Bee Jay’s Weight Loss Mods
I bought my 1979 L-82 Corvette new in the summer of 1979. The car weighed over 3600lbs and only had 220 horsepower. Over the 33+ plus years since of owning the car, it has been everything from my primary daily driver, a concourse car driven only to events, a gymkhana/autocross racer, a bracket racing drag car, and a canyon carving road car. Now it is just a hobby car that I enjoy driving on nice days, and wrenching on when I feel like tinkering. I think I’ve gotten everything I can get out of the engine while leaving it street able. So I’ve been focusing on losing weight. My goal is to get my 3600lb car down to 3000lbs. Today, I’m down to 3100lbs. 500lbs down, 100lbs to go. This is how I did it.
One of the first things I did with my car was to take off the steel Rally Sport wheels and install aluminum Pace Car wheels. Later I put C4 16” wheels and adapters, and now I run C5 Z06 replicas with adapters. The Rally Wheels were really heavy, but they sold really easy. I plan to install lightweight 19” wheels with the proper offset so no heavy adapters will be needed.

Aluminum Intake- The L82 engine came with an aluminum intake manifold, so I didn’t save much weight when I switched to an Edelbrock Perfomer. I now run an Edelbrock Performer RPM Air Gap. If you have a cast iron intake manifold, you can lose 15 lbs by switching to a good aftermarket aluminum intake, and gain a few horsepower. The cost, about $200 for a powder coated RPM airgap.

Headers- I resisted installing headers for the longest time because they were such a pain in my Camaro. But these headers have been a joy, and I lost 15 lbs by installing them. Cost about $500 including Jet Hot Coating.

Heads- The biggest improvement in horsepower came when I installed Airflow Research Heads. I’m running AFR 195s now, and I lost 45 lbs by ditching the iron heads. Cost about $1500.

Brakes- I lost a whopping 44 lbs by replacing the heavy 15 lb calipers with 4 lb Wilwoods. Cost about $1000. Here is a link: http://forums.corvetteforum.com/c3-t...e-install.html

Rear Springs- the steel rear spring weighs 50 lbs, the fiberglass replacement weighs 8 lbs, losing 42 lbs. Cost about $300.

Starter- the original starter weighed 20lbs. I went with an aftermarket gear reductions starter that weighs 8 lbs and lost 12 lbs. Cost about $150.

Water pump -initially I replaced the iron water pump with an aluminum one, but recently I’ve been running an aluminum electric water pump. It works great. Cost about $200.

Radiator – The stock Radiator weighs about 30 lbs, and an aluminum radiator weighs only 15lbs. I lost 15 lbs. Cost about $200 http://forums.corvetteforum.com/c3-t...post1580181414

Transmission Cross member- I replaced the heavy steel trans cross member with a Bowtie Overdrive tubular cross member when I converted to a 700R4 transmission losing XX lbs. Cost $200. Replacing the TH350 with the 700R4 actually gained weight. Also, I installed a 9” torque converter in place of the 10.5” stock converter and lost about 10lbs. The converter cost $500.

Aluminum bat wing- I replaced the heavy iron rear cover and rear end cross beam support, and another frame cross member and installed the 80-82 aluminum bat wing and lost 35lbs. http://forums.corvetteforum.com/c3-t...g-install.html

Dana 44 rear end install that lost 20 lbs.: http://forums.corvetteforum.com/c3-t...onversion.html

The next few mods will, or may, impact the safety of the car. I’ve received many objections on the forums for making my car unsafe for the street. Well, these mods return my car to the safety level of a pre ’73 Corvette, and the car is still way safer than my Harley. I doubt seriously that the 5mph front bumper, the 2 ½ mph rear bumper, and the spare tire, really added any protection at highway speeds. The side door beam might have actually slowed down a light vehicle side impact, but not a heavy SUV. So this is my disclaimer: proceed at your own risk, your mileage may vary.

Front air vacuum reservoir/ battering ram removal - this big *** air tank is also part of the 5mph impact system. Removing it save 43 lbs right off of the front end. http://forums.corvetteforum.com/c3-t...umper-mod.html

Removing spare tire-The spare tire, jack and it’s mounting hardware weighs 50lbs, a AAA card weighs ounces. 50 lbs lost. No cost.

Front bumper mods- I needed extra cooling so I removed the heavy rubber plated license plate pad, some of the steel bumper support, and lost 25 lbs. The car ran significantly cooler with the extra airflow thru the new central grill. http://forums.corvetteforum.com/c3-g...post1570560887

Rear Bumper mods- I removed most of the 2 ½ mph steel bumper reinforcement and lost 55 lbs. No cost. http://forums.corvetteforum.com/c3-t...umper-mod.html

Door beams- I removed the heavy post ’74 side door beams and saved 22 lbs per door, or 44 lbs total. No cost, lots of labor. http://forums.corvetteforum.com/c3-t...tion-mods.html



AC/HVAC removal – I live on the Central Coast of California and did not need Air Conditioning or heating. I removed the AC compressor and AD condenser, and heater core and lost 50 lbs. I used the AC block off plate to mount my cold air intake and filter. The block off plate cost about $100. Removing the AC and hardware was free.

Drive shaft- I replace the steel driveshaft with an aluminum driveshaft from a Camaro and saved 3 lbs. Cost $100 for the used driveshaft and $50 to shorten it.

