F30 328I: Impressions From a Track Day

WE WERE FORCED TO TAKE OUR F30 TO THE TRACK. WHY?

Our project F30 328i was only meant to be a test vehicle for various APEX fitments. We never thought about tracking the car or even driving it very hard. The F30 seemed like it wasn’t really that kind of BMW.

When modifying it, TOYO Tires and KW Suspension came in on the project as sponsors and we set it up for street use: low, flush, and more comfort than handling. This car was not going to see the track.

Lowered for a perfect street look. With a very comfortable ride and great handling, this is how the car should have come from BMW.

So there it is, a great street car with a lot of room, that gets over 34 MPG, and can go 0-60 in under 6 seconds. With the KW V3 coilovers, TOYO T1 Sport tires, and APEX EC-7s it has the perfect stance and the attitude we were looking for. Although we weren’t very concerned with the handling, the V3s and T1 Sports are so good, the car is a total pleasure to drive.

Fast forward a couple of months when our E36 M3 track car blew a motor just before an APEX Company track day and we had no choice. We were forced to take the F30 328i or cancel our track day. That wasn’t about to happen so the F30 it was going to be.

A BRIEFER

The event was at Thunderhill Raceway in Northern California, only a couple of hours away. As we drove up in complete comfort, getting phenomenal gas mileage, and listening to Godsmack — you read that correctly 😉 — to stay awake, we didn’t have high hopes for the F30 as a serious driver. It feels so soft and docile some of the guys at APEX call it the “Mom Rocket”. We were resigned to just trying not to get in the way of the other cars in the Race Group.

BMW’s recent history with turbo motors has been less than stellar and with heat over 100-degrees, it wasn’t boosting our confidence in the car. The odd feeling of the electronically assisted steering and the car’s larger size didn’t help it either.

Since we thought the car was so handicapped we thought it deserved a leg up. No way to better help the handling than to borrow the Hoosier R6s from our E36 M3.

As the first session rolled out we instantly forgot about the car’s shortcomings and it was on. With only KW V3s and track wheels we were able to run in the race group without any issues. One lap in and holy #$%!! this car is way better than expected and we weren’t thinking about staying out of everyone’s way anymore. It was about seeing how hard we could push the car and how many cars we could pass.

As the laps ticked by our confidence in the car grew. We were even setting people up for passes and doing a little door-to-door. In addition to passing a bunch of spec Miatas, there was one track-prepped Honda S2000 that really didn’t like the “Mom Rocket” catching them. It bothered them so much they almost spun trying to keep us in their rear view mirror. We took the opportunity and easily got by as we flashed our lights and honked.

Go “Mom Rocket!”

Easy and predictable handling even in this downhill, off-camber turn.

We came away from the event with a very different feeling about the car than anticipated. This is easily going to be a better track car than the E9X 328i. It has an incredibly light feel to it and with the KWs, it was crisp, poised, and had surprisingly little understeer. The understeer is still there but was it easy to eliminate most of it with a little technique and gentleness at corner entry. More importantly, the motor was great and didn’t seem to complain in the +110 degree heat. Has BMW exorcised their “Turbo Demons”? BTW, we never even noticed the electronic steering.

THE SPECS:

• Car: 2013 Base Model F30 328i
• Suspension: KW V3s
• Alignment: Reduced toe for mileage,
• Ride height: 25.25 front and rear
• Camber: -0.7 ft. -1.9 rr.
• Wheels: APEX ARC-8, 17X9″ ET42
• Tires: Hoosier R6, 245/40/17
• This size should be 245/45/17
• Brakes: Stock (look for more on this below).
• Transmission: Automatic. No flaming. It’s a street car

THE DETAILS

THE HANDLING, KW V3S, AND OTHER SUSPENSION BITS

Thunderhill has every kind of turn — high speed, low speed, sweepers, off camber, uphill, downhill, banked — and the car felt predictable and easy in every one of them. The first thing most people think of when it comes to tracking stock BMWs is understeer. Surprisingly, it isn’t nearly as prevalent as in the F30 as in the previous E9X chassis. How did it handle? It was just like any BMW that is a little too low for track duty:

• Predictable
• It will do what you want if you ask it nicely
• Very forgiving of driving mistakes….not that we made any 😉
• The low ride height puts the suspension in a less-than-optimal part of its travel/geometry creating positive camber in front and less, overall mechanical grip.

