Budget Minded BBK

[The HACK]

Originally Posted by tdott

Are you saying that is it not possible to interchange stock parts from another car and not have it work properly just because you failed at it??

Yes. I'm saying it is darn near impossible. And I'm not your average forum dweeb that thinks he knows everything just because he's spent half his life on the forums.

I am THE forum dweeb.

I leveraged years of shady tree mechanic knowhow and time spent on various car forums into a job at a prestigious aftermarket manufacture, one of the original founders of SEMA (a title I no longer hold unfortunately).

I'm saying, if *I* manage to f**k it up, the likelihood of your average forum Joe of doing it right is damn-right close to ZERO.

And IF my BMW knowledge is wrong, and those of you who know, PLEASE correct me, almost all 3 series master cylinders are "interchangeable" because there's basically only 3 different master cylinder sizes between E30, E36, and E46 cars. The ///Ms have it's own master cylinder size, the higher 6 cylinder trim has one master cylinder size, and the 4 cylinder has its own master cylinder size. The result is, almost all the piston sizes are the same (again, if I recall...The E30, E36, and E46 M3 pistons are all the same size). BMW alters the brake capacity by increasing/decreasing the size of the rotor, because sliding calipers are far more flexible in terms of the size of the rotor it can accommodate, where as fixed calipers can only accept a small range of rotor diameters.

The ONLY case where someone took a set of calipers from another car brand (Porsche) and got it to work on a BMW was the guys with MASSIVE, but they did an @SS load of research, and at the end of the day ONLY the 996 911 Brembos would fit and they ended up costing as much as going with a StopTECH.

My original point stands though. If you don't know the overall piston size of the CTS-V pistons, and can't compare it to OE piston size to figure out if it's overly large or small, you probably shouldn't attempt this "transplant" in the first place.

Call me a "sheep" all you want. I know what I am talking about.

[tdott]

Originally Posted by The HACK

My original point stands though. If you don't know the overall piston size of the CTS-V pistons, and can't compare it to OE piston size to figure out if it's overly large or small, you probably shouldn't attempt this "transplant" in the first place.

Call me a "sheep" all you want. I know what I am talking about.

Fair enough, I'll go calculate piston sizes and try to dig up the stock M3 sizes when I have some time. I'm not a typical forum 'dweeb', I prefer working on cars, try to stay out of internet arguments but I guess I deserve it for replying with a unresearched thought I had floating around in my head.

Regarding the all 3 series share the same piston size, they don't. M3s have a different master cylinder piston size (E46, E36). Also there are other MC that can be used to vary the sizes that are interchangeable with modifications, 750il is a common one.

Reason I mentioned the CTS-V caliper is that a rebuilt loaded caliper costs less than $200 a side from rockauto. Not saying they will work, but I met a guy this past weekend that mentioned them because he is doing a swap on a e46 m3 and measured all the sizes and is confident they will retain his stock balance.

FYI: If you know where to look sometimes you can find 996 911 calipers for cheap.

[aus]

Originally Posted by The HACK

I leveraged years of shady tree mechanic knowhow and time spent on various car forums into a job at a prestigious aftermarket manufacture, one of the original founders of SEMA (a title I no longer hold unfortunately).

.

Truth? One of the founders of SEMA??
.

[The HACK]

Originally Posted by aus

Truth? One of the founders of SEMA??
.

The COMPANY I worked for was one of the founders of SEMA. Not me.

SEMA came along LONG time ago, around 60 years I think. Long before internet existed. I'll have to look it up but there were like a dozen aftermarket manufactures that banded together to for the original SEMA.

[AP3X_FTW]

As a couple others have mentioned:

PFC DD Rotors
PFC / Pagid Yellow Pads
Castrol SRF Brake Fluid
SS Lines

[M3 Number 86]

I notice that most (less the years of experienced guys or too scared to turn traction control fully off guys) m3 owners at the track with shit loads of aftermarket upgrades are slower than me in a basic setup.

strange.

and I'm super slow. I need bbk soon. though but no says wife. I will try to get faster without it developing my technique instead.

