[f30bmw340i]

Before I start off, I wanted to thank a bunch of folks in the forum who helped me a ton with my questions. pauli18c PabloFAFFAN johnung jmanB45 danarino alohasurftoad AspektUSA Solidjake mh24 . Apologies if I forgot someone.

Also, shoutout to America’s Tire Mountain View. Thorin is the guy you want to talk to. He really helped answer a bunch of my questions and ordered different options, mounted it on the car and then let me make a decision. To be clear, he mounted the alloy and the tire was just put on it like a prop.

Thoughts after almost 1k miles of driving: My purpose was to use the car for road trips. I wasn’t looking to take it to the track or for the best control in the curves. Coming from a nimble roadster like the Miata, that wasn’t the goal. The goal was to be comfortable on road trips, with as minimal road noise as possible with decent handling.

Conti DWS06+ -

1. I have to say that the comfort of the sidewall is way better and the road noise is much lesser than the stock tire (which was the bridgestone potenza s001, I think). So as far as the tire choice, I made the right choice.
2. I think I saved a lb or so with the Continental DWS06+ 245/40R18 compared to the stock tire as well. I don’t think RFT’s are for me.
3. The low profile stock tires would send shocks through the car. Not to mention they were 19’s. I am not a big fan of big wheels & low profile tires. Neither am I looking to reduce the fender gap between the tire and the car for the looks.

Wheels - I went from my 19” 704M wheels to the Enkei Raijin 18x8.5 38 Offset

1. I absolutely love the look of these wheels. They even take the BMW floating centre hubcaps (super gimmicky but I am shallow).
2. I think it must’ve saved around 4lbs per wheel. Going by the stats on a few sites here and there, so don’t hold me to it.
3. I also confirmed that if I were to add the m sport brakes (to the rear alone), it would clear the wheel. Which is a mod I intend to do after the CPO period.

Squared vs staggered setup: I cannot advocate enough for the squared setup. It wasn’t only because it was a practical setup (for tire rotation or being able to carry a spare on a road trip) but just the driving dynamics feels a lot better. I’m by no means an expert, so I’ll try my best to explain it with my experience. I’ve experienced staggered setups before but in my 340i it had the weirdest feel. When I would try to accelerate in a curve/turn, it would almost feel like the chassis was twisting. It’s almost like the car naturally wants to oversteer but something’s preventing it from doing so. In a nutshell, it felt unnatural, I hadn’t experienced driving physics like that. Again, I am no expert and it could be because of a multitude of reasons (RWD car, heavy front because of the 6cyl engine, etc) but I don’t feel it anymore with the squared setup, so I can only assume that it’s because of it being staggered previously.
245/40 vs 255/40 - which to get: Quite a lot of our forum experts recommended the 255/40 and I sort of wish I had listened to them. My fears were two fold

1. Wider and thicker front tire (especially the Conti DWS06+) would make the steering sluggish while turning: I felt going with the 255/40 would be too far a departure from the stock, and that it would make the steering sluggish. I was wrong and overthought it, and should’ve just listened to the forum experts. The car feels super nimble (because of the weight drop in each tire & wheel) and I actually do wish it had a tiny bit more sidewall, cause I can still feel the bumps a tiny bit. FYI, my 340i has the adaptive suspension.
2. Front tire would rub on the inside: I’m still not sure on this. All our forum experts did say that it won’t rub, but everyone from Apex (I was considering one of their wheels) to Tirerack said that it would. I chickened out and went with the 245/40. For anyone else who is trying to achieve the same goal as me, I would recommend the 255/40.

Here are some photos.


Edited offset from 35 to 38 after Johnung pointed it out. Also changed Tire name from S006 to S001

[johnung]

Originally Posted by f30bmw340i

Before I start off, I wanted to thank a bunch of folks in the forum who helped me a ton with my questions. pauli18c PabloFAFFAN johnung jmanB45 danarino alohasurftoad AspektUSA Solidjake mh24 . Apologies if I forgot someone.

Also, shoutout to America's Tire Mountain View. Thorin is the guy you want to talk to. He really helped answer a bunch of my questions and ordered different options, mounted it on the car and then let me make a decision. To be clear, he mounted the alloy and the tire was just put on it like a prop.

Thoughts after almost 1k miles of driving: My purpose was to use the car for road trips. I wasn't looking to take it to the track or for the best control in the curves. Coming from a nimble roadster like the Miata, that wasn't the goal. The goal was to be comfortable on road trips, with as minimal road noise as possible with decent handling.

