Suspension Upgrade

[Bunky]

What year 911 front suspension is the one to get (part numbers)? How will the best affect the rear suspension (brakes)?

[Wayne 962]

Hi there. From what I've heard, the '83 carrera front end is the best one to get, although these can be expensive $900, maybe. Since the front brakes do most of the braking, the effect on the rears really won't be too noticeable. I've had people who have upgraded their rears complain to me that they cannot feel the difference.

-Wayne

[Brian R]

If you want bigger brakes up front, all you need are struts, shocks, rotors, and calipers. The 914 A-arms are the same as the 911. A newer front suspension will give you an aluminum beam, a bigger sway bar, and slightly bigger torsion bars, but will also cost you a lot. You might have to make modifications for the later style sway bar also.

[Dave at Pelican Parts]

Brian is pretty close. I believe you'll find that the splines on the 914 torsion bars and A-arms are different than those on the 911 versions. So you'll want the t-bars from the 911 as well. And, come to think of it, the end caps as well.

The 911 went to coil-over springs with the 962 Carrera 2/Carrera 4 in 1989. So you don't want anything 89 or later, unless you want to do quite a bit more work...

As usual with 911s, the later the better.

Many of the very earliest 911s (up through 68 or so?) had solid rotors and relatively small calipers. These would not be a really big improvement over the stock 914 brakes (though it would probably be noticeable).

Starting about 1969, all the 911s had ventilated rotors, and bigger calipers. The alloy 'S' caliper is a favorite for some because of the light weight, while some like the steel (iron?) 'M' caliper because it doesn't flex as much as the 'S' one. One or both of these were used on 911s up through 1975, possibly to 1977. However, starting in 75, larger brakes were an option.

I think these are the same as SC brakes. The 911 SC was made from 1978 through 1983. These are vaccuum-assisted, by the way. They stop VERY well.

The 3.2 Carrera went from 1984 through 1988, and had still bigger and better brakes. Also vaccuum-assisted.

I don't have part numbers handy, but the best bet is to try finding a wrecked car of whatever vintage and using the complete front suspension from that. It's probably not much more money than just getting the A-arms, brakes, etc.

If you upgrade your front brakes with anything but the earliest 911 brakes, your rears will probably become rather under-utilized. It might be a good idea at that point to put an adjustable proportioning valve in place of the stock one. Some people prefer replacing the valve with a 'T' fitting.

You could also replace the rear brakes with something bigger. However, most brakes available will not let you use the stock-type parking brake. I've read of some older Ferrari calipers that are nearly identical to the 914 rears, except larger. But I bet they ain't cheap. You can also split the rear calipers and use a spaker from some early 911 front calipers so that you can use an early 911 ventilated rear rotor. I don't know part numbers on these, either.

--DD

[Jeff Kinder]

Speaking from "Having done it MYWAYITIS", you have a lot of options. As Dave said the Torsion bar is the same between a 911 and a 914, EXCEPT that the 911 Tbar has one more spline. You can find complete assemblies or upgrade specific components, ie larger TBars and calipers rather than everything.

In my case I put in larger 914 Tbars and sway bar. Then I changed the struts to 911 Carrera Struts on the 914 a-arms. I then put 86 911 Carrera calipers and rotors on front and rear. This requires an adjustable proportionong valve to set the balance properly. Some people eliminate the proportioning valve when doing brake upgrades, but this is not something I personally recomend. As this does eliminate the 914 parking brake, you have several options:
1. Forget the parking brake.
2. Get the 911 parking brake assembly and have your 914 trailing arms modified to accept them.
or 3. Get a Line locking device. Puts hydraulic pressure on the rear calipers.(Good only short term and should not be relied on when parked on a hill unless left in gear also.

The 911 SC and Carrera brakes are both excellent choices, my preference for the Carrera version is based on the wider rotors (better cooled).

If you just want to improve your braking "on the cheap", consider a pair of BMW calipers up front on your 914 rotors.

If you do not plan to upgrade to an adjustable sway bar, a complete assembly from an SC or Carrera is a good choice. I know of a supposedly good setup available from an '87 at a good price.

In this process you may want to consider other springs in the rear and adjustable perches.

Let us know if you decide to put the Ferrari parts in.

Jeff Kinder
jazzman@deepwell.com

[Bunky]

Thanks for the advice. If I decide to go with the Carrera vacuun assisted units what vacuum related equipment do I need?