Pros drive faster in a bone stock car than we do with just skillzzzz

[jphughan]

Skip the rear BBK to save a bunch. I only upgraded my fronts, and StopTech has an article on their own site arguing that rear BBKs are unnecessary and can even be counterproductive. On the track I run PFC08s in my front ST-60 and keep my full-time StopTech Street Performance pads in my stock rear brake setup. Works great even on brake-intensive tracks like CotA. Maybe race pads all around would be better but I'm too lazy to swap pads back there. I run in advanced or instructor run groups for reference. Getting a used ST-40 front setup would save even more.

Skip the suspension, exhaust, and lip for now too if you're on a budget. The stock suspension on the M3, EDC or not, can definitely handle track duty. The exhaust is mostly bling (and power mods should be last anyway) and the lip is mostly bling too, especially if you won't be balancing it with rear aero. If you must get wheels (and you probably don't need those either) go with APEX EC-7s or ARC-8s. They have a great track reputation and are inexpensive even new, but chances are you can find a used set pretty easily. The size you want is 18x10 ET 25.

But do get camber plates if you'll be doing more than maybe 4 track days per year, unless you want to be destroying the outside edges of your front tires way early all the time.

[MSteve5036]

Might be slightly off topic, but considering swapping brakes from other cars...would f8x brakes be any easier to swap onto the e9x than say the CTS V brakes. Sorry for the newb question but I've never upgraded the brakes on a car.

Obviously won't be budget but I'm just wondering

[bigjae1976]

You don't need the rear BBK if you like to constantly replace your front pads. If you are in it for the long haul, 4 wheel BBK.

I like Stoptech. Not the best but the lowest cost to run.

Willing to bet that it would cost less than running OE brakes with the PFC DD rotors. Maybe it was me...I had 2 sets of the PFC rotors on a different car and they would heat crack and just wear out pretty damn fast.

If I had to hazard a guess, the aluminum BBK calipers will shed heat a lot faster than the OE brakes which I do not think are aluminum. OE system just can't withstand extended track use. I blew through 3 sets of front pads in 22 session at Road America. In the past, a set of PF01s would maybe last 1 weekend.

[wsybert]

I don't track my E93 but have other BMW's and Porsche's. Stock brake system, without engine power upgrades, will work fine with a good set of rotors and track pads. I've never pushed past the limits of my braking system. I'm not the fastest guy, but I'm no slow poke either. Try that route first.

[bigjae1976]

I guess it comes down to how you define "the brakes are fine for the track".

Will the pad squeeze the rotor at the end of the day? Then yes, the OE brakes are fine for the track.

I would classify the brakes being NOT fine for the track if you have to make the choice between continuously operating the brakes beyond its designed temp range so the dust boots burst into flames and having the nurse the brakes every other lap to keep them working.

[jphughan]

Originally Posted by MSteve5036

Might be slightly off topic, but considering swapping brakes from other cars...would f8x brakes be any easier to swap onto the e9x than say the CTS V brakes. Sorry for the newb question but I've never upgraded the brakes on a car.

Obviously won't be budget but I'm just wondering

I don't know how the difficulty would compare between getting those kits to fit, but my issue with installing brakes from ANY other car is that the sizing and progression of the pistons inside a caliper are based on the car where they'll be used, the piston design of the calipers on the opposite axle, and the sizing and front/rear bias of the master cylinder. Therefore if you mount some other random set of calipers onto the car, you can mess up your brake bias even if you do both axles -- and if you do only one, you can severely throw off the bias. That's why although StopTech for example only has a few BBK designs (ST-40, ST-60, etc), they have several variants of those calipers, each with design tweaks appropriate for the intended car, including piston sizing (to maintain stock front/rear brake bias) and piston progression direction based on which side of the rotor the caliper will be mounted on.

