Supercharger Steal - Part Two

This article was first published in 2004.

In Part One of this two-part series we looked at the Japanese-import superchargers that you can put to use on your existing atmo engine. In this instalment we look at the second-hand blowers you can grab from other engines...

Holden V6

The Australian-market Holden Commodore/Statesman (from VS Series II to current) is available with an optional Roots-type Eaton M90 supercharger.

A brand new M90 supercharger can be bought from a Holden dealer for AUD$1749, but scour the wreckers and classifieds and you might be able to find one at about half to two-thirds that price. The M90 is mounted in the valley of the Holden V6 and consumes a fair amount of space – it measures approximately 42cm long, 20cm wide and 13.8cm tall.

The M90 contains three helically twisted rotors with an epoxy coating. The lubrication system is sealed for life. The M90 displaces 90 cubic inches (approximately 1500cc) of induction air per revolution and uses a 1.8:1 drive ratio.

Note that boost pressure is controlled by an air bypass system, which is found at the rear of the supercharger. When the engine doesn’t require boost, induction air supplied from the blower is returned to its inlet.

With up to 7 psi boost, the Holden supercharged V6 makes 165kW and 370Nm. Later models make 171kW and 375Nm. We have seen the Holden/Eaton supercharger re-pulley’d to give 10 psi boost, which yielded more than 190kW. (See Blowing Harder). This is a good, strong blower.

Jaguar

There are two superchargers available from late-model Jaguar vehicles.

The first is the Eaton M90 installed in the 1990 XJ-R (the same supercharger as fitted to the Holden V6). With the M90 hung off the side of the 4.0-litre AJ16 straight-six, it puts out 240kW at 5000 rpm and 512Nm at 3050 rpm. In this application, the blower is spun to a maximum of 13,750 rpm thanks to a 2.5:1 drive ratio. Boost pressure reaches 10.5 psi and a water-to-air intercooler is installed to chill the charge-temp.

Following the sales success of this engine, a new supercharged 4.0-litre V8 was introduced in the late ‘90s.

Featuring twin water-to-air intercoolers, the Jag V8 is boosted to 12 psi by a big M112 supercharger. The M112 is the largest model in the Eaton line-up, displacing 1840cc of induction air per revolution. Peak power and torque of the supercharged V8 is 276kW and 525Nm. Interestingly, the charge-air exiting the M112 blower reaches 160 degrees Celsius – the twin intercoolers drag it back to a more manageable 60 degrees Celsius.

Jaguar dealers charge AUD$3054 for the XJ-R supercharger and AUD$4378 for the unit on the AJV8. You might be lucky to find one second-hand. Either blower should perform well making 30 percent more power than the factory engine tunes.

Ford

In the US, Ford Motor Company has released a couple engines equipped with superchargers.

The big Ford Lightning pick-up is fitted with a 5.4-litre V8 topped with a Generation 3 Eaton M112 supercharger. Boosting up to 8 psi, a compact water-to-air intercooler chills induction air to help make 269kW and almost 600Nm of torque. Like the M112 fitted to the Jaguar V8, this supercharger displaces 1840cc per revolution.

The M112 Eaton is also spun in the slightly smaller capacity Ford Mustang Supercharged. We’re not sure on peak boost, but – using a similar water-to-air intercooler arrangement – this 4.6-litre DOHC V8 is good for 291kW and 530Nm.

These superchargers sometimes appear for auction on ebay.com. Again, a 30 percent power increase over standard should be achievable.

Mini

The Mini Cooper S is equipped with an Eaton M45 pushing up to 12 psi of boost into the little 1.6-litre engine. It’s enough to generate an impressive 120kW and 210Nm from 2000 to 6500 rpm. The M45 is the smallest supercharger in the Eaton line-up and is officially recommended for 2.0 to 3.0-litre engines, depending on requirements.

The Cooper S supercharger retails for AUD$5560 brand new. Note that the JCW (John Cooper Works) upgrade gives you a version with specially coated rotors. This unit checks in at AUD$8795.

