar 30, 2016 11:25 pm    Post subject: Reply with quote

Paul,

No, it is a different one. It is pretty similar in many ways, except it is black as opposed to red, but under the skin it is very much the same car. It even has some of the same parts.

With the earlier red car, after a number of track days I eventually damaged the engine, broke most of the car for bits and sold it all off. In the last few years I decided to do it all again. So, bought a race car, returned it to the road. New engine, paint, other parts and so on.

The previous red one still lives on, but is sorned somewhere in the midlands, and parts that were on it are on this one, but they are not the same car.
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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 371
Location: Bristol

PostPosted: Wed Mar 30, 2016 11:31 pm    Post subject: Reply with quote

This was how I bought it:

http://i283.photobucket.com/albums/kk318/edwardgurhy/CIMG2601_zps05fac535.jpg


This is how it is now:

http://i283.photobucket.com/albums/kk318/edwardgurhy/IMG_2323_zps6a7dcqet.jpg
http://i283.photobucket.com/albums/kk318/edwardgurhy/IMG_2324_zps41vodtyi.jpg


Still a long way to go.....
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paulhide
P4


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PostPosted: Thu Mar 31, 2016 7:50 am    Post subject: Reply with quote

I know it's not the same car. I remember when the engine let go with Dave Peters in the car. Bill smith lent you a pepperpot exhaust end because your side exhaust was so loud and when you gave it back to him it was half ground away! Smile
Who towed you to the services then Question
Did you fix the engine after that or did it get put out to pasture then?
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Edward
Alfa 33


Joined: 21 Sep 2003
Posts: 371
Location: Bristol

PostPosted: Thu Mar 31, 2016 10:14 am    Post subject: Reply with quote

Paul, yep, sorry you are right, but it was late last night when I read your note and didn't quite read it properly.

I can't remember who towed me to the services. I think it may have been someone like Harry & Gary (Bianco) or even possibly Bill. It was a few years ago and that bit I don't recall.

I didn't fix the engine. I sold it all off and someone put it back together. Then interestingly I came up for sale again a couple of years ago. Somebody on AO had it for sale, but it was in bits again. I was looking for an engine, saw one for sale and I thought hmmm that looks familiar. After seeing a few more photos it was definitely my old one. I was tempted to buy it back, as it was pretty cheap, but decided to start over with all new parts. So, a set of brand new and expensive JE pistons arrived from the US and off we went again.

Last time, the engine managed 169HP on Mek Motorsport rolling road and this time around I spend a fair amount of effort and money to try and improve on that. Excitingly took to car to Mek rolling road..... and the car made .... wait for it ... 170HP. Oh well!
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johnboy
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Joined: 26 Jun 2003
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PostPosted: Sat Feb 11, 2017 6:53 pm    Post subject: Reply with quote

Hi Edward

Have you got the specs on the bracket to fit the coupe calipers please . Plus your old engine is sitting on the shelf Wink

Cheers John
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JeremyC
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PostPosted: Sat Feb 11, 2017 8:38 pm    Post subject: Reply with quote

This thread has to be the slowest burner on any forum on the WWW.
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Edward
Alfa 33


Joined: 21 Sep 2003
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PostPosted: Sun Feb 12, 2017 2:51 pm    Post subject: Reply with quote

Yep, a pretty slow post.

Well, what I can tell you is that my brackets are up and running and have been for a while.

One thing though, is that I have noticed that when the brakes get hot, and I mean really hot, (castle Coombe track day hot) the rotor expands enough for it to touch the calliper. I have made another bracket for the one that was too close and am going to test it shortly. I have another track day at Castle Coombe on the 27 Feb 17.

If it passes the test that day then I can get them measured and CNC'd. That way I can reproduce them at will.

Leave it with me for a couple of weeks and I will update here - on this incredibly slow thread. Smile
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johnboy
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PostPosted: Sun Feb 12, 2017 3:43 pm    Post subject: Reply with quote

Laughing
Ok cheers Edward. I'm still on a mission welding. So brakes are in the distance . But I'm getting bits together Cool
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BigAl
P4


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PostPosted: Tue Sep 08, 2020 9:28 pm    Post subject: Reply with quote

