[Atiqofsweden]

Hi!

Just switched to a -18 i3S from a -14 F31 328i, as i could not justify the cost of petrol for daily commute anymore.

Anyway, I am a part of a group here arranging car meets, so I have always been modding my vehicles, the i3 will be modded as well, I like to keep it clean and simple, and not rice it.

So I figured I got a couple of f32 340i front 4-pot calipers, should be the same ones as on the i8, just not painted.

Does anyone know if the i8 discs will fit on the i3 and if the calipers will clear the 20" rims, outwards towards the spokes?

If it fits and works properly they will be put on!

[ovekvam]

The i3S rims have a lower offset than regular i3 rims. If you get clearance issues, it could perhaps be a solution to go for regular i3 rims with spacers...

[Atiqofsweden]

Originally Posted by ovekvam

The i3S rims have a lower offset than regular i3 rims. If you get clearance issues, it could perhaps be a solution to go for regular i3 rims with spacers...

True, as I've got the calipers at home already I'm going to try to test mount them and see how it works out. Spacers might be a must!

[Obioban]

Very likely it'll downgrade your car in multiple ways.

Unless you're experiencing brake fade (doubt it), larger brakes means worse braking (more rotation mass) and worse handling (more unsprung mass).

Unless you've done the calculations to see if the and piston volumes are the same as stock, you'll also likely make the brake balance worse (which can range from worse stopping distances to dangerous behavior) and/or worse pedal feel.

Brakes aren't just bigger = better.

[Noggie]

Originally Posted by Obioban

Very likely it'll downgrade your car in multiple ways.

Unless you're experiencing brake fade (doubt it), larger brakes means worse braking (more rotation mass) and worse handling (more unsprung mass).

Unless you've done the calculations to see if the and piston volumes are the same as stock, you'll also likely make the brake balance worse (which can range from worse stopping distances to dangerous behavior) and/or worse pedal feel.

Brakes aren't just bigger = better.

True.

And how much do you really use the brakes, I guess 90% of my braking is regeneration, I rarely use the brakes on my i3s.

[Coastali8]

Who uses the brakes on an i3?

[Coastali8]

Originally Posted by Noggie

True.

And how much do you really use the brakes, I guess 90% of my braking is regeneration, I rarely use the brakes on my i3s.

There is absolutely no need for different brakes on an i3.
You could probably nearly drive the car entirely without any brakes.
I agree that changing brakes would most likely make the car worse and would be an exercise in futility.

And just a really bad idea.

[Atiqofsweden]

It's not because the i3 brakes are bad, quite the opposite they are not. this was mainly because I wanted to do something a bit different to the car. I will definitely not adventure any bit of safety as my whole family sometimes travel in this car. I'll just sell the calipers instead and put the money towards a fast charger at home instead!

[Coastali8]

Originally Posted by Atiqofsweden

It's not because the i3 brakes are bad, quite the opposite they are not. this was mainly because I wanted to do something a bit different to the car. I will definitely not adventure any bit of safety as my whole family sometimes travel in this car. I'll just sell the calipers instead and put the money towards a fast charger at home instead!

That sounds like a much better idea and a lot more useful too.

[Atiqofsweden]

Originally Posted by Coastali8

That sounds like a much better idea and a lot more useful too.

Agreed, found something else I can do instead as well, retrofit the "suite" interior lighting package

[-c-]

Originally Posted by Atiqofsweden

Agreed, found something else I can do instead as well, retrofit the "suite" interior lighting package

Awwww man! I was looking forward to seeing what you made.

You let people
Get to you to easily! Screw their thoughts and just tread your own path!

My Mini Cooper has a giant Brembo BBK on just the front and does it mess with break balance ? Nope!

My X5 has giant rotors with 6 piston calipers and looks great!

Hey for me it's all about the looks! Stance and all that jazz.

Im a car designer for my profession so I'm very biased! Lol.

Some here are all about eco and why mod an I3. It makes no sense ! Well why not who the hell cares!

Again I'm sure the same was said about Honda civics back when that trend was happening.

Until someone tries nobody will know.
I hate looking at the weak small rotors in the i3 with giant ass 20" rims. Need proportions and a BBK would fill it in Nicely.

Don't mean any disrespect and everyone has their opinion, well mine has always been just to do what I want and if your not on board that's fine thanks for watching! Lol.

