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Convert to a Carb/Turbo?

(Also read Part II, the Blow-Thru Turbo)

The most common request I get through direct e-mail and the Message Board are in regards to converting a non-turbo Buick 3.8 V6 into a Turbo V6. In order to prevent repeating my thoughts on this over and over, I will sum it up here. This just my opinion; I have done not a conversion like this, but I do know what is involved with this engine. I hope it will help others make the right decisions and know what they are doing before investing too much time and money.

WHY CONVERT? - 90% of the conversion requests come from two starting points. Either someone has found "a complete setup" cheap or someone has just learn that the 3.8 2-barrel is basically the same as the engine as the one in the '87 GN they saw at the Drag Strip (or something like that). Either way, it sounds very tempting because the Turbo is simply bolt on and the engine doesn't even need to removed from the car. The earlier 1978-'83 set up is often chosen because it is cheaper and viewed as simpler to do since it also uses a carburetor. If done properly, it could be a reliable source of power (that's why Buick did it). I think, if done right, this would be a great way to up the HP in a non-Regal application, such as a Jeep, mini-truck, Skyhawk, or anything else powered by the Buick V6.

THINK IT COMPLETELY THROUGH! - I personally do not recommend this conversion is most cases. Please think this conversion completely through. I am not trying to discourage you from having a Buick Turbo V6, I think they are great. I just believe this conversion is much more difficult than it appears. While the engines are very similar, the are many, many pieces involved other than the turbocharger. Also, the results from such a conversion, in most cases may be disappointing, because the carbureted set up does not have the power or potential for power that the more familiar 1984-'87 SFI Turbo V6's have. Please check the Acceleration of the Buick Turbo V6 page for a comparison. Also, you probably trying to do this on a budget (otherwise you would have bought an 1984-'87 Turbo Regal). You may find there are many unexpected things you will need that will put you over budget.

WHAT IS NEEDED - The more you can get the better. Ideally, you would have both the complete donor vehicle and recipient vehicle side by side and would move everything over. I know this is likely not the case (If you had a complete donor car, you wouldn't need to "Convert".) First, most "complete" set ups of far from complete. Here is what I believe you would need at a MINIMUM:

• Buick turbocharger, with wastegate and actuator (the Buick turbo has specific mounting provisions)
• Buick turbo V6 intake manifold with support brakets
• Buick plenum (turbo to carb adapter)
• Buick right side turbo exhaust manifold (in and out manifold)
• Buick crossover pipe
• Buick turbo up-pipe
• Buick turbo down-pipe

While non-Buick pieces could be used, without all the above, you may as well consider your system aftermarket since you will need to fabricate the items (expensive) and have unexpected problems. Use the above and take advantage of what the Buick engineer's designed. Keep in mind that the 1978 heads had different sized ports and they will be mismatch problems if 1978 parts are used on 1979 and later heads. I also suggest sticking with the quadrajet carburetor. It will fit and is cheap. Change it later if you think you need to.

THINGS TO CONSIDER / PROBLEMS YOU WILL LIKELY HAVE - This is a list of potential problems, in no particular order, that I predict will arise. (I haven't not done this conversion myself, so I am sure I am missing many problems).

• Engine Internals - The Turbo V6 uses a rolled fillet crank. It may also use a different cam, valve springs, and pistons than your motor. The turbo stresses the motor, and it needs to be able to handle. A non-turbo engine will hold up under reasonable boost levels
• Tired Engine? - If your engine already has high miles, will it handle the added stress of a turbocharger at the amount of boost you want to run?
• Turbo Lag - The Carbed Turbo engine suffers from a very noticeable "Turbo Lag".
• Maximum boost - The maximum boost will be dependent on your final engine set up, but it may be less than you expect. Stock set-ups ran 9 psi. The fuel injection and Intercooling helps the later car run 15 psi and more. It will be much more difficult to run high boost (without detonation) on the Carbed Turbo set-up.
• Computer Control - There are really two Carbed Turbo Set-Ups. Computer Command Control (with an ECM) and non-CCC. You should decide which way you want to go before you start. There will be issues both ways.
• Emissions - You probably have already decided to remove all the emissions components. Removing them may cause some unexpected problems. If you keep them, there will be some compatibility issues with your current system.
• ESC system - The ESC system is very important, but there are substitutes. Water injection may be suitable. Without some form of detonation control, you will need to run low boost (which defeats to purpose of the conversion) or destroy your engine (which again, defeats the conversion). There will be compatibility issues with ECM on later set ups.Using a 1978-80 ESC system may work, since it does not use an ECM. If you uses an ESC, you will need the sensor, controller, wiring and possibly the distributor.
• Carburetor Elbow - If you don't have the Buick elbow for the quadrajet, you need something to connect the carb with the air cleaner.
• Valve Covers - The Turbo V6 uses different valve covers than the NA motor. If you don't change them, you may find your oil fill hole in a location you can't reach.
• Throttle and transmission cable bracket - If you don't have this bracket, you are going to have to find one or make one. You need something to hold these two cables in the right place.
• Hood Clearance - The elbow above the carburetor sits in the hood bulge on the Regal. You may need to modify your hood depending on what kind on car you have.
• Rear axle ratio - Most NA cars do not have the rear axle ratio that you will want to realize the potential of the Turbo V6. The 1983-'87 Turbo Regal uses a 3.42 ratio.
• Torque converter stall speed - The Turbo V6 benefits from a high stall speed converter. You should change it to get the most from your conversion.

THE RESULTS / WHAT TO EXPECT - If done improperly, there is a good chance you will damage your motor. If you are conservative with the boost, to save the motor, the performance will be disappointing. This conversion must be done right to have both performance and reliability. Unfortunately, doing it right and doing it cheaply, which is usually the motivation behind this conversion, aren't always possible.

If done right and expectations are realistic, the Turbo will certainly add a "shot of adernaline" to your Buick V6! I recommend that you purchase a Helm Service Manaul for the model/year that is most similar to your set-up and a book called "TURBOCHARGERS" by Hugh MacInnes

ALTERNATIVES - Here are some alternatives to consider before converting your non-turbo V6 to a Turbo V6.

• "Traditional" build-up - The 231 and 252 V6 respond well to traditional performance modifications. There are many aftermarket parts available. 4-barrel intakes, cams, and headers are available.
• V8 Engine swap - If you have a Regal (or similar car), the engine compartment will hold just about anything. A small block Chevy will work, but a Buick 350 is an even better choice. The Buick 350 will use many of the V6's accessories (basically it's the same motor with 2 more cylinders). A Buick 455 has also be done successfully by many; check the Turbo Regal website Tech pages.
• "Transplants" - Instead of simply converting a Normally Aspirated (NA) motor to Turbo, this involved swapping the complete engine or even better, the complete drivetrain. Another possibility, would be to rebuild your NA motor using all Turbo V6 components since the blocks are the same. This obviously is not as simple and inexpensive as converting. This would be the best choice for installing the Turbo V6 in a non-Turbo Buick vehicle.
• Buy a Turbo Buick - Buying a Turbo Buick, instead of making one, has to be more economical and much easier. Use your money to make improvements. Finding one, can be difficult. The best "Bang for the Buck" Turbo Buick is probably the 1984-'85 Turbo Regal (Fuel Injected/non-Intercooled).
• A BLOW-THRU TURBO V6! I believe that this may be the best way to go from both a performance and money aspect. Basically copy the 86/87 exhaust configuration using factory parts, but have the system feed into a carburetor. Blow-thru carb systems are well proven, have great potential and are relatively easy to do.

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