[AdrianRex]

I'm heading into my second year of occasional HPDE with my 2009 328i x-drive. The number one frustration last year was the brake fade after a few laps. The car is a fat pig and the stock pad and rotors make no bones about reminding me.

It seems like either I just deal with fade or go with a dedicated track setup of rotors and pads. Any suggestions on a decent rotor and pad setup that won't break the bank?

[CJ421]

What brake fluid have you been running? That's the critical and often overlooked component. Upgrade to high-temp fluid if you don't already have it. Your braking power is basically gone once the brake fluid gets too hot/boils. Standard braking fluid is comparatively detrimental on track because it will boil earlier than a good high-temp fluid. I've had good success with Motul 600 RBF. Make sure you get the fluid flushed every six months or every couple of events, whichever is sooner.

It's generally only the front brakes that overheat on these cars. You can run stock rotors and pads on the rear.
I don't know a whole lot about X-Drive differences but - the most economical brake upgrade for a 328i is to get 335 brakes up front (rotors/calipers). The larger rotor is very helpful (increased mass + surface area). Maybe see if a 335xi brake setup will fit?

If you want to stay with your stock brakes up front, I'd suggest some track pads - I use Hawk DTC's; try one of the less aggressive versions of those. Keep the stock rotors; they're both economical and durable. Considering the 328's rotors are relatively small, you wouldn't want to get perforated/slotted versions because such rotors have less mass = less thermal capacity, and your rotors already have an especially limited amount of that.
Another thing - have your stock rotors measured for thickness. If they're on their way out - get new ones. New rotors have more mass and therefore more thermal capacity.

[AdrianRex]

Originally Posted by CJ421

What brake fluid have you been running? That's the critical and often overlooked component. Upgrade to high-temp fluid if you don't already have it. Your braking power is basically gone once the brake fluid gets too hot/boils. Standard braking fluid is comparatively detrimental on track because it will boil earlier than a good high-temp fluid. I've had good success with Motul 600 RBF. Make sure you get the fluid flushed every six months or every couple of events, whichever is sooner.

It's generally only the front brakes that overheat on these cars. You can run stock rotors and pads on the rear.
I don't know a whole lot about X-Drive differences but - the most economical brake upgrade for a 328i is to get 335 brakes up front (rotors/calipers). The larger rotor is very helpful (increased mass + surface area). Maybe see if a 335xi brake setup will fit?

If you want to stay with your stock brakes up front, I'd suggest some track pads - I use Hawk DTC's; try one of the less aggressive versions of those. Keep the stock rotors; they're both economical and durable. Considering the 328's rotors are relatively small, you wouldn't want to get perforated/slotted versions because such rotors have less mass = less thermal capacity, and your rotors already have an especially limited amount of that.
Another thing - have your stock rotors measured for thickness. If they're on their way out - get new ones. New rotors have more mass and therefore more thermal capacity.

I had fresh fluid put in before each event last year but it was pretty standard DOT 4. It didn't really cost anything so I went with that. Considering the fluid was fresh i really didn't consider that it could be the weak point. I'll try the brand you recommended before spending more money for mods I'm probably barely fast enough to need.

My understanding is larger rotors do not fit in the back on the xi and I'm petty sure I'd need new wheels if I went with 335 brakes in the front as my car came with 16s.

But let's say I got 335 brakes for the front, and somebody donated adult sized wheels, wouldn't that throw the bias off by quite a bit?

[CJ421]

Originally Posted by AdrianRex

I had fresh fluid put in before each event last year but it was pretty standard DOT 4. It didn't really cost anything so I went with that. Considering the fluid was fresh i really didn't consider that it could be the weak point. I'll try the brand you recommended before spending more money for mods I'm probably barely fast enough to need.

My understanding is larger rotors do not fit in the back on the xi and I'm petty sure I'd need new wheels if I went with 335 brakes in the front as my car came with 16s.

But let's say I got 335 brakes for the front, and somebody donated adult sized wheels, wouldn't that throw the bias off by quite a bit?

High temp fluid should help you quite a bit.

