Big Brake kit expert thoughts needed

[Bruno]

The E34 already has a pretty large master cylinder, and I do not want people to start messing with it. So the idea is to keep the same pedal travel as let's say upgraded brakes like 750i front and 540i rear.
If I can keep the numbers the same and determine what size pistons I need then it would be a no brainer for everyone to upgrade if they want.

The equation is (Master Area/Caliper piston Area) x pedal stroke = piston stroke

I think that the Brembo caliper upgrade for the E34 is using around 42mm pistons and the E28 M5 / E24 M6 4 pot calipers were 40 mm pistons.

You are on the right track about needing bigger master cylinder to compensate for brake travel on larger pistons calipers or otherwise the pedal does go to the ground.

I don't know the equation of the fluid dynamic but cracking open a brake handbook should yield the info. I will check my Bosch handbook later tonite to see if they mentioned anything about this.

The smallish piston on multiple pistons caliper means more contact area on pads and thus more force on the greater area of the brake pad and thus better pad perfomance and better braking. As your website said, the balance of the front and rear braking performance is very important.

[Tiger]

F1 wheels are not as small as you think it is.

[healtoeit]

Wilwood superlite calipers and pads that go along with them. I am using my car on the track so I am not worried about pad noise but performance.

On UUC website it says...

Wilwood PolyMatrix
Carbotech
Cobalt Friction
EBC
Hawk
KFP Magnum (formerly Cool Carbon)
Pagid Racing
Performance Friction
Porterfield

sell pads for the kit

[healtoeit]

I think that the Brembo caliper upgrade for the E34 is using around 42mm pistons and the E28 M5 / E24 M6 4 pot calipers were 40 mm pistons.

So that would make the pedel travel greater? You are obviously an engineer...all you equations and what not! hehe! just playing man.

I do think that their si a bigger master cylinder that will fit in the e34. I can't remember which but their is one out there!

[Triton540i]

Why would anybody want larger wheels and larger discs for more rolling mass? Look at F1, small wheels with lots of skin, small, compact braking systems... any huge investment in "Big Brakes" for the streets is a waste of money as I look at it, get some nice cross drilled rotors with a great set of kevlar pads and you're set!

Just my two cents worth on the subject.

-Eric

[Bruno]

Why would anybody want larger wheels and larger discs for more rolling mass? Look at F1, small wheels with lots of skin, small, compact braking systems... any huge investment in "Big Brakes" for the streets is a waste of money as I look at it, get some nice cross drilled rotors with a great set of kevlar pads and you're set!

Just my two cents worth on the subject.

-Eric

Eric... Cross drilled rotors and kevlar pads? Is that what you have on your car?

Big Brake kit is mainly about heat management... and the comparison to F1 is similar to comparing a plane to the space shuttle...

And then you have the talk about fix calipers vs floating calipers, and brake torque... but it is late.

And it does look better under 18" rims hehehe.

[Bruno]

So that would make the pedel travel greater? You are obviously an engineer...all you equations and what not! hehe! just playing man.

I do think that their si a bigger master cylinder that will fit in the e34. I can't remember which but their is one out there!

Bigger pistons mean that you need to push more fluid to make them move... so the pedal goes further down.

Interesting non the less, I will do more testing.

[healtoeit]

And it does look better under 18" rims hehehe.

Ok, here is what i was wondering in my brake thread! What breaks will fit under what wheels? The chart on e34.net only goes up to 345mm rotors fittting under 17in. Wheels. Will the 348mm wilwood kit from uuc fit under 17in. wheels?

[healtoeit]

Bigger pistons mean that you need to push more fluid to make them move... so the pedal goes further down.

So, then how does the UUC Wilwood system allow for you to keep the stock cylinder?

[Bruno]

So, then how does the UUC Wilwood system allow for you to keep the stock cylinder?

Simple calculation to keep the overall piston size the same.

2 AP for single piston floating calipers should be roughly = to 4 AP for 4 pot calipers fixed.

AP = Piston Area.