weight loss program for the 81 SC ???

[rickeolis]

Duckman, thanks!

[Superman]

No need to get an early car. An SC with all early car features would weigh roughly the same. I am told that sunroof stuff is in the 30-lb neighborhood, so that's fruitful particularly since it is in the absolute WORST location. BAttery is another place where you can save 20-30 lbs by going to one of those new-fangled batteries. Plastic parts don't weigh much, so console issues are fairly moot. The bumperettes on the rear bumper have to go. They are heavy and also in the wrong location

Traditionally, the mantra is "bumpers and seats." Changing out these items to fiberglas bumpers and race buckets can save perhaps 200 lbs.

[dd74]

I agree with Supes. In fact, if I had to do it all over again, I'd probably get a pure SC, and not what I have now - though I have no plans to do it all over again. The SCs and Carreras are very strong and reliable, not prone to rust, and have more power than most can utilize with reasonable control. Weight can be saved universally with either model.

One thing to consider with an early car is the weight of certain suspension components. '74 and later cars have aluminum banana arms in the rear, and SCs and Carreras have aluminum cross members in the front. I don't know what the weight savings are, but understanding that these components were steel on the early car should stand for something.

[Randy Webb]

"absolute WORST location"
- pitch/yaw/roll.....

"An SC with all early car features would weigh roughly the same" -- not sure what you mean here. ANything you do to the heavier SC (after stripping out the comfort featrues) can be done to further lighten an early car. Light wt. suspension parts from (mainly) 1984-88 can be swapped in to the early car. Just compare the engine wt.s and see.

[Randy Webb]

dd - the Al banana arms will save you 11.5 lbs (but the savings is low down and near teh center of yaw). The front Xmember saves even less - but I did both anyway. A little known fact is that the later models have lighter seats....

[dd74]

Originally posted by Randy Webb
"absolute WORST location"
- pitch/yaw/roll.....

"An SC with all early car features would weigh roughly the same" -- not sure what you mean here. ANything you do to the heavier SC (after stripping out the comfort featrues) can be done to further lighten an early car. Light wt. suspension parts from (mainly) 1984-88 can be swapped in to the early car. Just compare the engine wt.s and see.

SCs and '74s to '77s (which were earlier cars) weigh roughly the same. Early SCs and '73 Carreras (touring) have about a 100-pound difference; the lightness nod going to the '73.

Sure, you can swap out 84-88 running gear, but there goes any hope of having a reasonable budget after putting fiberglass pieces on the car. Next thing you know, you're in for a "lightness" bill that's a heavy $5K.

[dd74]

Okay: three questions:

1) Fiberglass bumpers and a hood will save on a '74-'88 911 what? 120 pounds?

2) CroMoly vs. Steel rollbar. My Autopower, which is steel, comes in at 50 lbs. What's the CroMoly weigh?

3) I saw a thread a month or so ago that showed the weight of all (or nearly all) aftermarket seats. Anyone know where that thread is? I can't find it.

[Randy Webb]

It would be expensive if you pay somebody to do it. I paid $125 for the rear arms from a wreck and about that for the F. Xmember. For $5,000 I'd want a 935 front susp. or a 993 rear....

BTW, when I say early car I mean up to '73 -- _not_ '74 and later.

[mr.bch]

No one mentioned Helium filled tires?!?!

[Trust Me]

The summer air is much lighter than the winter air.

[911nut]

What must be considered when comparing the weight of an SC or mid-70's car to an early car is that both front and rear structures were beefed up with thicker metal to carry the shock load from the impact bumpers. It's possible that the factory increased the thickness of other sheet metal in the body structure to address durability and/or corrosoin issues that we will never know about.
Also the doors on the "later" cars have beams in them to meet the side impact intrusion standards mandated by USDOT. Finally, factor in the two-sided galvanized coating that the early cars don't have and you could account for 100-150 lb. of weight differential between early and late cars BEFORE accounting for A/C, power windows and mirrors, power sunroof and the headlight washer system.

[Randy Webb]

Thx, Paul. That's useful info. Do you remember where you saw the first part re beefed up body structure?

[widebody911]

Originally posted by 911nut
What must be considered when comparing the weight of an SC or mid-70's car to an early car is that both front and rear structures were beefed up with thicker metal to carry the shock load from the impact bumpers.

Actually, I was looking at mine, and it looks like it's simply an extra layer of metal spot-welded to augment to plain layer, with a hollow space in between. When I decide to get really aggressive in my weight loss program, it's coming out.

I'm corner-balancing my car this weekend, and one mod I'm contemplating is to cut off the stock bumper mounts, since I don't use them any longer. I already did 1/2 of the LR mount, which took about 1/2 hour.

When I painted my car a couple years ago, I cut a series of holes across the metal under the reflector. In hindsight, I could have been more aggressive there.

I have a set of 911R lights which have undergone the initial sanding, and just need some spot-fiiller and prep to be ready for paint.

On the later cars, the rear deck actually contains two layers of metal with a hollow spot underneath; for a track car, the top layer could go without any structural issues.

[911nut]

Originally posted by Randy Webb
Thx, Paul. That's useful info. Do you remember where you saw the first part re beefed up body structure?

I haven't seen it per se but I'm in the auto manufacturing business. In 1975 the federal standard for bumpers was increased so that cars had to withstand 5 mph impacts both front and rear without damage to safety items. Some cars like the Pantera could not meet this without major changes (Panteras were made from tissue paper as it was) and went out of production. All other cars that were staying in production underwent revisions so that the bumpers could stroke without causing major structural damage and the bumper mounting method had to change to accomodate this feature. The mounting areas had to be beefed up to handle the load. Every manufacturer selling cars in the U.S. had to comply.

Frere discussess the weight increase in Porsche 911 Story (see page 201 of the 7th edition) but doesn't get into much detail except to note that galvanizing added 22 lb to the body.

[Randy Webb]

OK, I was wondering if PAG beefed up the body for sure and how much wt. it added. I guess we don't know if they did or not, but that it seems likely.

BTW, Frere does say that the lighter seats ans susp. parts were to help counteract the added wt. elsewhere, otherwise they would have weighed even more.

But I think we are safe in saying that an early car will be lighter than a later one, unless the latter is stripped down a lot more.