128i Brakes on the Track

[NA_Villhauser]

I was wondering with experiance tracking a 128i could chime in on their brake setup.

I recently did my first HPDE at Gingerman Raceway last weekend. I changed to Pagid S pads a few weeks ago in preparation and bled the brakes with super blue (I know they don't sell it anymore but I had an unopened can in my garage). The Pagid Ss are supposedly good for mild track use and seemed serious enough (all the pad material deposited during bed in was wiped off the rotors within a couple days of street driving).

This was first time driving on a track (I do have a few autocrosses and a car control clinic under my belt), and I was told that stock brakes would hold up fine as a novice. By the end of my first day I had pad fade (huge pedal effort gave little stopping power) and by the end of second day I had cooked the fluid and the pedal would suddenly drop an inch or two in a couple of the hard braking zones. I had a scary moment at the end of the back straight (105-110ish mph) where a 335i was taking off way too much speed but came off the brakes just in time!

post-track analysis showed that everything got very hot! The stick on wheel weights migrated and my parking brake began sticking a week later, even though I didn't use in on the track. I ate up 65-70% of the front pads and about 30-40% of the rears. The stock front rotors are in good shape, but the rears are scored pretty badly. I also noticed that the 128i has completely closed front wheel wells! No air directed at the brakes!

Despite the fact that the brakes faded, it was a blast! I need to figure out a better brake setup before I go back to the track. My instructor suggested that I move to a full race pad. I also think I will upgrade the fluid.

Any suggestions? I'm not running super grippy tires, just 225/45 17 PSS all around. I would love to go to a BBK except they're pricey and I want to continue running 17s. I don't want to throw away a bunch of money trying different pad and other components if I really need to run a bigger setup.

Thanks!

[FactorX81]

I wonder if there is a way to add cooling. Hopefully that would be cheaper than upgrading the brakes.

[NA_Villhauser]

Originally Posted by FactorX81

I wonder if there is a way to add cooling. Hopefully that would be cheaper than upgrading the brakes.

Yeah I've been thinking about that. Ducts from the front bumper to the well well would require either an M-sport or BMW performance bumper (expensive) or fabricate something to work with the stock bumper.

ducts directly to the rotors (especially ones that would get air to the centers) seem like they could be difficult to fabricate.

[Pyrat 2]

I was at the same event. Too bad we didn't catch up. In any event, did you have your stability control ALL the way off? The DSC + ediff on the 1s will cook the rear brakes if not disabled all the way. (edif actually can't be disabled). The paint on my calipers is discolored in back from the heat. Known challenge with both the front and rear brakes on the 1.

Also you can fit remanufactured calipers and larger rotors from a 335i onto your 1 and get all the brake power you need for a fraction of the cost of an aftermarket BBK. I did this on my e90 330 and it works great. Calipers only cost $100 a piece including new carriers. Rotors and pads are extra but in your case sounds like they need to be replaced anyway. So for $100 an axle on top of what you are going to spend anyway you'll be set.

[NA_Villhauser]

Originally Posted by HeelToe

I was at the same event. Too bad we didn't catch up. In any event, did you have your stability control ALL the way off? The DSC + ediff on the 1s will cook the rear brakes if not disabled all the way. (edify actually can't be disabled). The paint on my calipers is discolored in back from the heat. Known challenge with both the front and rear brakes on the 1.

You weren't the one who pointed out your discolored fronts to me, were you?

I did start out with the controls fully on, and then turned them half way of on the second day when the intervention became very noticable. I would have thought the rear pads would be more worn. Surprisingly the DTC allows a lot of rotation.

[Pyrat 2]

Backs are discolored on mine and not the fronts. I highly recommend the 335 brake conversion. I was fighting with brake issues like you are describing for years. Put the 335i calipers and rotors on and problem was instantly solved. No more pedal to the floor events like you describe (I use fresh RBF600 before every event). I had these some very uncomfortable situations where the pedal went away on me with the original rotors. This conversion will bring you from a 300x24mm front rotor to a 348x30 mm rotor. BBK kits are only 7mm larger in diameter. Personally I suspect that it is the extra width of the rotor that is making just as much if not more difference than the diameter. Regardless of which is contributing more, the end result is problem solved. I only wish I made the swap years ago.