Battery-I replaced the 40 lb battery with a 15 lbs dry cell battery and saved 25 lbs. Cost $85. http://forums.corvetteforum.com/c3-t...lbs-saved.html

Exhaust System- I lost about 25lbs when I converted my dual exhaust, dual Flowmaster exhaust system to a dual exhaust with one two in two out single Magnaflow muffler. Cost $200. http://forums.corvetteforum.com/c3-t...w-exhaust.html

Master Cylinder replacement- I replaced the iron MC with a C6 style all aluminum MC and lost 7lbs. http://forums.corvetteforum.com/c3-t...brake-mod.html

Hood-You can lose 5 to 10 lbs by lightening your hood or replacing it with an aftermarket hood. http://forums.corvetteforum.com/c3-t...ning-mods.html


I’ve done a few things that added weight over the years. The 700 R4 tranny, a weld in roll bar for chassis stiffness, and about 20 lbs of fatmat for sound deadening. The offset trailing arms are beefier and heavier than the stock trailing arms. Some things I will keep, like power windows and a sound system.
All of the above weight loss mods have gotten me down to 3100 lbs. My goal is to get down to 3000 before going to an aluminum block. My future plans include:
Rack and Pinion steering I did the Borgeson swap instead. Lost 4 lbs.
Aluminum or tubular A arms Done, May 2013, good for 9 lbs
Plexiglas Rear Window passed
An 80-82 aluminum rear end Done Feb. 2013, good for 20 lbs
Lightweight aftermarket 19” wheels with no adapters needed.
Alloy block Done, LS 427 conversion summer 2019, 100lbs lost.
I’ll keep this thread updated.
Bee Jay

 

Well done, thats impressive work, Iam on the same mission as you!

Ive done a fair amount of stuff on your list, but you have enlighten me to lots of other stuff I had not thought about

many thanks

dave

 

Very interesting and and informative write up. Thanks for taking the time to put it all together in one thread. I look foward to reading the updates.

 

That last 100 pounds will be difficult. It seems you have really dug deep already.

 

Wow. Excellent.
But the only thing that concerns me is the removal of the side guard door beams. If some moron runs a red light while you're crossing the intersection..............
We worry about ya. 'Cus we luv ya!

 

Your a man BeeJay!!!

very work buddy!!!

keep it up!!1

 

I'm surprised you haven't gotten rid of the wicked heavy flip up lights for fixed headlights yet.

 

Now you did it! Just gave him another idea of how to take off some more weight. By the way, My 77 intake was way more then 15 lbs compared to my weiand. If I remember correctly I believe I saved about 25lbs. Keep up the work

 

Hey, Bee Jay, why don't you lighten up, huh?

Anyway, you are probably already aware of this, but I'm gonna throw it out there anyway, just in case. The '80-'82 batwing does not bolt to the frame the same way as the pre-1980 diff crossmember does. Some fabrication will be required. Also, I'm not sure about this one, but I think the c4 diff is the same as the '80-'82, for when you are sourcing your diff. Again, not sure about that, but they sure look the same. See ya!


Keep the shiny side up!
Scott

 

Do you have power steering? Ditch the PS pump when you do the rack conversion... Ive been running mine manual since I put it together and I love it - Even on tight auto-x tracks.
A few things you did not mention:
Replace the steel tie-rod and strut rod sleeves with aluminum. I run alu. tie-rod sleeves and they are feather light!
Shortened C4 aluminum half shafts?
80-82 stamped steering column support
80-82 thinner door glass (I know you have at least one thin window. Did you end up getting both?)

I was at 2960 sans-driver before I added a few new things (scattershield, 7QT oil pan, power windows ). Now Ive got to try and shed that weight, again!

I really enjoy your weight loss threads and have stolen a few ideas from your posts


Also... the 80-82 aluminum diffs are not the same as the C4 dana 44 or 36 diffs

 

You seem to know what you're talking about, so I'll ask you this for Bee Jays benefit: If he wants to install a batwing in his 'vette, he's going to need to do some fabricating anyway, right? Would it be a better idea to go with a C4 diff, if he's gonna need to scab it in anyway? There are probably a lot more C4 diffs out there than '80-'82 diffs to choose from. Or would it be easier to use a '80-'82?


Keep the shiny side up!
Scott

 

I've already installed the 80-82 batwing. See this link:
http://forums.corvetteforum.com/c3-t...g-install.html
Since I have the 80-82 batwing, I will eventually install an 80-82 aluminum rear end. I have a core, but I need it rebuilt with a 3.55 gear set. Or if anyone has one laying around...............
Bee Jay

 

Thaks 427sbc. I have power steering and the power steering pump powers my Hydroboost brake system. One of the best mods ever done to my car.
Bee Jay

 

I'm keeping the pop up headlights, but I would like to do the Firebird electric conversion.
Bee Ja

 

Removing the side door beams and the 5mph front bumper and the 2 1/2mph rear bumper only reduces my safety to that of pre '73 Vettes. Still way safer than my Harley Davidson.
Bee Jay

 

OOOOOOHHHHHHH!!!! Now I get it! Sorry to be so slow on the uptake, guys.........


Keep the shiny side up!
Scott

 

Bee Jay I've always wondered how much lighter the optional aluminum wheels are when compared to the ralleys. Do you remember?

 

Great information and keeping track, the kind of post i read top to bottom.

I am just curious how does the car handle being so much lighter? Does anyone have a significantly lighter vette?

 

I have always wondered what the weight difference is between the iron diff and the aluminum diff. Obviously you have to factor in the batwing since it has to be added as part of the conversion. I don't think I would do it for any of my cars but I see it come up a lot in discussion and I'm curious.

 

Question for Bee Jay and vette427-sbc: for the weights you quoted for your cars, what fuel load was in your cars when they were weighed?

Thanks