Brake upgrade for HPDE

[325isBimmer]

I am debating a couple kits and determining if the price difference is worth it. I currently have stock m3 calipers with the brass guides and hawk dtc-70 pads. I also have brake cooling ducts. I want to upgrade the brakes because at road America I am hitting 160+mph and don't want my brakes to give out. I am thinking these options:

https://www.wilwood.com/BrakeKits/Br...temno=140-9300

https://www.ecstuning.com/b-ecs-part...00505ecs02kt4/

https://www.bimmerworld.com/StopTech...5X32-ST40.html

These are the 3 options I'm thinking about. My main thing I want to know is what is the difference between wilwood and the stoptech to validate the big price jump.

Thanks
-Mike

[AlpineM345]

I haven't researched in a while, but I would look into Massive instead of those.

http://massivebrakes.com/brake-systems.php

Massive Lee is the owner of the company and produces excellent brake kits.

Aa I mentioned earlier, it has been a while since I researched this topic though so things might be a little different nowadays...

Sent from my SM-G970U1 using Tapatalk

[eacmen]

Why do you think the stock calipers are any more likely of giving out than a BBK? Most brake failures on track are either hydraulic (what happened to Turner this weekend) or pad related. No matter what brake kit you put on there if you cook the pads they will fall apart.

Did you put thermal stickers on your caliper? What temps are you reaching?

If the cooling ducts are doing their job you should be in good shape.

Not trying to dissuade you from an upgrade, just curious what indicators you're seeing that led you down the BBK route. There are plenty of spec racecars running RA on OEM calipers.

Brass guides, routine caliper rebuilds, routine brake hose inspection and you should be safe to ride. This is true for OE and BBK.

I had stoptech ST40 fronts. The front rotors would crack too quickly. The consumables became too much. Now on OE with brake cooling. And so far I dont miss the BBK. This is on 200TW rubber.

[Evergreen Dan]

Z3 M Coupe with has stock E36 M3 brakes and Turner brake duct kit. Brass guides were a disaster. They are overconstrained and would bind no matter how clean I kept them. They cause the pads to wear, causing excessive heat and wear.

Every once in a while I would enter the turn and get about 70% braking with a hard pedal. I believe the rear was in ABS and the ABS computer was denying the front more hydraulic pressure. Happened often at WGI T1 where there is lots of room, but it scared me.

Switched to UUC Wilwood kit - Superlight 7420 pads, 4 piston, front and rear. Had terrible uneven pad wear until I realized the at the PFC 7420 pads are *slightly* too big. You need to grind or file the flat edges smooth so they are slightly loose. Others in a E36 M3 had no problems, but I would occasionally get the same problem. I probably could have solved it with a less grippy pad in the back, but I went with a one-size-larger piston in the front. Pedal feel is still pretty good. Brakes are reliable.

The kit uses E46 M3 front rotors and E38 rear rotors. The rotors aren't super thick, so you still will crack them and replace them every 2nd or 3rd set of pads. But Centric blanks are dirt cheap. BTW, I could not get Wilwood pads to work. Judder even on brand new rotors with proper break in. PFC pads never do that, you can swap with street pads (PFC Z), and no break-in needed. They are more expensive than Wilwood, but much cheaper than stock.

In short, if you are happy with your current brake performance, I would probably not change anything. Otherwise, I'd say the WW setup is cheap and works pretty well.

[eacmen]

Z3 M Coupe with has stock E36 M3 brakes and Turner brake duct kit. Brass guides were a disaster. They are overconstrained and would bind no matter how clean I kept them. They cause the pads to wear, causing excessive heat and wear.

Every once in a while I would enter the turn and get about 70% braking with a hard pedal. I believe the rear was in ABS and the ABS computer was denying the front more hydraulic pressure. Happened often at WGI T1 where there is lots of room, but it scared me.

Switched to UUC Wilwood kit - Superlight 7420 pads, 4 piston, front and rear. Had terrible uneven pad wear until I realized the at the PFC 7420 pads are *slightly* too big. You need to grind or file the flat edges smooth so they are slightly loose. Others in a E36 M3 had no problems, but I would occasionally get the same problem. I probably could have solved it with a less grippy pad in the back, but I went with a one-size-larger piston in the front. Pedal feel is still pretty good. Brakes are reliable.

The kit uses E46 M3 front rotors and E38 rear rotors. The rotors aren't super thick, so you still will crack them and replace them every 2nd or 3rd set of pads. But Centric blanks are dirt cheap. BTW, I could not get Wilwood pads to work. Judder even on brand new rotors with proper break in. PFC pads never do that, you can swap with street pads (PFC Z), and no break-in needed. They are more expensive than Wilwood, but much cheaper than stock.

In short, if you are happy with your current brake performance, I would probably not change anything. Otherwise, I'd say the WW setup is cheap and works pretty well.