[pj.rodriguez]

What about brake bias issues? You're drastically changing the diameter of the front brakes which would increase stopping power significantly. Is it too much for the fronts only?

Also, another apparent upgrade is the e90 330i front caliper carriers and then you can use the 128i calipers and just use the bigger 330i rotors. I might go this direction also.

[NA_Villhauser]

I am definitely considering the 330 and 335 brake options, however I am concerned about brake bias and abs issues.

I know CTSCC 128s run custom 2 piece 330 rotors and stock calipers, but they may also have dual master cylinders/ standalone abs to make it work. I'm not sure what the rules allow.

[Pyrat 2]

Originally Posted by pj.rodriguez

What about brake bias issues? You're drastically changing the diameter of the front brakes which would increase stopping power significantly. Is it too much for the fronts only?

Also, another apparent upgrade is the e90 330i front caliper carriers and then you can use the 128i calipers and just use the bigger 330i rotors. I might go this direction also.

Master cylinder, rear brake rotors, and all plumbing are identical between 330 and 335 so swapping to 335 rotors/calipers has not created a bias issue. I can attest to this personally since its on the car already.

Not sure about a 128i to 330i rotor swap. I haven't heard of someone doing this but then I admittedly haven't looked. The carriers are different (per realoem) as are the calipers so I don't know that this will work.

[pj.rodriguez]

Originally Posted by HeelToe

Master cylinder, rear brake rotors, and all plumbing are identical between 330 and 335 so swapping to 335 rotors/calipers has not created a bias issue. I can attest to this personally since its on the car already.

Not sure about a 128i to 330i rotor swap. I haven't heard of someone doing this but then I admittedly haven't looked. The carriers are different (per realoem) as are the calipers so I don't know that this will work.

Apparently there are a lot of 125i in Europe that have done the swap. All you need are caliper carriers to accommodate the larger rotors and the 128i calipers stay.

You have done the 330i to 335i? Or did you swap your 1er brakes out?

[Pyrat 2]

I did the 330i to 335i swap. Was considering doing the same on my 135is. I wouldn't have the blingy calipers but I would have more brakes - still investigating.

[andrey_gta]

For cooling on a 128i look at the BMW sink drain mod to the front grille to have ducts custom fitted into the $40 OEM girlle , than run duct into a custom hole in the wheel liner

best example was using Ceiling pod lights domes from Home depot- look at the e39 M5 boards

[NA_Villhauser]

hmmm... I will have to look into the 330 brakes further... and possibly get some air into the wheel wells.

Any recommendations on pads. Pagid RS29s? Hawk HT-10s?

Instructor said skip the Hawk HP pluses and go to full track pads. Other people are really pushing the HP plus and saying that my instructors advice to go to full track pads is bad for a novice. I'm inclined to trust the instructor.

[andrey_gta]

Originally Posted by NA_Villhauser

hmmm... I will have to look into the 330 brakes further... and possibly get some air into the wheel wells.

All you need are used Caliper carrier usually $100/set - UK ebay, Sweesigh breaker websites (https://en.bildelsbasen.se/, https://www.allabildelar.se/, https://www.markesdemo.se/) always email dont "Buy"

BUT if price of Carriers is alot you are better off with 330i/ 2009 only z4 rebuilt calipers

For Rotors:
2009 z4 e89 - 330mm rotors are alot like 135i rotors with semi twopieace Aluminum hats

ALSO at this stage compare Price to 335i brake calipers & disks cost[e89 z4 2010+ Rotor has semi-two piece aluminmum hats]

[chris82]

The brake fluid is probably what did you in. Get something like Motul 600 or Padgid RBF next time. As a novice, you shouldn't have had those issues.

