Project Summary

Difficulty	***
Time	6 hours
Specialty Tools	yes
Vehicle	Alfa Romeo 105 Series

Required Tools

Basic Tool Set

• Box Wrenches: Metric (7mm - 19mm) and Standard (3/8" - 3/4")
• Screwdrivers: Philips (small, medium) and Flat (small, medium, large)
• Hammer
• Socket Set: Metric and Standard (100+ pc)
• Hydraulic Floor Jack

Specialty Tools

• Drill Press
• Chop Saw (With metal cutting wheel)

[edit] The Project

The Alfa Romeo 105 Series (GTV, Spider, Berlina, and TI/Super) was available with disc brakes on all 4 wheels at a time when most cars were still running drums on at least the rear wheels. As a result the 105 series had stunning braking performance for its day. But 40 years of braking evolution have since passed and better options are available. Keeping up with modern cars gets harder as time passes and these great classics deserve an upgrade. There are a couple of kits out there for cars of this make and age that provide great performance for anywhere from a reasonable to a completely ridiculous price bracket. But nothing compares in price to doing it yourself. Here's one way to do that. There are lots of others and hopefully someone will put them up.

[edit] A Solution

One solution developed by WebMechanic in partnership with others on the Internet is a combination of a Saab rotor with a Mazda caliper to put some very large 4-piston calipers on the front of the car. Many people consider a Wilwood Dynalite-sized caliper a good upgrade for an Alfa. See the attached photos for a comparison in size of the calipers. Another advantage of the Mazda caliper is that it's not only much larger and capable of taking a larger rotor, but it will use all of the stock brake lines without modification, including hosesThat keeps the cost down and makes replacement parts easy to get. Just order the original Alfa part. An important point is that they work well with the stock master cylinder.

This would be complete overkill on the stock Alfa brake rotor, though, which is not large enough to take advantage of the additional swept area of the Mazda-sized brake pad and being a solid rotor is too thin to use safely with the Mazda calipers--which were designed to handle a thicker disc. There are a lot of solutions for this. The best would be to buy custom rotors from a company like Wilwood. Again this is expensive. The Alfa uses a somewhat odd bolt pattern that excludes it from using rotors for many other cars. Given that the rotor sits behind the hub it also requires a larger hole in the center of the rotor than is commonly found. One solution, and the one demonstrated here, is to use a rotor from a 1986-1987 Saab 900 Turbo which has the correct thickness, correct hat height, and a large hole already in the center--through which the Alfa hub fits without issue.

The Saab rotor is also really cheap. They are available from about $16 a piece which is a major advantage. The only hitch is that the rotor needs to be machined to have the correct bolt pattern. This is something you really need to pay a machine shop to do because getting it absolutely correct is important and getting that kind of precision at home is very difficult. The good news is that the cost of this is not extreme. The original author of this article had a set done for US$90 total. That combined with the low cost of the Saab rotor brings the price of a new set of front rotors in just barely above a stock set of non-vented Alfa items. <p>The only "hard" part about doing it yourself is that you will have to build the adapter to mount the caliper to the upright. 1750 cars and later (including all 2000 spiders up to 1995) have a 3.5 inch spacing between caliper bolts. This is in contrast to the earlier cars which have a 3 inch spacing and can thus use the calipers from the GTV6/Milano like this Brembo upgrade. The Mazda calipers have a very wide 5 inch spacing between bolt holes which actually makes the adapter pretty easy to make to fit these calipers. How to make this adapter is the focus of the main section of this article.

Advantages: Cheap(!), Easy, do it at home.

[edit] Cost Breakdown

You'll need to buy some materials to build this setup. The costs are for both parts and services. The only thing you really need have machined by someone else is the rotors so no other costs are listed. Quotes have been given at around US$100 each for machining the necessary brackets to mount the calipers.

Item	Cost (USD)
Rotor (2)	$32
Rotor Machining (2)	$90
Calipers w/Pads	$100 on Ebay
Aluminum Bar	$20 on Ebay
Total	$232

== Article In Progress ==

This page was last modified 21:44, 28 June 2007 by SpannerBros user WebMechanic.