After a few months the engine began to develop a lot of blow-by, so I did compression and leak down tests to find the problem. The tests reveale... Show mored 3 cylinders with little or no compression with the problem being the pistons/rings. The engine was getting really bad, so I planned to do an engine swap. First, I removed the 305 from the car.
With it out of the car, I disassembled the engine to see what damage was done. The first thing I noticed was 5 piston skirts broken off in the oil pan. I then removed the pistons. In the 3 cylinders with low compression, the pistons were broken.
Instead of replacing the pistons/rings and putting the 305 back in the car, I decided to look for a used 350 instead. A friend had one available, so I got that from him. The engine code revealed that it was from a '70 to '73 Camaro. I then cleaned it up and installed it in the car. To avoid ruining this engine too, I left the turbo components off. I plan on building an engine with forged internals later on so that it will hold up to the turbo. For now, I'm just running the stock 350.
In July, someone backed up into my passenger side fender while the car was parked on the street. With the insurace money, I'm going to get another fender from a junkyard and paint it to match.
I couldn't find a good replacement fender, so I repaired it myself. I used body putty to re-form the shape and then spray painted it to match. Show Less
Over my winter break, I installed a single turbo on my �86 trans am. The whole process took about 2 weeks, and now I am left with some fine ... Show moretuning. I began a few months before by ordering all the parts that I would need. I used eBay, Summit, Racepartsolutions, and some local automotive stores to acquire everything.
Some of the technical information on the car before the build up: �86, 305ci, carb, ~110,000 miles, no prior engine mods. The turbo is a remanufactured Garrett. The compressor has a 4� air inlet and 2�� outlet. The turbine is a T6 1.05ar and 4� outlet.
So the first thing was to start tearing stuff off the engine. I removed the dual snorkel intake, carb, distributor, intake manifold, coolant overflow bottle, battery, fuel pump, exhaust manifolds, and the rest of the exhaust.
Then, I modified the Carter mech. fuel pump to increase fuel pressure 1:1 with boost pressure by connecting the vent holes to the bonnet.
Next, the new Holley 600 double pumper had to be sealed for blow through. This included removing the choke horn, using solid floats, and sealing off areas where boost could escape.
I replaced the stock intake manifold with an Edelbrock Torker II intake so it would bolt up to the carb and get better top end with the turbo.
Now, the real fabrication would begin. I used C4 Corvette exhaust manifolds for my turbo headers. The driver side header would be flipped upside down to clear the power steering pump.
For the passenger side I had to do a little more work with the header to have it clear the downpipe and also support the weight of the turbo.
I then combined the two headers with a 2�� crossover pipe with a slide-joint in the middle. This was the final result.
Next, I moved on to the cold-side plumbing. I mounted the intercooler in front of the radiator. It was a tight squeeze, but it fit. I also made the 2�� piping from the turbo to the intercooler and from the intercooler to the carb. I used couplers/clamps to connect everything up.
I then worked on the oil supply line. I used a T fitting from the oil sending unit to split the oil to the gauge and to a 3AN braided line. Also, I connected the vacuum and throttle lines to the carb at this time.
The air conditioning condenser box was going to be in the way of the downpipe, so now was a good time to eliminate that. Next, where the battery used to be on the passenger side, I cut a 4� hole so that the 4� aluminum flex pipe for the air intake would get cool air from underneath the engine bay.
The oil pan had to be removed so that I could weld in a steel bung for the 12AN braided steel oil return line.
I machined the oil return flange myself and welded pipe so that the braided line would clear the turbo housings.
Then, I started working on the carb bonnet. This consisted of a 5� canister to mount to the carb and a 4� to 3� exhaust reducer to act as a diffuser for the incoming dense air.
Next was to fabricate the wastegate plumbing. I ran 2 smaller pipes from each exhaust pipe to feed the wastegate.
I then put the distributor back in so that I could fire the engine up, without the turbo, to make sure the new carb, intake, fuel pump, and exhaust plumbing were all working correctly with no leaks. The new combo worked great.
The air filter was mounted right below where the battery used to sit and the new hole was made. Next, I worked on the downpipe. I used a 4� to 3� reducer from the turbo and joined the wastegate exhaust into it.
This is the completed exhaust system that feeds the turbo.
I routed the lines for my boost gauge and BTM boost retard dial. I set the timing without the boost retard at first, because I screwed up the wiring and didn�t figure that out until later.
Tonight was the first test drive with boost! It made 8psi which is what the wastegate is set at. Boost starts to build at 3,000rpm and full boost is achieved around 3,500rpm.
The next day I worked on routing the rest of the exhaust from the downpipe out to the back of the car. A muffler shop bent me a piece of 3� pipe and I installed it.
I then installed a manual boost controller to increase boost at a later time. Also, my digital air/fuel ratio gauge shows if I am too rich or lean at different speeds, and I welded a bung in the downpipe for the oxygen sensor for this.
The last thing to do was fabricate a replacement box where the A/C condenser used to be. I bent some sheet metal and used caulk to seal it up.
I am now at the point where all the physical components are done, and all that�s left to do is tuning. This will be in the form of changing jet sizes and adjusting timing. Right now, I am getting a sputter at high RPM�s with the boost (possibly a lean surge). I jetted the secondaries up and currently I have 68 in the primaries and 86 in the secondaries, with the PVCR�s drilled to 5/64".
This project ended up taking two weeks to fabricate (120hrs). The total cost was around $2,000. Research prior to starting the project could be estimated in the thousands of hours with my sources being: thirgen.org, turbomustangs.com , Turbochargers by Hugh Macinnes, and Maximum Boost by Corky Bell. I plan on going to a track or dyno once tuning is finished. Show Less