Help me choose a BBK

[NathanR]

The brakes on my E30 coupe are on their last legs, so I’ve begun searching for their replacement.

Barring economic collapse, I’m planning on turbocharging the car over the winter, with a target of ~350whp. The car is driven on the street aggressively with the occasional canyon drive and plans for rare track/autocross days in the future.

As I see it, my considered options are:

• Replace with OEM rotors, EBC Yellow Stuff pads
  • I know the existing brakes are fine with current power and likely ~okay~ with 350whp, but I do really value safety and confidence in the car, so I’m not mad about upgrading to bigger brakes instead.
• Replace with RX7 BBK upgrade
  • Seems like this is no longer a “budget” upgrade. The calipers are tough to find, along with the adapters both for the lines and mounting. From what I can tell, Ill be all in in the neighborhood of $800 if I can even find the parts, including used, non-rebuilt calipers.
• Silvermine BBK
  • https://www.silverminemotors.com/pro...1f9074d4&_ss=r
  • I don’t know anything about Silvermine but this seems like a decent price for the kit.
• UUC BBK
  • https://store.uucmotorwerks.com/big-...l-ix-p563.aspx
  • No adapter required

Overall, I think I’m torn between the Silvermine and UUC. From what I’ve read, it sounds like UUC is solid on customer service and people like the kit, but it looks like the Silvermine kit is similar with 1 piece rotors and Dynalight instead of Dynapro calipers, but requires adapters at a lower price.

Additional questions:

• Should I upgrade the master cylinder while I’m there?
• Should I upgrade the booster?
• Do I need to remove the proportioning valve if I’m just upgrading the fronts?

[MrBurgundy]

I don't think you have to do the master

but e32 25.something would be a nice addition

[82eye]

also Massive Lee who's active on the board. https://www.massivebrakes.com/shop

[Massive Lee]

I offer a dozen different BBKs for e30s and e30 M3s. Many front as well as rear kits. I was actually the first to offer BBKs for e30s starting 25 years ago. I have "inspired" a few shops too ;-)

There are a few factors that will dictate what BBK to select.
- Budget
- Wheel size and clearance
- Purpose of the car - street, HPDE, full race
- Engine power
- Is front-only enough, or do you need front and rear?

My thoughts on your selections

• Replace with OEM rotors, EBC Yellow Stuff pads - This will not get you any improved performance. But stock is good too ;-)
• Replace with RX7 BBK upgrade - VW G60 rotors and RX7 was cool topic in the early 2000s. It sure looked cool. RX7 are big though, and flexible. Back in the days, I took the idea to another level by replacing the used RX7 calipers with brand new Wilwood Dynapro calipers with 4 pistons. Great clearance. Then when the 6 piston Dynapro calipers came out, I bought one for testing. And it is totally interchangeable. Great looks and slightly more pad area than Dynapro 4 pistons. https://www.massivebrakes.com/shop/p...k-e30-280x22mm . 320$cad is $230usd + $80usd Centric rotors + $600usd calipers = $910usd (much less in fact since calipers can be had for cheaper)
• UUC BBK - Still way overpriced

No need to change the bias valve if the front caliper pistons are spec'd properly.
No need to change MC, but a tab bigger MC doesn't hurt if you want a decreased pedal throw at the expense of increased force needed.

[NathanR]

Thanks for the feedback everyone!

I think at this point I'm kicking RX7 calipers out of the equation, and doing the math here, UUC doesn't make sense..

Lee, to answer your questions,

1. Budget - Ideally I'd like to keep this around $1k or under.
2. Currently have 15" wheels, will move to 16" when it comes time for tires.
3. Street car, but plan for it to be capable of a very rare track day once in a while.
4. Stock M20B25, plan to turbo targeting 350whp
5. I hope that front is sufficient given my needs

• Massive Brakes - $897 + ? - https://www.massivebrakes.com/shop/p...k-e30-280x22mm
  • Kit - $230
  • Rotors - $86
    • https://www.summitracing.com/parts/c...o/submodel/g60
  • Machining for rotors - $?
  • 4 Piston Dynapro Calipers - $518
    • https://www.buybrakes.com/wilwood-12...V_gDBIiubtgevP
  • BP-10 Pads - $63
    • https://www.buybrakes.com/wilwood-15...iiODWBsSAti5pA
• Silvermine - $826 - https://www.silverminemotors.com/pro...44700902195514
  • Everything included
  • They offer 290mm and 300mm rotor options.
  • 4 Piston Dynalite
  • 6 Piston Dynalite option - $955 - https://www.silverminemotors.com/pro...pr_seq=uniform
    • If I went this route, I assume the larger master cylinder then comes into play.

