Glass vs Metal Parts

[speedster]

Loaded question for you guys:
I am trying to keep the front end weight of my car down and since I have not bought the front end yet, is there any reason why you would recommend NOT using glass to save weight ? Inner/Outer Fenders, Hood, Lower Valence Panel, Bumper. (Car is a 68 Firebird) I know many of you like "all metal" but weight is an issue. Other alternatives ? Battery is already in the trunk.

Any insight is greatly appreciated.

[Kenova]

The first and second gen. F-bodies (and X-body) used the front sheet metal (inner and outer fenders mostly) to give the front end more strength and support. It's something to keep in mind when you start replacing steel with glass.
Ken

[speedster]

Thanks for the info Kenova. The structural integrity is one of the items I am trying to address.

[Jim Nilsen]

When contemplating the question yrs ago I weighed my fenders,valance and header panels and found that you will only lose about 25 to 30 lbs if you go with heavy street glass so it isn't worth the change IMHO. If you really need to lose the extra weight it might be worth it but the extra work to make glass parts fit and look as good as steel was not what I thought was worth the compromise.

If you add a cage and front downtube supports along with removing the rubber cushions to the subframe you start to lose the need for the structural support you will get from the fenders, however in case of a collision the steel is a crumple zone all of its own that stops more than you may believe.

You can save a lot of weight just in the hood alone and not lose the rest of the integrity of it all.

Jim Nilsen

[speedster]

Thanks for the info Jim, especially the actual difference in weight.

Based on the input I have so far, see if you think this sounds like a reasonable balance:
-Car has Martz Chassis with solid body mounts
-DSE Subframe Connectors
-10 point chrome moly cage, but no downtube supports (I assume you mean the ones that tie to the front of the subframe)
Then use:
-Steel fenders for fit/finish/structural integrity/crumple zone
-Fiberglass inner fenders and hood for weight savings

[CAMAROBOY69]

Jim pretty much covered what I would have said. You could safely go with at least a glass hood and glass inner fender wells. The hood will save I believe around 25# all by itself.

[speedster]

Tanx for the info...

[Jim Nilsen]

If you are going to use chromoloy tubes I wouldn't skimp out on the front downtubes(you were correct about what they are) instead make them bolt in if you want to not have them in the way all of the time, they add a considerable amount of support and also help a lot in the event of a collision.

A fiberglass hood will easily lose you 25lbs. especially with lighter springs. Inner fenders will help loose about 10-12lbs max but trimming your steel ones can help you in the weight situation and still keep some strength and durability. Look at Steevo's (Streetfighter)car and you will see what I mean.

As far as the chromoly cage you might want to reconsider? They are very expensive and require someone who really knows how to weld them to do it right. Inquire a lot more about it before you buy the cage or materials to make it. Maybe Matt will have some advice for you about chromoly welding. Most leave it to the real racers who need to lose the extra weight for class purposes.

Jim Nilsen

[speedster]

Hey Jim -
We have a local guy down here that does only NHRA certified chromoly cages, so with respect to that I am pretty safe, I have also looked at 3 of his recent installations on 8 second cars that have recent cert stickers.
I thought that I could save more weight with the inner fenders, but if is only 10-12 lbs, i will definately look at Steve's gold camaro.
Tanx for your help !

[speedster]

Jim -
So you think bolt in downtubes are viable ?
I had ruled them out, since I don't know if they will fit with the 2-1/4 headers and the F-2 blower/intercooler plumbing, but if I could have someone custom fit a set after that COULD be removed for component access, that would be the best of both worlds.
Thanks for the ideas...