Concur with the appoach here. If you go BBK get one that uses OE rotor sizes. Many bbk vendors lock you into their floating rotor rings and they are very pricey.

I have not had the same experience with brass bushings, but the car is garaged and trailered.

[325isBimmer]

Thanks for all the input. My car does brake well as is and I get 2.4 60-0mph times with toyo r888r tires. The main reason I want to upgrade is because I have warped the front rotors a couple times and was going to try a big brake kit and possibly get more brake torque and heat dissipation with 2 piece bigger rotors. Maybe I can just put some floating rotors on or use some of the tape to measure how hot it is getting. I am running about 650whp on the road course and I haven't had fade but definitely some pulsation. I think the wilwood kit looks good for the price and is what I am leaning towards now. I would be nice to know if somebody has had good experience with this kit.

Thanks
-Mike

[aeronaut]

If you're already using quality track/race pads, and you need to upgrade due to overheating (eg, RA and 160mph), then using OEM rotors is the wrong answer.

There's a myriad of questions that need answered before you upgrade.
Pad selection, brake bias, buy-in cost vs yearly cost, future suspension upgrades, wheel sizes, track only or road/track, etc.
Talk to an expert, like Lee at Massivebrakes.

My guess is you'll stay with OEM, use good track pads, and good brake fluid, and be happy.

Also, it is VERY unlikely you warped a rotor. Much much much more common is getting an uneven transfer layer on the rotor.

[eacmen]

If you're already using quality track/race pads, and you need to upgrade due to overheating (eg, RA and 160mph), then using OEM rotors is the wrong answer.

There's a myriad of questions that need answered before you upgrade.
Pad selection, brake bias, buy-in cost vs yearly cost, future suspension upgrades, wheel sizes, track only or road/track, etc.
Talk to an expert, like Lee at Massivebrakes.

My guess is you'll stay with OEM, use good track pads, and good brake fluid, and be happy.

Also, it is VERY unlikely you warped a rotor. Much much much more common is getting an uneven transfer layer on the rotor.

Agreed rotors don't really warp anymore.

Just to clarify I didn't mean for op to use the same rotor sizes as stock but find a BBK that uses larger rotors from other BMW models where more economical consumables can be found.

[aeronaut]

Not always, but there can be false economies is using an aftermarket "BBK" caliper with an OEM rotor. One: almost always the 'cheap' OEM rotor has a life 1/4 (or much less) than that of a quality 2 piece rotor. While the initial purchase price can be high, hats can be $150-$200. Two; usually "BBK" calipers are made to work with thicker rotors than OEM style rotors, meaning you'll waste 10-20% of the pad because the pad locator pins in the caliper won't hold the pad if it's allowed to wear down completely.

I did the quick math on a Massive/Wilwood setup (fronts only), including 2-piece rotors, adapters, calipers, etc, against my current Porsche calipers and OEM E46 rotors, and the Massive/Wilwood setup would completely pay for itself in less than 3 years in consumable savings (plus selling the porsche calipers for a few bucks). Some of that savings if from lower lifetime rotor cost.

And I know about 10% of what Lee knows.

[eacmen]

Not always, but there can be false economies is using an aftermarket "BBK" caliper with an OEM rotor. One: almost always the 'cheap' OEM rotor has a life 1/4 (or much less) than that of a quality 2 piece rotor. While the initial purchase price can be high, hats can be $150-$200. Two; usually "BBK" calipers are made to work with thicker rotors than OEM style rotors, meaning you'll waste 10-20% of the pad because the pad locator pins in the caliper won't hold the pad if it's allowed to wear down completely.

I did the quick math on a Massive/Wilwood setup (fronts only), including 2-piece rotors, adapters, calipers, etc, against my current Porsche calipers and OEM E46 rotors, and the Massive/Wilwood setup would completely pay for itself in less than 3 years in consumable savings (plus selling the porsche calipers for a few bucks). Some of that savings if from lower lifetime rotor cost.

And I know about 10% of what Lee knows.

FWIW I had opposite experience. I was cracking stoptech st40 rings every two sets of pads. PFC08 compound.

[Evergreen Dan]

The economics depend largely on how long cheap rotors last. The E46 M3 rotors last me 2-3 pads and I often change them just because. Rotors are about $100 an axle whereas pads are roughly twice that. So rotor cost not significant with the OEM rotor WW setup.

I will say that I was AMAZED at how long pads lasted with thicker rotors on our Mustang race car. We were using WW pads, which I could not make work on the M Coupe because of judder. And the rotors last a long time, but are expensive.

With both setups, pad cost was much more significant. I also find that I only get a great pedal feel with fresh pads, even using shims on used pads.

[aeronaut]

The standard pad size for many of the aftermarket calipers is 20mm thick, and cheaper than the thinner OEM style rotors. Pad costs for a race caliper can be 1/2 that of a OEM style caliper.

