Some cars greatly benefit from a big-brake kit, as the factory pieces just can’t handle the heat. Just see how the upsized hardware transformed our Corvette Z06 and Toyota MR2 track cars.
But does every car need big brakes–like, for an example, an E46-chassis BMW M3 that primarily sees street use? So we asked BimmerWorld’s James Clay. He knows BMWs …
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For the time being, we went with Powerstop's carbon fiber/ceramic brake pads and we've been amazed at the stopping power with hardly any brake dust on the wheels. could be an alterative tot he stoptech brand.
I mean, really it comes down to use. The Z06 and MR2 are track cars, they need track brakes. The E46 "sees primarily street use" so street brakes (the stock ones) are just fine.
Tom1200
UltraDork
3/23/22 4:31 p.m.
In reply to codrus (Forum Supporter) :
It really does come down to use; for street car I just use quality components.
wspohn
SuperDork
3/24/22 10:44 a.m.
90% of big brake kits are installed not for braking but for showing off purposes. On the BMWs you generally have more than adequate systems that can be optimized as done in the article, using only a proper pad choice and perhaps the steel Aeroquip style brake lines which expand less under pressure and can give a firmer pedal.
There were some cars that were designed with inadequate brake systems by the factory. Take a look at the early Mini discs that were 7" or analyze the wisdom of Sunbeam sticking an American V8 in a Tiger and leaving it with brakes that were all but uncoolable inside 13" wheels.
In reply to wspohn :
See also: If I remember correctly, doesn't the 240Z have solid, non-vented rotors up front?
On the street, I don't think I've come across a (modern) car that wasn't just fine with good pads and rotors. Even my notoriously bad GMT400 pickup works fine with good parts.
I thought my E30 had decent enough brakes for the track stock, but eventually I got better at using them (as you have to with no power to make up time on other parts of the track), and even with brake ducts and DTC70 pads, I was melting the backing plates (imprints of the pistons in the backing plates) and cracking front rotors every few sessions, and completely killing the front pads in one day at the track. So now I have big brakes. It doesn't stop any faster than the originals did before they got too hot, but it can stop just as fast over and over and over.
Can't seem to find pictures of the pads, but it was a good thing these rotors were so cheap.
wspohn
SuperDork
3/25/22 10:42 a.m.
David S. Wallens said:
In reply to wspohn :
See also: If I remember correctly, doesn't the 240Z have solid, non-vented rotors up front?
Indeed they did - fine for the street but not for track.
A couple of friends were running a 240Z and having all sorts of brake problems and the rules did not allow brake substitutions. What they came up with was brilliant and elegantly simple. Wheels were free and all the 240s ran allots of course (on the track) and some bright bulb figured out that if you took the alloy engine fan from a Corvair flat 6 and machined it so they could attach it to the outside of the wheel it would act as a powerful extractor fan and would suck air past the overheated brakes.
The ended up with wild looking wheels and brakes that actually worked well through whole race.
Tom1200
UltraDork
3/25/22 11:17 a.m.
My little Datsun 1200 as what are huge brakes for it's size; 280ZX front (vented rotors) and 240Z alloy drums (1" larger than stock 1200)
They aren't on there for the extra stopping power, it's purely a case of my trail braking and left foot braking puts a ton of heat in the brakes. The 280ZX brakes added 2lbs of unsprung weight....................well worth the trade off.
It depends on the car, doesn't it?
If you're starting with an E46 M3... That seems more like an outlier than a baseline.
A lot of older stuff (and we don't have to go Bronze Age) benefits from increased brake torque for a given pedal pressure from a control and enjoyment standpoint, even if heat management isn't an issue.
j_tso
Dork
12/26/23 3:26 p.m.
In reply to wspohn :
I saw something similar but it was a fan insert behind the wheel:
This was at the SCCA races at COTA.
In reply to wspohn :
Yeah, I remember seeing a pic of a Corvette with Corvair fans attached to the rims from many years ago.
Corvair fans (the later centrifugal type fans) are made of magnesium also, so brake fires could get fun....
