In order to accurately gauge the horsepower and torque gains from the GIAC software flash, it is recommended that you put the vehicle through at least two 15-mile driving cycles. This allows the vehicles' engine control unit to fully adapt to the new set of parameters. We ended up putting 120 miles on the vehicle before we ran this test.
What can I say about the E46 M3 that hasn't been said before? The car has it all-looks, solid suspension, a powerful inline six, rear-wheel drive. It's an overall well-oiled machine and even with over 80k miles on this particular M3, it performed as if it was factory fresh.
After the intake was installed, I took the Bimmer out for a quick spin. But something was amiss-as a certain audible notification traditionally associated with intakes was missing. The usual induction growl was nowhere to be found as I ran through the gears and took the M3 to its redline. Besides the increase in part throttle and full throttle response, you would never know that an intake had been installed-a result of the enclosed design of VFE's cold-air intake.
Graph 3: Compare All
Over the years, after almost exclusively owning turbocharged vehicles, I have learned not to get overly excited about a chip for a naturally aspirated engine running 91 octane. They are typically only useful in smoothing out the power curve and increasing throttle response and rarely offer large horsepower and torque gains. The GIAC software did just that: increasing throttle response and smoothing out the powerband. The real surprise was how the software combined with the intake allowed the motor to pull so strongly. The high revving S54 took well to the new software and pulled all the way to 8000 rpm instead of dropping off around 7200 rpm. Together, the GIAC and VFE intake are quick and simple ways to enhance the E46 M3's performance without completely overhauling or changing an engine that is near perfection from the factory.
When it comes time to address the horsepower plan for your BMW E46 M3 you have to make a decision go for big power (forced induction) or just enhance what's already there, as we did here. Because those two paths go in completely different directions and require a complete different set of upgrades.
VFE Cold-air intake $475
GIAC Software $475
MSRP total. $950