I am wanting to know the gross vehicle weight on an 81 vette, and what type of things can be done to reduce this weight (ie switching cylinder heads, etc...). If you could list the amount of weight saved by each modication, it would be greatly appreciated. Thank you for your help.

 

Well the '81 is already one of the lightest C3s so you've already got a head start. Easy weight saving techniques would be getting rid of the spare tire, jack, and emissions crap. That catalytic convertor is a heavy sob. You could lose some weight with aluminum cylinder heads, if you want to spend that much money. Also removing the A/C system helps a bit. Aluminum brake calipers (Wilwood is a good choice I hear) can save some substantial weight. You've already got the fiberglas rear leaf spring. There are some other things you can do.

Search the forum for "diet" I posted a thread about this a few weeks ago.

 

thanks for the suggestions. Trying to get it to 3100 pds (said gvw was 3307lbs in 81). I'm also considering a corbeau seat conversion. Will this save some weight also?

 

Sports seats can save you a few pounds, yes.

3100 lbs on an '81 is pretty easy to obtain. Getting under 3000 becomes a challenge.

 

Anyone know the gvw on a 79?

 

3503 lbs.

 

Jenny Craig And do a search.

...Also, one of my mechanic friends was telling me that reducing unsprung weight is even more effective than reducing sprung weight i.e. lighter wheels, driveshaft, half shafts. Dunno if that's true, just throwing it out there.

 

I've heard this about sprockets for motorcycles. The argument is usually steel sprockets vs. aluminum allow sprockets. I'll take the durability of steel over aluminum, thanks. Unless you're doing nothing but racing, the price of those parts generally isn't worth it.

Wheels I can agree on, though. Those are a serious weight advantage.

 

try searching on titanium rotors

 

I've had heard this to be very true of auto Xers. The less upsprung weight you have, the better your susupension works, therefore it is easy to set up for w/e weight the rest of your car is. Mainly trailing arms, wheels/tires, brakes, half shafts are the main unsprung weight as well as front springs, and a arms. Reduce all this = much better ride and greatly improved handling. Not to mention lots of weight savings.
Thanks kalaway for the weight.

 

One of these days I'm going to have to actually add that a in my screennames so that happens less. No problem man.

 

Anyone tried running aluminum tie rods?

That seems like it'd be an easy one... The street rod/circle track catalogs carry them, havent ever heard about street use though.

 

82 FE7 used aluminium strut rods, the tie rod sleeves can easily be replaced w/ aluminium just measure them and buy the same length w/ 5/8th threads.

 

http://www.corvettefaq.com/c3/WeightReduction.mht
hope that helps

 

Sorry man i noticed as soon as i clicked submit and went oh sh**. Then oh well. Sorry bout that though. lol. :o

 

The struts on the rear?

If so... I had not thought about that!

 

