TURBO PARTS AND FABRICATION

When I first thought about turbochaging the car I was told that the best stock turbo to look for at a decent price was a T3 from a Buick GN. Reason being those fed a 3.8L V-6 and I would be powering a 3.7L inline 6. I checked around on a few Buick specific message boards when I came across a killer deal. I found a guy selling a T3 Garrett / AiResearch turbo from an 85 Buick Riviera T-Type. Close enough for $60 I had it in my hands, completely rebuilt set up for blow through application. It has a .60 Compressor housing and an .82 Exhaust which I am told is an upgrade the stock housings are .63 or .48 normally. When I got it home you could tell it had been run but barely. It was in excellent shape with no shaft play what so ever. The only problem it did have was one bolt hole that was mangled, but that was repaired with some drilling and a Heli-Coil kit.

Now I did receive the stock Internal Wastegate elbow but for my application and the way it mounted it would just not work. I purchased a flange for the GN turbo but it did not fit, luckily the guy I purchased it from was more then happy to not only take it back but in a weeks time custom cut me a flange. The stock opening in the hot side is 2in which we welded on a pipe that bumped that up to 3in. This worked out great, although forcing me to run an external wastegate it solved the problem.

Next since the motor was in the car was to attach the turbo to the stock exhaust manifold. Now I know there is a company that builds manifolds for the 6's that are cast and have a mount for a T3 turbo and an external wastegate but their $600 price tag was out of my range. So the help of McMaster-Carr I was able to use 2" schedule 40 Steel pipe to build an up pipe. This part took some time, fitting it and trying to make it clear everything but it was well worth the time. It took 2 90deg elbows, 2 45deg elbows, and about 2ft of pipe to complete. All butt weld style fittings, a bit of trial and error and I had it made, along with a few flanges from the local part shop and it was complete. After it was fully welded we located a spot to mount the external wastegate by using some 1 1/2" pipe and the supplied flanges. You can see where it fits and still give me hood clearance. There were many other ways I could have done this but this proved to be the easiest for me. Once the up pipe was completely welded I then had to figure out where to mount the Wastegate.

The wastegate I used is a "knock-off" piece similar to the well known TIAL wastegates.  I is a 38mm piece that came with a 3.63psi spring installed.  It also came with all the necessary flanges.  So with a piece of 1 1/2 sch 40 Steel pipe I was able to mount this.  I used the cutting torch to blow a hole in the bottom bend of the Up-Pipe and weld it on, then weld a flange on.  After that was done I took the time to wrap the up-pipe with Heat Wrap.  This stuff works wonders, it kept the under hood temps way down as well as keep the heat in the pipe making it flow better.

With this complete I re-mounted the turbo onto the pipe and bolted it all down. Next on the agenda was to set up some sort of filter for the intake of the turbo. Simple enough, took a 2in exhaust flange and welded a 90 bed of sch 40 pipe onto it attached a 2in to 3in reducer and clamped down a 3in Conical filter. The filter I just got from Auto Zone since it was convenient. With that taken care of next was to move onto the exhaust side of the turbo. I took the car to the local shop and had them bend up a piece of 3in pipe and clearance it for the steering box. This worked like a charm, I fit it welded it on and then used the remaining Heat Wrap I had to cover it. Once this pipe was on the car I was able to located and weld on the bung for the Wideband 02 Sensor.

Next was onto the carb hat.  Now sure I could have went out and bought a $180 hat from someone like Procharger or CS but were on a budget right and I wanted to get the car on the road so ill make my own. Basically I purchased a Stainless Steel Glass Top kitchen canister from Wal-Mart ($5) turned it upside down, cut a hole in it and welded a piece of 2.5" pipe on.  Not fancy and the welds sucked but it will work temporarily. I was wanting to test drive the car and take it to the local car cruise that's just a few miles away.  So we stuck on some flexible black tubing and JB welded some barb fittings onto the back of the hat.  These two lines are used to send boost pressure to the wastegate, and to the Fuel Pressure Regulator. Whenever you use a blow-through setup such as this you much have a boost referenced FPR so as your boost increases you make sure the fuel bowls stay full by upping the pressure.  Now they sell ones made for carbureted application but they run from $75 & up.  But I was told that you could modify a $30 Holley FPR for just this by putting a barb fitting in the topside and blocking off the stock vent.  Sure enough by doing this when you add pressure to the FPR the pressure increases from the base setting.

One last thing to address at this point was the Oil Feed and drain.  To supply oil I tapped into the oil port on the pass. side of the block.  I put a T fitting on to supply the oil pressure sensor and the turbo.  To keep too much oil pressure from getting to the turbo I also put a adjustable restrictor valve and a gauge to keep tabs on it.  This was then connected to a -4an braided line from earls and into the turbo.  On the drain side we connected a few 45deg -8an fittings and a piece of  socketless hose.  Simple yet effective.

Now at this point everything under the hood was done, All that was left was to hook up the boost gauge, wire up the LC-1 Wideband O2 sensor and Moates "O" Meter. For this I purchased a fuse panel. Its from Blue Sea part#5025. This allows me to run a clean 12V power and ground direct from the battery to my electronics, plus the ability to fuse them all to prevent frying anything. Basically follow the direction and it all went together fine. The "O" Meter will give me a quick and easy to read AFR display and some data logging abilities. Also with the LC-1 I am able to hook up a laptop to data log from there as well. This was probably the most expensive investment I had to make but it will be well worth it so I don't lean out and melt a piston.

With everything installed, hooked up and ready to go it was time to test fire the car.  She fired right up, I set the idle and idle a/f which was easy to do with the Wideband o2 Meter.  Then I turned out the adjusted on my Adjust-a-jet plate and away we went.  The first drive was easy going, made sure the TV cable was adjusted correctly and that it shifted good also kept an eye on oil pressure and the water temp.  After a short drive on no boost I brought the car back and let it set.  Re-Tightened everything and set back off.  I rolled into the throttle a few times watching the A/F ratio, it spiked to 17:1 when boost came in so I quickly let off pulled over and adjusted the jets out more.  I nailed it on the head and was getting a 11.4:1 AFR at WOT.  Now it peaked @ 4psi on the gauge and the first time I stayed into the throttle for a good amount of time, the Charge pipe Blew off the turbo.  Oh well couldn't expect much from the flex hose we used.  I took it to the local car show and got in it a few times, felt strong with tons of blowby so I will definitely need a PCV setup.  But all went well I feel for a shake down run. Below you can see me and my cousins Nova parked at the car show.