Brake discs for 2.5 to 3.0si upgrade

[Swizzle]

Hi all, after a poor performance on a recent trackday im doing the “easy” brake upgrade, ive sourced the front calipers from a 3.0si and the rears from a 320d, my question is does anyone know if i have to use the z4 3.0si discs or can i use the e46 330 front and 320d rear discs as there seems to be more available and at better prices if you say e46 even though the disc specs look exactly the same? Thanks

[G600]

Have a look at real OEM and compare part numbers, I e got E46 discs on mine but the calipers are E46 too so double check but I'm 99% sure they are the same.

[brillomaster]

just out of interest, what was the poor braking performance you experienced? are you already running decent brake pads and fluid?

[TheDan]

Short answer, yes.

Longer answer, the E46 330i and Z4 3.0si use the same caliper carrier, caliper and discs (325x25mm) at the front. Therefore all you need to look for is a disc which is 325x25mm and is compatible with either Z4 3.0si or E46 330i/Ci/d to make sure its the correct offset from the hub.

[Swizzle]

just out of interest, what was the poor braking performance you experienced? are you already running decent brake pads and fluid?

Almost instant fade due to the fluid overheating, i was running ebc drilled and grooved discs at the front with bluestuff pads, standard rear and fluid, brakes were hot by the end of the sighting laps, lasted about 10 minutes on track before the pedal was on the floor and the brakes were smoking

[Swizzle]

The specs on the fronts look the same but the rears now look like they’re deeper on the e46

[Swizzle]

Sorry deeper on the z4

[TheDan]

Yes that is correct. Despite the Z4 3.0si and E46 320d rear calipers and carriers being the same, the Z4's disc is far more "dished" due to a drive flange (hub) that sticks out further.

[Swizzle]

Yes that is correct. Despite the Z4 3.0si and E46 320d rear calipers and carriers being the same, the Z4's disc is far more "dished" due to a drive flange (hub) that sticks out further.

Answers my question perfectly

[brillomaster]

just out of interest, what was the poor braking performance you experienced? are you already running decent brake pads and fluid?

Almost instant fade due to the fluid overheating, i was running ebc drilled and grooved discs at the front with bluestuff pads, standard rear and fluid, brakes were hot by the end of the sighting laps, lasted about 10 minutes on track before the pedal was on the floor and the brakes were smoking

Ha managed to do the same thing with the same set up at snetterton! Decent high temp fluid is very useful, i also found that a standard car has zero front brake cooling. I found a free mod was removing the front fog lights and access panel behind them. Getting fresh air into the wheel well really helped keep brake temps down.

Ebc blues are ok... but if you do track stuff often you'll need decent pads like pagid rs, performance friction or carbotech. They arent cheap, but last so much longer than other pads so they are good value.

[nfo]

What brillomaster said. I've been through the same process. Totally cooked standard brakes on track, upgraded to 3.0si setup, cooked those on track too. Rigged up cooling ducts from front fogs to a set of Bimmerworld backing plates, huge improvement. I've since gone to a Megane Brembo 4-pot and E46 M3 325 x 28 mm setup which has improved feel and consistency no end.

I've found Bluestuff NDX to be well behaved (quiet, no tricky bedding, no fade issues) but to wear quickly. In the current setup I got through a whole set in one day at Bedford! Last 4 track days (Anglesey, Combe, Cadwell, Combe) have all been on the same set of Pagid RSL29s - highly recommend but they are squeaky. And expensive - but much cheaper per track day!

[Swizzle]

How do you find the more track focused pads on road, i only do a couple of track days a year so dont want to lose everyday drivability, might be a case of swapping pads before trackdays

[TheDan]

How do you find the more track focused pads on road, i only do a couple of track days a year so dont want to lose everyday drivability, might be a case of swapping pads before trackdays

With the standard calipers its quite a faff to change pads frequently (might be okay a couple of times a year).

I have Carbotech XP8 front pads which feel great on track and I am yet to fade them. On the road they actually have quite an impressive bite from cold for track pads, however, they do squeal a bit in the final 20-30mph coming to a gentle stop, but it barely bothers me. Bear in mind I have Brembos from a Megane RS so the pads are quite a lot bigger and there wasn't space for an anti squeal shim.

Rears are just yellowstuffs which do naff all tbh.

[Scooba_Steve]

I have Carbotech XP8 front pads

Are they E marked? Just curious.

[TheDan]

I have Carbotech XP8 front pads

Are they E marked? Just curious.

Not sure.