Alfa Brembo Calipers...what hubs?

[Nickelplated5s]

I've been pondering this for awhile and have some questions. Car is a '66 build date, '67 sale date. Where do I take the hub measurement? Second is for Chris P. Are the Alfa's fine or just go Boxster from the start? 6x16 Fuchs on it. 2.2 MFI motor in it. Half tank of fuel and no passengers weight is 1960-1980. My neighbors CAT scale apparently runs in 20 lb increments and a breeze could explain it. Originally I was thinking just the fronts but the brake bias answered that for me. So, all 4. I may or may not auto cross it this season. I'll probably end up with a lift for this job.

Lastly, as I forgot. A local shop did some work on the car. Replaced the maser cylinder without permission (amongst other things). How can I tell which size? Paperwork doesn't say.

[Chris Pomares]

After going back to the start of the thread I realized I'd already posted most of this. But since I took the time I'll leave it up. First. What struts do you have as far as bolt pattern? 3.0 or 3.5. Second. After owning the Alfa's I'm not a fan. They flex. If staying 3.0 I prefer the ATE Euro BMW 323iS caliper from the same time period. It was used on the 1977 American BMW 320i for the first year if I remember correctly. Then they pulled the spacers and went solid rotor. I'm guessing to save on costs. For those who are staying solid front rotors the ATE, and make sure it's the ATE 320i front caliper of the late 70's and 80's is a nice upgrade. The Euro 323iS caliper uses the same pads as the Alfa. Basically a SC ATE pad with snipped corners to clear the 3.0 bolt spacing. The 323iS is much stronger. If you have 3.5 struts and 16's already I prefer the non S Boxster calipers. Big upgrade. I also run, one of, as far as I know, 42 mm piston rear calipers currently. It keeps the 1.6 brake bias. So I went from a 19 mm master to a 20.64 master as I had a little free play in my pedal. It's perfect now. If you stay with the 35 mm piston rear calipers you probably can stay with the 19 master. Your bias will be a little more toward the front, but that's probably livable. If you want to stay with the SWB front suspension and use a 3.5 strut, Rebel and Elephant have a solution. This will sound like sacrilege. If I had a LWB car I'd remove the front suspension and go SWB like the pictures. It makes for very easy camber adjustment. I used the Rebel bushings, no grease and no flex. I've since gone to Elephants GT3 type front suspension. Probably overkill for most folks. It looks awesome and works great. More sacrilege. I have very little rubber in the suspension. Basically the bushings in the trailing arms to the body. It's very smooth riding and very little alignment movement. I let bushings bush, and springs spring whether its T bars or coil overs. I have never understood why people want a bunch of rubber throughout their front and rear suspension. Yes I know that's how Porsche did it. That was the economic way at the time and car companies hoped the car would rust out in 3 or 4 years and we all would buy another. My car is NOT stiff, it's smooth. The car has made 3 round trips from Colorado to California and back in the last 12 months and I'll be 72 next month. I don't like getting beat up.

A 69 POLO car I'm building will go Non S Boxster at all 4 corners. It will get a 22.2 master. My guess is the 23 mm ATE master will be too stiff. If anyone needs one I have a new 23 ATE on the shelf.


https://www.ebay.com/itm/174196088700

https://www.rsrproducts.com/product-...89-911-912-930

https://www.elephantracing.com/porsc...ystem-for-911/

[Nickelplated5s]

Thank you, that is the answer I was looking for. After poking around under it the whole front suspension is going to get redone too. Time to start ordering parts.

[Nickelplated5s]

This has started me down a rabbit hole. I still have no clue where to measure the hub diameter from without pulling it all apart. Caliper bolt spacing is +/- 3", hard to be exact. I've found (thank you Chris) parts for the front rebuild. Then I looked at the GT-3 front. Deep in the weeds but hey, my birthday is coming up. Obligatory photos will be posted at some point.

[Nickelplated5s]

This is what I found out. 3.0 spacing Boxster's are not available. Chuck at Elephant found a pair of 3.5 struts in the shop for me that will work. That means Boxsters for me with a bunch of bushings and such. The GT-3 is nice but coil over only and I want to keep my externally adjustable Koni's. Those are custom fit and I can pull part #'s at tear down if anyone wants. Here's the kicker - Elephant is working on 930 calipers for 3.0 spacing. More money, obviously, but overkill for a <2,000 lb car.

[Chris Pomares]

There are no 3.0 front Boxsteer calipers. You are referring to rears. On my front Boxsteer calipers with Rebel brackets I only needed to make a 1 mm thick by 1 inch wide by 4 to 4.5 inch long brass spacer to move the caliper out. That centered the caliper to the rotor perfectly. I bought the brass from Ace Hardware.
Maybe Chuck is working on a rear Boxsteer caliper to put on the front of 3.0 struts.

[Nickelplated5s]

It was a rare dry day here in the PNW and the shop had space. So, in it went. Didn't get pic's of the parts as they were boxed but at some point. Dry fitted the calipers this morning and they should fit. I've got to say those Boxster calipers are a lot larger than stock. I'm expecting some teething problems but hopefully not to much. Perhaps a week or two before I get it back. Other than alignment this could be a DIY job. I've got the tools and space but chose not to. One of the benefits or drawbacks of getting older I suppose.

Hopefully I give accolades to Chris instead of complaints....

[Nickelplated5s]

Sort of a bump but here's where I'm at. Stopped by last week to check on things, happened to be in the neighborhood. One of the teething problems is that the Boxster calipers have to be tilted to fully bleed air. Glad they caught that issue. Second issue is shocks. Wanted to keep the custom Koni's but perhaps should have gone coil over and/or GT-3 front. Third issue is the rear. I want the front done first before I do anything there. What I've found is Koni 8040's are the only replacement for a SWB. Only other options are coil over or possibly rebuild the existing Bilstein's. I will figure that out when I get the thing back. Feedback on rear shocks would be nice.

Forgot one other tooth problem. The new master cylinder wasn't a bolt on. Shout out to ER tech for help sorting that out.

[Chris Pomares]

If I recall I had to swap sides with the front Boxster calipers. The calipers are in front of the rotor on the early cars, and behind the rotors on the early Boxster. As you can see the crossover lines are on the bottom and the bleeders are on top. If you don't swap the small and large pistons will be in the wrong place. The fronts need the 24mm Carrera rotors. The 20mm rotors are too thin. I had no issues bleeding the brakes. As mentioned earlier I went with a 20.64 mm master. https://www.ebay.com/itm/174196088700
I also ran these calipers with Koni's before the coil over install with no issues.
The rear calipers are in front of the rotor on both cars. On the SWB cars use a early 20 mm 944NA rear rotor.

[Chris Pomares]

Another thing. I've slowly made upgrades to the suspension and brakes over 12 years. Single 19 mm master to duel. Stock brakes to Alfa Brembo's front and spacer installed in rear calipers to allow vented rear rotors. Then small steps in suspension specs. SWB to LWB front Koni's with SWB to LWB after market ball joints. 15 mm F&R sways to 16's. 19 mm stock front T bars and moved from 67 23 mm rear T bars to 24. Then coil overs and 3 different front and rear spring sets. The spring numbers I'll keep to myself. More trial and error. Then Boxster front Calipers and 20 to 24 mm front rotors. Custom 42 mm piston rear calipers. Then the need for the 20.64 master. I now have a set of factory 18 mm F&R sways. Might use them? Might not. The point is I got to see how each change affected the car. Slow and methodical. Or maybe just slow.