With our E46 M3 giveaway build happening, we’re pretty much thinking all about the S54-powered 3-series and how awesome they are. These cars are some of the best values for the performance out of the box, and insanely fun to drive, especially if you modify them. Speaking of modifications, since this short series will be focused on what you can do to make the biggest difference with the least amount of money, we’re going to run through some of our recommendations to make your E46 M3 on a budget. These are the best modifications for upgrading performance and visual elements on a budget for the BMW E46 M3.

The E46 M3 is one of the most celebrated performance platforms ever built. Some would call it the last ‘true’ M car since it sports the holy trinity of combinations in the straight-six, naturally-aspirated, individual throttle bodied S54. With 50-50 weight distribution, a limited-slip differential, and a fairly quick ratio in the steering rack, the E46 M3 has incredible handling characteristics to match that 333hp engine. That said, the newest of these cars are still almost fifteen and the oldest closing in on 20, so there is plenty to be done in terms of maintenance and upgrades for improving your driving experience. 

Maintenance:

The E46 has a few maintenance concerns that will rob you of performance or the car’s ability to even drive. They should be tackled before you start to improve other areas, especially since you have the opportunity to make some improvements over the factory replacements. 

Oil change with LIQUI MOLY and HENGST filter, regardless of what the previous owner says. Always start with fresh oil and a filter. Check out our oil change kits featuring the best oil and filters for your M3 here.

Brake service including pads, rotors, fluid, and lines. For pads, we recommend HAWK, who make some high-quality products intended for more aggressive driving. Our rotors and lines from right here at ECS Tuning are specifically designed to improve your stopping distance and pedal feel respectively without breaking the bank. For fluid, we have to suggest MOTUL. A full fluid flush, new braided steel lines, and upgraded rotors and pads will have your M3 stopping better than when new, which will translate to more time on the throttle. Our brake service kits have everything you need right in the box and are a great place to start improving the stopping power of your M3.

Tires should be purchased based on how you intend to drive. These contribute not only to your grip but power delivery, stopping distance, and handling since are the only things connected to the road. While we don’t offer tires at this time, a set of performance summer tires and winter tires, if you live above the snow belt, will be tremendous additions to your performance resume.

Bushings are something even the youngest of E4 M3s will likely need to have replaced. Polyurethane, Delrin, and even solid upgrades are excellent to help reduce deflection and increase your ability to transmit power to the ground, but unless you plan on driving the car hard, you should probably consider OEM replacements. They will still bring the car back up to snuff and are generally inexpensive. If you do, however, think you can live with much stiffer bushings on the daily basis that come with significant handling benefits, you will notice a huge difference with upgrades like the Turner Motorsport Monoball Front Control Arm Bushings and Powerflex subframe, differential, and sway bar bushings. 

Rod bearings are a serious concern on the 2001-2003.5 E46 M3s. While there was a recall performed on most, you should always call BMW with the VIN and confirm that the service has been done. Even so, if they are higher mileage, you should probably go ahead and knock out the service. This will also include a new pan gasket and should be done before you change the oil and filter for the most economical service since you will have to re-fill the engine after the service. Our rod bearing service kits have everything you need to service the rod bearings in your M3 making the kit your best option to tackle that concern with peace of mind.

Clutches are not fun to replace, but if your car is above 100,000 miles, it probably needs one even if it has been babied its whole life. An OEM replacement isn’t expensive if you perform the work yourself, but an upgrade is always a good idea if you plan on driving the car harder than average commuting. Simply upgrade the clutch disk itself will support more horsepower and offer the engagement you need to handle aggressive driving situations.

Lastly, in the maintenance department, a common issue with E46s, especially hard-driven M3s, are the shock tower, strut tower, and subframe mounting locations cracking or mushrooming as the result of aggressive use. To prevent this from happening, reinforcement plates are needed to distribute stress from hard driving more evenly. This helps keep your M3 from suffering the dreaded subframe cracking or mushroomed strut tower mounts and also adds a bit of rigidity for improved weight transfer.

With maintenance concerns tackled with either OEM or aftermarket upgrades, you can start improving the car with some tasteful changes to both the visual appeal and the overall character of the car to make your E46 M3 unique. 

Suspension Upgrades

We left out shocks and struts in the maintenance section because we’re going to consider a few different options. If you’re on the tightest budget, the least expensive options for replacement are Bilstein B4 shocks and struts that come in at roughly half the price as performance alternatives, but if you want to change your look and handling, you should consider spending the money on a good set of coilovers. For roughly the same price as upgraded shocks and struts, you can have a set of BC Coilovers that will lower your car and drastically improve handling without much sacrifice to ride quality. Other more affordable options exist, like Godspeed, which will give you all the benefits of ride control and ride height adjustments, but for real performance on the track, you might consider more purpose-built suspension. On a budget, however, Godspeed and BC Racing are both solid choices. 

Power and Performance Upgrades

The stock ECU leaves a bit to be desired. Tuning the software with an off the shelf map from Shark Injector will give you a bump in horsepower, torque, and will raise the rev limiter.

Intakes from the factory are fairly well-engineered to be the least restrictive and quietest they can be. For a little more performance and noise, AFE offers an excellent upgrade that gives you a slight bump in power and great looks under the hood for relatively little cost.

Everyone loves a throaty exhaust note. The S54 is notoriously raspy, so fitting it with a well-toned exhaust system can be a fun addition that does add some marginal performance gains. They aren’t exactly cheap, but a good exhaust doesn’t have to be the most expensive out there. We have several options that will help you find the right sound that fits your budget.

Another bang for your buck mod is the Turner Motorsport Power Pulley Pack. These underdrive pulleys reduce the parasitic loss of horsepower to accessories being driven by the engine by decreasing the amount of work needed to run them with different pulley sizes. Since they are relatively inexpensive but offer a noticeable performance increase, these are one of the better choices early on for a safe and effective performance upgrade bolt-on. 

A huge improvement to your driving experience, but not necessarily a performance modification, a short shift kit will make each shift feel more engaging and adds an overall sportier feel to each drive. The Turner Motorsport Ultimate Short Shift Kit is precisely what we would recommend.

Of course, there are seriously infinite numbers of performance bolt-ons, visual improvements, and avenues to explore to make your M3 perfect for you. With this comprehensive list, though, you should have a fairly sorted E46 M3 that is slightly more powerful, refreshed mechanically and handles fantastically.