Im wondering weather there is a aluminum frame replacement for are steel frames??

cheers

dave

 

There is a lot of aftermarket and re-pop stuff available at impressive high prices, but it depends on what you're trying to achieve... If you are trying to lighten the car up, there are better ways to do it. The complete steel frame is light enough that 2 guys can easily lift it and carry it. Going to aluminum isn't going to make a major weight reduction. You can go to an aluminum block and heads and cut more weight at a lower cost...

 

There are also lots of aftermarket tubular frame options that are reasonably light and will provide major performance improvements. Again, they are pretty pricey.

 

so if its not the frame that weighs that much, which are the worst offenders with in the car?

 

Frame, rear spring (stock/steel) , engine, trans, other suspension and brake components ARE the weight of the car.

 

overall its the drive train not so much the frame itself.


There are some other things you can remove to get rid of weight.....

1. rear inner bumber (at least 40 lbs)
2. change the rear spring to composite.
3. change the front spring to composite 80's style.
4. as much aluminum in the engine as possible (heads, intake etc)

 

My son and I can pick up and move a bare frame, and I'm 57 so that gives you an idea of the frame mass

I have a rolling chassis with 550# springs in front and a composite rear spring. The LS1 engine is much lighter than the iron 350 and the T56 trans is heavier than the Muncie 4-speed, but without the body there is only ~1/4" clearance from the top of the bump stop to the upper A-arm. I'll have the body down in a couple of weeks so I'll know if I have to cut the front springs, but I'd say the biggest weight loss you will see is by switching to an all-aluminum engine.



Rick B.

 

one must also keep in mind the differance between the two. Steel last much longer and when gets tired,starts cracking. Alum,on the other hand,will simply fail,at no set time frame.Thats why you see the time limits on aircraft.

 

These folks have some nice looking frames. Nice options also.

http://www.sriiimotorsports.com/

 

yes they do, i just wish the web site gave a complete listing of what comes with each kit (brake lines, ect. ?).

 

My '69 already has aluminum heads, intake, water pump, and composite rear spring, along with the OEM aluminum bell housing and tranny case. If I were looking to significantly lighten the car, I would investigate the weight difference of the front suspension components, i.e., upper and lower A-arms and upright from a C4, and most importantly aluminum brake calipers. The cast iron C2/3 calipers are extremely heavy. Then I would look at lighter wheel/tire combinations that would fit. The lighter suspension members, calipers and wheel tire assemblies would reduce unsprung weight, an important advantage. And finally I would look at the late C3 aluminum final drive center section. If my budget allowed, I would look to adding an aluminum block; Chevrolet has several Bow Tie blocks that would save maybe an additional 100 pounds.

I think that would result in a significantly lighter C3 and you wouldn't have to be concerned with the reduced structural rigidity you would face with an aluminum frame. A <2,900 pound fully streetable C3 would be cool.

Cheers,
Pete

 

thanks for info guys

dave

 

Just to chime in, if you want a car that's going to be some kind of lightweight thoroughbred a C3 Corvette is not the best starting point. With the exception of the (very) early 1960's-tech IRS it it a 1950's-tech body-on-frame car. Since aluminum does have a better strength modulus than steel (i.e., Strength-to-weight) it is concievable that an aluminum frame made specifically for C3 Vettes could produce some weight savings but it would be no more than 50-60 lbs. at best and it would already be weight that's down low in the car so there would be little measurable CG advantage. The PRIMARY weight offender in the car is the body- Corvettes are made of thick fiberglass that's patched together from a number of pieces with big thick tie strips- and since said body is just basically bolted onto the car all it does is add weight while contributing very little to the car's structural rigidity. As said by others, if you want to lighten the car the best way is to go with lighter, more modern bolt-on components like cylinder heads, composite springs, etc.

 

Aluminum Engine
Aluminum Tranny
Aluminum Control Arms
Coil Overs (No heavy springs or mounts)
Aluminum Rear diff
Lighter rack & pinion
Aluminum Driveshaft
Aluminum Gas Tank
Aluminum Wheels
SRIII Triangulated design Tubular Steel Chassis

What's it weigh... Don't know yet. Plan to get on the scales soon. But I would hope it would come in at least a couple of hundred lighter than stock.

 

I've got about 80% of those items on my current project. My main curiosity is the weight comparison between the stock frame and the SRIII frame.

 

thats a nice looking frame!, very nice.

dave

 

I agree with many things on Pete's list. Composite spring, aluminum heads or whole block, calipers, early C3 seats are also heavy- later sport seats lesser so. Remove old heavy copper radiator and swap to aluminum radiator. New lightweight aluminum starter,- the OEM starters are huge, heavy beasts; light weight Braille battery can drop you 20 lbs instantly. The AC system on these cars weighs 50-55 lbs, too.

As noted, unsprung weight is important so lightweight rims, calipers and aluminum A-arms can changes things in a hurry there, too.

The doors on these cars are insanely heavy, too; heck the giant electric window motors are crazy heavy themselves.


But also think about where the weight is coming from- if you switched to a composite rear spring, an aluminum rear end, and got a smaller capacity aluminum tank- did the rear bumper hack- you'd end up with a pretty terrible weight distribution from the front to the rear- from the factory they're somewhere around 52%/48% weight distribution; don't screw that up- try to remove equally from the front and the rear as you go.


Also weight reduction from higher on the car helps with lowering the center of gravity. -Aluminum intake, heads, and water pump- going with something like an Astrotop- these things help, as does relocating the gas tank to sit lower.


Seriously weigh those doors, though; the late C3s are looney and you can tell just when you push them open and close them.


Adam

 

Taking weight out of these cars ain't an equal opportunity (F/R) deal. There's more stuff going on up front, which makes it harder to get enough weight off the front to make it lighter than the rear. Ya gotta take the weight off wherever you can get it. If it's a choice between a 50/50 heavy car, and a lighter car of most any F/R ratio, I'm going for the lighter car. A lighter car accelerates and decelerates quicker than a heavier car.

I've got my '69 down to 2775# (With complete interior. I don't care for stripped down street cars.), but the F/R weight distribution is IIRC 53/47. I wish it was the other way around (47/53), but I still prefer this to a 3200# car at 50/50.

ps: I have still never received an answer from several of my inquiries around the forum about the weight of those SRIII frames.

 

You guys are responding to a 9 year old thread...

 

Yes, I'm quite familiar with the concept of time and mathematics.