What Are You Doing/Have You Done To Shed Weight?

-
Are you drag racing this car ?
If not whats the point ? Like AJ said ...spend money on making more torque .
If you are racing a convert is a hard way to do it . Any weight savings will be replaced by chassis reinforcement .
 
Not racing it, just want to make it lighter and increase hp and torque down the road, as well as reinforcing the chassis, so it’s kinda like pushing a string...drop weight using lighter parts, add weight in strength and stiffness. When I’m done, hopefully it’ll weigh less than stock but be way stronger, stiffer, more powerful and handle better.
 
Last edited:
My line of thought is that any gains could only be measured in tenths of a second reduction in ET but not by the seat of your pants . And any chassis compromises would make the car less enjoyable to drive .

Aluminum intake and heads
Aluminum 4sp OD if its a manual
Manual steering and brakes
Lighter wheels and skinnier tires
3.55 gears

You would notice a big difference in all those changes. Much more than spending hrs whittling away 3 lbs here and 4 lbs there.
 
mbaird said:
My line of thought is that any gains could only be measured in tenths of a second reduction in ET but not by the seat of your pants . And any chassis compromises would make the car less enjoyable to drive .

Aluminum intake and heads
Aluminum 4sp OD if its a manual
Manual steering and brakes
Lighter wheels and skinnier tires
3.55 gears

You would notice a big difference in all those changes. Much more than spending hrs whittling away 3 lbs here and 4 lbs there.
Click to expand...
I agree with most of this but why do you say chassis compromises would make it LESS enjoyable to drive?
 
Assuming you have a 1967-1972 A-body, replace the front inner fender splash shields (metal) with later ones from a similar car (plastic). Not only weigh less, but don't ever rust...
 
Topless69 said:
I agree with most of this but why do you say chassis compromises would make it LESS enjoyable to drive?
Click to expand...

If you do any mods that lessen chassis stiffness ( ie .. cut holes ,remove reinforcements etc ) it will make the car more flexible which coverts already have an issue with . Although they are boxed front and rear having no roof really comprimises the chassis stiffnes.
The worst I ever experienced was a new 1992 Olds Cutlass covertable... if you drove over railroad tracks you could feel the car flex like a wet noodle ! I sold them new and once had a middle age woman ask me " Did this car just move ? " lol.. I said "yes maam it did ..."
 
I personally would add weight via frame connectors and front/rear sway bars. Then tweek the engine with a torquey cam and a good tune ( dizzy curve and carb jetting ) .
You will love driving it ! Way more smiles than just cutting weight out .
I have f/r sway bars on both my cars and think its the best mod I have ever done .
 
mbaird said:
If you do any mods that lessen chassis stiffness ( ie .. cut holes ,remove reinforcements etc ) it will make the car more flexible which coverts already have an issue with . Although they are boxed front and rear having no roof really comprimises the chassis stiffnes.
The worst I ever experienced was a new 1992 Olds Cutlass covertable... if you drove over railroad tracks you could feel the car flex like a wet noodle ! I sold them new and once had a middle age woman ask me " Did this car just move ? " lol.. I said "yes maam it did ..."
Click to expand...
Don’t know if you’ve read thru my posts in this thread, but I never discussed weakening the chassis, I want to strengthen and stiffen it while reducing weight in other areas that don’t affect the structural integrity of the car.
I’m going to add frame connectors, sway bars, etc. while saving weight elsewhere - aluminum radiator, intake, heads, etc. with the focus on a stronger more capable handling ‘vert that’s equal to or less than factory weight.
 
It's kinda tough to remove weight from these older cars since they didn't come jam-packed with safety features, electronic gizmos and sound insulation like newer cars; the weight is all in "necessary" components like the mechanicals and the body itself. I've taken a similar approach with my Duster; it's been lightened with modern aluminum wheels, aluminum top end on the 360 and most of the interior trim has been missing since I got it. That weight reduction has been basically offset by swapping in a B-body 8 3/4" and welded-in 2"x3" steel box tube subframe connectors. Which is actually good in a way because it at least shifted the weight more towards the rear so in theory it has better weight distribution but I haven't actually confirmed that with scales. My car is a constant work-in-progress I do amateur road-race stuff with (time trials, open lapping days etc.) so handling is very high priority, right now more so than power it already has more than I can use on the small track I race at.

The car does have factory undercoating but I have no interest in trying to remove it (effort vs. reward ain't worth it to me lol). It's all at the bottom of the car and is evenly distributed over the whole underside anyway so it doesn't affect the center of gravity a whole lot, could be argued it's almost somewhat of a benefit.
 
If I pull off my 3 1/2" rear bumper exhaust, and replace with header mufflers, and remove my street steelies and t/a combo, and put on the centerline skinnies and slicks, I can save 150 lbs.
3250 lb b-body.
Easiest way to be light, is to start with a light car. Aluminum head smallblock and a 904 in a toad.
 
I didnt think that you planned on weakening the chassis . I am just reinforcing the message .
I have spent energy in the past trying to lighten a street car / driver and the outcome wasnt worth the effort .
I would love to have an A-Body convert. What a great cruiser !
 