The early Z32 gen Z's had mucho problemos with rotor warpage, I know from past experience. So, when I purchased my second Z32, the first upgrade was Racing Brake two-piece rotors and attendant calipers, inside 18" TGW wheels......problem solved, great braking, good looks, no warped rotors. Win, win, win.
I will admit that I put E46 330i brakes on my old 318ti just for the looks. They really filled out the M3 rims I had on the car.
I remember someone quoted in GRM saying brakes on most cars before around 1995 need some help but for street, autocross and light track they are fine after 1995. That stuck with me and it really does seem to be true.
aircooled said:
In reply to wspohn :
Yeah, I remember seeing a pic of a Corvette with Corvair fans attached to the rims from many years ago.
Corvair fans (the later centrifugal type fans) are made of magnesium also, so brake fires could get fun....
As seen at the Eyes On Design show at the Eleanor Ford House, Fathers Day 2023. front wheel diameter is tiny on these cars. I thought I had pix of the info signs with these cars, but I do not. Shadow, perhaps?
docwyte
UltimaDork
12/27/23 10:29 a.m.
For the street and auto-x the stock E46 M3 brakes are fine. For the track, a good BBK makes a big difference. I had the Stoptech BBK front/rear on my E46 M3 and it was amazing. So much better performance and the pads lasted forever.
On my 996 Turbo I've gone with the 997 Turbo rotors and 6 piston 996 GT3 front calipers. Again, amazing performance on track.
DavyZ
Reader
6/11/24 1:41 p.m.
Tom1200 said:
My little Datsun 1200 as what are huge brakes for it's size; 280ZX front (vented rotors) and 240Z alloy drums (1" larger than stock 1200)
They aren't on there for the extra stopping power, it's purely a case of my trail braking and left foot braking puts a ton of heat in the brakes. The 280ZX brakes added 2lbs of unsprung weight....................well worth the trade off.
I need to remember this if I come across a decent 1200 to modify. Using factory parts is great when it's possible. I have been looking at a number of brake upgrades for the 240Z, but have not jumped at anything yet. So many choices, especially if wanting to cobble something together that isn't brand-specific.
NOHOME
MegaDork
6/11/24 2:41 p.m.
I am about to go to 11" rotors on the Molvo because the car is a few hundred lbs heavier than a stock Miata and the increased leverage can't hurt. You can lock the fronts but u really have to lay into the pedal. The little 9 inch ish rotors also look silly in the16 inch wheels.
In reply to NOHOME
The ND Miata I bought came with 12.88" rotors and 6 piston calipers......gross overkill for the street, but it does stop really well :)
Tom1200
PowerDork
6/11/24 3:38 p.m.
In reply to DavyZ :
The 240Z is 500lbs lighter than a 280ZX so those brake parts for the front would probably make a good upgrade.
Additionally Porterfield makes both street and track pads for that set up.
Regarding fans on wheels, just from memory it seemed to be a very popular item in the World Rally Championship. I think they were loosely referred to as "turbofans."
Edit to add a photo.
ShawnG
MegaDork
6/11/24 5:37 p.m.
If you can lock up the wheels, you have enough brake.
What you want is good modulation and fade resistance.
In reply to ShawnG :
I'd change that to "you have enough brake for one stop" :) Also, you can lock wheels way early if your proportioning is off - so you need good proportioning, good modulation and heat management.
Keith Tanner said:
In reply to ShawnG :
I'd change that to "you have enough brake for one stop" :) Also, you can lock wheels way early if your proportioning is off - so you need good proportioning, good modulation and heat management.
Exactly... the joy isn't how powerful the brakes are when everything is good, the joy is how good the brakes are when everything is heat soaked.
What is slightly annoying is I can make the brakes useless in my Volvo in a couple miles of zig-zag country roads. (Accelerate to 60, brake for turn at intersection, accelerate to 60, etc). This in a car with 330mm vented disks at all four corners.
My Sentra, which had solid tiny disks up front, could get the brakes so hot that smoke roiled from the wheelwells, but they kept working adequately. I don't know how hot that was, but the rotors were purple after a country road drive