Conti DWS06+ -

1. I have to say that the comfort of the sidewall is way better and the road noise is much lesser than the stock tire (which was the bridgestone potenza s006, I think). So as far as the tire choice, I made the right choice.
2. I think I saved a lb or so with the Continental DWS06+ 245/40R18 compared to the stock tire as well. I don't think RFT's are for me.
3. The low profile stock tires would send shocks through the car. Not to mention they were 19's. I am not a big fan of big wheels & low profile tires. Neither am I looking to reduce the fender gap between the tire and the car for the looks.

Wheels - I went from my 19" 704M wheels to the Enkei Raijin 18x8.5 35 Offset

1. I absolutely love the look of these wheels. They even take the BMW floating centre hubcaps (super gimmicky but I am shallow).
2. I think it must've saved around 4lbs per wheel. Going by the stats on a few sites here and there, so don't hold me to it.
3. I also confirmed that if I were to add the m sport brakes (to the rear alone), it would clear the wheel. Which is a mod I intend to do after the CPO period.

Squared vs staggered setup: I cannot advocate enough for the squared setup. It wasn't only because it was a practical setup (for tire rotation or being able to carry a spare on a road trip) but just the driving dynamics feels a lot better. I'm by no means an expert, so I'll try my best to explain it with my experience. I've experienced staggered setups before but in my 340i it had the weirdest feel. When I would try to accelerate in a curve/turn, it would almost feel like the chassis was twisting. It's almost like the car naturally wants to oversteer but something's preventing it from doing so. In a nutshell, it felt unnatural, I hadn't experienced driving physics like that. Again, I am no expert and it could be because of a multitude of reasons (RWD car, heavy front because of the 6cyl engine, etc) but I don't feel it anymore with the squared setup, so I can only assume that it's because of it being staggered previously.
245/40 vs 255/40 - which to get: Quite a lot of our forum experts recommended the 255/40 and I sort of wish I had listened to them. My fears were two fold

1. Wider and thicker front tire (especially the Conti DWS06+) would make the steering sluggish while turning: I felt going with the 255/40 would be too far a departure from the stock, and that it would make the steering sluggish. I was wrong and overthought it, and should've just listened to the forum experts. The car feels super nimble (because of the weight drop in each tire & wheel) and I actually do wish it had a tiny bit more sidewall, cause I can still feel the bumps a tiny bit. FYI, my 340i has the adaptive suspension.
2. Front tire would rub on the inside: I'm still not sure on this. All our forum experts did say that it won't rub, but everyone from Apex (I was considering one of their wheels) to Tirerack said that it would. I chickened out and went with the 245/40. For anyone else who is trying to achieve the same goal as me, I would recommend the 255/40.

Here are some photos.

Thanks for the mention and congrats on your wheel/tire project. Photos look nice!
I have a couple of comments/questions:

Are you sure that your offset is +35? For the Enkei Raijin 18x8.5, the only 5x120 bolt pattern that I see listed is an ET38 (which might require a small spacer). See Enkei catalog photo.

TireRack lists your DWS06+ 245/40-18 as 22lbs so I'm guessing that you probably saved more than 1 lb vs your previous tire. You should look it up on TireRack (found in each tire's Specs tab)

I'm curious what your Enkei's weigh. They don't list many wheel weights in their catalog.

Curious…How do you know for sure that your Enkei's will clear the rear Brembo 345x24 brakes? Clearance issues are usually the bulbous caliper hitting the barrel of the wheel, not the diameter of the brake rotor.

I'm curious if the Enkei's will clear the front Brembo 370x30 brakes? That make be easier to estimate since it appears that you currently have front Brembo 340x30 brakes. So with the 370's the entire caliper essentially moves out 15mm from the center. There still needs to be a certain amount of clearance between the caliper and the barrel of the wheel. Too small of a gap there allows road debris, twigs, etc to get caught and potentially scratch wheel and caliper. Brembo had a clearance spec on their BremboGT website but I don't recall the number.

I think that Apex and TireRack are probably being conservative in saying that 255/40-18 might hit. I think that some offsets and tire models might hit. I recall a while back FaRKle! mentioning a 255/40-18 hitting but I do not recall the wheel size/offset or the specific tire.

I've been discussing some wheel/tire upgrades with the guru Alohasurftoad and he's told me that 18x8.5 ET35 with MPS4S 255/40-18 won't hit with my Eibach lowered, stock alignment spec F30 335ix.

For several years, I've been running square 245/40-18 MPS4S on my stock BMW 400M 18x8 ET34 wheels. Amazing handling and rotating front to back has allowed the tires to wear evenly and perform their best throughout their lifespan.

