Updated with new photos and wheel fitment info!
As we said in our Best Trackday Mods for the E46 BMW M3 guide a while back, if you’ve ever taken your M3 onto the track and driven it in anger, you’ve probably discovered its achilles heel. Its cooling system.
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
The best mod is the one that allows you to COMPLETE a track day on a average-temperature summer day. I can tell you from firsthand experience, even if you have a brand new car and a bigass intercooler, on a hot day when you push the car, THAT is where a beefed up cooling system really pays off- and that’s why we had to call it quits in our Stage III Fiesta ST recently after one session in the heat. So yeah, heat’s a hell of a problem. I’m sure you probably know that a “blown head gasket” is a big expensive fix and many just sell the car rather than fix it.
Unfortunately while the cooling system is fine for the conditions of extended idling and just cruising around, it really can’t cope with the heat generated by working that sweet sweet inline six for all its worth around say, Streets of Willow or Laguna Seca. Nope. This simple mod will make a huge difference in performance at your next trackday – and it’s an electric cooling fan & shroud and a radiator from Mishimoto Engineering.
SO, if you live somewhere that’s on the hotter side like SoCal or a desert area, cooling mods are going to be a big boon to your engine’s longevity as well. As E46 Trackday enthusiasts were finding, the OEM radiator core doesn’t provide adequate heat transfer, making it very possible to overheat the E46 M3 during a hot lap – which is what brought this sexy Imola Red E46 BMW M3 into the shop for the Mishimoto treatment.
Here’s a look at the car as we got started.
Here’s a shot of the engine bay with the stock fan clutch and shroud removed.
Side by side, the Mishimoto Fan Shroud for E46 BMW M3 is much more compact than the fan clutch, and because we’re removing a thing that was attached to the crankshaft by deleting the fan clutch, your M3 will also make 2-5 more horsepower to the wheels as a nice bonus. It’s not earth shattering, but free horsepower is free horsepower.
Mishimoto’s fan shroud was completely redesigned after track testing established that the radiator alone wasn’t enough to resolve the E46 M3’s cooling issues – they went back to the drawing board and developed a solution that solved the problems the factory shroud created.
Next we had the radiator out of the car – making for an excellent side by side comparison between the stock radiator and the Mishimoto Aluminum Radiator for BMW E46 M3, complete with Mishimoto’s own Liquid Chill coolant.
The Mishimoto Radiator is noticeably thicker than the stock design and the endtanks are aluminum rather than failure/leak prone plastic end tanks like factory. To this day, it baffles me why manufacturers continue to use plastic endtanks when the failure rate is so high. Aluminum End Tanks for the win.
As silly as it might sound to say that a different coolant can help the car run much colder and transfer heat more efficiently, it’s definitely true. For many years there have been additives and such on the market that bolster heat transfer efficiency by doing things like reducing the surface tension of the coolant itself, allowing it to get into more crevasses and such it might not otherwise penetrate for more effective cooling. Mishimoto’s done something similar and taken it to the next level with coolant that’s formulated to be extremely efficient.
Now it was time to mount the radiator itself. Tech Juan carefully guides the radiator into its final position. 
Though significantly fatter than the stock radiator (that’s a good thing), it does fit very neatly in place of the stock radiator.
Here’s how it looks roughly mounted into position – none of the hardware is installed here because once we put it back together, the radiator won’t be this clearly visible.
Here’s a shot of the Mishimoto Radiator and Fan Shroud mounted into position before we start reattaching cooling hoses, intake etc, so you can still see how it all fit.
Under the car there were quite a few other modifications to this M3 – let’s walk through all of it. The most obvious of the car’s mods is the Rogue Engineering El Diablo Exhaust for E46 M3, which gives the car a lot more bark and a little more bite.
A careful eye will note that the brakes have been upgraded with a set of StopTech Stainless Steel Brake Lines for BMW E46 M3 as well, along with a bright blue set of H&R Sway Bars for BMW E46 M3 to make its handling behavior even tighter, and those telltale yellow springs also tell us the car’s on coilovers.
Here’s a look at the H&R Front Sway Bar.
Giving the car its great stance and the handling it needs to carve corners on any track is a set of KW Coilovers for BMW E46 M3 – and a better look at the StopTech Stainless Steel Brake Lines for BMW E46 M3.
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
Rocking a staggered set of gorgeous 19in Forgestar F14 Super Deep Concave wheels wrapped in NITTO INVO Tires, this E46 has the grip it needs to hold in the corners- combined with its suite of other modifications, this car has to be a joy to drive on the track or on your favorite stretch of Mulholland.
From behind, the quad stainless tips of the Rogue Engineering El Diablo Exhaust for E46 M3 really fill out the E46’s rear bumper nicely, and with its lowered stance, it looks wonderfully aggressive.
Up front, the car sports the complete Grille Black Out Package for BMW E46 M3, with matte black kidney grilles and matte black fender grilles, it’s a perfect compliment to the red/black color theme the car has going.
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
As we set up next to the car to get its profile, we couldn’t help but notice the red accents peeking out from behind the Forgestar Wheels.
The E46 M3 Brakes have been upgraded with a E46 M3 StopTech Big Brake Kit – the massive front calipers could stop a damn house.
Not one for leaving things half done, the rear brakes have also been upgraded with a StopTech Big Brake Kit, meaning you have balanced extremely high performance braking.
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
With the latest round of mods this E46 M3 is ready to conquer the nearest road course or carve Turnbull Canyon, and the car proves once again that Imola Red is the best color for the E46 M3 (in this writer’s opinion) as you never forget the M3s in High Impact colors like Imola.
Forgestar F14 19×8.5 & 19×10 Semi-Gloss Black with 245/35-19 / 275/30-19 NittoTires on KW V3 Coilovers
We hope to see this beauty again in the future and we hope you enjoyed the read and the photos.
Interested in upgrading your brakes, or have questions? Call us at 714-582-3330 to speak to our friendly, enthusiastic and knowledgeable Mod Experts for advice on what setup is right for you, your budget and your goals or to make an appointment to have your brakes serviced. See you next time!
Story & Photos Nicholas Gregson