Had your eye on the V8 M3, but with the economy in its state of duress, you're not sure what the future may bring? Here's a low cost alternative worth looking into. With depreciation and the state of our auto sales, it is now possible to locate and purchase a previously-owned E46 M3 in excellent condition for under $20K. If you take that lower cost E46 M3 and add VF Engineering's Streetsport bolt-on supercharger kit you can boost the 3.2-liter engine horsepower output to the same levels as the new E92 M3 V8. This will allow you to get the performance you desire at half the price.
2004 BMW M3
Engine: 3.2-liter I6
Transmission: Six-speed manual
Testing octane: 91
The baseline and all subsequent testing were performed utilizing the same tank of 91-octane fuel. All horsepower and torque numbers are SAE corrected and quoted at the wheels. The vehicle did have a catalytic converter efficiency below threshold fault code stored in the ECU, with no check engine light. We were informed this was a common issue on the E46 M3 and it would not affect the results
HKS coilovers, HRE wheels, Brembo brakes, Vorsteiner aerodynamics
Peak Power: 275 hp @ 7300 rpm
Peak Torque: 233 lb-ft @ 5100 rpm
Ambient temp: 72 F
Test gear: Fourth
*All horsepower and torque figures quoted are measured at the wheels
In late 2006, after three years of development, VF Engineering released its 480-hp Stage 1 blower kit for the E46 M3. Problem was the $10,000 price tag put it just out of reach of some enthusiasts, so to cut cost and increase its market share VFE chose to design a low-boost version that did not require the use of an aftercooler. It has been designed so consumers can upgrade their "Streetsport" kit to Stage 1 or 2 by adding an aftercooler system and swapping out a few parts.
The supercharger mounting bracket is CNC machined from aircraft-grade billet 6061-T6 aluminum. The CNC process allows precise fitment to the front of the S54 motor and does not require the relocation of any factory components. The bracket, combined with a chrome-moly support brace, creates a triangulated support system for the Vortech V3 Si-trim centrifugal supercharger. This mounting system retains the stock active belt tensioner and features additional OEM BMW idler pullies that help position the belt allowing for the maximum amount of the belt to wrap around the supercharger pulley. The Vortech V3 still requires regular oil changes, so it has been fitted with an oil drain line that allows the synthetic fluid to be evacuated without having to remove the supercharger from the vehicle.
The Superstreet system includes a cast aluminum replacement intake plenum to replace the restrictive factory unit. The final one-piece manifold's internal flow dynamic was optimized using multiple 3D prototypes and extensive test data gathered by VFE's in-house Superflow bench. The manifold was designed to accommodate a slide-in air/water heat exchanger cartridge, allowing it to be easily upgraded to an aftercooler system when it comes time to upgrade.
The cast aluminum supercharger inlet pipe features smooth internal surfaces and is shaped to keep air turbulence to a minimum. This allows VFE to retain the factory mass air flow (MAF) sensor, a critical part of making sure the vehicle ECU accurately reads the amount of air coming into the motor. The intake design also prevents off-throttle and deceleration turbulence.
VFE Supercharger system
Because of the amount to time it took for installation, the after test was performed the next day.
Peak power: 350 hp @ 8000 rpm
Peak torque: 261 lb-ft @ 6000 rpm
Max power gain: 83 hp @ 7900 rpm
Max torque gain: 36 lb-ft @ 6000 rpm
Parts: Vortech V3 Si-trim supercharger, VFE 6061-T6 mounting bracket with OEM idler pullies, VF cast intake aluminum plenum, Greddy Type R bypass valve, VFE cast aluminum supercharger intake pipe, MAF Housing, serpentine belt, custom GIAC software, VFE airbox with K&N air filter, hardware and hoses
Installation time: 6-8 hours
Tools needed: 1/4" ratchet, 10mm 1/4" drive deep socket, 8mm 1/4" drive socket, 3/8" ratchet, 3/8" 13, 16mm deep socket, 5/8" spark plug socket, 5, 6, 8mm hex socket, T30 torx,T25 security torx, panel pulley, fan wrench 6, 7mm nut drivers or flathead screwdriver, wire cutters, soldering iron, 13mm crowfoot wrench (for SMG tanks)
* Can be used as a standalone upgrade and no additional upgrade is required as long as the engine is in good working condition
* Self-lubricating Vortech blower eliminates any need to tap into the engine's lubrication system.
* Intake plenum outlets feature beveled edges to create a velocity effect wherein air enters each individual throttle body.
* In addition to dumping boost when you let off under full throttle, the large bore bypass valve system ensures that all the boost is removed during non-boosted driving situations ensuring factory like driveability
* GIAC software eliminates the need for piggyback electronics or removing the MAF sensor by precisely calibrating the ECU to accept the larger fuel injectors, MAF housing and boost generated by the supercharger
* Bosch EV6 injectors utilize the same spray angles and cone size as the factory units, ensuring clean colds starts and optimal combustion.
* Cast aluminum components features smooth internal surfaces to maximize airflow.
* 6061-T6 mounting bracket system uses factory BMW idlers.
* GIAC software has been calibrated in such a way that running gasoline with higher octane ratings will automatically add power without requiring additional changes
* Cutting and soldering of certain wires is required.
Having owned an E46 M3, I thought it appropriate I do the evaluation. In hindsight, selling it was a bad idea. I am once again smacking my head into hard objects, wondering why the hell I got rid of it.
That the M3 is quick is well known. Its engine is about horsepower rather than torque, typically European in style. The VFE supercharger makes it feel like it's got both now. Launches through first and second gears had the big 275mm rear tires spinning in place. I don't remember having that problem with my M3, even with the power button activated (more aggressive throttle ramping). Deep into third, I was pulling close to 7800 rpm and the car was still pulling hard. By fourth gear I was well into "go to jail" speeds.
The VFE supercharger feels much different than most aftermarket turbo kits I've driven. There's no sudden surge of torque and no fall-off at high rpm. Basically it feels just like the stock power curve; there's just more of it. The engine still loves to rev but responds with greater urgency, like it's in a huge hurry to ping the rev limiter.
While VFE has done a terrific job packaging its system, I'd be remiss in mentioning the GIAC software tuning. You can have the most perfectly engineered and expensive components in the world but without proper ECU management, it's all junk.
Truth be told, Nik Saran of VFE is a proper bastard. He's assembled a brilliant piece of kit here. For the money, the VFE system represents an exceptional value--you'll be hard-pressed to find better. But I fear all it's going to do is make folks want even more. The healthy 27 percent output boost just won't be enough. We've been sniffing around the VFE website, already thinking about another power fix.--Les Bidrawn