upgrades for '73 911

[ryan j]

I've recently acquired my first Porsche. It's a 1973 911 with a 3.2 engine out of a 87 carrerra that's rebuilt to a 3.4L. The car moves pretty good, and I'm happy with the straight line performance.

What I'm looking for is information on the common upgrades for brakes and suspension. I've read posts from the search button, and haven't found anything specific. Will the newer style suspension out of a, say for example, 89 carrerra bolt up to my car. What about brakes? I need to keep the 15" wheels, so that limits my options.

One other thing, is it worthwhile to have a dual outlet muffler? I've got the SSI's, but a stock single outlet muffler. What are the opinions of that setup?

[carmaneddy]

Congrats on your P-car purchase. IMHO the LWB early cars are the best.
With regards your question. You dont say if your car is an S. So if not you should try and upgrade to S front brakes and struts and a bushing upgrade.
Is your car a daily driver, track car, etc.?

[carmaneddy]

Also, what tires? and wheel width?

We need more data!!
I am sure lots of opinions will follow

[klaucke]

For suspension, the budget is the limiting factor. You can get Bilstein's, adjustable roll bars, poly-bronze bushings, and lower you car. You can also upgrade to larger diameter torsion bars. For brakes, you could also upgrade to S calipers or early model turbo calipers, put in stainless braided lines, and even high performance fluid (I'm skeptical about the validity of this, but others use it exclusively).

One of the easiest and cheapest methods, especially if your car is dedicated to track time, is to remove stuff from the interior and rest of car to lower the weight. Again, there are a lot of options, like RS door panels, RS carpet kits (or no carpet at all), lighter seats, fibreglass doors, etc. A lighter car handles better and stops quicker.

"It's a 1973 911 with a 3.2 engine out of a 87 carrerra that's rebuilt to a 3.4L. The car moves pretty good, and I'm happy with the straight line performance."

Are you joking? That thing must be a rocket ship!

[ryan j]

Sorry about the lack of details. Here's the low down on the car.
It's the ex Chizma/Olson SCCA prorally car.It's been raced for the last four years. It's caged,has absolutely nothing extra in it and fiberglass panels everywhere it can. (no lexan yet) I'm not sure what model it started out as, but it has alot of the basic upgrades for racing.

I'm looking at different suspension and brake options that I have with the car and wondering if switching over to a coilover setup would be worth the time/money, or is it even possible?

It's street legal and driven on the street twice a week. I'm thinking about doing some track events with it, along with rallying it as long as it's still in one piece. I'm limited to 15" tires for rallying, so that's what I'm using on the street and that's what I'd like to stick with.

Would brakes from a 78 turbo be the best upgrade that fits under 15" wheels?

[Randy Webb]

Al rear trailing (banana) arms will save you about 11-12 lbs. in the rear.

You can put on a fiberglass rear bumper and rear deck (w or w/o duck tail) and save more wt. Removing the goopy sound and heat barrier on the interior of the firewall is said to save 30 lbs. If a street car, add back some lighter, newer materials (search for threads on this and other suggested mods).

I would go with a complete Carrera font suspension rather than just the S calipers. There is an add on kit to put bigger calipers onto the Carrera struts w/15" wheels but duct some air in ther first - you may not need it.

Read the Excellence article on Jim Calzia's lightwt. car for ideas. See his table of wts. at the Early 911S site, title = "What's it Weigh?"

[ryan j]

The car is the E model. It has 22m front and 28mm rear torsion bars. I'm not real familiar with the t-bars yet, does this sound like a good setup? Is there a step up that is even more firm than this?

[Randy Webb]

Yes, much more firm. You need to tell everyone if it is track only - and if not, then what your tolerance is for uncomfyness in street driving. You'll just get advice all over the map otherwise.

BTW, 1. the dual outlets, I think don't add much more power - just noise. Get dyno results to see if that's right.

2. The one thing Jim C. did not do was to construct a "figure of merit" for wt. loss. He did calculate the cost per lb. tho. For the former, you can estimate the distance from the CG or roll center to where the wt. will be removed. e.g. Far in the rear or up high above your head (sunroof0 are more valuable places to lose it than the bottom of the car's center (e.g. trans support bracket).

Have fun.

[Jack Olsen]

First: figure out (or list here, if you know it) what you've got in there.

Turbo brakes are heavier than stock. If your car is lightened (as the Lexan suggests), then bigger brakes will only add unsprung weight (and worse, rotating mass) and make your car slower. They also won't make the car stop any faster. Are you having problems with brake fade? Coil-overs wouldn't offer much improvement over 22/28 t-bars, given that they would compromise the amount of tire you could run in front. What kind of swaybars does the car have?

If you recently got the car, then your first priority ought to be to work out what you've got, and to make sure it's all working within spec, and that the car is properly aligned and set up for your specific type of use.

[Bill Verburg]

Will the newer style suspension out of a, say for example, 89 carrerra bolt up to my car. What about brakes? I need to keep the 15" wheels, so that limits my options.

The '89 has the same 'style' suspension as your '73 it is just newer. Can you swap an '89 suspension into a '73? the front yes, easily, the rear not so easily , as the torsion bars were changed in '87, It coud be done but wouldn't be wort the cost/effort.

The things I would want on a hot rod '73;
front - SC/Carrera later style aluminum front crossmember, late Bilstein H/D Struts w/ 3.5" ears, Smart Racing(or equivalent) adjustable sway bar

rear - SC/Carrrera aluminim trailing arms and -'86 adjustable trailing arms, Bilstein Sport shocks, Smart Racing(or equivalent) adjustable sway bar

brakes - Min. Carrera front rotors and calipers(leave the rears and m/c alone), Max 930 f/r rotors and calipers w/ 23mm m/c
no matter what use fresh quality fluid, appropriate to use pads, ducting.

Suspension is personal but most hardcore users will want big t-bars and non compliant bushings.

wheels & tires are going to be a problem because of the lack of choice in 15" sizes probably 7&8x15 w/ 205/50 & 225/50 tires

Mufflers are very personal listen to as many as you can before purchasing