In Late 2020 I bought an 85 Corvette with the intent of swapping my turbo 5.3 from another project. I ended up putting the 5.3 turbo in a BMW . Since I blew up my max effort ls3 I built in 2018 for another car I have been craving some high reving v8 NA power and I felt like the c4 was the perfect platform for it.

I decided to put in a ls3 and try to keep everything as light as possible but the car ended up lighter than I thought which makes me want to try to get it even lighter.

I got the car on the road mid 2021 and have driven it on and off since then. But there are several things that have really annoyed me and I have the car back apart now to correct them.
Old set up

LS3
Stock Heads with dual valve springs ti retainers
1 3/4 Cheap c6 headers modified to fit and single 3.5 inch exhaust
sheet metal intake and 104mm throttle body, Which I hated. It made a hollow tin can whining sound.
summit 8711 Cam
dynoed at 492whp

To save weight I went with a basic super t10, aluminum flywheel and Aluminum cbeam adapter.
I am currently running a d36 rear end as well

Removed all wiring, ac all underdash components, sound deadening everything I could.
replaced carpet with a really thin replacement and replaced the seats with kirkeys
I have used carbon fiber to replace some of the interior panels

Motion steering Column
Exotic muscle harness bar

Upgrades I am working on now.

2 inch headers into dual 3 inch center exhaust. I am trying to figure that out so that I dont add weight over my current exhaust.
holley ultra low ram intake and motion throttle body. Awesome pieces but they do weigh more than my current setup
holley intake fuel cell pump to replace my out of tank set up.
larger aluminum radiator which is going to weigh more bc of the higher capacity.

I have been replacing bolts with titianium ones where i can and also aluminum bolts on non critical components.
I plan to gut the hood
I just picked up a set of baer two piece front rotors which saved 2.5 lbs per side.

Car weighed 2540 before these newest upgrades started.

 

 

 

Wow, the LS Miata owners will be somewhat impressed. Seiously though, weight is everything and everything improves with with lower weight. It's fun to think about these projects diffrently. It's often said every 100 LBS is 10 HP but few talk about cooling, braking and handling improvements.

I'm actually doing a similiar thing on a Old GMC motor home. It's fun and scratches the OCD itch. Gutted it and I'm re-doing everythng for lower weight in the house now. I already did alu calipers, intake, heads and A/C compressor and headers for the mechanical side and dropped about 500 LBS which did make a noticable dfferance. I am somewhat self amused with my own efforts in using aluminum 3/8-16 bolts for the intake manifold on a 12k LBS motor home. Every pound counts.

 

Nice! ... how did you do the fuel cell? Where did you get those door panels? I'm trying to do something light weight also with manual brakes, but not anywhere near 2500.

 

I built the fuel cell to fit in the stock location. It is similar in size to stock tank. I also built the door panels out of abs plastic I bought off eBay. I plan to replace them in the near future with carbon fiber. More for looks than weight. The abs is very light as is. The manual brakes are awesome. They feel better than the boosted ones did. I assume my large cam didn’t help the power brakes

 

In case anyone wanted to know what titanium bolts weigh. this is a comparison of the m10 bolts that hold the steering column.

Its not much but when you multiply it by hundreds of bolts it adds up.

 

C6 2 inch headers fit on drivers side but the outer tube has to be rerouted on the passenger side

 

Here is a picture of my modified 1 3/4 ebay headers I modified to fit also my single 3.5 inch exhaust. Im going to sell the entire set if anyone is interested.

 

I started gutting the hood today. So far I have removed 20lbs. I am going to cut more out and clean it up soon.

 

Whose manual brake kit did you use ?

 

https://www.manualbrakes.com/

he sells them for aftermarket master cylinder but I modified it to work with stock master

 

I started working on my frame mounted front splitter. I first built it out of 1/2 plywood and it weighed 20lbs. I then cut a new one out of alumilite sign material and it weighs about 10lbs.





Im gonna clean up the edges a little and paint it flat black

 

excellent build.

he prob made the door panels like I did.
saves 9 lbs per door

Would love to see closer how he trimmed the top edges - i havent done that with mine yet

 

I’ll take some better pictures of the door panels tomorrow. I’m about to re make them better. Where did you get the carbon?

 

summit racing equipment last spring
ill see if i can dig up receipts showing the size and pn

 

SUM-590403

2 sheets needed at $171.99 a sheet

Note that one sheet wont be long enough to cover the entire door from fore to aft.

its missing a few inches at the front - since this area is covered when the door is closed; i didnt worry about it

good luck

let me know ideas on how to put a trim piece on top if you have any

 

My heads came in from GPI. These things look awesome.

 

I just about have the car back together. At it is lighter than I imagined. I havent cut any corners as far as weight is concerned. Titanium and alumium fasteners. stripped out evertyhing that was not needed. grinding and cutting. Maybe in the next month I can get it back on the dyno and see what the new setup makes.

 

Great job on shedding weight on that thing! Just one question about the brake master... wouldn't the newer 86-87 single reservoir master cylinder be slightly lighter?