From what I gather their calipers off a Mini Cooper so a JCW BBK would or may fit and the rotors theirs so many two piece options you could probably make one.

The car has reached its braking limit when I run it hard plenty of times so having a little extra probably wouldn't hurt.

Without R&D nobody will know.


In a sea of the same and boring some just like to be different!

[ovekvam]

I also think it would be interesting with M-Sport brakes on an i3. The arguments against are of course valid. It would probably upset the brake balance a bit, and increase the unsprung weight. The calipers are however made of aluminium, so the brakes are not as heavy as they look. Besides, the M-Sport is a straight swap without messing up the brake balance on the 1/2 and 3/4 series. It would surely look good.

I have owned the F20 1-series with both small brakes and M-Sport brakes. Stopping distance is the same. Brake feel is quite similar with cold brakes. The car feels slightly more light footed over bumps with the smaller brakes, but the bigger brakes are superior after a few laps on a race track. The small ones fade a bit, and wear a lot when they overheat.

[-c-]

Originally Posted by ovekvam

I also think it would be interesting with M-Sport brakes on an i3. The arguments against are of course valid. It would probably upset the brake balance a bit, and increase the unsprung weight. The calipers are however made of aluminium, so the brakes are not as heavy as they look. Besides, the M-Sport is a straight swap without messing up the brake balance on the 1/2 and 3/4 series. It would surely look good.

I have owned the F20 1-series with both small brakes and M-Sport brakes. Stopping distance is the same. Brake feel is quite similar with cold brakes. The car feels slightly more light footed over bumps with the smaller brakes, but the bigger brakes are superior after a few laps on a race track. The small ones fade a bit, and wear a lot when they overheat.

Yep, My f15 40E with the added weight of the batteries made the stopping distance and panic stops where that of nightmares as it didn't want to stop. So I fitted M brakes on it and what a difference.

Night and day.


Some cars don't need both front and rear and some do. Also the computer can also adjust if needed. But rarely would we even use the brakes in a sporty fashion and I'm sure if you kept it to a certain size it be perfect.

In fact the front caliper being solid steel going to a two piece design with an aluminum hat may get you a larger rotor with less or even the same weight of heavier not by much.

The aluminum mono-block caliper are also very light weight.

Either way I'd do it for looks as it's hard to argue a BBK looks great no matter what it's on. I'm sure performance would also be better despite others thinking otherwise.

[GPVG39]

Question! I want to keep the same brakes on my i3, but the original disks just rust like crazy! Means the car look old. Can I change the disks only to something else? And if, which ones? Has anyone done that at all? Thanks guys!

[-c-]

Originally Posted by GPVG39

Question! I want to keep the same brakes on my i3, but the original disks just rust like crazy! Means the car look old. Can I change the disks only to something else? And if, which ones? Has anyone done that at all? Thanks guys!

I've seen some use a rotor that has the cross drilled style on it if you want something a little more exciting.

You can take your rotors to any custom shop and they can use high temp powder coat and spray them and it will keep the rust from forming.

Their are some aftermarket companies that also sell coated rotors. Just have to look for them.

The OEM plating doesn't last to long.

The coating like zinc and whatnot is great for cooling and such as it's extremely thin and creates a protective barrier for a little while the ceramic coating works much longer. Usually the life of the rotor but it does retain heat a little more.

The fact you use the breaks so little in the i3 I don't see it being an issue at all.

[ovekvam]

One little trick to avoid brake rust, is to park your car with dry brakes on wet days. Do a little left foot braking to get a bit of heat into the rotors just before stopping to park.

[GPVG39]

Thanks for all the info. I heard the brake calipers are aluminum made. Is that true?

[-c-]

Originally Posted by GPVG39

Thanks for all the info. I heard the brake calipers are aluminum made. Is that true?

Most calipers nowadays are aluminum.... I haven't seen a non aluminum caliper on any modern day car for quite some time........

[MsGoGoMoto]

Originally Posted by -c-

Most calipers nowadays are aluminum.... I haven't seen a non aluminum caliper on any modern day car for quite some time........

I almost forgot my i3 had brakes until the fluid change reminder came up 😂🤣

When I switch to my gas powered Dakota, I let off the gas waaaaay before getting to a stop light, kicking myself into the but because I didn't regenerate jack! But I do save on brake wear though!!!