As standard discs are NLA from brembo, although i have heard that they will be making them again soon, and that upgraded discs are silly money, I was thinking of doing Level Three: (for 14" alloys)

calipers from
Vauxhall Astra Mk3 (1991-1998)
(2.0L 16v 150 bhp 256mm) 24mm
(2.0L 115 bhp 256mm) 24mm

discs from
alfa 145/146 1.7 16v /155 brembo pt no
09.9631.14 center dia 59mm thick 20mm 4x98 257mm H40.5mm

original alfa 33 are brembo pt no
09.3140.10 center dia 58.5mm thick 22mm 4x98 239mm H46mm

apart from the brake pipe needing vauxhall on the caliper side and alfa on the other side, is there any probs with the discs being 4mm thinner than what the vauxhall calipers use?

other options are to get HiSpec Motorsport Billet 4 calipers, for disc sizes 245mm to 360mm
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Bobkelso
Alfa Sprint


Joined: 09 Aug 2011
Posts: 211
Location: Milan - Italy

PostPosted: Sat Sep 12, 2020 7:00 pm    Post subject: Reply with quote

Hi,
about brake upgrade on 14 rim using
GM-vauxall-opel 52mm diameter piston caliper
(originally for 256x24mm disk):

>> you cited fiat-alfa 155 disks 257x20 mm is a bit thin for Gm caliper;
it exists a similar fiat 257mm but 22mm,
see on brembo catalogue disks for Alfa Mito or Fiat 500,

It has the same low off-set, I mean quite low total height of 40.5mm

it will need MILLING 3-3,5 mm of GM caliper bracket mounts
in the area where the bracket matchs the alfa 33 hub,
to have caliper centered on disk; this can be done as there is a lot
of metal in that area ( I had these Gm calipers milled 3,3mm ), but also
disks will need to be reduced at least 1mm in diameter to fit the caliper,
and ideally some trick to fix the small 0,5mm play at disk centering hole

>> we know some had used Alfa 164 disk 257mm x 22mm 5.4kg,
(or the 257x20mm version) but these disks have an excessive off-set
( total height about 49/51mm ), they will need 5-6,5mm spacers
between caliper bracket mount and hub, longer bolts for bolting
the caliper bracket to the hub, removing of the disk shield,
and some other minor machining of disks in the inner side

>> an alternative it is use disks from other brands with height
similar to the original of alfa 33 (best is about 44-46mm),

these disks can need machining their centering hole to fit alfa hub,
but GM caliper will be almost already centered respect disk,
it will be required very little or also none spacers
or machining of GM caliper bracket to center the caliper

There is a list of quite easy suitable disks
from toyota, mazda, mitsubishi, audi, hyundai,
they are all about 255-258mm diameter and 22-24mm thickness,
with optimal off-set (total height) of 44-46mm (but allowed also 43-48 )
and need just some minor machining (on disks, not on other parts)

Best diameter disk to use is 252-255mm, as pads will not use more
than 249mm and caliper will not apcet more than 256mm
(257mm disk will need to be reduced a bit)

This is because GM caliper when used on 33 hub
will stay about 2 millimeters more near the wheel axe
than what it would be if GM caliper was used in his original GM car hub,
so using GM caliper on alfa 33 will need disks of slightly smaller diameter

EDIT:

>>> most easy conversion it seams to me using

Toyota Yaris 255mm x 22mm disk - total height 46,2mm,
( Brembo 09.A707.10 - disk weight 5.1 kg )
they are 255mm and with suitable off-set
and wheel bolt holes already match 4x98 fiat-alfa design

It will need just:
1) machining centering hole from his 55mm to 58.53mm
2) drill the small hole for the small bolt used to hold disk at hub
3) caliper bracket will need 2,5mm spacers ( 2 or 3 mm ready
to use and available on-line precision shim washers will be ok )


---------
With a little more work it is possible save another bit of weight:

Another 0,2 kg of weight will be saved using a disk
with a better design, toyota yaris 258mm x 22mm disks,
( Brembo 09.A913.14 - disk weight before machining 5.0 kg);
this will need also machining the diameter from 258 to 255-254mm

Other suitable disks are
(but could need to remove disk shield and using 4,5-5,5mm
spacers on caliper bracket, as they have a quite strong off-set
almost as the alfa 164 disk):
- Brembo 09.5736.14 – 4.95kg - Toyota Corolla 255mm
- Brembo 09.A713.21 - 4.8-4,6kg - Toyota Corolla 255mm
(this one is 4.8kg from Brembo and 4.6-4.5kg from other brands)

Some Mitsubishi disks instead are more heavy use being 256 x 24 mm:
(I didn't try these, I'm not sure if pads will fit surface area,
but maybe Brembo 09.A116.10 or 09.9991.10 will fit pad area)