Compressing the F30 in Turn 9 at Thunderhill

KW V3S AND THE SUSPENSION

The KW V3s are very, very good and we highly suggest them for a dual duty, street/track car. KW targets the performance street driver but we found them to be very capable for track use. The V3s have the feel and control of a much more expensive coilover and even with the the street-focused, progressive springs**, the car was very poised and predictable. We didn’t adjust them from the factory settings but the compression and rebound damping should have been dialed up. It’s what KW suggests. Stiffer damping would have helped the handling and body roll would have been reduced.

With the factory suspension setup, throttle steering in sustained corners was easy and we only had to compensate for understeer a bit. Inducing a little oversteer to rotate the car in slower, tight turns was like any BMW: a little trailing brake to induce the rotation then on the gas as much as you need to complete the turn. Even off camber turns weren’t an issue with the limited understeer. Just light on the gas after a good turn in, wait for the track to come back to you, and back on the gas. Predictable!!! It’s a BMW like any other BMW and with KWs, more composed and more nimble.

The “Mom Rocket” loved going at it with some seriously prepared track cars

MOVING FORWARD AND SUSPENSION MODIFICATIONS

No modifications are necessary but if we wanted to make the F30 handle better while keep it street-focused, swaybars and raising the ride height a bit would be our choice for the next mod. Swaybars are a perfect upgrade since they can control excessive body roll while retaining the comfortable ride of the V3s. They also would not compromise* any other part of the suspension like more extreme upgrades might.

Although we prefer stiffer springs, as opposed to larger/stiffer swaybars to control body roll, stiff springs overpower the soft, OEM bushings. The car would tend to wallow because of the OEM bushings being an overly soft component when compared to the springs. Optimally, everything in your suspension, chassis, tire setup should be matched as a system – you can include brakes in that. The softest or least capable component will exhibit its negative characteristics under hard driving conditions. In this case that would be the bushings.

Although it doesn’t sound like an upgrade, raising the ride height would help the car create more grip by allowing the suspension to operate in a more optimal range of its geometry. Let’s face it, BMW is much better at engineering suspension than any of us. So when we go way beyond their original intent there is always going to be a risk making the car worse. Excessively low BMWs handle worse and ours is a little too low. It is currently at 25 ¼” and we will bring it up to approximately 25 ¾ – 26″. By doing this we will experience less camber gain** in front, which will increase mechanical grip***

CREATING MORE TRACK-FOCUSED SUSPENSION FOR YOUR F30

If a more track-oriented car is your preference, we recommend more extreme suspension modifications than the KW V3s will allow. Coilovers with linear springs, stiffer bushings throughout, and camber plates would be the preferred starting point to create a more track focused suspension setup.

Since the new M3/4 isn’t available yet and the aftermarket hasn’t caught up to the F30 with high performance chassis and suspension components, we suggest waiting until this happens. Although not on the market yet, the KW Clubsports is our preference over modifying the V3s. The Clubsport is a track-focused coilover and built as a system with linear springs and more aggressive damping for adaptability to varied tracks, driving styles, and spring rates. They also come with integrated camber plates, which the F30 desperately needs.

Whatever your choice for high performance, track-oriented suspension, you should look at it, the chassis, and the tires as a system. They should all be matched to your requirements: car, driving style, street or track or both. For instance, our F30 had Hoosiers, which overpowered the street-focused coilovers, soft bushings, and lack of stiffer swaybars.

