Working as Chief Justice of the 24 Hours of Lemons Supreme Court, I see a lot of superchargers bolted to racing hoopties and adding tremendous engine
destruction power on the track. Yes, everything from an AMC Pacer with an Eaton-blown Jeep 4.0 straight-six to an ill-advised blower rig on a BMW E30 3-Series. Supercharging your street beater is an even better idea, but who wants to spend real money on such a project? Roadkill is here to help, with a guide to the three types of blowers that are cheap and plentiful right now in North American wrecking yards. Put on your grubbies, grab your junkyard toolbox, and get ready for booooooost!
I love junkyards, and so I went to several Denver self-service wrecking yards and pulled one of each of the three types of supercharger that usually live in high-inventory-turnover self-service wrecking yards right now. There’s the Eaton-made Roots-type blower used by GM and Ford, the Aisin-made Roots-type blower used by Toyota, and the IHI-made twin-screw blower used by Mazda. You’ll find other types occasionally, on your random Mercedes-Benz C-Class or Volkswagen Corrado or other junkyard oddball, but these three superchargers make up 98% of the blower inventory in North American wrecking yards in 2017. Let’s take a look at each.
Where to find it: 1994-2007 GM cars, 1989-95 Ford Thunderbird Super Coupes
Boost potential: Medium
Dimensions (late-90s M90): 21-1/2″ long, 9″ wide, 5″ tall
Junkyard Extraction Hassle Factor: Low
Awesomeness Factor: High
These Eaton blowers are by far the easiest superchargers to find in your local wrecking yard. In fact, there’s no need to even go to a wrecking yard to get one these days, because so many guys yanked and stockpiled them a decade ago (when they first showed up in quantity at U-Grab-It yards) that the going rate at swap meets is about 50 bucks. Note: I have used a commemorative Blucifer Pabst 16-ounce can for scale in the photographs, because that’s the current standard for supercharger sizing.
If you can’t find at least three of these superchargers in the GM section at a U-Pull-&-Pay, Pick-n-Pull, Pick-Your-Part, or other yard owned by a big self-service chain, you’re not looking hard enough. GM put these things on the 3800 Buick V6 starting in the 1991 model year; look under the hoods of 1991-2005 Buick Park Avenues, 1995 Buick Rivieras, 1997-2004 Buick Regals, 1992-1999 Oldsmobile 88s, 1992-1995 Oldsmobile 98s, 1992-2003 Pontiac Bonnevilles, 1997-2007 Pontiac Grand Prix, 2004-2005 Chevrolet Impalas, and 2004-2005 Chevrolet Monte Carlos— each of these cars had special editions with supechargers. In fact, just look at all the 1990s and 2000s V6-powered front-wheel-drive GM cars, because lots of supercharged 3800s got swapped into cars that never had them from the factory. 1996 and newer cars got the M90 version, which makes usable boost at a lower RPM than does its M62 sibling, so get that one if you have a choice.
You’ll also find M90s on 1989-1995 Ford Thunderbird Super Coupes, which used Eatons on Ford Essex 3800 V6 engines. These cars are nowhere near as plentiful as the GM machines at El Pulpo, but they’re out there.
The Eaton blower is laughably easy to remove, being located right on top of the engine without any covers or weird plumbing in the way. Remember to get the blower-compatible crankshaft pulley off the donor engine while you’re there… unless you plan on spinning your new blower a lot faster than stock speeds with crazy pulley switcheroos.
Roots superchargers are inherently inefficient and the M62/M90 doesn’t make tremendous boost, but who cares? This blower is easy to obtain, easy to install, and it makes a proper blower whine that will make you happy every time you hear it. We suggest that you install one on a Datsun F-10, just because.
Where to find it: 1994-1997 Toyota Previas, 1988-1989 Toyota MR2s
Boost potential: Low
Dimensions 11″ long, 8″ wide, 6″ tall
Junkyard Extraction Hassle Factor: Very high
Awesomeness Factor: High
The Toyota Previa was the supercar of minivans; it was available as a mid-engined, supercharged, intercooled, 5-speed-equipped, all-wheel drive machine… and nobody noticed. The 1994-1997 Previas have a nicely compact Roots-type blower made by Aisin, mounted where no casual junkyard shopper would ever notice it, and that blower comes equipped with an air-conditioning-compressor-style electric clutch. You can find members of this blower family, in theory, on Toyota MR2s equipped with the supercharged 4A-GZE engine, but I have yet to find one in all my years of junkyard crawling.
This Aisin blower first came to my attention when an innovative 24 Hours of Lemons team installed one on a BMW E21 3-Series. The crazy Ukrainians of the Communists-Я-Us team saw a big performance increase out of their BMW M10 four-cylinder engine… right up until the moment when all the connecting rods were ejected onto the tarmac in a dramatic fireball. By far the coolest thing about this blower is the electrically-controlled pulley clutch, which allows the driver to actuate it manually. Why is this something you want?
You want to be able to turn your supercharger on and off with a Cole-Hersee switch made for two-speed truck axles, of course, because that’s how Mad Max did it! The Previa blower makes this setup easy to do. Another advantage of this supercharger is that it has its own oil reservoir, so there’s no need to plumb pressure and return oil lines to it.
Be warned, though: this blower is something of a nightmare to remove from a discarded minivan. The Previa has an I4 engine that lays on its side beneath the front seats, and all of the accessories— including the supercharger— live on a complex assembly located near the grille and powered by a long shaft from the engine. This assembly is known as the Supplemental Auxiliary Driveshaft by Toyota, with the all-too-apt acronym of SAD, and it hungers for the flesh of your tender knuckles.
