Over the past few years the E36 BMW M3 has become more affordable for enthusiasts, and commonly they're purchased with the sole purpose of modification. While some purists may think that's a shame, the real tear-jerker is that the current Honda Accord V6 makes more power!
Modifying the S50 3.0 liter OBD1 motor from the '95 M3, or the S52 3.2 liter OBD2 motor from the '96-99 M3 is easily done. The only question is what route the owner should take. Considering a stock S50 or S52 lays down about 210hp at the wheels (SAE corrected) on a chassis dyno, some normally-aspirated upgrades might keep you happy up to 245whp. If you want to keep up with the latest muscle cars, maybe a supercharger is for you. Or perhaps you need the wheel-spinning mid-range of a turbo.
Each stage has its own advantages but it's often a case of how much you can afford. So we talked to a few companies who offer off-the-shelf upgrades and have broken down your options by price.
Remember, we're assuming a 210whp baseline and gains will vary from car to car. Additionally, installation prices aren't included.
The best bang for your initial few bucks is a good cold-air intake (CAI), which will usually bump power over 215whp, and mid-range torque by 6-8 lb/ft. And since the kits replace the factory airbox with a conical filter, you'll enjoy a roar over 4000rpm. It's also worth mentioning that almost anybody can install one of these.
The cheapest on the market is the MSDS system. It includes a g-Force filter with internal velocity cone and fitting bracket. It's only $165 but doesn't include a heatshield to divert engine heat.
The East Coast Induction System (ECIS) retails for $239 and is CARB legal. It features a shield, mandrel-bent tube, 8" cone filter, silicone hose and hardware.
Active Autowerke (AA) has a kit for $349 with an intake runner, black powdercoated grille and K&N air filter.
For $370, Turner Motorsport's (TMS) intake system uses a carbon intake tube, heatshield and ITG filter.
Dinan's intake costs $449 but comes with a carbon intake that draws air from under the engine bay. The kit also includes a fuel pressure regulator for better top end performance. It's CARB legal and has a two-year warranty.
In addition to intake systems, there are other options like power pulleys. These replace the power steering, A/C and water pump pulleys. They can be had from TMS for about $250, and should gain an additional 5-8whp. You could also throw in a fan delete nut and traction control delete elbow from Eurosport, which will provide 2-3whp for under $100.
Apart from MSDS, the aforementioned companies provide software for both OBD1 and OBD2 cars. Coupled to their intakes, these should get you around 220whp while keeping the cost under $1000. However, you'll notice an even bigger increase in mid-range torque-usually 5-8 lb/ft.
Note: if your car's a '95 M3, we recommend the $999 TMS/Conforti Euro Intake system for the most power in this category. The use of the Euro-spec HFM (airflow meter) should give you around 220whp with a stock exhaust, providing 12-15whp around 5500rpm.
Once a car's equipped with software, intake and pulleys, the next step is to upgrade the cat-back exhaust. Many companies offer one, including AA, Dinan, TMS (Borla and Supersprint) and UUC Motorwerks, with prices ranging from $600-950. These systems should net you 4-8 lb/ft of torque in the mid-range but usually won't give much more than 2-4whp up top. However, you'll save 20-30 lb in weight and get a more aggressive exhaust note.
If you're starting with a stock car, a good package in this price range uses a larger HFM. Turner's $1250 stage 2 setup for the '95 M3 can give up to 230whp with its Euro 3.5" AMS and intake, 24 lb/hr injectors and software.
If the car's an '96-99 OBD2, Turner's stage 2 features a 3.5" intake, HFM, 24 lb/hr injectors and software for $1655. At around 225whp, the peak horsepower won't be as high as the OBD1, but mid-range torque will be 12-15 lb/ft thanks to the S52 intake runners and larger displacement.
Dinan's $1999 S Package consists of its stage 2 software, CAI and cat-back exhaust. They don't quote wheel horsepower but we estimate about 227whp.
In this range, TMS offers a stage 3 package. For OBD1 cars its $2340 kit, including Schrick cams, 24 lb/hr injectors, Conforti Euro intake and software, will bump power to 240whp, with over 220 lb/ft. The OBD2 stage 3 kit again claims less top end power with around 230whp, but you can expect 240 lb/ft at 4000rpm for this $2755 setup.
