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F32 435i Project Car
We continue looking into the future and what we might see on the grids in the coming years. We already took an in-depth look at what it took to build a competent and reliable N54 335i track car and now we're going even further by building an N55 435i track car. This is by no-means our first exposure with the N55 - BW owner James Clay has raced several M235i and M240i Racing models in the USA and in Germany, including earning the 2022 SRO TC Driver's Championship and 2022 BMW Sport Trophy.
The M235i Racing model is a special car and continues to be a fantastic club racing platform. That is a turn-key race car and we wanted to start fresh with a basic street car to see what it would take to build a proper N55 race car from scratch. We're going to do more than scratch the surface with bolt-on upgrades. With our history of racing factory cars like the M235i, M4 GT3 and M4 GT4 our standards are pretty high. How can we transfer that factory team car experience to everyone? We'll get into the usual power upgrades and brake and suspension improvements but we're also diving into the abyss of these late-generation F-series cars to understand the network of extensive electronics, vehicle coding, and other hurdles to building a safe, reliable, and fast N55 track car.
Current Build Summary:
| Car: | 2015 F32 435i coupe |
| Drive: | RWD |
| Transmission: | ZF 8HP45 automatic |
| Engine: | N55 |
| Engine internals: | S55 oil pump upgrade, WPC-treated rod bearings |
| Engine flash tune: | stock |
| Intake: | Evolution Racewerks chargepipes |
| Cooling system: | stock, Rein aluminum coolant flange |
| Exhaust: | Evolution Racewerks racing downpipe, BimmerWorld Race Exhaust |
| Engine & Transmission mounts: | BimmerWorld semi-solid inserts |
| Front suspension: | MEYLE HD thrust arms with BimmerWorld Precision Monoball bushings |
| Rear suspension: | BimmerWorld Delrin/Aluminum subframe mounts, rear toe arm mount reinforcements |
| Differential: | Diffsonline 4-clutch limited-slip |
| Brakes: | M Sport S2NH package (370mm front, 345mm rear) |
| Wheels: | black |
| Body: | BimmerWorld 8-point roll cage |
| Aero: | stock BMW sport package, BimmerWorld Hood Vent |
| Seats: | Racetech RT4200HR |
| Harnesses: | Lifeline |
Video: Intro
We are diving straight into our newly acquired 2014 BMW F32 435i, equipped with a N55 and ZF8 automatic, and we are going to build a fun little racecar out of it. Our approach will be build it as a very capable, quick, and more affordable version of a M235iRacing, or perhaps you could look at it as a GTMore without the M-car price tag. Should prove to be a very fun and popular combination and we are about to show you the BimmerWorld way of how to build one.
Video: Post-Purchase Inspection and Disassembly Begins!
Follow along as Phil and the BimmerWorld team start dismantling the car to see how much weight it can shed and also document the process for future customers that will be going down the same path. With these modern cars and so many modules and computers on board that are sensitive to change, we take a step by step approach to removing interior items and record how it changes the car - for better or for worse.
The 435i Post-Purchase Inspection
Before tearing into it we gave the car a quick go-over to look at common N55 problem areas: oil leaks around the oil filter housing, oil pan, and valve cover, coolant leaks from the various hoses and coolers, and a scan of all of the electronic modules. There's also several infamous and urgent items that need attention: the intake chargepipe and the coolant hose to the cylinder head (aka Mickey Mouse connector). We weren't overly concerned with brakes or suspension as all of that will be replaced as it progresses to a race car. Overall, our starter car is in very good condition with expected wear and tear and there's nothing any new owner wouldn't address anyway.
Video: BimmerWorld Unplugged
In the name of science, Phil and Dave did just that and in turn got the BimmerWorld F32 435i racecar build much closer to being ready to get on track. Follow along while this modern BMW goes through a strict pre-cage diet plan while Phil makes sure he records the process to help other in the future do the exact same thing.
Simplify, then add lightness.
We've noticed two things at tracks and events around the country: no one wants to touch the electronics and “to go faster, just add power”. These are two misunderstandings that we want to correct as this project moves forward. We will attempt to remove the barriers that the modern electronics present to a clean and fully functional race car build. And as a bonus to the simplicity we will remove weight.
The power:weight conundrum is something that we often ponder. It's so easy to just add more fuel to the fire, crank up the boost, and make the car faster without taking any weight out. In fact, we add more weight with extra coolers, roll bars, etc. “Just crank up the boost!” is the common remedy for increased weight. But the already-hefty stock weight takes its toll on everything - tires, brakes, vehicle dynamics, and even engine and transmission wear. To make up for the hefty weight we're adding more stress to engine, transmission, cooling, and other systems. Not to mention spinning the turbo faster to a point where it becomes self-destructive. Add a bigger turbo? You'd better think twice because you're not addressing the elephant in the room.
This is why our F32 build series is starting with the un-sexy stripdown of the interior and electronics. Anyone can “go FBO” but that's not how it's done at our level. Imagine making the car faster and more reliable BEFORE touching the engine.
Video: F32 (and F82) Roll Cage Walk-Through
“The Devil is in the details” and in this video we go over some of the obstacles and solutions to installing a full roll cage in the F32/F82. Phil and James discuss the reasons behind a revised design, why it's not important to settle for “good enough”, and the fitment and installation of pre-built cage. Soon we will have this entire cage kit on this website, ready to ship to your door so you can create the exact same finished product and have a safe F32/F82 ready for the track.
When ‘Good Enough’ Needs To Go.
