Early brake/suspension upgrades (Bilstein/Carrera?)

[Luke Hudson]

One of my winter projects is a suspension/brake upgrade. Now this is a street car so I'm not going crazy, but a little more stopping power is always a good thing. I’m doing a straight swap on the back for new Bilstein shocks and will recondition the existing “M” callipers.

The Front is a little more ambitious, I plan to replace the existing Boge shock and strut with a Bilstein unit. As I understand it “M” callipers do not fit the Bilstein strut due to bolt spacing. My plan therefore is to upgrade the front brakes while I’m at it to either “A” callipers or Carrera callipers.

My questions are;

Will the “A” or Carrera callipers fit a 1972 spec Bilstein strut, if so which is the better calliper?

Will “A” and/or Carrera callipers work with a standard 19mm dual circuit master cylinder? (I don’t want to replace the master cylinder)

Will I need new brake discs (rotors) for the new claipers?

Your input is , as always, greatly appreciated

[Al G]

Hi Luke,

I'm not sure about a '72, but I fitted 3.2 Carrera struts, callipers and discs to my '76 C3. Doing a complete swap out ensured compatability and it was easy to get brand new HD Bilstein inserts, callipers and discs.

I am not sure about the MC question - not a problem on my car.

What about the anti-roll bars? - Do you have a through the body or underslung type? I went for a 22mm bar off a turbo up front.

At the rear I fitted 24mm early 3.2 rear torsion bars (NOS), and a 21mm anti roll bar off a late 3.2, with HD Bilsteins.

My car is used on UK A & B roads and around town so needs some suspension travel! Having said that it goes round corners like its on rails!

Al G

[Luke Hudson]

Al,

I'm not too sure what I'm doing with the torsion bars at the moment as I don't kow what I've got installed. Once I start the project I'll check the bars and get thicker ones if necessary. Assumeing the bank balance can handle all of this!

Luke

[Jim Smolka]

May also be a good time to inspect/replace the rubber bushings in the A Arm. The OEM rubber pieces are NLA w/o buying the whole arm. The bushings can be replaced with aftermarket stuff that works 'better'. One can also replace the rubber bushings with bearings.

Good time to upgrade to Turbo tie rods too.
IMHO, going to A caliper struts and using Carrera calipers and rotors is a good option. However, if you go with Carrera calipers, you will need Carrera Calipers for the rear. The Carreras also had a proportioning valve. You can go with SC front calipers in the front and keep the back the same.

There are also big brake kits that will mount to the 3" spacing of the earier calipers.

[Luke Hudson]

Jim,

The turbo tie rod ends are already in my lounge awating fitment, and I'm looking at some Weltmeister bushes to replace the old rubber ones.

So from what your saying the "A" spec caliper is the best bet for me. I can keep the existing back brakes, don't need a balance valve and can keep my existing master cylinder?

Will SC brakes require new discs?

What are the "big brake" kits of which you speak?

[Kahuna]

I think that the Carrera calipers and rotors are the better choice. Bill Verburg has a web site somewhere outlining all the possible choices and neccesary mods that go with them.
try a search.

[Luke Hudson]

I just looked at Bill's site. It appears that the "A" or SC, and Carrera calipers will both fit the struts, and the "A" or SC don't need new rotors either.

I would prefer the Carrera calipers but if i need to update the rear brakes too then it starts to get very expensive.

Are the Carrera units significantly better than the "A" or SC brakes, to warrant the cost of 4 rotors, 2 extra rear calipers, possibly a new master cylinder and a balance valve?

[Chuck Moreland]

Counterpoint -

Your existing brakes are plenty adequate for street use. Later brakes won't stop the car any faster, they will just be more fade resistant. If you are not experiencing fading, then you have nothing to gain.

"A" would be a suitable upgrade if you planned to track the car.