If you're willing to sacrifice low- and mid-range torque for more straight-line acceleration in your OBD2 M3, Eurosport has an alternative. Its stage 2.5 kit uses an S50 manifold conversion from the OBD1 cars. The kit sells for $2297 and includes a Euro HFM kit, S50 intake manifold conversion, 24 lb/hr injectors, traction control delete elbow, fan temp switch and fan delete nut. With the manifold conversion you lose significant torque up to 4200rpm, but after that, power peaks at around the 235whp. Peak torque remains about the same as stock but happens much later. Stay tuned as we test this kit on our own OBD2 M3.
In this category Dinan has a $3394 kit. It includes everything in the S package, plus a larger throttle body, stage 5 software and a high-flow airflow meter. This should give a CARB-legal 237whp.
Eurosport's OBD2 stage 3 kit can be had for $3396. It's everything in the stage 2.5 kit plus Schrick cams for up to 245whp. Power is slightly down from stock up to 4000rpm, with a 10 lb/ft loss around 3900rpm, but the trade off is a dramatic power increase ranging from 35-40whp from 5700rpm to redline.
Turner Motorsport focuses on power through the rev range with its stage 4 upgrade for OBD2. For $3655 you get its stage 3 cam kit plus "shorty" headers, which bolt up to the stock cats. Even with the S52 intake manifold, power is around 235whp from 5500-6300rpm, and peak torque is an impressive 245 lb/ft at 4000rpm.
Once you get into this territory, the real bang for your buck comes from forced induction. Active Autowerke comes into play here with its C38 Rotrex supercharger upgrade for $3995. With everything included to run your car, it's good for 300whp at 7psi. Now we're talking about serious fun.
In this price range we have VF-Engineering's stage 1 supercharger kit for OBD1, which boasts 295whp at 6psi with the stock exhaust for $4500. It uses a polished Vortech V2 SQ blower, which comes with a three-year, unlimited mileage warranty and is tuned with GIAC software. VF states its kits will work on S50 manifold-equipped OBD2 cars and the systems are undergoing CARB certification for street-legal use in all 50 states.
For $5700, AA sells its C30 supercharger kit, which includes an intercooler, oil cooler and two-year warranty. Power is expected to be 300whp at 8psi, but unlike the C38 kit, you can expect intake air temps to be consistently lower.
If you desire instant torque, a twin-screw supercharger is for you. Unlike the linear build of boost from a centrifugal 'charger, which peaks boost and power at redline, twin-screw blowers keep torque flat to redline; it's similar to the instant torque of a V8 and is the preferred method of Jaguar, Mercedes and Mini. AA's stage 1, non-intercooled, twin-screw system sells for $5900 and makes 300whp at 6.5psi.
By the time you read this, VF should have its stage 2 supercharger available for about $6500. It includes everything in the stage 1 kit, adding a chargecooler built into the intake manifold. The kit uses factory mounting locations so no drilling is required. Boost is bumped to 9-10psi and they expect around 340whp.
If neck-snapping torque is what you desire, then Technique Tuning (TT) offers its stage 1 turbo system for $6800, including a front-mount intercooler (FMIC) and external wastegate. The turbo uses a 60:1 compressor, tuned for 330whp at 8psi with a stock exhaust, and similar peak torque numbers. At this torque level, the stock M3 clutch can be used but won't last long.
Squeezing into this category is the Dinan stage 1 supercharger kit.It boasts 300whp at 6psi with a Vortech supercharger, has a two-year warranty and is offered to M3 automatics as well.
The Active stage 2 twin-screw supercharger is offered with 9psi boost and includes a front-mount chargecooler plus oil cooler. It's been tuned in-house to make 340whp for $7900.
Technique offers a stage 2 turbo kit using the same 60-1 turbo as its stage 1 but running 13psi. For $7700 it delivers 400whp, but off-boost performance will suffer because it requires a compression-lowering head gasket, and its 400 lb/ft will definitely necessitate a sturdier clutch. With the head gasket and clutch replacement you're looking at an extra day's work. TT sells UUC's Ultra Cerametallic clutch for $688 that should take the power, bringing the total to $8388. If you have your own boost controller, the stage 1 kit is tuned for 6-8psi, and stage 2 is tuned for 8-13psi adjustments.