I'm almost certain you would need 17"+ wheels for a 335 brake setup. I believe 17" was the minimum wheel size the 335 was sold with. I don't know about the brake bias ...I want to say it'd be fine since when people go to real BBK's like Brembo, it may only be on the front ...but that's not really evidence. I just don't know.

Worst comes to worst on the track - take a cool down lap and point people by. See what your instructor suggests of course.

Best of luck with everything.

[AdrianRex]

Originally Posted by CJ421

High temp fluid should help you quite a bit.

I'm almost certain you would need 17"+ wheels for a 335 brake setup. I believe 17" was the minimum wheel size the 335 was sold with. I don't know about the brake bias ...I want to say it'd be fine since when people go to real BBK's like Brembo, it may only be on the front ...but that's not really evidence. I just don't know.

Worst comes to worst on the track - take a cool down lap and point people by. See what your instructor suggests of course.

Best of luck with everything.

Just dropped off the car for the AA performance header install and asked them about the brake fluid. The man had every reason to upsell a better fluid that needs to be replaced more often but told me I'm overthinking it as an occasional track day driver. I think that was the common sense I needed to hear from both you and him; just take it easy for a lap or two when that happens.

As a complete aside, again for the novice, traction control is going to kick in, admittedly fewer times per session between my first day and the end of my sixth last year, but those do certainly wear down the rear pads.

All in all, I'm stressing what should just be a fun day way too much.

I see you're in PA, do you go with NJ Chapter BMWCCA to NJMP? I'm registered for the April 13-14 weekend.

[CJ421]

I've done events with NJ CCA before but I'm principally a member of Del Val CCA. Both are good clubs. NJMP Lightning is my favorite track. I'm going to be away April 13-14 - but enjoy it, and consider me jealous. Spring and fall are the best times to go on track.

I ran my first several events with stock everything including brake fluid. I don't remember issues. If it helps, you'll actually use the brakes more efficiently as you become a more advanced driver. Managing how much braking power you have is part of being an advanced driver, especially when they heat up.

Note that NJ and Del Val CCA require you to have a brake fluid flush performed within six months of the event. If you're due, just get the high-temp stuff ...you'll notice no difference on the street, but on track it will help you because it has a higher boiling point. Your braking power will fall off drastically once the brake fluid reaches a certain temp ...and that threshold is appreciably higher with high-temp fluid. Your shop is probably right that it may be overkill especially if you have only done a couple of events. But as you progress, you will find the high temp fluid advantageous at some point. Your original post in this thread was to find out how to improve your braking performance - high-temp fluid is #1 on that list, even above a BBK.

[AdrianRex]

Originally Posted by CJ421

I've done events with NJ CCA before but I'm principally a member of Del Val CCA. Both are good clubs. NJMP Lightning is my favorite track. I'm going to be away April 13-14 - but enjoy it, and consider me jealous. Spring and fall are the best times to go on track.

I ran my first several events with stock everything including brake fluid. I don't remember issues. If it helps, you'll actually use the brakes more efficiently as you become a more advanced driver. Managing how much braking power you have is part of being an advanced driver, especially when they heat up.

Note that NJ and Del Val CCA require you to have a brake fluid flush performed within six months of the event. If you're due, just get the high-temp stuff ...you'll notice no difference on the street, but on track it will help you because it has a higher boiling point. Your braking power will fall off drastically once the brake fluid reaches a certain temp ...and that threshold is appreciably higher with high-temp fluid. Your shop is probably right that it may be overkill especially if you have only done a couple of events. But as you progress, you will find the high temp fluid advantageous at some point. Your original post in this thread was to find out how to improve your braking performance - high-temp fluid is #1 on that list, even above a BBK.

Thanks man. That is a solid point, adapting to the changes in grip and braking is paramount, and something I was really concerned about last time. It's funny, you nail one corner perfectly after a day and you're carrying way more speed than before so you blow entry/exit of the following one.

Going with higher rated fluid as recommended.

[trohde78]

I only plan 1-2 track days this year, and went with Motul DOT 5.1 fluid. It's a decent upgrade from the stock DOT 4, but isn't a full blown race fluid like 600 RBF.