I think I'm between the two here, would be curious what I'm looking at in machining cost for the Corrado rotors. The 6 Piston option is enticing for the price from Silvermine, but I'm not entirely sure I'm going to benefit from it without really messing up my brake bias, and at that point needing to add a adjustable bias or a rear kit along with the upgraded master cylinder to balance things out again.

[Massive Lee]

Currently 165hp but aiming at 350hpo.
Street car, but track capable.

As long as you stick to 165hp. Street or track use, any of those kits will do.

But if indeed running 350hp, it is a totally different ball game, especially if tracked.
Then you will need FRONT and REAR upgrades

0.81" rotors will no longer be sufficient to handle tracj heat at 350hp
You are into 1.25" thick rotors, that's 32mm thickness. Both front and rear.

And 350hp tracked power calls not only for 1.25" rotors, but of a larger 13.09" diameter. That's 332x32mm Which will call for 17" rims.

https://www.massivebrakes.com/shop/p/massive-brakes-bbk-e30-332x32mm-monster

Therefore, setting your goals straight is quite important. And if you only intend to hit 350hp in three years from now, then do a first 280x22mm step now, and see later for the next step.

Also, just because a caliper has 6 pistons, it doesn't mean it will unbalance the brake bias, as just because it has 4 pistons will keep it in check. What matters is to total piston area.

On 280x22mm rotor, get 1.375" pistons for a 4 pot caliper. For a 6 pot caliper like the Dynapro 6, then it shall be 1.375" + 1.00" + 1.00"

Pricewise, Wilwood's products have seen a huge price increase in the past 4 years. The Dynapro 4 was only $150usd back then. Now $300usd. And in my opinion, that caliper is not worth $300usd when a much more potent Superlite costs $250usd
(used to be $170usd back then)

But that stiffer Superlite caliper using bigger and thicker brake pads is only used on "higher level" brake set-ups like the Sport 300x21mm and Race 300x32mm BBK, or the Monster kit.

https://www.massivebrakes.com/shop/p/massive-brakes-bbk-e30-300x32mm-superlite

https://www.massivebrakes.com/shop/p/massive-brakes-bbk-e30-332x32mm-monster

Anyway, start with what you need now, and see later once you upgrade that engine.

[NathanR]

Super helpful info Lee!

So the 350whp would definitely be more near term, like within the next couple months, so that’s where being said, I’d rather get what’s right for the long-term now. I have no plans to exceed that target for this car really ever.

I do think I’m probably giving too much weight to the idea of tracking the car, I think it would be rare if ever.

All taken into account, what is the most economical way to get into sufficient brakes for that power goal for a street car only, and is it possible to do so without upsizing wheels?

[82eye]

is it possible to do so without upsizing wheels?

never seen a bbk that didn't need larger wheels. comes with the territory.

[digger]

for serious track use something from Massive.
For street use >95% of time i would look for an OE upgrade from similar vintage BMW.

[litu]

and if you have room in the engine bay, e90 brake booster, that is so good upgrade, I highly recommend

[Dj Buttchug]

OP I have a Silvermine kit. It is very impressive for the money. 6 pot front 4 pot rear. I used the stock booster and installed an adjustable bias valve. The braking power is incredible. For comparison to your goals my car makes 300 wheel hp. This kit provides more than enough braking power for my setup. The install is fairly straightforward however you do have to trim the factory splash shields both front and rear. They also fit behind a 15 inch wheel. Best of luck in your decision.

[Northern]

Dj Buttchug Front Corrado G60 rotors and rear E36 of some kind? Do they give you info for replacements or do you have to buy from them?

I've been drooling over Massive's stuff for the past 10+ years... glad the website is back up

[Dj Buttchug]

Dj Buttchug Front Corrado G60 rotors and rear E36 of some kind? Do they give you info for replacements or do you have to buy from them?

I've been drooling over Massive's stuff for the past 10+ years... glad the website is back up

From what I have researched you can get all parts needed directly from WIlwood. Silvermine is just a dealer that built a specific kit using Wilwood calipers, pads and rotors.