Instead why not just rebuild the existing brakes. Calipers, MC, flex hoses, pads and rotors. You'll save a boatload of cash since you can keep your existing struts. Money that could be used for other suspension upgrades that will truly improve performance and make your driving more fun.

[Luke Hudson]

You make a good arguement Chuck, the Bilstein struts are GBP350 each over here, so inserts would make more monetary sense, but I just know I'll end up spending the extra..........

What do you mean by "other suspension upgrades that will truly improve performance "? Torsion bars?

[Chuck Moreland]

You didn't list your planned suspension upgrades, but a good plan for street performance would include the following:

PolyBronze Bearings
Torsion bars (21/26 or 21/27 for the street)
Bilstein HD shocks
Strut brace
Adjustable sway bars
Factory adjustable spring plates
Performance alignment
Ride height and corner balance

Your savings on struts and calipers would cover a nice slice of the the above.

[Randy Webb]

Be sure to replace the rubber brake hoses -- that's critical.

Also, replace all the rubber in the suspension. You can get the rear banana arms off an SC and save about 11 lbs. with the Al parts. Hollow T bars will also save some wt.

[Bill Verburg]

Originally posted by Luke Hudson
Will the “A” or Carrera callipers fit a 1972 spec Bilstein strut, if so which is the better calliper?

As long as the struts have the 3.5" ears for the brake mounts it will fit fine.

Will “A” and/or Carrera callipers work with a standard 19mm dual circuit master cylinder? (I don’t want to replace the master cylinder)

Yes! No Problem.

Will I need new brake discs (rotors) for the new claipers?

the stock rotors in good condition will work fine w/ an A or an S caliper

For street use I would stick w/ stock rotor and either an A or S caliper. The 3.5" struts are a good upgrade regardless and I am also partial to Bilstein.

If you plan on tracking the car and rules allow the Carrera rotor which needs to be used w/ the Carrera wide A caliper is a nice cheap upgrade, likely not really critically necessary w/ your light car. The later heavier SC/Carrera w/ more speed potential and heft are the ones that got the short end of the brake stick.

[Luke Hudson]

Thanks for the response guys!

I've bascially got my project sorted now from all your advice and it's goes a little something like this:

Turbo tie rod ends
21/26 Torsion bars, preferably hollow (should they be needed, as I haven't checked what I've already got)
Full set of new Welmeister Bushings front and rear (Poly Bronz are way too expensive in the UK)
Bilstein rear Shocks.
Steel braided brake Lines
Either Bilstein inserts for Boge strut or Bilstein struts and shocks (cashflow dependant)
2 x A caliper's if I get the new strut, or recondition all four "M" calipers"

Once i manage to price up all these items and source them (sadly when you add shipping to the UK and tax to Pelican's prices it gets a little pricey) I'll let you know hwo the build goes.

Thanks for all the help

[Luke Hudson]

Oh one last question, is there any difference between a 1977 Bilstein front strut and a 1972?

I can source some used 1977 struts in v good condition and want to know if they will fit my car.

Thanks

[Randy Webb]

Avoid Steel braided brake Lines. They offer little benefit in pedal feel and are dangerous unless replaced very frequently. Put on new OEM rubber hoses all around -- and do it about every 5 years.

Also, replace every piece of rubber in your suspension. don;t foret to check wheel bearings, balljoint, and replace the grease in your CV joints every few years -- nobody really knows how frequently.

[Bill Verburg]

Originally posted by Luke Hudson
Oh one last question, is there any difference between a 1977 Bilstein front strut and a 1972?

I can source some used 1977 struts in v good condition and want to know if they will fit my car.

Thanks

Yes, but be warned struts, as well as the inserts, do go bad and those are awfully old.

My original '76 struts needed replacement ~6yrs ago

[Randy Webb]

A common upgrade is to just swap in the entire front end from a 1984-89 (Carrera). The crosspiece is Al so you save a few lbs., and you can then run various other calipers, tho the Carrera calipers are fine upgrades.