If you thought we were just going to add a rollbar and hit the track, you'd be wrong. If you thought we'd build a cage for style points, you'd also be wrong. We put a lot of thought and considerations into our cage designs [and time = money, btw] but the final result is something we'd bet our life on. Literally. This cage update video is a little overdue and that's because we threw out the first cage that was “good enough”. This second design checks all of our boxes while also over-coming some challenges in the F32 body.
What is James looking at? Watch the video here!
Video: F32 (and F82) Roll Cage Complete & Moving On
In this update the team continues with the long list of small projects and details that turn an ordinary street car into a proper race car. The cage gets painted with new non-sunroof sheetmetal over the top. Additional details like AeroCatch hood and trunk pins as well as some additional dash mounting brackets and wiring harness install. This feels like a tipping point with a lot more of the fun stuff on the near horizon.
Video: 435i Build Update - Rods, Bushes, Lubrication, & More!
A LOT has been happening on our 435i race build with the goal of a shakedown / initial drive by the end of the 2025 season. The cage is fully installed and painted and now it's onto the “usual” N55 / F3X track car goodies that we know and love. And a sneak peak at some new parts coming down the pike. This is an update video hitting lots of areas of the car with a bonus clip of the car back rolling through our new Pulaski parking lot.
F3X & F22 Front Control Arm Options
We've been up to our shoulders in ball joints, bearings, thrust arms, wishbones, tension struts, FCABS, UCAs, LCAs, and some other acronyms and here's our insight on optimum upper and lower control arm options for the RWD F22, F30, and F32.
1. Camber. These cars need more front camber, even for regular street use where the outside tire edges wear first. You have 3 options for gaining more negative camber - top camber plates, lower wishbones (complete), or lower inner wishbone bushings (for stock arms). Camber plates are the default but be prepared for the potential for more noise as these are solid mounts with no bushing for NVH. The F8X wishbone is the obvious lower control arm option because it's OEM and widely available. But the arm will also push the wheel forward in the wheel well so these should only be used with different upper control arms (NOT F8X arms). SPL tubular race arms are available for the committed track cars. In-between is a Powerflex urethane bushing with an eccentric mounting bolt. This fits in the stock F3X wishbone and does not require a different upper arm. The camber gain from wishbones is less than upper camber plates but they are better for daily-driver, street, or mixed street-autox/track cars.
2. Stability & Behavior at The Limit. What we found when racing the F30 (2018 IMSA champions) was that the front upper control arm (aka thrust arm) moved the wheel/tire so much under braking that it triggered the ABS, even when not at the threshold. The stock hydro-rubber F3X bushing and the all-rubber F8X bushings allow too much deflection. We tried Delrin and different urethanes but the cars never felt planted until we went to the spherical or monoball bearings. It doesn't have to be a fully solid race part either. Our current monoball upgrade uses an OEM sealed bearing with a Teflon inner liner. It's actually an OEM part for another street car - meaning it's quiet, high-quality, affordable, and replaceable. It's one of the first upgrades we look at for any RWD F22, F30, F32, F87, F80, and F82.
Here are some kits we put together to cover everyone from daily-drivers to full race.
A Stage 4 is in the works but not ready for listing yet.
Video: 435i Shakedown to Dialing-In!
The 435i hits the track for the first time in anger. The final “spec” of the car is still TBD but most of the big pieces are here - suspension, brakes, wheels & tires, safety, engine & transmission prep, etc. This weekend at Mid-Ohio was planned as a shakedown to work out some electronics or other potential problem areas before giving it the full send. But the car was reliable and fast all weekend without any headaches which allowed James and Phil took dig into multiple facets of car setup - dampers, sway bars, brake balance, tire condition, and more.
Parts: 435i Race Wheel Sets
Tires are important. So we endeavored to fit the meatiest race rubber on this dedicated-track / full-race platform. Conventional fitment advice pegs the easy or ideal F3X square set at 18x9.0 or 18x9.5 and plan to use spacers on the front depending on your coilover arrangement. We have those covered pretty well elsewhere in our catalog. But can we get to 10.0 inch? It's just a better width for 275 race rubber than the 9.5. It turns out - yes we can!
Our TA5R in 18x9.0 size with ET31 offset on the front and rear. This is a "safe" and easy square set, especially if you're running 225 or 245 tires or with OEM springs. Front wheel spacers are required with any suspension. Front negative camber via camber plates required with wide 245 or 255 tires.
Our TA16 in 18x10.0 size (offset TBD) on the front and rear. This is an extreme fitment and requires spacers and camber. More details to be released when we have some final details ironed out. But we ran this setup at Mid-Ohio and are very happy with it.
Bonus Content: Grassroots Motorsports 435i Build
Coincidentally, our friends at Grassroots Motorsports have also embarked on a F3X N55 track car build. Their build is a true dual-purpose car, focusing on the N55's needs and upgrades to compete in SCCA Time Trials without stripping the car and affecting daily usability. Their build is already well along in 2024 so check out their growing library of F3X articles and videos -
Click here to follow along: grassrootsmotorsports.com/project-cars/2015-435i/
Bonus Content II: Another Track-Prepped 435i
Word is getting around and we put together the track fundamentals for this customer's F32 435i. Join Phil as he walks through the installation of a range of performance and safety upgrades: MCS 1-Way Non-Remote dampers, a JP Marketing bolt-in roll bar, Racetech 4200HR seats, Lifeline harnesses, and our F3X / F8X fuel starvation kit.
TO BE CONTINUED....
There's more to come! Bookmark this page, or better yet, subscribe to our Email Newsletter now and we'll send you periodic updates on our BimmerWorld Project Car transformations.
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