need advice on supsensions & brakes for early car resto

[911SCfanatic]

I am restoring a '72T for 75/25 track/street use. Originality not an issue, but I am striving for a somewhat original look. Here are the known parameters:
a) 240-265 hp 2.7RS-type engine
b) 1900-1950 lbs.
c) no flares, but willing to roll
d) 15" Fuchs
e) shocks: adjustable Koni's
f) Elephant monoballs, etc.

Need help with the following:
1) What's the biggest 15's I can/should run?--6's & 7's or 7's & 8's? Do I need any particular offset on the 7's or 8's? Tire considerations (profile for looks, clearance, stability)?
2) What brakes can/should I use that will fit under the 15's? The car's light, but has lots of power. Are the Brembos available for 15's ($$$) overkill for my application or is there some other solution?
3) Should I upgrade the front and rear suspension to a Carrera or other newer suspension? I need to get newer front struts at a minimum because my '72 struts have 3" spacing.
4) Torsion bars--21/27 or stiffer?
5) What size should I use for sway bars? What can I use for the front through the body mount that's OEM?
6) What's advisable for a m/c?

I've searched threads and done research. I want want help applying the info out there to *my* car. In particular, I wasn't sure how to mesh all the info out there with all my known parameters. There's a lot of experts out there that are *much* smarter than me. Please weigh in.

[Bill Verburg]

240-265 hp 2.7RS-type engine

Not likely

1900-1950 lbs

maybe, stock brakes are fine for low 200hp & low 2000# race cars

no flares, but willing to roll

that limits you to 7 maybe 8, front 7 woud want ~+24mm o/s 7x15" Fuchs are +23.3, rear 7x15 will want ~+39mm o/s, Fuchs R type are +49 and generally want a ~10mm spacer in the back for the +39. There are a few that have squeezed +23.3mm 8s in the back but to me the wheel sticks out too far. No way 9s will fit w/o flares

[Shuie]

1900lbs and 240hp is not going to be easy. Grady's 2.8 will get you the HP number in a very lightweight package. 1900lbs is going to be really tough for even a 100% full on track car. It would be easier with a SWB car or a 914. My car is 2350 with half a tank of fuel. Its not stripped to the bone, but its not a pig either (its actually very similar to the car you are describing). Honestly, I dont know that I could remove another 400 lbs from it.

I dont know if this will help, but here's how my car is setup in comparison:

1) What's the biggest 15's I can/should run?--6's & 7's or 7's & 8's? Do I need any particular offset on the 7's or 8's? Tire considerations (profile for looks, clearance, stability)?

Im running 15x7s on all four corners with 205/50/15 yokohoma AVS-ES-100s. All of these cars are a little different, but it would not be easy for me to run anything with a standard fuchs offset and narrow flares under the rear. I can fit a 8" wheel in the back as long as it has a 45mm+ offset and a little extra camber.

2) What brakes can/should I use that will fit under the 15's? The car's light, but has lots of power. Are the Brembos available for 15's ($$$) overkill for my application or is there some other solution?

Im running stock rear calipers and front calipers from a '87 Carrera. Honestly, this is probably overkill. this are the biggest brakes that can be run with non-boosted 19mm Master cylinder. Alloy S-calipers will help you keep the overall weight down if you can find them. I dont even think you can push the Brembos with a non boosted master cylinder.

3) Should I upgrade the front and rear suspension to a Carrera or other newer suspension? I need to get newer front struts at a minimum because my '72 struts have 3" spacing.

You need to go to a 3.5" eared strut if you want to upgrade your brakes. Keep your '72 A-arms (see sway bar question)

4) Torsion bars--21/27 or stiffer?

should be fine with 21/27. Mine are 22/28 (struts are Koni adjustable sport yellows) and I like them. Just make sure they are a good match for your strut/shock choice.

5) What size should I use for sway bars? What can I use for the front through the body mount that's OEM?

Yes, if you keep the '72 a-arms. Size? I dont know. Ask Chuck when you get your polybronze bushings. So far, I have set up my suspension according to what he has told me and Ive been real happy with it.

6) What's advisable for a m/c?

19mm non-boosted for anything up to Carrera A front calipers. There is a bigger Mercedes master cylinder that some people use to push bigger front calipers.

Im not an expert on any of this stuff but I hope that helps on some level. Keep us posted. This sounds like a cool project.

[TimT]

final weight is really dictated by which year tub you have ( also how extremely you moiodufy the car) .

My 69 car was something like 2254# stock out of the box. You can make an early tub super-light.

I expect my car when done... there is light at the end of the tunnel LOL.. to scale at less than 2000, and more than 1900, and I did extreme lightening, glass roof, all glass fenders and lid, carbon doors (impulse buy), stripped all the goo from the tub etc.

[Bill Verburg]

A completely stripped PCA legal 2.7 RS lightweight, w/ mandatory lightweight carpeting and only necessary wiring, will come in ~2K or maybe a little less and need ~116# of lead bolted in to make weight.

[Randy Webb]

See my compilation on light weight stuff for some articles on people who have lightest known 911s out there + what the factory did way back when. You'll have to saerch for it - I don't remember the URL.

Like the above worthies, I am also dubious as to a 240-265 hp 2.7RS-type engine being a known parameter... I won't say impossible but I doubt it will live very long. Also, the cam would be veeeeery peaky - maybe not worth using on most tracks -- unless you put in a CVT....

[Chuck Moreland]

I have / am developing a similar car that is a 73.

It's currently 2100 lbs and I've taken considerable pains to to get there. For now, I'm happy with 2100 lbs. But I could get down to 2000 lbs pretty easily, it would require glass / CF doors and fenders. Getting to 1900 would be a stretch but possible. It would require removal of ALL undercoating, tossing the wiring harness, lexan windshield, and gutting the interior. Below 1900 would take serious effort.

I'm also building a hot 2.7, RS+ specs. S heads and cams, Twin plug, high compression, EFI, boat tailed case. I'm hoping for 240-250 hp. Time will tell.

I would forgo the Brembos and use Carrera brakes with ducting and other proven hardening methods. Stock MC. That will help you get to your weight target too.

Torsion choice depends on multiple factors. How much street/track time? Personal tolerance for a harsh ride? How fast/smooth are th tracks? Will you be running a wing?

I wouldn't worry too much about sway bar size. Your car is light, you don't need huge sways. You need adjustability to get the balance dialed in.

[Randy Webb]

OK, Chuck -- let's hear about those considerable pains to get to 2,100 lbs. Anything we haven't seen before?

[Chuck Moreland]

Nothing ground breaking. Proven stuff like lexan windows, no door cranks, fibergless bumper/ lids, lightweight everything.

Nothing was installed in the car without considering the implications on weight. In most cases, lightweight alternatives were used when availble - CRoMo partial cage, hollow torsion bars, hollow sways, etc.