But if you opt for a transplant, at the very least, if the calipers from the donor car use more than one piston size in their design, make sure that the donor car mounts its calipers to the same side of the rotor as your car does for each axle. For calipers that use multiple piston sizes, calipers that are mounted on the trailing side of the rotor, like the M3's fronts, increase piston size from bottom to top, whereas calipers that are mounted on the leading side, like the M3's rears, have their smaller pistons at the top and larger pistons at the bottom (that's kind of a bad example since a stock E9x M3 uses single-piston sliding calipers on both axles, but you get the idea). The reason is that you want your larger pistons where the rotor exits the caliper since that's where the rotor will be hottest and therefore where increased pad taper can occur, and the increased clamping force of the larger pistons helps compensate for that. So if you got this backwards, you can end up with severe taper on the side of your pads where the rotor exits the caliper.

Originally Posted by bigjae1976

You don't need the rear BBK if you like to constantly replace your front pads. If you are in it for the long haul, 4 wheel BBK.

My last couple of sets of front PFC 08s have lasted me I think 5-6 weekends while I've had StopTech Street Performance pads in the stock rear setup. I'm pretty happy with that wear rate. PFC 01s may be another story since they're more aggressive and would therefore amplify the imbalance further. But right now my gripe is that nobody sells PFC 08s for the ST-60 caliper anymore. Fortunately I've got one last set and then a set of PFC 06s if I still have the car at that point, otherwise it looks like I'd have to get the 11s.

[M3 Number 86]

ST40 and ST60 - would they make that much of a difference?

Would you eventually say, shit why did I get 40 in front?

[jphughan]

Originally Posted by socal TW

ST40 and ST60 - would they make that much of a difference?

Would you eventually say, shit why did I get 40 in front?

BigJae has ST60 in front and wishes he'd gotten ST40 instead, partly to enable pad rotation from front to rear. It may also open up more wheel choices, but there are plenty of 18" options that clear the ST60. As for a performance difference, I haven't found anybody who's done a detailed comparison of the two. ST60 probably allows your pads and rotors to last longer purely due to the load being distributed across more surface area, and it's probably a bit cheaper per mile as a result, but I don't know where the breakeven point is given the higher upfront cost or how significant or even important that difference is. I haven't seen anybody complain of fade issues with an ST40 front setup though, fwiw.

I got the 60 purely because fade drove me to a BBK in the first place, so I wanted to minimize the risk of that remaining an issue even after a BBK, and the extra cost of the ST60 didn't bother me. But for all I know I would've been just as happy with an ST40 front.

[lutfy]

Originally Posted by bigjae1976

Willing to bet that it would cost less than running OE brakes with the PFC DD rotors. Maybe it was me...I had 2 sets of the PFC rotors on a different car and they would heat crack and just wear out pretty damn fast.

If I had to hazard a guess, the aluminum BBK calipers will shed heat a lot faster than the OE brakes which I do not think are aluminum. OE system just can't withstand extended track use. I blew through 3 sets of front pads in 22 session at Road America. In the past, a set of PF01s would maybe last 1 weekend.

This statement (burning through a set of PF01s in one weekend, heck 1 day at Summit Point for me) is correct.

The PF DD rotors were the last attempt before I ditched OEM to get a set of front BBKs. I am glad I tried it.

Long and short, I dont have to molly cuddle the system and I am b**ls out until cool down. No overheating the stock system. Set of PF08s last me 2-3 weekends depending on the track (still have 1/3 left but I chuck them as I dont like the pedal travel) and front rotors 4 weekends before being replaced. Not an engineer but according to folks at Bimmerworld, the design helps with cooling. Happy to share links chasing down P cars and other M3 members running BBK with no issues under braking.

Are the BBK better? Ofcourse. For me I couldnt justify the economics of dumping any more cash into this heavy street car.

FWIW, I spoke with Mo Karamat of offcambermotorsports. He has developed a kit for the front of the E9X which uses Wilwood calipers. Its measured right to ensure proper brake bias. I did co-drive in one of their e36 race cars (Enduro) and found the brakes to be fantastic for whats considered the price... ready for this? $775 setup (comes with lines, calipers, race pads, brackets). Uses stock rotors so in this case my PFDD should suffice. One of my students just installed this kit in his E46 M3 and I will try it out for a few laps at the Glen next weekend with PCA.