Other disks form Hyunday, Renault (and Mazda, Kia)
with suitable off-set and light weitgh (4,7kg)
but they need a centering hole to be made
and a bit of drilling on bolts holes

Other possibilities are using some calipers from 1990-2000
Fiat cars positioned on alfa 33 hub with a small custom plate,
this will avoid brake fluid pipe with mixed Opel-Fiat connectors,
I skip description as these calipers are not easy to find out of Italy

---
this is a photo of 14 wheel brake conversion on 33 from an italian forum
with vauxall 52mm piston calipers and yaris 22mm disks
( it was used the slightly lighter 258mm type, machined to 255mm ),
you can see toyota disk bolt holes are already fitting:

https://forum.clubalfa.it/attachments/013-jpg.93711

------------

Ps: if one have a lighter 1.3 alfa 33 and want to save a bit of weight,
similar 14 wheel brake disk conversion can be done but
using a Vauxall-GM-Opel smaller caliper with 48mm piston diameter
( same diameter piston than alfa 33 calipers = same stopping force )
originally from Vauxall-GM-Opel cars with disks 256mm x 20 mm,

to see images of how these smaller calipers look like you can google
for example "caliper brake opel tigra (A - first version) 1.6 16v",
but very common, used on some vectra, astra, corsa, etc
with 1.6-1.8 engines ( be carefull to avoid calipers from GM cars
with 236x20mm disks, the caliper is similar but it has a lower height brasket that will make it not suitable for using on alfa 33; the correct
"small" GM caliper and bracket are from GM cars with 256x20mm disks)

Also this GM caliper when used on alfa 33 has a list of almost ready disks
with off-set between a quite suitable 43mm ( yaris 255x20mm )
and almost perfect bolt-on off-set of about 45-46mm
( Maxda MX5 I-II 255x20mm , Toyota IQ 255x20mm , etc)

this lighter option will not give more evident lightness/power
to the brake pedal, just a little improuvement, because the increase
in radius of disk is small (255mm vs 239mm) and the piston diameter
in the caliper is same as original alfa 33 caliper (48mm piston),
but it will give a lot more resistance to heat, having a bigger ventilated disk
and larger pads than alfa 33, already an improuvement for intense use

---------

Surely the Hispec Billet 4 option
(caliper for 240-290mm, 4 pistons 35mm or more diameter, with dust protection)
it will be the best option, saving a lot of weight also respect original set-up,
and using each millimeter of external radius of any disk you will choise;

the initial expence for calipers and preparing mounting adapter
is quite serious, but after reading your post I have see in their web site,
they have also chip pads choise togheter with more expensive pads options,
so one will have not necessary to stay every time with buyng racing pads
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BigAl
P4


Joined: 06 May 2003
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PostPosted: Sat Sep 12, 2020 7:27 pm    Post subject: Reply with quote

Hi bobkelso
I have looked at most of the options, i'm trying to do a conversion that means no machining of parts and fits under 14" wheels, but it is all very confusing

HiSpec Motorsport do a conversion for an astra mk3 but at 285mm & 310mm
i wanted to ask them if they could supply the bracket made for a 257mm disk with a narrower 22mm caliper and the correct offset.

thanks for the info on
AlfaMito Fiat500
09.5843.10 center dia 59mm 22mm 4x98 257mm H40.5mm

based on the height differences, assuming the thickness is the same on the hub surface side and i use the mito disc vs the astra disc
09.5148.24 vauxhal astra center dia 60mm 24mm 4x100 256mm H41mm

33 disc is 46mm high USED AS REFERENCE POINT
astra disk is 41mm high 5mm difference
mito disc is 40.5mm high 5.5mm difference
do i need to get them to adjust the bracket for their kit to be 5mm or 5.5mm outward / inward tp correct the offset
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Bobkelso
Alfa Sprint


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PostPosted: Wed Sep 23, 2020 5:52 pm    Post subject: Reply with quote

Hi BigAl

..I edited previous post, I added a toyota disk that
don't need machining his diameter, to make it almost bolt-on
--------

And I tried to have an idea on how HiSpec 4 billet calipers
will fit as brake upgrade on alfa 33 with 14 rims,

they have plus of saving weight and preparing
a custom bracket permits to use each millimeter
of the external diameter of any selected disk

As you noticed, one issue is that calipers are large,
using disks with low height, caliper could interfere with spokes
of some wheel rims, maybe it will need adding some wheel spacers

