Z435is rotors, F30 backing plates, StopTech pads

[rwalker]

I've had trouble keeping my stock pads and rotors happy in my daily commute/romp in my 2010 E90 335i.

No real failing of the stock bits, it's just that my daily commute includes a run up to 120+ followed by a rapid downhill haul-down to 70 or so. Under these conditions, I've experienced a pronounced judder/moan/steering wobble that largely cures itself on cool down. Well, until the next day that is. BMW (and my dealer) have been very forgiving/generous. They've replaced my pads and rotors twice since new, only 19k miles ago...

My own attempt at a fix is F30 backing plates, Z435is rotors, and (while I'm at it) StopTech Street Performance pads.

The F30 backing plates have an air scoop that improves cooling air flow to the rotors. I have to admit it wasn't my idea: the E82 guys have been doing the same mod for years. The F30 bits mostly bolt right up. The top and bottom mounting points are identical to the E90. To properly secure the F30 plates to our spindles you need only drill one extra hole, which I templated by using the stock backing plates.

I won't get to try my romp until the 23rd, and I have a track day on the 27th. I'll keep this thread updated with how I've fared.

Pics attached.

[Roadkillrob]

What exactly is the difference between Z435is rotors and standard E9x Sport Package Rotors?

[blackshan]

The z4 has 2 piece rotors from the factory. So I believe there is a 2 to 3 lb difference per rotor.

[rwalker]

yeap, 2 piece rotors with aluminum hats

[Roadkillrob]

Good to know, thanks!

[Sticky]

So your thread is a link to a thread on a forum that doesn't allow links? Ok, neg repped and cleaned up your lazy post to how it should look.

Don't do it again.

[Roadkillrob]

So your thread is a link to a thread on a forum that doesn't allow links? Ok, neg repped and cleaned up your lazy post to how it should look.

Don't do it again.

Thanks, that is much better than the link!

[rwalker]

This setup has fared well in my commute, though I've only been able to do the romp a few times since my last post.

No problems in my HPDE yesterday either, though I did experience some fade after the 3rd or 4th hot lap.

The HPDE was held at Fontana's Auto Club Speedway in the Sports Car track configuration. Additionally, the LA chapter puts a chicane at the end of the front straight. The chicane requires you haul down from Vmax on the straight for a quick left right before heading into turn 1. In my case, I was braking from 140 down to around 90. In my experience, this would have really challenged the stock setup, but the new setup really impressed with its resilience.

Next time out, I might try more aggressive pads.

[rwalker]

For those who need them, here are the part numbers.

backing plates: 34116792237, 34116792238
number 4 in this dagram: http://www.penskeparts.com/DiagramsR...iagram=34_1949

rotors: 34116782593
number 1 in this diagram: http://www.penskeparts.com/DiagramsR...iagram=34_1475

[Sticky]

This setup has fared well in my commute, though I've only been able to do the romp a few times since my last post.

No problems in my HPDE yesterday either, though I did experience some fade after the 3rd or 4th hot lap.

The HPDE was held at Fontana's Auto Club Speedway in the Sports Car track configuration. Additionally, the LA chapter puts a chicane at the end of the front straight. The chicane requires you haul down from Vmax on the straight for a quick left right before heading into turn 1. In my case, I was braking from 140 down to around 90. In my experience, this would have really challenged the stock setup, but the new setup really impressed with its resilience.

Next time out, I might try more aggressive pads.

@rwalker How do you like running the Auto Club Speedway?

[rwalker]

The BMW CCA LA chapter put on a first-class event. I had a blast.

The weather was primo.

I had a garaged parking spot (first-come, first-served).

The chicane on the straight removed the only boogie man I have for the track.

Track-wise, the only areas some might fault Fontana are:

• there are no elevation changes to speak of
• it's less technical than, say Buttonwillow

These criticisms are valid, but these supposed shortcomings had no impact on my ability to have fun out there. I think at my level there's still more than enough to learn, and more than enough opportunities to scare oneself.

I'm gonna do it again: It's just too cheap, easy, and fun to pass up at $300 and change for a CCA member.