- - - Updated - - -

FWIW I had opposite experience. I was cracking stoptech st40 rings every two sets of pads. PFC08 compound.

That would suck.

[olemiss540]

650whp? I typically am in the "stock brakes with rockauto rotors and high temp fluid/pads" camp but with that kind of power I would think brakes may be of utmost importance. I would pay once and do it right. 18" wheels with a seriously beefy rotor from any of the big names. Would want to upgrade ABS to an e46m3 system and go with upgrades on all 4 corners along with brake cooling ducts. 650 whp is a serious amount of power.....

[aeronaut]

1/2mv^2 is a bitch.

[325isBimmer]

650whp? I typically am in the "stock brakes with rockauto rotors and high temp fluid/pads" camp but with that kind of power I would think brakes may be of utmost importance. I would pay once and do it right. 18" wheels with a seriously beefy rotor from any of the big names. Would want to upgrade ABS to an e46m3 system and go with upgrades on all 4 corners along with brake cooling ducts. 650 whp is a serious amount of power.....

The reason I want to upgrade is because of how fast I am going and the power level. I was looking for assistance with what kits people recommend and I am already on 18" wheels and want to put on 345mm-355mm rotors. I already have brake cooling ducts going to the back of the rotors so I already have that part done. Does anybody have experience with the wilwood kit. I am still leaning toward this kit. After brakes I need to get a transmission that will hold up longer, already on my 4th transmission ZF320. Going to upgrade to the GS6-53BZ transmission also. 650whp is fun but hard to get reliable for road racing

Thanks,
Mike

[golgo13]

FWIW I had opposite experience. I was cracking stoptech st40 rings every two sets of pads. PFC08 compound.

What rotors? Are you running brake ducting?

EDIT: OP that's a lot of power! I would consider an upgrade as well, I don't think my car gets over 120mph lol

[emoore924]

If the rules allow, you might want to consider lightening the car too. Makes the brakes work less.

[325isBimmer]

If the rules allow, you might want to consider lightening the car too. Makes the brakes work less.

I'm at 2920 with a full tank. Gutted with a full cage.

-Mike

[lcrain]

With the amount of money you have spent elsewhere on the car, I would think you can justify a top tier kit. I had a willwood kit and was not impressed. I have since gone to a PFC BBK and they are considerably better in terms of feel. The downside of the PFC kit is the cost of consumables, rotors mainly. I go through rotors almost as fast as I go through pads. I wish I could find a cheaper rotor alternative than the PFC direct drive. Even with the replaceable "hat" the front rotors are almost $1000/set.

[aeronaut]

With the amount of money you have spent elsewhere on the car, I would think you can justify a top tier kit. I had a willwood kit and was not impressed. I have since gone to a PFC BBK and they are considerably better in terms of feel. The downside of the PFC kit is the cost of consumables, rotors mainly. I go through rotors almost as fast as I go through pads. I wish I could find a cheaper rotor alternative than the PFC direct drive. Even with the replaceable "hat" the front rotors are almost $1000/set.

THAT'S insane.
So every season, you're buying a few race Miata's worth of brake consumables.

[lcrain]

Ha! None of what I do makes any sense with this hobby. I would say this car has averaged 30 days on track the past few years since I have had the brakes and have done pads/rotors annually. The pads have an insane amount of material. So for the fronts it is ~$1600/year or so. For an e36 that may seem insane, but compared to some of the cars I run around with, not that bad. When I compare it to my endurance miata, it does seem a bit excessive.

[aeronaut]

Agreed, it's all relative. Talk to the guys who have OEM carbon fiber rotors.
$1600/30-days....that's not horrendous, probably less than 2x what my consumables are.

[lcrain]

Another variable is tires and the combination of pads and tires being used. Using a super aggressive pad like a pfc11 with even a sticky street tire may be too much pad for the tire. Switching from a nt01/r888/maxxis rc1 to a hoosier paired with the pfc11 made a big difference in the confidence I felt under braking. Add a good aero package on top of that and you are in serious business.

[olemiss540]

I'm at 2920 with a full tank. Gutted with a full cage.

-Mike

Mike,

You really should talk to someone like bimmerworld and have them set you up. It's going to cost a pretty penny but I am sure you will appreciate an AP or Essex or PFC based kit the first corner you approach at 180mph!

[nvrtoofast]

Pads and rotors are key in the brake set up. 4 and 6 piston set-ups are great but the Rotor is the key. I've run EBC rotors and Yellowstuff pads for long time. I never get brake fade (unless they cool off too much - Doesn't happen on track). Last track outing required consistent 120 MPH+ braking before corners and no warping, fading or anything. This is on an M3 with stock M3 calipers. Surprised me, honestly. I increased lap times as I got more comfortable that the brakes wouldn't stop working. They won my vote.
Though for full race applications the upgrade to large calipers and rotors is a plus.