I roughly calculated measures of the custom adapter bracket
and how much caliper will protrude towards wheel rims;
eventually verify calculation, I could have done some errors

Data of smaller size Hispec 4 billet “radial mount” for diameters 240-290mm:
http://www.hispeccalipers.co.uk//b4-280-dataroad.html

For a 22mm disk, caliper is assembled with a central 28mm spacer;
so horizontally the caliper will occupy:
46,5mm external side + 28mm central spacer + 49mm internal side;
according to their tables:
radial mounting holes will be 38,5mm from center of the spacer

About alfa 33 hub mounting holes description:

caliper bracket holes on 33 hub are at almost 68mm radius from wheel axe,
distance between holes is about 76,3mm center to center,
line connecting holes is at about 56,2mm vertical distance from wheel axe;
this (56,2mm) permits with HiSpec tables to calculate vertical spaces;

horizontal distance between rotating face of the hub (where disk is bolted)
and caliper bracket holes hub faces is about 55,7mm
( Ken McCarthy on this forum measured 55,6, I measured 55,8 , so 55,7 );
this (55,7mm) permits to calculate horizontal off-set of the adapter

So a custom adapter bracket for the radial mount caliper will have:

A) adapter height

( vertical distance between the radial caliper mounts
and axis of bolts that fix the adapter to alfa 33 hub)

a = (disk diameter / 2) – 110mm

19,0mm for 258mm diameter disk
18,5mm for 257mm diameter disk
18,0mm for 256mm diameter disk
17,5mm for 255mm diameter disk


B) adapter horizontal off-set

( horizontal distance between vertical axe of bolt holes in the radial caliper
and the vertical face of the adapter that will be fixed to alfa 33 hub holes;
holes on this face will be 76,3mm distant to mach holes distance in alfa hub;

I call “inner height” of disk his total height minus 6-7mm thickness of external face,
I'll use as an example a Toyota disk with:
>> total height 46,2mm = 6,2mm disk face + 40mm inner height
on Brembo web site “inner height” of a disk is available from each disk drawing

https://www.bremboparts.com/europe/en

for 22mm disk with inner height of 40mm, resulting off-set is 16,8mm,
General calculation resulting is:

b = ( disk inner height ) – 23,2mm


C) how much caliper will protrude (out of external disk face) toward wheel rim spokes;
using the example disk with total height 46,2mm (= 6,2mm +40mm )
the caliper will protrude toward wheel rim spokes 25,3 mm
General calculation is:

c = 71,5mm – ( total disk height )

----------
examples of custom braket using HiSpec 4 billet calliper with
some different available disks, diameter 258-257-255mm, thickness 22mm

> Toyota disks will need machining the centering hole
from their 55mm diameter to 58,53mm to fit alfa 33 hub 58,5mm

> Alfa-Fiat disks ideally will need to fix the 0,5 mm play
at centering hole, as they have 59 mm instead of old alfa 58,5 mm
with some trick, as using some paint or some thin shim,
to avoid disk can move a little respect hub face when changing the wheel,
I mean, if disk will move, pads will need to adjust another time respect
incisions on the disk surface

> Hyundai and Renault disks will need to made a centering ring,
as they have larger centering hole 61-62mm

Note parameter c) about how much caliper will protrude toward rim,
changing disk used it will vary from 20,8mm to 31mm

---------

>> Toyota Yaris disk - Brembo 09.A913.14 – 5.0kg
- 258mm diameter – 22mm ( it can be used until 20mm )
- inner height 40mm + 6,2mm face height ( total height 46,2mm )

a) adapter height 19,0mm b) adapter of-set 16,8mm
c) caliper protruding toward wheel rim spokes 25,3mm

---------

>> FIAT-ALFA Mito disk - Brembo 09.5843.10 – 5.0kg
- 257mm diameter - 22 mm
- inner height of 34mm + 6,5mm face height ( total height 40,5mm )

a) adapter height 18,5mm b) adapter of-set 10,8mm
c) caliper protruding toward wheel rim spokes 31,0mm
( quite a lot, probably it is better verify free space in wheel rim )

----------

>> Alfa 164 disk - Brembo 09.5215.10 – 5.4kg
- 257mm diameter - 22 mm
- inner height 44mm + 6,7mm face height ( total height 50,7mm )
- it will need removing disk shield and some light machining

a) adapter height 18,5mm b) adapter of-set 20,8mm
c) caliper protruding toward wheel rim spokes 20,8mm