Lost a lot of weight from my '81 by ripping out the aircon system (apart from the bit left in the firewall) & changing the stock mufflers out to Monza glasspacks. It's loud &, if I lived somewhere hot, it could have an interior temp problem! Losing the aircon made the steering feel far more responsive.
Also lost weight by fitting an ally water pump. Removing the horns & replacing them with one or two 12v m/cycle horns will also drop a bit. Under ther rear bumper are 2 large steel brackets that just hang down & do nothing (for towing????). These weigh a fair amount, so rip them off. I've had the seats out of mine & don't think they weigh enough to justify spending cash on replacements.
Alloy heads will lose a substantial amount of weight (& give decent power).
Easiest way to lose unsprung weight is alloy calipers, but thats $$$. The driveshaft isn't unsprung weight.
Remove the spare wheel & carry a cell phone in its place! I wouldn't remove it's carrier as I reckon that it's better for aerodynamics with it in place.
The front bumper support (large metal frame that bolts to the frame horns) weights a lot & can be lightened substantially by drilling it full of holes. Has Norval done that???).
Remove the stock radio/tape player as it's quite heavy (plus it sounds crap!). Then remove the electric aerial.
Remove the jack if you've removed the spare wheel.
Replace the vacuum headlights with some fixed ones (preferably with a perspex cover sitting flush with the body to prevent massive air resistance from them).
Fit a lightweight battery.
Don't start pulling off all the flimsy covers/flaps underneath as they do a good job of keeping the underside smooth & the ones at the front help direct air through the rad. While the underside of the C3 is hideous from an aerodynamic perspective, there's no point in making it worse.
The stock fan & fan clutch weigh a fair amount (and can't be helping the life of the water pump bearings) so they can be replaced by much lighter electric fans. I don't know if the stock electric fan would have any hope of keeping the engine cool on its own?
Mini starter (a good idea anyway if you ever fit headers).
Dual stainless pipes with no cat(s) if it's legal to modify the exhaust system. Unlike earlier years, I don't think Headers will lose weight (probably gain it) as the stock manifolds are so light. The rest of the stock system is heavy & my duals weigh a lot less. With duals you can also lose the center exhaust hanger (mine are held in place by the Headers & muffler hangers).
Lightweight alternator?
Take out the p.seat. This will save several stone in weight More seriously, you can pull out the d.seat tracks & replace with ones from an earlier year (with spacers underneath) & lose the electric seat functions. There was a big weight difference that could be felt when I was painting the seat tracks on mine (p.side was light, d.side was fairly heavy in comparisson).
If you really start getting serious you can lose the central locking stuff, the electric window motors, get one of those 1 piece jobs to replace the T Tops, etc, etc, etc.
The last obvious one is easy. Most of the weight I've removed is from the front, so in the interests of trying to keep a nearly 50/50 front/rear balance (& due to our criminal fuel costs) I never fill the gas tank much
If you've got an auto then a custom x-member will lose some weight (& allow true duals to be fitted). I think my BTO one dropped nearly 10lbs?
Measure the ride height if you do put it on a serious diet as it may sit higher afterwards. Then you'll have to trim the front springs a bit to let it sit at the correct height. This'll have the bonus of losing a little bit of unsprung weight.
The '81 is kinda tricky to easily lose weight from in that most of the popular ways people do it were done by the factory eg thin glass, alloy intake manifold.

Kalway, unsprung weight is crucial on a bike. Losing as much as possible makes a real difference, though with modern bikes the weight has been trimmed down pretty well by the manufacturers. In the case of a "traditional" design of bike, the main areas that count are the lower 1/2 of the shocks, the rear 1/2 of the swing arm, brake calipers, the rear drive chain (so a butch looking fat one isn't so good!), tires, the fork sliders & both complete wheels. Alloy sprockets for road use won't last as long as steel, obviously, but I once used one & was surprised at how well it lasted (tip: if you're running a steel sprocket, get it chromed! Something about the chroming process seems to toughen up the metal & the sprocket lasts longer - several people have found the same, it's not just me).

 

hi, on top of what UKPaul is advicing you (mods that i did on my '77) also consider to swap the whole front suspension for a transverse monospring, there is plenty of savings there.
also, clean up the engine bay of all the heater and its ancilleries, personally i've also got rid of the windows, on my model they are abt 10 lbs (of course the power windoes with motor and ancillaries flied sometime ago as well...), i think last step i'd have to take is a perspex windshield.
corvettes, specially years around my model, are extremely heavy cars for a so called sport car, everything is oversized, specially the front and rear defences, they weight more then 200 lbs alone...
after the cure your car will rise quite a lot so you'll have to drop it back playing with the bolts front (if you went to composite monospring sistem there) and rear...good luck

 

one last question, Are there any other seats besides corbeau ($900)(that's a lot of money to save a few pounds) that will save me some weight and look good in a c3. I don't really like the way the c3 seats look. Just curious what kind of ideas you could come up with.

 

C3 seats are not that much heavier then race seats UNLESS you dont get carbon fiber ones which costs quite a lot of money though...the main reason i've changed the stock leather seats is that they look made specifically for supporting the heavy a....s of an old limousine pal