Weight reduction: Running out of ideas.

[mrvette]

After a few busted up knuckles I got the crossmember pulled out. I tried to not disturb any more items than I had to in the removal. (The rack bracket bolts to the crossmember so that the rack location can be changed without removing or altering the crossmember.)



The "original" crossmember is a bolt-in unit so I could modify or replace it for any of a multitude of reasons, and not be stuck with the first pass geometry if it had been welded in. The new crossmember will have a few tweaks to change the geometry, in an effort to get a bit better front grip in mid-speed corners. A few pounds less weight on the front tires is also a goal.



The dimensions and wall thicknesses are larger than the steel crossmember specs to retain sufficient strength and safety.

Which rack you using there man?? how many U joints in the steering linkage?? are you doing rear or front steering....looks like it has to be rear/stock position.....also what are those two aluminum looking channels on each side, look to be fastened to the lower arms....how come so many holes in that black metal mount for the rack???

:yahoo:

 

[69427]

After a few busted up knuckles I got the crossmember pulled out. I tried to not disturb any more items than I had to in the removal. (The rack bracket bolts to the crossmember so that the rack location can be changed without removing or altering the crossmember.)



The "original" crossmember is a bolt-in unit so I could modify or replace it for any of a multitude of reasons, and not be stuck with the first pass geometry if it had been welded in. The new crossmember will have a few tweaks to change the geometry, in an effort to get a bit better front grip in mid-speed corners. A few pounds less weight on the front tires is also a goal.



The dimensions and wall thicknesses are larger than the steel crossmember specs to retain sufficient strength and safety.

Which rack you using there man?? Custom width Unisteer rack. how many U joints in the steering linkage?? Two. are you doing rear or front steering....looks like it has to be rear/stock position.....Front. also what are those two aluminum looking channels on each side, look to be fastened to the lower arms.... A couple of air deflectors to get a bit more air directed towards the brakes. how come so many holes in that black metal mount for the rack???

:yahoo:

Holes weigh less than steel.

 

[mrvette]

After a few busted up knuckles I got the crossmember pulled out. I tried to not disturb any more items than I had to in the removal. (The rack bracket bolts to the crossmember so that the rack location can be changed without removing or altering the crossmember.)



The "original" crossmember is a bolt-in unit so I could modify or replace it for any of a multitude of reasons, and not be stuck with the first pass geometry if it had been welded in. The new crossmember will have a few tweaks to change the geometry, in an effort to get a bit better front grip in mid-speed corners. A few pounds less weight on the front tires is also a goal.



The dimensions and wall thicknesses are larger than the steel crossmember specs to retain sufficient strength and safety.

Which rack you using there man?? Custom width Unisteer rack. how many U joints in the steering linkage?? Two. are you doing rear or front steering....looks like it has to be rear/stock position.....Front. also what are those two aluminum looking channels on each side, look to be fastened to the lower arms.... A couple of air deflectors to get a bit more air directed towards the brakes. how come so many holes in that black metal mount for the rack???

:yahoo:

Holes weigh less than steel.

:beer: HA HA HA.....I had a suspicion but had to ask, and my surmise/guess was right......:beer: U maybe retired, but your BRAIN not dead.....:beer:

Holes weigh less than steel.....

Swiss Cheese Catalina......;-)

 

[BBShark]

I think I found one, and it's up high! Does your car have the rear view mirror attached to the frame with a pot metal bracket? Probably save a little using a modern glue on assembly.

 

[vette427sbc]

Apparently this was a one year only thing for the C4... My '96 rear suspension has composite dog bones. I was just digging through some of the parts I got with it and noticed they were not aluminum like all the other years.
Now to find a scale a bit more accurate than the one in my bathroom...

 

[Kid Vette]

A buddy of mine just bought a big block hood from this guy.

1968 to 1972 Corvette big block or LT1 new quality hood looks press molded

Its a LOT lighter than a stock hood!

 

[mrvette]

A buddy of mine just bought a big block hood from this guy.

1968 to 1972 Corvette big block or LT1 new quality hood looks press molded

Its a LOT lighter than a stock hood!

No doubt, years ago I bought a SB hood with the aftermarket BB bulge like shown above, it took some issues with the bonding letting water in and pimpling up on the surface, I finally got disgusted with it and cut out all the old glass from under the bulge, 3/8" thick and heavy as hell....did that to get access on the edges, poured in glass good and thick, and fixed it for the last time, this was maybe 6 years ago...I must have cut the weight by 40% or so.....

:yahoo:

 

[69427]

I think I found one, and it's up high! Does your car have the rear view mirror attached to the frame with a pot metal bracket? Probably save a little using a modern glue on assembly.

I've still got the original rear view mirror. It's starting to show its age, and this is a good reminder to spend a few minutes sometime (trying) to take it out and getting a weight on it.

If I do find an acceptably lighter substitute I have to confess I don't have a clue how to remove the glued on base off of the donor car windshield.

