Catching Up: The E90 and New Plans for 2025
I can’t believe it’s been almost two years since I last spoke to you (Build Journal E90: Intro/Weight Reduction). That’s unforgivable, so I wouldn’t blame you if you bullied me online. Go ahead, send me a message right now. Done? Good. Now that you’ve had your revenge let’s catch up on the E90 project and our big plans for 2025.
Quick Recap: Why the E90?
I started with this non-M, non-turbo E9x chassis because Club TR rules allowed me to run a 3.0L non-M naturally aspirated engine. The N52 engine is perfect for this—capable of 250-270 wheel horsepower with bolt-ons while staying legal in the class. My original plan was to transition into the Gridlife Touring Cup (GLTC), but plans have changed.
Gridlife recently introduced a new class: Grand Touring (GLGT). It’s based on a 9:1 power-to-weight ratio (a step up from GLTC’s 12.5:1) with minimal restrictions beyond requiring 200tw tires. That 9:1 ratio means I can finally run a turbo, like the car gods intended! So, I’m skipping Club TR and GLTC altogether and diving headfirst into GLGT. Dumb idea? Maybe. Cool? Absolutely.
We’ll also be applying aero principles from our friends at Professional Awesome. The possibilities in this new class are exciting, and I can’t wait to share more with you as we push forward.
Braking Down the Upgrades
In the spirit of practicing what I preach, I went all-in on the braking system. I wrote an article on Brakes 101, so it would’ve been hypocritical not to upgrade the E90 accordingly. Enter Paragon’s big brake kits on all four corners, complete with nickel-plated calipers that look as good as they perform.
Why nickel plating? It resists deterioration from high heat better than paint or powder coating—no more discolored calipers like those sad Brembos. The calipers are also titanium, which handles heat exceptionally well, and they’re light—just 6.5 lbs each compared to 13 lbs for the stock M calipers.
Each corner also features two-piece floating rotors. I did remove the handbrake, not because it was necessary, but because I accidentally nicked the cable while cutting the brake dust shields. My OCD wouldn’t let me leave it like that, so I just yanked the whole system out. Lazy? Maybe. Effective? Definitely.
Paragon’s brakes have proven themselves, too—Team Honda Research West used them in the 25 Hours of Thunder Hill. If they can survive that, they can handle GLGT.
Safety First (and a Little Style)
Safety is non-negotiable when it comes to competition. I installed a roll bar—temporary, of course, since full side impact protection is required for wheel-to-wheel racing. For seats, I scored a used Sabelt X-Pad for the driver’s side and repurposed my trusty Sabelt Taurus for the passenger side. Both are paired with 6-point harnesses from Sabelt.
The roll bar and seats are more than functional—they give the E90 that unmistakable race car vibe. Once you see a jungle gym through the rear window, you know it’s serious.
Finishing Touches: Wheels
Every car deserves good wheels, and the E90 is no exception. I went with Advan RG-D2s because I’m a sucker for JDM legacy brands. These 10.5-inch-wide beauties with a +24 offset fit perfectly with the widebody. I hate black wheels, and chrome lips aren’t my thing, so these hit the sweet spot.
Advan’s reputation for quality and design made them an easy choice. If you’re building a car, do yourself a favor and invest in a great set of wheels. It’s worth it.
Looking Ahead
It’s been a busy year for the E90 project, and 2025 is shaping up to be even more exciting. From turbocharging to tackling GLGT, there’s much to look forward to. Stay tuned—I’ll keep you updated every step of the way.