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Just A 1972 Twin Turbocharged LS3 (Street car) Build
You read the thread header right. I'm taking a LS3, and a 4L80E putting two
62mm T3/T4 turbonetics turbos on it, and shoe horning it into a heavily modified body 72 C3 for the owner.
Now the thing with this car is, it will never be drag raced at the track, or
autocrossed. This car is a cruiser, and show car (he loves going to cruising the coast). So just some long burnouts,
and some 40 mph rolling burnouts in the future.
The car Has a very cool back story. It is a 1972 base model coupe,350 with quadrajet
(255 horsepower) and a turbo 400 transmission.
The owner of the car bought it new in 1972, (yes he is the original owner) then went crazy on the fiberglass mods.
The car has a I think has a It has a 74 front end,67 side louvers,69 side exhaust, ZL1 flares He also made the car into a hatch back!
The guy also made his own cowl hood. So he could remove the vacuum powered windshield wiper cover.. The owner is very mechanically inclined
but the level of fabrication need to do this swap was more then he was comfortable doing. so He ask me to take over.
This is 100% a restomod, all the P/S, P/W, Power door locks ,heat, and A/C, Gages, and entertainment center will work.
When he brought me the car it had a blue print 383 with a FI tech EFI unit (that never worked right). Fi tech is a great design but poor build quality( in my opinion) The A/C and heater don't work. I'll change that.
So the old 383/turbo 400 comes out, and the build is started.
I have read the stock 10 bolt rear end is going to be my weak link.
That's a problem I'm gonna have to deal with, If and when it breaks. I know there is a limited supply
of 3.73 12 bolt gears (A 12 bolt conversion my first choice).
There is also a Ford 9" IRS from ridetech (I think) So not the end of the world.
My son and I had the block, and rotating assembly washed, We had the block honed as there was no need to bore it.
New cam bearings, and a aluminum dog bone installed.
We gapped the rings for boost, and installed ARP hardware. The heads were rebuilt with new guides,
S/S Ferrea valves, and the springs, locks, and retainers that match the Texas speed stage 3 turbo cam.
We also did the AFN/VVt delete with a 3 bolt cam. All the standard stuff you do to to a gen 4 LS.
Sorry i don't have many pictures of the the short block,but it was a boring build.
Just a stock rotating assembly with new bearing, gapped rings, a good oil pump, stage 3 texas speed turbo cam,
and ARP stuff.Ill post updates and pictures on here as I go.
Here are some pictures to get us started on the project. The old 383 Driver side 383/400 turbo out
.
Last edited by gearheadib; 03-24-2024 at 04:50 PM.
I have seen all the C3 turbo builds on the internet (I think) , I can find full on race cars with A/C, and the old banks Kits on the gen1 sbc that came in a C3. But I can't find anything like I'm building. I want it to look like Zora Duntov himself put a TT Ls3 in this car. You are right there is not much room under the hood of a C3. So I'm putting them under the car. and keeping the side pipes. And the hood will use all the factory hood hinges, and latchs.No pin on race hoods. so i can't move the radiator.
Last edited by gearheadib; 10-16-2023 at 07:28 PM.
You could move the radiator if you placed it where the spare tire goes. You'd probably need fans running full time for that to work, though.
I'm really looking forward to seeing your approach!
So when the owner did the hatch back thing he used a camaro fuel tank with a license plate filler so the floor of the oem truok has been modified with no spare tire location. So there is no room in the back of the car for a radiator. Wishful thinking. I like the idea, but just no room back there. Besides I like stuffing ten pounds of **** in a five pound box.
I have seen all the C3 turbo builds on the internet (I think) , I can find full on race cars with A/C, and the old banks Kits on the gen1 sbc that came in a C3. But I can't find anything like I'm building. I want it to look like Zora Duntov himself put a TT Ls3 in this car. You are right there is not much room under the hood of a C3. So I'm putting them under the car. and keeping the side pipes. And the hood will use all the factory hood hinges, and latchs.No pin on race hoods. so i can't move the radiator.
Have you considered (like Hotrod Jim with his C2) placing the turbo's in the area behind the front wheel wells and side gills?
Have you considered (like Hotrod Jim with his C2) placing the turbo's in the area behind the front wheel wells and side gills?
I have considered placing them there, but the evaporator core and A/C lines in and out of the factory A/C box are in the way on the passenger side. By the time you cram a turbo, hot Air in and out, cold Air piping, a air filter, and the A/C box there just no room. The driver side is no problem, lota room, but i need to make it symmetrical from side to side so placing them out in the fenders behind the front tires is not a option. There is a lot of room where the headers dropped down to go out to the side pipes. That's the space the turbos will occupy
Last edited by gearheadib; 10-17-2023 at 12:55 PM.
I had to pull the dash to change the heater core. I will add some intellitronix digital gauges the owner supplied. The holley terminator X will run the tach, and I got GPS sender to run the speedometer. I love the old school mechanical drive tach and speedo. But you can't beat a tach that doesn't bonce, and a speedo you don,t have to calculate the teeth on the gear when you change tire size. I can,t believe it had a mechanical oil gauge. While i'm in here, I'm adding a shiftworks 4 speed gate and neutral safety switch so the 4L80E will work with the factory shifter. One of the first thing I did when i got the car was to add a vacuum pump and isolate the cars vacuum from the vacuum/boost the engine will make. That means I can run the vacuum pump and check All the vacuum operated accessory's.Like the head lights A/C and power brakes
Changing the heater core and gauges intellitronix digital gauges
Last edited by gearheadib; 11-03-2023 at 11:42 AM.
I have considered placing them there, but the evaporator core and A/C lines in and out of the factory A/C box are in the way on the passenger side. By the time you cram a turbo, hot Air in and out, cold Air piping, a air filter, and the A/C box there just no room. The driver side is no problem, lota room, but i need to make it symmetrical from side to side so placing them out in the fenders behind the front tires is not a option. There is a lot of room where the headers dropped down to go out to the side pipes. That's the space the turbos will occupy
Understand the potential issues with a/c etc on the passenger side - even 'ordinary' Vettes are perhaps limited on header selection if running a/c.
If you really want a 12 bolt 3.73, contact Gary (gtr1999) NOW. Believe he got the last half dozen Corvette 12 bolt 3.73 gear sets left (not the same as regular 12 bolts).
I have considered placing them there, but the evaporator core and A/C lines in and out of the factory A/C box are in the way on the passenger side. By the time you cram a turbo, hot Air in and out, cold Air piping, a air filter, and the A/C box there just no room. The driver side is no problem, lota room, but i need to make it symmetrical from side to side so placing them out in the fenders behind the front tires is not a option. There is a lot of room where the headers dropped down to go out to the side pipes. That's the space the turbos will occupy
Look into a Vintage Air ac system.
It eliminates everything on the firewall and the new unit fits up under the dash on the passenger side.
It should solve the room problems you’re having.
Look into a Vintage Air ac system.
It eliminates everything on the firewall and the new unit fire up under the dash on the passenger side.
It should solve the room problems your having.
I have seen the vintage air system.But that just isn't in the cards. Besides the owner spent a lot of money to get the OEM A/C to work......So I'm going to build a set of headers and hang the turbos in the space the old header collectors occupied.
10-14-2023, 03:06 PM
Just A 1972 Twin Turbocharged LS3 (Street car) Build