Mercedes-Benz

The most potent supercharged Mercedes is the SL55 AMG. With a 5.4-litre V8 thumping out 350kW and 700Nm (from just 2650 rpm) that should come as no surprise!

The SL55 AMG’s highly efficient Lysholm-type supercharger (manufactured by IHI) features Teflon coated compressor screws and is driven at more than 23,000 rpm at an engine speed of 6500 rpm. At this speed, the blower displaces 1850kg of induction air per hour and generates up to 12 psi of boost pressure. The supercharger is also equipped with an electro-magnetic clutch that is used to switch it on/off depending on rpm and load. A water-to-air intercooler is also used to help achieve that magic 350kW.

And then there’s the smaller Mercedes SLK32 and C32 AMG.

Using a 3.2-litre V6, these cars apparently use the same Lysholm-type supercharger unit as the SL55. In this application, however, maximum boost is up to 14.6 psi and at maximum engine speed (6220 rpm) the blower is flowing up to 1200kg per hour of induction air. Interestingly, the blower does not engage at engine speeds above 3000 rpm due to the resulting belt stress. Maximum outputs are 260kW and 450Nm of torque.

And price? A Mercedes dealership quoted us AUD$10,933 (new) for either ...

The relatively garden-variety Mercedes SLK230 and C-class is equipped with a less sophisticated Eaton M62 supercharger. The M62 displaces 1000cc of induction air per revolution and is smaller overall than the M90. On the SLK, the Eaton M62 generates up to 7 psi of boost and with the aid of an air-to-air intercooler it makes 142kW. Again, an electro-magnetic clutch is used to switch the blower on/off.

The Eaton M62 is generally suggested for use on 2.5 to 4.0-litre engines and is about 40cm long, 20cm wide and 12.5cm tall. A new one from Mercedes Benz will cost you AUD$5558 but, again, check out the wreckers.

Other Production Cars with Eaton Superchargers... Other mass produced cars equipped with Eaton superchargers include the US-market Pontiac Grand Prix and Bonneville, Buick Park Avenue Ultra, Riviera and Regal GS and the Olds Eighty-Eight and Ninety-six. The Ford Thunderbird Coupe, Mercury Cougar XR-7 and certain Aston Martin models also employ Eaton blowers. Most of these vehicle use either a M90 or M112.

Eunos 800M (aka Millennia)

Another vehicle to use the top-shelf Lysholm-type supercharger is the Eunos 800M (aka Millennia).

Again, the 800M’s Lysholm-type supercharger is manufactured by IHI. The twin-screw compressors feature a Teflon coating and are made from lightweight alloy. We believe there are four common sizes in the IHI Lysholm range – these displace 750cc, 1000cc, 1500cc and 1840cc per revolution. It appears that the 800M’s supercharger is the 1000cc version. The 800M supercharger measures approximately 40cm long, 17.5cm wide and 15cm tall.

Fitted to the KJ-ZEM 2.3-litre Miller-cycle V6, this supercharger boosts induction air to around 14 psi and twin air-to-air intercoolers are fitted. The 800M engine and supercharger are good for 149kW (more depending on market and specs).

The 800M supercharger can be bought from Mazda dealers for AUD$6153, but there are some to be found in local and import wrecking yards for around half that price.

OE Superchargers – Roots-type v Lysholm-type As you would have discovered, there are two types of superchargers used by car manufacturers – Roots-type and Lysholm-type. Which is better, you ask? Well, to quote Pumpin'... Roots type blowers force air into an engine using two counter-rotating rotors. In modern Roots blowers, the rotors are helically formed to help reduce pulsing from outlet. Even so, Roots blowers are relatively inefficient, producing the most charge air heat for a given amount of boost pressure. Their attraction is their ability to produce boost pressure from idle rpm, turning any engine into an instant torque monster. Lysholm (aka twin-screw) superchargers operate similarly to a Roots unit, but their rotors and drive system is more complex. Lysholm rotors have a twisted lobe profile and each one rotates at different speed. Induction air is compressed as it travels along the length of the rotors, giving less charge-air temperature increase than a similar Roots design. These are probably the most desirable of all blower types.