*An overly stiff sway can have negative effects on handling. This depends on how stiff it is, is it front or rear, and how you you drive. Consult with a suspension expert before choosing swaybars.

** Due to BMW’s MacPherson Strut front suspension, the suspension will compress while cornering and generate positive camber (wheel is angled out at the top). This is called camber gain. Positive camber on the outside wheel in a corner is bad for grip and means most of the lateral load is on the outer shoulder of the tire when it should be distributed evenly across the tire.

*** Mechanical grip is the adhesion influenced by suspension and its setup, chassis, the angle of the tire in relation to the ground, tire pressure and compound. Some refer to grip provided by tires as chemical grip since the tire compound so much to do with adhesion.

THE MOTOR

We were coming from an E92 335 with the N54 (twin turbo) and although the torque was amazing the reliability on track had something to be desired. There were so many ways it could let you down but the worst was with heat. The big question was did BMW learn anything with the N54 and was this motor going to be reliable and be able to handle heat.

“…we wouldn’t have been surprised, if the car went into limp mode.”

It’s already been said but worth mentioning again, it was 110 degrees! You can understand if we wouldn’t have been surprised if the car went into limp mode. We were so used to Limp Mode in our E92 335 and the 328’s Turbo 4 was so new we didn’t know what to expect.

Heat and an automatic transmission with a BMW turbo motor; we didn’t care. It was driven as hard as we could go and the motor performed beautifully. Even with the automatic transmission, it never complained and was strong, crisp, and with plenty of power.

There was no limp or obvious power loss in 110-degree heat with hard, to-the-red-line, driving. It makes us hopeful the N20 will be a solid and reliable platform for the track and performance driving in general. With aftermarket intercoolers, tunes, and other turbo-related modifications it looks to be a solid, powerful and torquey, track-worthy motor. Hallelujah!!!!

APEX ARC-8S AND HOOSIER R6S

Of course we’re biased. How great are 17 lbs. wheels that you can bounce over berms, dig into the dirt when you’re a little too aggressive, and then drive home on them? We didn’t drive home on ’em but you get the picture. The 17X9″ ET42 ARC-8 is a spacerless fitment that can accommodate a 255/45/17. The only limitation is what the F30 has space for.

We ran the 245/40/17 Hoosier R6s, which are a little small in diameter (they should be 245/45/17). The Hoosiers are an incredibly grippy and predictable tire. They were a little overkill for this track day and for the way the car was setup but we were out for fun so it really didn’t matter.

“We had never driven a car where, in a way, the tires had more grip than the car.”

The normal home of the ARC-8s and Hoosiers we used for the F30

There is one big issue with the Hoosiers for newer drivers. They don’t make any noise when you’re driving at the limit. Without the typical screeching and squealing, you really need to feel them from the seat of your pants to know where the limit is*.

NOTE: The F30 is sponsored by TOYO with the T1 Sport Ultra-High Performance Summer Tire. It would have been a shame to destroy them just to have a little fun. We love them too much and for 99.9% of what we use the car for they’re perfect. They’re quiet, handle perfectly, and with almost 10,000 miles on them they look almost new. Thank you TOYO!

* We don’t recommend tires that are this aggressive unless you’ve progressed through tires with less grip.

WRAPPING IT UP

It’s definitely a BMW and not the nondescript car we thought it had become: balanced, easy to drive fast, and better than you think. The N20 motor is great and although it won’t pin you in your seat, it has enough power and torque to keep it interesting and chase down all kinds of cars. Most importantly, it seems like keeping the motor cool won’t be difficult; we have to wait and see before that’s a definite.

After a day at the track with the F30 and coming away with a lot positives, we couldn’t help but conjure how good the car could be with a more track-oriented suspension and chassis setup. With the lighter curb weight and some the bolt-on turbo upgrades, this is going to be a fast car that handles incredibly well.

We can’t wait to see what people do with it.