What model is this ? Dart or Barracuda ? Big block or small block ? I saw a reference to dropping the bigblock but you stated you have a 904 which was never available for a bigblock , Also you stated you are running an 8 3/4 out of a 75 Imperial ... 73 was the last year for 8 3/4s so you might have a 9 1/4 . And I thought 71 was the only year for rear discs on an Imperial ... maybe up to 73 ?
 
mbaird said:
What model is this ? Dart or Barracuda ? Big block or small block ? I saw a reference to dropping the bigblock but you stated you have a 904 which was never available for a bigblock , Also you stated you are running an 8 3/4 out of a 75 Imperial ... 73 was the last year for 8 3/4s so you might have a 9 1/4 . And I thought 71 was the only year for rear discs on an Imperial ... maybe up to 73 ?
Click to expand...
It’s a ‘69 Barracuda. Original 318 2bbl replaced with a mild rebuilt ‘70 340, 904 console, 3.55 Imp rearend. You may be right that’s it’s 9 1/4, I’ll check again, but what I’ve found online indicates it’s 8 3/4 and 74-75 were the only years with rear disc. It’s an unusual design with 1 caliper leading the axle and 1 trailing - came that way from the factory.
 
One starts with placing iron with aluminum where applicable. Start with heads/intake. Then get rid of heating components. Core and motor. Wipers and motor. Replace battery with olm or even new lithium options. Car then is like a motorcycle. Only nice weather vehicle. Brakes. Lighter weight disc brakes with aluminum master cylinder. Steel rims certainly have to go. I would not look at drivetrain components. Rotating weight is different. And "lighter" doesn't necessarily mean faster there. Fiberglass bumpers. Front clip, doors and trunk deck if available. Glass. Replace side and rear with Lexan. (Windshield might be illegal in your state for street use.)

All of these changes at once would probably be for race only. But each are available for your consideration.
 
Topless69 said:
It’s a ‘69 Barracuda. Original 318 2bbl replaced with a mild rebuilt ‘70 340, 904 console, 3.55 Imp rearend. You may be right that’s it’s 9 1/4, I’ll check again, but what I’ve found online indicates it’s 8 3/4 and 74-75 were the only years with rear disc. It’s an unusual design with 1 caliper leading the axle and 1 trailing - came that way from the factory.
Click to expand...

If it is a 9 1/4 it will have bolts holding a cover on the rear . 8 3/4 have the whole gear pumpkin that drops out of the front and a smooth backside.
I am running 1998 Jeep discs on the rear of my Barracuda . Pretty easy to adapt to an 8.75 and super light . Although I have not hooked up the park brake yet... that will take a little more work but doable.
 
Rims are a significant amount of weight and effect everything.
Caveats are:
Super light flex excessively and or fatigue under hard use.
Can lose the weight gains by using much larger tires.
(I've posted a table of tire and rim weights I've used over in the wheel sub forum)

Aluminum intake. Some pulleys, although that's pretty minor weight savings.
Slightly smaller battery. That's about 10 pounds off the nose.
Removed the aftermarket A/C. No extra sound deadner or insulation. Manual steering.
Mini-starter.
Tried the K-H brake booster and didn't like it. Not sure that would be a weight savings, but its gone.
Drums to front disk was probably a wash since the '67 came with the smaller drums.

Weight and weight placement effects braking, steering response, cornering, as well as acceleration. Its very under rated in the hot rodding circles, maybe because it doesn't drive magazine and product sales??
 
I have done all that I can but still didn't want to take away from all steel, all windows street car. Hole sawed everywhere that cannot be seen. Tubular K frame and control arms with a rack. Aluminum heads and intake and light weight wheels. However, 25.5 c.m. cage, safety such as net, chute, fire system, Dana 60, anti-roll bar and Mega Block all added weight back on.

100_1508 [640x480].jpg


20150424_205804_resized.jpg


IMG_8664.jpg


20210915_171016.jpg
 
If its a nice car or a real car leave the poor thing alone and by a body to maul on
Ive had more fun in cheap cars than in allyour $$$ cars put together
My 69 weights 3300 with ps and runs 6.40 s
Enjoy them all

BAB3B588-9552-4C63-ACDF-A330C5AFB91C.png


A034506A-C952-4997-AFF6-5206FEB9E254.png
 
If it was a fastback removing the fold down rear seat and colsole would save 100+ lbs . Man those peices ar heavy !
 
mbaird said:
If it was a fastback removing the fold down rear seat and colsole would save 100+ lbs . Man those peices ar heavy !
Click to expand...
True, and it would save a chunk of weight to remove my rear seat too, but there’s some things I won’t give up like seats, AC and heat. On the other hand everybody is being very helpful with ideas and weight reduction they’ve done. I’m confident that replacing anything under the hood with aluminum - heads, intake, water pump, pulleys, accessory brackets, radiator, fan, as well as lighter battery, bumpers, bumper brackets, master cyl., brakes, wheels, tires, swapping 8 3/4 for 8 1/4, etc. will result in enough weight gone to suit my purposes. After all, modding our cars is half the fun!
 
Last edited:
You must log in or register to reply here.
-

Back
Top