Eurosport originated the twin-screw for the M3 and offers its system for $8495. With a V8-like 300 lb/ft of torque that's almost flat to redline, the 1.7-liter Opcon Autorotor twin-screw sees about 350whp at 8psi. The kit also features a Laminova chargecooler integrated into a CAD manifold, 255 L/hr fuel pump with 36 lb/hr injectors, high capacity coolant reservoir and electric water pump, FMIC and Conforti-tuned software.
Active, the pioneer of successful M3 turbo kits, sells its stage 1 turbo for $8700. The intercooled system uses a Mitsubishi TD06H-20G turbo with an external wastegate making 300whp and 300 lb/ft. A good factory clutch should hold the power, but OBD1 cars will see it at 7psi, and OBD2 at 8.5psi - slightly higher because of the more restrictive S52 intake manifold. In addition, AA reports its customers see up to 330whp at 10psi on stock compression with its optional $470 GReddy boost controller.
We couldn't find any packages in this price range, so let us recommend a few things you could add to the previously mentioned conversions to increase power and extend durability.
First off, we love AA's water/alcohol injection kit, which will suppress detonation during vigorous use - especially on track - by keeping intake temps near ambient for maximum power. We'd recommend this with any of the forced-induction kits, but especially non-intercooled stage 1 systems.
A cat-back exhaust system added to forced induction systems and exhaust headers (for superchargers only), will definitely make more of a difference in the 300-400whp range.
The factory M3 radiator tends to fail at 60-80k miles when the plastic end tanks crack. Ranging from $500-750, we'd recommend an aluminum rad from AA, or perhaps Fluidyne or PWR units from BimmerWorld. These will keep water and oil temps down during hot summer days. They even help for track use thanks to the extra capacity.
While you're at it, you might as well add a $199 Stewart Components high-flow water pump, a new thermostat and thermostat housing (on a '95 M3), plus Samco silicone radiator hoses, all available through BimmerWorld.
To further regulate oil temps on non-oil cooler packages, Victory Product Design sells an oil cooler that's easy to install for $595. This would come in handy for guys thinking about track days.
Active's stage 2 turbo system is in this category because it requires a $995 clutch upgrade, bringing the total to $11895. The price also reflects the inclusion of a thicker head gasket and ARP head studs. With a GReddy boost controller and external wastegate included, you can adjust the boost on the GT35R from 300-420whp (15psi). At full boost, expect over 400 lb/ft from this turbo system
If you're a power junky with wads of cash, there are some crazy, custom setups we'll touch on. First off, Boost Logic sells a turbo kit, the smallest of which uses a T61 turbo on a tubular stainless steel manifold for over 450whp on pump gas. The kit necessitates not only its 3" turbo-back exhaust (canceling out the stock cats) but its clutch system and Electromotive TEC3R stand-alone engine management system they can tune in-house. The parts in the T61 package start at $12050, but the company also offers higher horsepower packages if you can stomach it.
ICS Performance made its mark with a couple of turboed BMWs laying down over 1000whp. The company doesn't sell a turbo kit, but tunes a variety of boosted M3s ranging from 400-1000whp. Bear in mind, once you're over 550whp, the engine internals are reaching their limits. For a rebuilt engine you're looking at a minimum of $3000 in forged parts alone.
Lastly, something to think about is converting to a stand-alone engine management system to get the most from your upgrades, be it normally aspirated or forced induction. With access to everything from fuel injection, spark advance, knock control, idle, cold-weather starts and practically anything your stock computer can do, your tuner has total control for a custom tune.
Sias Tuning sells the Electromotive TEC3R system for $2750, and evosport uses the AEM EMS for $3195. Both units are plug 'n play, which means they'll plug into your wiring harness for hassle-free installation.
I'm sorry, did we lose you at the $300 intake kits?
East Coast Induction Systems
Victory Product Design