[chris82]

Originally Posted by NA_Villhauser

hmmm... I will have to look into the 330 brakes further... and possibly get some air into the wheel wells.

Any recommendations on pads. Pagid RS29s? Hawk HT-10s?

Instructor said skip the Hawk HP pluses and go to full track pads. Other people are really pushing the HP plus and saying that my instructors advice to go to full track pads is bad for a novice. I'm inclined to trust the instructor.

Hawk HPS, HP Plus, or any 'high performance street' pads are apparently a bad idea as they will completely fade without warning. They also provide little increase in performance over the OEM.

http://www.m3post.com/forums/showthread.php?t=745679

[NA_Villhauser]

Thanks for the input everyone. Pad fade likely exacerbated my fluid problem as I had to stay hard on the brakes longer rather than braking hard initially and gradually releasing. Nonetheless I will still upgrade to rbf600.

I don't think I'll get a chance to go back to the track until spring. So it looks like I've got all winter to figure this out.

I also need to find wheel weights with adhesive that won't melt under high heat.

[3002 tii]

Originally Posted by NA_Villhauser

Thanks for the input everyone. Pad fade likely exacerbated my fluid problem as I had to stay hard on the brakes longer rather than braking hard initially and gradually releasing. Nonetheless I will still upgrade to rbf600.

I don't think I'll get a chance to go back to the track until spring. So it looks like I've got all winter to figure this out.

I also need to find wheel weights with adhesive that won't melt under high heat.

Use high heat aluminum tape over the wheel weights.

[Pyrat 2]

A few additional things to consider if you are considering the 330 or 335 brake swap:

The 330i weighs 3417 lbs and the 128i weighs 3208. Harder to decelerate.
The 330i has 255 HP/220 ft-lbs torque. The 128 has 230 HP/200 ft-lbs torque.
330 is 13.3 lbs/hp and 15.5 lbs/ft-lb. The 128 has 14.6 lbs/hp and 16 lbs/ft-lb. 3208 lbs. Faster to accelerate???
People, like myself, have swapped out 330 calipers and disks for 335s because of the same issue you are trying to solve on your 128i.

I'm not sure what the right answer is for you. A 330 swap or 335 swap? Like you said, you have the winter to sort it out.

[NA_Villhauser]

Originally Posted by 3002 tii

Use high heat aluminum tape over the wheel weights.

Thanks! I'll give it a try.

Originally Posted by HeelToe

A few additional things to consider if you are considering the 330 or 335 brake swap:

The 330i weighs 3417 lbs and the 128i weighs 3208. Harder to decelerate.
The 330i has 255 HP/220 ft-lbs torque. The 128 has 230 HP/200 ft-lbs torque.
330 is 13.3 lbs/hp and 15.5 lbs/ft-lb. The 128 has 14.6 lbs/hp and 16 lbs/ft-lb. 3208 lbs. Faster to accelerate???
People, like myself, have swapped out 330 calipers and disks for 335s because of the same issue you are trying to solve on your 128i.

I'm not sure what the right answer is for you. A 330 swap or 335 swap? Like you said, you have the winter to sort it out.

Power wise the car should at the very least be on par with a 330. I swapped to the 3-stage manifold from the 330, catless headers, and software to make it all work. No where near as quick as a 135 but it sure feels a lot quicker than when I bought it!

Any rotor swaps will depend on weather I can get the dealer to replace my rotors. I still have 6 mo. left of free maintenance. I'm afraid they might find it suspicious that my rotor are chewed up, my calipers are heavily discolored, and yet my stock pads are in nice shape/half worn!

[andrey_gta]

Keep in mind that the z4 2009 e89 3.5i with n54 used 330i Front brakes. Lookedup its weight - its 3,450 LBS!

[Pyrat 2]

And were the Z4 brakes adequate or not? I think the OP has to think through it. The answer is not obvious on how much more brake you need. I have only 1 datapoint from personal experience and unfortunately that experience doesn't really map directly to the OP issue.