----------

>> Toyota Corolla disk - Brembo 09.A713.21 – 4.8-4,5kg
- 255mm diameter – 22mm
- inner height 43mm + 6,3mm face height ( total height 49,3mm )
- it will need removing disk shield

a) adapter height 17,5mm b) adapter of-set 19,8mm
c) caliper protruding toward wheel rim spokes 22,2mm

----------

>> Toyota Corolla disk - Brembo 09.5736.14 – 4,95kg
- 255mm diameter – 22mm
- inner height 42mm + 6,2mm face height ( total height 48,2mm )
- nor sure if it will need or not removing disk shield

a) adapter height 17,5mm b) adapter of-set 18,8mm
c) caliper protruding toward wheel rim spokes 23,3mm

----------

>> Toyota Corolla disk - Brembo 09.5676.20 – 5,0kg
- 258mm diameter – 22mm (but it can be used only until 21mm)
- inner height 42mm + 6mm face height ( total height 48mm )
- nor sure if it will need or not removing disk shield

a) adapter height 17,5mm b) adapter of-set 18,8mm
c) caliper protruding toward wheel rim spokes 23,5mm

----------

>> Huynday Accent IV disk - Brembo 09.C171.10 - 4,7kg
- 256mm diameter - 22mm
- inner height 36,7mm + 7mm face height ( total height 43,7mm )
the low weight is the interesting part,
but it needs more work to fit than previous ones

-----------

>> Renault Clio IV - Brembo 09.C285.10 - 4,7kg
- 258mm diameter - 22mm
- inner height 36,9mm + 7mm face height ( total height 43,9mm )
the low weight is the interesting part,
but it needs more work to fit than previous ones

-----------

Ps.: 258mm disks was the measure initially used on Alfa Sud Wink
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BigAl
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PostPosted: Fri Sep 25, 2020 2:16 pm    Post subject: Reply with quote

Do you know how far the original alfa caliper sticks out / offset and what the reference point is?

A disc as close to the original 46mm height would save using a spacer if using lower height disc.

I cant/dont want to machine anything. straight bolt on, save finding machinists and easy to replace.

The toyota disc needs machining Sad

Thanks for more info, esp the "GM caliper when used on 33 hub"
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Bobkelso
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PostPosted: Tue Sep 29, 2020 12:57 pm    Post subject: Reply with quote

Hi,
using the brake disk face where rim is bolt as reference point
to measure how much caliper will protrude outside horizontally,
I mean toward space where rim spokes are, I think:

> many common 14 rims and also Alfa 33 alloy rims 14 x 5.5 with ET 39
are suitable for caliper protruding about 18 mm

> larger rims 14 x 6.0 with ET 35 probably are suitable for calipers protruding about 25-28mm
( for example I like 14 x 6.0 with ET 31 alloy rims from Alfa 155 1.8 )

> if caliper protrude more than 25-28 mm it depends on rim spoke design and his ET
to be suitable or to need spacers

-----------------

Resuming about how much space a 4 pots caliper or GM caliper will occupy,
details and other reference points you can use to make a drawn are below.
Ps: I looked a bit more at option 2) maybe it could avoid machining, see discussion

1) first Alfa 164 disk – total height 51,7 – 20mm thick
- 4 pot caliper protruding 17,8mm
- GM caliper not an option on this thin disk

2) later Alfa 164 disk – total height 50,7 – 22mm thick
- 4 pot caliper protruding 20,8mm
- GM caliper protruding 8,3mm

3) toyota corolla (Huyndai, Mazda) disk – total height 49, 48, 47 mm – 22mm thick
- 4 pot caliper protruding about 22-23-24mm
- GM caliper protruding 10-11-12mm

4) Toyota Yaris disk– total height 46,2mm - 22mm
( use 258 mm diameter for 4 pots caliper – use 255 mm diameter for GM caliper )
- 4 pot caliper protruding 25,3mm ( maybe needs rims large 6.0 and with ET 35 )
- GM caliper protruding 12,8mm ( safe with any rim )

5) Alfa Mito-Fiat – total height 40,5mm – 22mm – 257 mm
- 4 pot caliper protruding 31,0mm ( can need specific rim or spacers )
- GM caliper protruding 18,5mm ( still safe probably with most rim )