I verified the price of the pads for the Wilwood calipers and they are some 30% cheaper than OEM caliper pads so there the savings will be justified. This option, I may lean towards if I track the M3 as much as I'd like. Current stable includes a C2S and a GT4 Exige which takes up a bit of time as well.

Lutfy

[bigjae1976]

Originally Posted by socal TW

ST40 and ST60 - would they make that much of a difference?

Would you eventually say, shit why did I get 40 in front?

The ST60 pad size is slightly larger than the ST40 pad so there will be a slight advantage maybe in braking power and pad longevity. The pad height between the ST60 and ST40 pad is nearly identical...so is the rotor friction area. The rotor hat will be larger in diameter. It's not like you are getting a lot more rotor surface area for more cooling.

The main advantage of an ST40 kit is you can run the Apex 17s. This is great for those who are R comps since most 275/40R17s are cheaper than the 18s. I run 275 NT01s which are $200 less a set. Not even an option with the ST60.

ST60 pads are generally 50% more expensive than ST40 pads.

The ST40 kit is far more economical while give up very little.

[Killerfish2012]

Originally Posted by lutfy

1) PF Direct Drive rotors. Much better cooling. Not cross drilled so pads last longer.

http://www.m3post.com/forums/showthread.php?t=532815

[lutfy]

Originally Posted by Killerfish2012

http://www.m3post.com/forums/showthread.php?t=532815

Look at the no of track days he has had. When the spider cracks get up to the rim of the rotor, its time to replace. If you run it any further, the result is pretty much what he got. Nothing surprising; can happen to any rotor.

I change my rotors after every 8 track days regardless if there are cracks to the rims or not. By that that they are pretty shot with cracks/wears etc. Cheap insurance.

What's your track setup? Be very curious.

Lutfy

[bigjae1976]

Originally Posted by lutfy

Look at the no of track days he has had. When the spider cracks get up to the rim of the rotor, its time to replace. If you run it any further, the result is pretty much what he got. Nothing surprising; can happen to any rotor.

I change my rotors after every 8 track days regardless if there are cracks to the rims or not. By that that they are pretty shot with cracks/wears etc. Cheap insurance.

What's your track setup? Be very curious.

Lutfy

Just my experience with those PFC DD rotors...they crack badly even when running PFC pads (01 and 97). This was on a 3400lb E46. I went thought 2 sets of discs pretty quickly. I wanna say 6 days each set of discs...can't be sure.

I eventually swapped in a stoptech BBK. Rotors lasted about 24 days of track driving and 10k miles of street use with no pad changes (PF01s). But this was with street tires.

...just some data

[boostincincy]

Guys I bought my E92 yesterday!!!

So it begins.

[jphughan]

Originally Posted by lutfy

I change my rotors after every 8 track days regardless if there are cracks to the rims or not. By that that they are pretty shot with cracks/wears etc. Cheap insurance.

If your rotors still have plenty of thickness and lack any cracks that would be cause for concern, why replace them early? It's not that cheap an insurance policy. I'm all for safety at the track, but not needlessly throwing away perfectly good equipment after some predetermined number of days if it appears to be fine.

Originally Posted by bigjae1976

I eventually swapped in a stoptech BBK. Rotors lasted about 24 days of track driving and 10k miles of street use with no pad changes (PF01s). But this was with street tires.

I'm too lazy to go back and count track days, but it looks like I'll get roughly that same number of track days out of my StopTech rotors, plus about 20K miles of street use. I use PFC08s at the track and (usually) street pads on the road, always on street tires.

[Killerfish2012]

Originally Posted by lutfy

What's your track setup? Be very curious.

Lutfy

Unfortunately stock rotors. Was gonna buy the PF rotors, but after seeing what can potentially happen, I'll stick with stock for now, until I can afford a BBK. Quality control is better on the stock rotors, me thinks.