The SAD is down low in the Previa, and that means you’ll need to remove just about everything under the hood in order to get access to the fasteners holding the supercharger in place. The hood opening is tiny, and the big assembly containing all the HVAC components has to go.
On my first attempt to obtain a Previa supercharger, I enlisted a mechanically-inclined friend to help out, and we discovered that the Previa’s HVAC assembly will not come out as a unit. Instead, it must be disassembled by removing a lot of around-the-corner-inaccessible fasteners. We ran out of time on this attempt, and I went after another Previa a week later, with more success.
Most online sources will tell you that you must pull the SAD (using an engine hoist) in order to pull the Previa’s supercharger, but this is not the case. You’ll need patience for the job, and you’ll build up a big heap of yanked parts as you work your way down to that elusive Aisin blower (which is barely visible when installed in the van), but the Aisin will come out with the SAD in place.
If your junkyard Previa is an All-Trac-equipped AWD van (as mine was), you’ll have the added headache of the front-wheel axles and differential, but everything comes out if you work at it and can handle removing fasteners you can’t see. The air-intake and intercooler-ducting connectors are held in place by a brigade of maddeningly unreachable 10mm nuts, but I got them off and so can you.
You’ll want to wear some good mechanic’s gloves for this job, for obvious reasons. Find a big piece of trunk carpeting to put under the van, because you’ll spend a lot of time on your back down there, trying to turn bolts, blinking a rain of antifreeze out of your eyes, and cursing Kiichiro Toyoda (to be fair, Toyota’s engineers did their best to make this job possible, given the tough constraints of the Previa’s innovative design).
Because the Previa’s supercharger is about five feet from the engine, there’s plenty of space for intercooler plumbing. You’ll find the intercooler behind the left side of the front bumper; intercooling adds power, so you’ll want to grab this little devil while you’re there.
I went back later and got the main drive pulley off the Previa’s SAD, made to match the clutch pulley on the Aisin, because I have a terrible idea for this blower’s application.
Where to find it: 1995-2002 Mazda Millenia S
Boost potential: High
Dimensions 20″ long, 6″ wide, 5″ tall
Junkyard Extraction Hassle Factor: Medium
Awesomeness Factor: Extremely high
The Millenia was Mazda’s top-of-the-line luxury sedan around the turn of the century, and it was packed full of interesting technology. The Millenia S version had a futuristic Miller Cycle engine, which benefits from the use of a supercharger that makes serious boost at low engine speeds. See where we’re going with this?
When you look under the hood of a Millenia, you don’t see anything that screams “Here thar be supercharger, matey!” to the junkyard buccaneer; a few might notice the strangely small intercoolers and assume that the engine has an impossible-to-reach turbocharger or two. For this reason, nearly every Millenia S blowers that goes to the junkyard ends up being eaten by The Crusher. The long, skinny IHI supercharger lives in the V of the Millenia’s transverse V6, beneath a bunch of intercooler plumbing and a big plastic cover.
IHI is a very respected manufacturer of turbochargers and superchargers, so the quality in the Millenia unit is excellent. It appears to be an license-built derivative of the Lysholm 1200 AX twin-screw unit, but I am going mostly by appearance and dimensions with that guess.
The twin-screw design is more efficient than the Roots-type design, and this type of supercharger costs a lot more to manufacture than the Eaton and Aisin units we just looked at. The Miller Cycle engine in the Millenia S doesn’t take full performance advantage of the boost potential of the IHI blower (the Miller Cycle design is more about fuel efficiency than balls-to-wall power), but it appears likely that boost levels of over 20 pounds— maybe way over that— should be attainable with this thing.
Because the Millenia S supercharger is long and narrow, it would be well-suited for use alongside inline engines. Say, for example, a pair of them, mounted on either side of a Buick straight-eight?
Removing one of these superchargers takes a fair amount longer than grabbing an Eaton off a Park Avenue Ultra, but it’s nowhere near as tough as getting a Previa Aisin. You’ll find many finicky rubber hoses and metal lines that must be cut, and the supercharger sticks tenaciously to the engine block, even after you have removed all the fasteners (in the timelapse video above, shot on a 100° day at a Colorado All You Can Carry For $59.99 sale, you’ll note that I had to enlist help from a nearby parts shopper to pry up the blower from both ends simultaneously).
I have removed three of these superchargers by now, and by far the trickiest part is separating the intercoolers from their plumbing; they use sadistically inaccessible spring clamps, so the easiest removal method involves sawing through the rubber hoses with a big serrated blade. Keep in mind that this supercharger requires pressurized oil delivery, just like a turbocharger, and the fittings for oil feed/return are on the underside of the blower housing.
Of course, fuel delivery is the tough part of rigging up a backyard-built forced-induction system; you can go old-school and use carburetion, or you can get all futuristic with electronic fuel injection. You definitely need to install some sort of safety relief valve, such as the homebuilt one made for the Lemons Pacer, especially if you’re using a draw-through design that involves a big volume of fuel-air mixture; explosions caused by backfires are no joke!
The price tag on superchargers varies by region. Here in Colorado, the self-service yards have extremely reasonable prices for such things; I paid $53.45 with all taxes and fees at the Aurora U-Pull-&-Pay for the blower out of a 2000 Millenia S.