About the option 1),

using narrower vented disk of first alfa 164, 20mm thick instead of 22mm;
this disk has a huge off-set ( total height 51,7mm ); Brembo 09.4768.10 – 5.0 kg;
https://www.bremboparts.com/europe/it/catalogue/disco/09-4768-10

this permits to save some weight and have some more mm of lateral space for the large 4 pot caliper
it will need machining disk at inner one side angle to clear the bracket mounts;
it is well explained with pictures at a topic I link here;
the author used Willwood 4 pots caliper, that have same measures of HiSpec 4 pots caliper
(they will occupy 49,5mm laterally starting from disk external crown surface, where pads contact disk)
and he says it will fit not only 14 rims, but also 13 rims ( more easily 13 iron rim than 13 alloy rims I think )

http://www.classicalfaforum.co.uk/forum/viewtopic.php?t=847

caliper 4 pot will protrude in the rim space about ( 49,5 – ( 51,7-20 ) ) = 17,8mm
so suitable with any type of rim


About the option 2)

this is similar to 1) but using the later vented disk of alfa 164 with 22mm thick
it still has a quite high off-set ( total height 50,7mm ); Brembo 09.5215.10 - 5.4kg
https://www.bremboparts.com/europe/it/catalogue/disco/09-5215-10

this disk is 1mm less total height than previous, interference with bracket mounts on hub is less
it will need a machining of disk inner side so light, that probably you can alternatively
mill diagonally by hand 1 mm of the angle of the brackets mounts on the caliper;
if you absolutely don’t want machining any part and stay on 14 rim this seams an option

caliper 4 pot with this disk will protrude in the rim space about ( 49,5 – ( 50,7-22 ) ) = 20,8mm
that probably will be still ok on some type of rims

calliper GM with this disk will protrude in the rim space about ( 48 – ( 50,7 -11 ) = 8,3 mm
but as said it is possible that disk must be slightly reduced in diameter
( it was so with the calipers from GM Calibra I had, I’m not sure if later GM Vectra/Astra
calliper can be or not a fraction of millimetre different from the ones I had )


About disk shield:

1), 2), 3) higher total height disk options and need removing disk shield;
4) same total height disk configuration as original alfa 33 disk (disk shield can stay)
5) lower total height disk configuration (disk shield cans tay)

About machining
( PS: simple machining can be done also by a brake workshop )

If 4 pots caliper (Hispec or Willwood) are used, a custom bracket-adapter is needed
If Gm calipers are used, disk 257mm can need to be slightly reduced;
1) needs some simple machining of inner side of disk (see details below)
2) no machining disk if instead milling 1mm of mounts angle on hubs
3), 4) machining toyota disk centering hole
(or modifying some rim centering ring for use for huyndai disk)
5) if using GM calipers, milling 3.3-3.5mm metal from caliper bracket is needed to center caliper on disk

About more reference points you can use to draw a scheme:

> alfa 33 vented 22mm disk are 46mm height ( 6.2 face + 38.8 inner height)
> alfa 33 solid 12.5mm disk are 46mm height ( 6.2 face + 38.8 inner height)

> caliper bracket mounts on alfa 33 are positioned 55.6mm horizontally inside
respect external surface of rotating part of the hub (surface where disk are bolted)

> disk shield surface on alfa 33 is positioned about 42mm horizontally inside
respect external surface of rotating part of the hub (surface where disk are bolted)
(using disk of 48mm or more total height it will need removing or modify disk shield)

> caliper 4 pot HiSpec or Willwood will occupy horizontally toward external side about 49,5mm
starting from horizontal reference the external side surface of disk crown (where pads contact disk)

To compare with GM, we can calculate using the center of the disk crown as reference point:
- 4 pots cal. occupies horizontally toward external side about 60,5mm if the disk is 22mm
- ( 59,5mm if the disk is 20mm )

> GM cal. from vectra/calibra 2.0 occupies horiz. toward external side about 48mm
starting from (using as reference) the center of the disk crown (crown can be 24-22-20mm thick)

> caliper alfa 33 for vented disk I think it occupies on the external side 3-4 mm less than GM

So it seams
- caliper 4 pot are about 12 mm more protruding than GM one
- caliper 4 pots are about 15-16 mm more protruding than Alfa one

------------------
A no machining option, you know is 15 rims, Alfa-Fiat big disks 284mm, GM big caliper ,
I don’t like it so much because it is a configuration with
quite heavy suspended mass respect the 33 car body weight,
this can give some minus with handling and confort,
mainly when car is used on normal streets;
also, I’m not sure is car will be still balanced front-rear or
almost breaking only on front wheels,
ideally needing some mods also on rear brakes
or about front-rear brake valve regulator,
but many people that have directly tried
seams appreciate this configuration
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