[G20 WestMid]

Hi all just a quick question. I was wondering can i upgrade my front rotors from 340mm to 370mm.

On the back of my 4 piston caliper it says 340 p440

[insanecoder]

I thought the 370mm rotors are generally paired with the bigger brembo calipers
then there is also the issue of whether your rims will fit over the brake calipers afterwards

[Blacktan]

You need 370/380 callipers for fronts not of 340.

[cfm56d7b]

What's the primary reason for installing larger rotors? Cosmetic? Effectiveness?

Brakes are designed as an integrated family of components: rotors, calipers, and pads. Different pads can be the delta between squeaky or quiet braking performance. More effective braking performance is achieved by changing calipers with corresponding rotors: 6 pistons vs 4 pistons in the front, 4 pistons vs 2 pistons in the rear.

[insanecoder]

Other factors involved but in general larger rotors allow better potential of increased breaking force.. and imo they look better too..

[G20 WestMid]

The reason why I want the bigger rotors are looks nice plus the braking will be better.

I've looked at calipers on a M135i which is the blue caliper. Looks exactly the same as mines.

The m3/m4 caliper looks exactly the same.

I think I will just buy some 370mm rotors to see if it fits.

Only way to find out.

I will let you guys know how it goes

[G20 WestMid]

I've just purchased rear m4 2 piston calipers and also pick up 370mm rear brake disc for the rear from a mate.

So I will fit them on in the next few days. I will send some pictures.

I've just lowered my car h&r sports springs 40mm all round. The car is sitting perfectly very happy with it.

[MickAv8r]

Braking isnt automatically better by going to a larger rotor. The larger rotors are to help dissipate heat. If you need to increase your braking performance the best bang for your buck is always going to be upgrading your tires first. The biggest baddest rotor/caliper possible is useless if your tires have shitty grip.

Next best option is simply upgrading your pads. The OEM BMW pads are pretty mediocre. Simply upgrading to a performance pad will give you improved heat resistance and better torque and feel.

If all you do is commute and the occasional spirited drive then you are done. You arent likely to notice any further improvement, it will mostly be esthetic from that point on.

If you are tracking the car then going to a bigger rotor and pad and switching over to a high temp racing fluid will be noticed as you'll be able to push the car harder ie brake later and harder and more often without heat building up and boiling your fluid.

[Blacktan]

Originally Posted by F30 AAR

I've just purchased rear m4 2 piston calipers and also pick up 370mm rear brake disc for the rear from a mate.

So I will fit them on in the next few days. I will send some pictures.

I've just lowered my car h&r sports springs 40mm all round. The car is sitting perfectly very happy with it.

Subscribed about this mode.
Pls keep me posted about this.
Thanks

[cfm56d7b]

Originally Posted by MickAv8r

Braking isnt automatically better by going to a larger rotor. The larger rotors are to help dissipate heat. If you need to increase your braking performance the best bang for your buck is always going to be upgrading your tires first. The biggest baddest rotor/caliper possible is useless if your tires have shitty grip.

Next best option is simply upgrading your pads. The OEM BMW pads are pretty mediocre. Simply upgrading to a performance pad will give you improved heat resistance and better torque and feel.

If all you do is commute and the occasional spirited drive then you are done. You arent likely to notice any further improvement, it will mostly be esthetic from that point on.

If you are tracking the car then going to a bigger rotor and pad and switching over to a high temp racing fluid will be noticed as you'll be able to push the car harder ie brake later and harder and more often without heat building up and boiling your fluid.

This is one of the best posts on the subject. Could not agree more.

Larger rotors will indeed help dissipate the heat but under normal driving conditions (vs multiple taps on the track) the benefits will be marginal. There is a reason why big brake kits costs on average $3K per axle. The engineering required to improve braking performance involves all components, not just rotors.

[G20 WestMid]

Originally Posted by Blacktan

Subscribed about this mode.
Pls keep me posted about this.
Thanks

I will let you know how it goes

[G20 WestMid]

Originally Posted by MickAv8r

Braking isnt automatically better by going to a larger rotor. The larger rotors are to help dissipate heat. If you need to increase your braking performance the best bang for your buck is always going to be upgrading your tires first. The biggest baddest rotor/caliper possible is useless if your tires have shitty grip.

Next best option is simply upgrading your pads. The OEM BMW pads are pretty mediocre. Simply upgrading to a performance pad will give you improved heat resistance and better torque and feel.

If all you do is commute and the occasional spirited drive then you are done. You arent likely to notice any further improvement, it will mostly be esthetic from that point on.

If you are tracking the car then going to a bigger rotor and pad and switching over to a high temp racing fluid will be noticed as you'll be able to push the car harder ie brake later and harder and more often without heat building up and boiling your fluid.

I agree with what you say

I will be doing track days in the car.

I have upgraded my tyres. I'm running ( 275 35 19 rear ) and ( 255 35 19 front )

I have upgraded quite few things to be honest. The list is long. Brakes is what I'm working on now. After that it's tuning the engine.