 

[redvetracr]

If I do find an acceptably lighter substitute I have to confess I don't have a clue how to remove the glued on base off of the donor car windshield.

easy, kill two birds with one stone...Lexan windshield, I will even help pay for it if you send me those J-56 pistons...

 

[rtj]

"already have your calipers and just want to change to our pistons, you will want these second design improved titanium insulators. We designed them for the road racer who has had enough of brake fade caused by boiling brake fluid. They are expensive, but so is going off the track and hitting a tree. Included are an axle set of seals, dust boots and O rings."

Would these work. They sell j56 calipers too. Must have bought out a warehouse.

 

[BBShark]

I think I found one, and it's up high! Does your car have the rear view mirror attached to the frame with a pot metal bracket? Probably save a little using a modern glue on assembly.

I've still got the original rear view mirror. It's starting to show its age, and this is a good reminder to spend a few minutes sometime (trying) to take it out and getting a weight on it.

If I do find an acceptably lighter substitute I have to confess I don't have a clue how to remove the glued on base off of the donor car windshield.

I think you can buy the little dovetail metal pieces that glue to the windshield at the store with a glue kit.

 

[69427]

Killing time with a couple projects while I'm scratching my head with a brake issue. Still making progress on the C4 D36 batwing adapter to bolt to my present C3 differential. The C4 batwing is 7# lighter than the C3 batwing, the spring mount is another pound lighter, and the toe bracket simplification with the C4 batwing ought to save another 1-2 pounds. I expect the batwing adapter to be about 2-3 pounds, so I still ought to be able to net an additional five pounds off the car. That's in addition to the 15# that the C3 batwing installation pulled off the car.
The newest distraction is a lighter muffler (pair) that I'm playing with. (I'm happy with aluminum muffler I welded up for the '84, so now I'll try a couple for the '69.). The current Dynomax 3" turbo muffler is a nice piece. Flows well, sounds nice and quiet, and well built. I just wish they were about 5# lighter weight (they're 16# each). Here's a cheap quick jig to start the project:



And here's the start of the aluminum muffler (with a long way to go):

 

[69427]

Lighter weight brake booster

Getting some work done on eventually installing an '84 brake booster. I'm currently having some issues with the original ('69) booster, so I'm switching gears and working on this project a little sooner than I planned. The stock booster is 8.8#, while the 84 booster is 3.8#. Here's the two boosters (the C3 booster in the picture is an old part I've had sitting on the shelf):



There's definitely a difference in physical size, and also the attachment to the brake pedal arm. I cut the end off the '84 booster rod, and threaded it (7/16-20) and installed a forged steel clevis.



The aluminum piece in the background is the work-in-progress adapter/spacer that will fit between the firewall and booster. This piece adapts the two different bolt patterns and also puts the booster at the point in space so that the pedal pushrod will plug into the pedal arm correctly. So far the adapter is about 20 ounces, and the eventual weight should be about 16 ounces, giving a net weight reduction in the system of four pounds (and thankfully on the left side).

 

[phantomjock]

Lots of effort there!

I've pulled a number of reduction ideas for the C3 and made an Excel spreadsheet. Still working it. I'll load in Downloads section and make a note here when its posted too.

Maybe a few days away. Unless you want it really rough - but I'm on body work that is ruff as my first priority!

Cheers - Jim

 

[69427]

Lots of effort there!

I've pulled a number of reduction ideas for the C3 and made an Excel spreadsheet. Still working it. I'll load in Downloads section and make a note here when its posted too.

Maybe a few days away. Unless you want it really rough - but I'm on body work that is ruff as my first priority!

Cheers - Jim

All the easy weight reduction stuff is long done.

 

[Danny Boy]

How much does the driver weigh?
Just askin...

 

[mrvette]

How much does the driver weigh?
Just askin...

Funny you ask that as a very old buddy of mine, when racing SCCA in Dodge Colts/Mutsobitchy he let his 100 lbs g/f drive instead of him weighing some 200 lbs/close.......:surrender:

OH BTW, welcome to the motley crew.....:thumbs:

 

[69427]

How much does the driver weigh?
Just askin...

205#


(9/10/15 update: 200#)

 

[phantomjock]

Got it covered! 199 now - shooting for 190.
Here's a shot of the "Other Redux" worksheet:
She-WHO-Must-Be-Obeyed is fortunately in that "petite category. Just not "mad" enough to race.
At a base 350 HP at the rear wheels, 100# is equivalent to about 10 HP increase!

Any idea where the car is to date - weight wise?

Cheers - Jim

 

[69427]

Got it covered! 199 now - shooting for 190.
Here's a shot of the "Other Redux" worksheet:
She-WHO-Must-Be-Obeyed is fortunately in that "petite category. Just not "mad" enough to race.
At a base 350 HP at the rear wheels, 100# is equivalent to about 10 HP increase! I tend to think more in terms of F=mA, and losing 100# is about 3% of the car/driver weight.

Any idea where the car is to date - weight wise?

Cheers - Jim

About 2820# during track days, and about 2790# during autocross events ( no T-tops or rear window, less fuel, and no heavy wheel adapters to run the C5 wheels).