375-380mm rotors/discs under 18" wheels

[M Coupe]

Hi fellas, can anyone share their 375-380mm rotor & caliper setup under an 18" wheel? Photos would be great and please specify radial & lateral clearance as well. Thanks!

[Obioban]

AFAIK there's only 1-2 18" wheels that'll clear 380s... I'm tempted to say Volkes, but not certain on that.

Really, the same thought process that leads you to wanting 18" wheels should lead you to wanting 355mm brakes-- lighter, better performing, cheaper wear items, only a cosmetic "penalty" in exchange.

[jareds941]

AFAIK there's only 1-2 18" wheels that'll clear 380s... I'm tempted to say Volkes, but not certain on that.

Really, the same thought process that leads you to wanting 18" wheels should lead you to wanting 355mm brakes-- lighter, better performing, cheaper wear items, only a cosmetic "penalty" in exchange.

I mean to be fair, the larger brakes will perform better, at the limits on track.

[Obioban]

I mean to be fair, the larger brakes will perform better, at the limits on track.

Eh, probably worse. Unless you’ve 2Xed your HP and are magically not overheating, you would be past the thermal limits of the 355s... and the 380s have more rotational inertia (worse) and weight (worse).

[Hyperboost]

FYI all 18" TE37 wheels clear 380mm BBKs. I had a Brembo 8!!!! piston 380mm kit and my TE37 18X9.5 cleared no problem. my TE37SL cleared as well.

[Hyperboost]

380mm is just for looks. they are too heavy and don't make sense. AP/Essex makes a great kit and will work with 17" wheels

[liam821]

I mean to be fair, the larger brakes will perform better, at the limits on track.

You'd need to have a pretty hot e46m3 to approach the limits of a Brembo 355 kit with race pads, good fluid, and cooling ducts. The AP racing competition brake kit uses 355x32 rotors and radical 6-piston calipers which is the go-to for most racers...

https://www.essexparts.com/essex-des...668355mm-e46m3

[jareds941]

You'd need to have a pretty hot e46m3 to approach the limits of a Brembo 355 kit with race pads, good fluid, and cooling ducts. The AP racing competition brake kit uses 355x32 rotors and radical 6-piston calipers which is the go-to for most racers...

https://www.essexparts.com/essex-des...668355mm-e46m3

Noted to both you and Obioban. Not that I had any intentions of anything more than 355. I had been planning on this kit for some day https://www.essexparts.com/essex-des...060355mm-e46m3 but seems to be discontinued now.

Anyways, back on topic. Looks like Hyperboost had some good info for the OP

[liam821]

Noted to both you and Obioban. Not that I had any intentions of anything more than 355. I had been planning on this kit for some day https://www.essexparts.com/essex-des...060355mm-e46m3 but seems to be discontinued now.

Anyways, back on topic. Looks like Hyperboost had some good info for the OP

Yeah it was replaced by https://www.essexparts.com/essex-des...668355mm-e46m3 which uses a newer caliper.

new caliper: https://apracing.com/race-car/brake-...25mm-thick-pad
old caliper: https://apracing.com/race-car/brake-...mm-thick-discs

[jareds941]

Yeah it was replaced by https://www.essexparts.com/essex-des...668355mm-e46m3 which uses a newer caliper.

new caliper: https://apracing.com/race-car/brake-...25mm-thick-pad
old caliper: https://apracing.com/race-car/brake-...mm-thick-discs

And price went up at least $1k from my memory 🤣I'm sure they are better...

[liam821]

And price went up at least $1k from my memory 🤣I'm sure they are better...

haha I'm ssuuuurrrreeeeeee they're $1k better. 🤣🤣

[r4dr]

And price went up at least $1k from my memory 🤣I'm sure they are better...

That price kind of shocked me too but it seems that’s the ballpark for 6pot kits:

https://www.turnermotorsport.com/p-585100-stoptech-front-6-piston-big-brake-kit-355x32mm/

I'm not sure what the real world benefits over a 4pot kit of the same size are though, and if it’s worth the price.

[Sharocks]

I believe Apex EC7's and TE37's with the right offset will clear 380mm rotors. IDK why you'd want them though. My Brembo GTR kit is heavier than the stock setup and they're only 4 piston calipers with 355m discs. Imagine what a bigger rotor, bigger caliper and bigger pads weigh more? Obviously not a ton more but you're adding weight to stop better. Car is relatively light, it doesn't need 6 pistons to stop. Needs good tires, pads and fluid at the bare minimum.

[Obioban]

I believe Apex EC7's and TE37's with the right offset will clear 380mm rotors. IDK why you'd want them though. My Brembo GTR kit is heavier than the stock setup and they're only 4 piston calipers with 355m discs. Imagine what a bigger rotor, bigger caliper and bigger pads weigh more? Obviously not a ton more but you're adding weight to stop better. Car is relatively light, it doesn't need 6 pistons to stop. Needs good tires, pads and fluid at the bare minimum.

The Brembo 355/4s are lighter than the stock rotors/calipers. Maybe (don't know) more rotational inertia, but lighter.

The benefit to 6 pistons is larger pads, which gives you longer longer pad life. I don't think it's worth the trade off, but that is a benefit... the only benefit AFAIK.

I have to say, my Brembo GTs (355/4 front, 345/4 rear) are one of the best mods I've done to this car. I've now had them for 14 years/140,000 miles/20,000 track miles, and they've been 100% flawless throughout that entire time. I believe they are the only mod I've done to the car that I haven't later redone with something else/better. I can't see any room for improvement. (well, I see the allure of free rotors/pad by using FCP, which they don't allow, but that's no fault of theirs... and I decided that benefit wasn't worth the trade off in performance).

[r4dr]

How often do you rebuild the calipers with fresh seals and etc?