[ronin951]

Great article. Looks like bimmerworld is doing some good R&D. Hopefully that will eventually pass down. Of note...


“In E36s, the M cars had subframe reinforcements and non-M cars didn’t,” says team owner/driver James Clay. “We found that you really needed to weld those in for cars that were going on the track. In the E46s, BMW did a better job, but even the E46 M3s were tearing out subframes. In the E90s, BMW made them stiffer still, but on the race cars we pick up the cage points all the way down into the subframe to give it extra support. In the F30, it’s almost like they took that element of a race car and built it with support down to the rear subframe.”

...

In 2013, the CTSCC required AST dampers, which BimmerWorld fitted to its E90 and F30 328i racers along with Hyperco springs. For 2014, teams will have freedom of choice where dampers are concerned, so BimmerWorld switched to Motion Control units (still with Hyperco springs). It’s a return to the familiar: Motion Control is run by engineers who were at Moton when BimmerWorld used that company’s shocks in Speed World Challenge (2002 to 2009).
Along with the appropriate shocks and springs, BimmerWorld also installed larger roll bars, which Clay says are crucial to handling. The team also replaced the stock rubber chassis bushings with stiffer items in either Delrin or hard polyurethane (Powerflex Black Series).

...

Besides the ongoing engine work, the limited slip differential in the F30 race car also presented some challenges in the build process, but it was nothing Diffsonline couldn’t handle.

“BMW hasn’t provided a limited slip in a non-M car for over a decade, so it’s always a challenge to put one in,” says Clay. “The ring gear on the F30 was welded to the carrier, the piece that we needed to substitute, and the required offset for the ring gear to run in the correct position had to be changed. The F30 also runs a new half-shaft in which the output flange is integrated versus staying in the differential. When adding a limited slip unit, the drive gears had to be modified to not only retain the axle in the differential but to also have enough clearance to not add lockup under suspension droop.”

If swapping ECUs and differentials wasn’t enough, BimmerWorld also removed the F30’s electrically assisted steering rack in favor of one with hydraulic assist. That may sound simple, but the boost levels in the F30’s electric rack are part of the engine control strategy and thus feed into the ECU. BimmerWorld’s use of the Bosch Motorsport ECU forced the team to use the hydraulic rack from the E90 3 Series, which had to be lengthened to fit into the F30.

The brakes were modified, as well, though here BimmerWorld was limited by CTSCC rules that require that brakes be within five percent of the stock size; interestingly, the rulemakers have allowed that to be defined on the basis of the rotor size from the 2006 E90 330i, which at 330mm is larger than that on either the E90 328i (312mm) or the F30 328i (also 312mm). BimmerWorld uses the stock calipers fitted with Performance Friction pads and rotors for both the F30 328i and the E90 328i.

http://www.bimmer-mag.com/issues/122...1#.U04C7VfB0es

[dc503]

Very good article, thanks for sharing. Always neat to get folks like BimmerWorld to describe the differences and a high level of development between the two cars.

[DVC]

Interesting about the subframe mounts... guess we're good to go in that regard. As far as the bushings and larger ARBs, hopefully this means that we'll see similar options available for aftermarket upgrading as well!
Rolling my eyes about the use of the e90 steering rack though... more fuel for the never-ending F30-vs-E90 debate - lol

[DVC]

I was just rereading this article and noticed that they specifically mentioned that they used Powerflex Black Series chassis bushings:
http://powerflexusa.com/powerflexblackseries.aspx
I think I'll give these guys a call on Monday to see what they might have for us.

[ronin951]

Originally Posted by DVC

I was just rereading this article and noticed that they specifically mentioned that they used Powerflex Black Series chassis bushings:
http://powerflexusa.com/powerflexblackseries.aspx
I think I'll give these guys a call on Monday to see what they might have for us.

Good catch, keep us posted. BW told me over the phone that the brake issues they had are nothing to worry about for us. No details though.

[DVC]

Originally Posted by ronin951

Good catch, keep us posted.

I have been trading e-mails with Powerflex - my contact said the bushings are in development (those being used by team BW are prototypes, of course), and that she expects to have something for us toward the end of the year.
I reiterated strong interest, and indicated that I thought they'd be a popular item... she replied that she might be able to push things along, and asked which specific bushings we'd be most interested in.
So, any thoughts on what we need most? I would thing ARB bushings, but if they are spec'd to the stock ARB, then they wouldn't fit when we finally get an upgraded after-market ARB (I spoke to H&R, and they have one in R&D). So what bushings would we most benefit from?

[SergioK]

Well it's not just that... There are quite a few ARB size's across all the F30 chassis.

Fronts:
328
Stabilizer front with rubber mounting 24MM 31356792111 - Baseline N47
Stabilizer front with rubber mounting 24MM 31356792124 - Baseline N20
Stabilizer front with rubber mounting 24,6MM 31356792112 -
M Perf Susp w/rubber mounting 24,2MM 31356792125 - M Sports Suspension S704A
335
Stabilizer front with rubber mounting 25MM/21,2MM 31356792118 - Baseline
Stabilizer front with rubber mounting 25MM/22,2MM 31356792119 - M Sports Suspension s704A

Rear all models
Stabilizer, rear D=12MM 33556853473 - Baseline & Sports Line suspension
Stabilizer, rear D=13MM 33556853474 - M Sports Suspension S704A

[Dog Face Pony Soldier]

Price and installation difficulty aside; I always thought it made sense to strive to have the suspension geometry remain as stable as possible before stiffening up the ARBs...