chip_962

Other than being beefed up because of the technical bulletin that forbid the use of 18" wheels, is the 3.6 turbo front suspension otherwise identical to a narrow body? Put another way, is the hub in the same qeometric position as a narrow body car? The answer is yes for the 92 turbo, as the parts are the same as the late narrow-bodied cars. The oddity is the the technical spec. book identifies a narrower front track for the 3.6 turbo. Yes, I said narrower. Knowing the answer helps in determining wheel offsets to use if you update the 964 NB front to turbo knuckle and hub.

Thanks in advance.

-CD-

Narrow body, Turbo II 3.3 and Turbo 3.6 all different in the hub carriers!

The Narrow body hub carrier has an axial mounting for the brakes!

Turbo II 3.3 (same as 964 RS) and Turbo 3.6 has radial mounting for the brakes!

And the Turbo 3.6 is made in forged steel and it is the strongest hub carrier of all 964!!!

It is the perfect part for using 18" wheels and the Big Reds!

I hope my english is correct!

Greetings Christian

Geoffrey

The 964 Turbo front suspension uses some of the same parts as the narrow body. The 3.3 and 3.6 Turbos both use the outer mounting position for the front suspension subframe where the narrow body uses the inner mounting points. The early narrowbody chassis do not have both sets of holes, only the later chassis, 91 and later I believe but I'm not positive on the cutoff date. The suspension cross member, side members, and control arms are the same (RS have different bushings, but otherwise the same). The wheel carrier is specific to narrow body and 3.3 turbo where the 3.6 turbo has a different wheel carrier. Hubs vary, but are generally interchangable except you cannot use a 2wd hub with a C4. RS hubs are essentially modified C4 hubs. Inner tie rods are the same between C2 and Turbos but Carrera RS and C4 are different than the C2. Outer tie rod ends are all the same. The tie rod adjuster is the same C2, C4, RS but different than Turbos.

So, to answer your question, the suspension main components are the same between the models but are mounted in an outboard position on the turbo, inboard position on a narrow body. Other components are different to accomodate the difference in track as well as 3.6turbo brakes which mount differently. The difference in width is about 1" each side and the offsets on the wheels are different. The TSB for 18" wheels is only a small piece that attaches to the steering rack mounting point. To be honest, I'm not sure really what it does. It doesn't look like much.

I posted some pictures of this during my car build. Do a search on "Racecar Project" and you will find them.

chip_962

Found your post(s). Thanks. So where does that leave the 964 3.8 RS? If it used turbo brakes, what knuckle did it use? RS's? And did it use the inboard mounting, since the chassis is 964 RS? And make up for the track with those speedlines?

Geoffrey

The 964 RS3.8 used narrow body rear control arms, not turbo, and basically turbo 3.6 setup in the front since it is a widebody car. This means the front is in the outboard position.

chip_962

Geoffrey, on your racecar build post someone mentioned trying to drill and tap for the outboard mounts on an early chassis. Was that ever determined to be safe and practical? Was the subframe part different in any other way?

Geoffrey

It is the chassis that is different, not the subframe components. I haven't seen an early chassis to answer the question.