In the Spring, I'm looking to go to at least square 18x8.5 wheels so that I can run 255/40-18 MPS4S. The differences are slight but I only get new tires every three years so might as well do it now.

With 255/40, the diameter increases by 0.3" to the stock diameter of 26.0". And the tread width increases from 8.4" to 8.7" for maybe a little more stability. I don't expect to detect any comfort difference by increasing sidewall height by 0.15". The massive comfort improvement really came previously when I changed from stiff sidewall runflat Pirelli to the non-runflat Michelin Pilot Sport 4S.

I'm very curious about the poke, if any, with your new wheel/tire setup. Can you please post photos looking down the front and rear sides to see how flush they look. Again congratulations on your project. Great result!

[f30bmw340i]

Are you sure that your offset is +35? For the Enkei Raijin 18x8.5, the only 5x120 bolt pattern that I see listed is an ET38 (which might require a small spacer). See Enkei catalog photo.

Crap, a spacer at the front or at the back? But there's no rubbing in the front.
This is my current setup's comparison to the 18" stock setup. Makes my tire 10.4mm closer to the suspension strut.
Also, I checked with alohasurftoad on this thread and he said I won't need a spacer. Not trying to point fingers or anything, just want to make sure I didn't misunderstand anything.

And you're right, it's 38, I'll edit the original post. Been a minute since I made the swap. I also made a mistake with my stock tire name I think (S001).

TireRack lists your DWS06+ 245/40-18 as 22lbs so I'm guessing that you probably saved more than 1 lb vs your previous tire. You should look it up on TireRack (found in each tire's Specs tab)

Yes, per my calculation the weight savings should be around 5 to 6lbs per wheel+tire.

Enkei Raijin weight - 21lbs (per Tirerack's site). I read somewhere the 704M 19" were ~25 to 26lbs. I spent 2 months researching these and would find random info in YT videos or links, but I can't find this particular link for the life of me right now.

Conti DWS 06+ are 23lbs (some sites quote it at 22 and some at 23, so I'm taking the 23 to be conservative about my weight saving calculations) and the Potenza S001 (19x8) were 25lbs.

Curious…How do you know for sure that your Enkei's will clear the rear Brembo 345x24 brakes? Clearance issues are usually the bulbous caliper hitting the barrel of the wheel, not the diameter of the brake rotor.

I'm curious if the Enkei's will clear the front Brembo 370x30 brakes? That make be easier to estimate since it appears that you currently have front Brembo 340x30 brakes. So with the 370's the entire caliper essentially moves out 15mm from the center. There still needs to be a certain amount of clearance between the caliper and the barrel of the wheel. Too small of a gap there allows road debris, twigs, etc to get caught and potentially scratch wheel and caliper. Brembo had a clearance spec on their BremboGT website but I don't recall the number.

Couple of posts in the forum (post from mh24), Tirerack employee asked Enkei customer care (although I wouldn't really bank on it), but also visually, there's a ton of space in the back (pictures attached).
Enkei's won't clear the front. The above link answers that as well.
In all honesty, even if I don't make the upgrade, I am not too bothered about it. I have no intention of upgrading the front brakes. My upgrade path will be to first change the brake pads and see if that makes a difference. I'll upgrade the rear brakes only if that isn't satisfactory.

I think that Apex and TireRack are probably being conservative in saying that 255/40-18 might hit. I think that some offsets and tire models might hit. I recall a while back FaRKle! mentioning a 255/40-18 hitting but I do not recall the wheel size/offset or the specific tire.

I've been discussing some wheel/tire upgrades with the guru Alohasurftoad and he's told me that 18x8.5 ET35 with MPS4S 255/40-18 won't hit with my Eibach lowered, stock alignment spec F30 335ix.

For several years, I've been running square 245/40-18 MPS4S on my stock BMW 400M 18x8 ET34 wheels. Amazing handling and rotating front to back has allowed the tires to wear evenly and perform their best throughout their lifespan.

In the Spring, I'm looking to go to at least square 18x8.5 wheels so that I can run 255/40-18 MPS4S. The differences are slight but I only get new tires every three years so might as well do it now.

With 255/40, the diameter increases by 0.3" to the stock diameter of 26.0". And the tread width increases from 8.4" to 8.7" for maybe a little more stability. I don't expect to detect any comfort difference by increasing sidewall height by 0.15". The massive comfort improvement really came previously when I changed from stiff sidewall runflat Pirelli to the non-runflat Michelin Pilot Sport 4S.

Best of luck man, looking forward to hearing from you. Do you track the car or is this for daily driving? Tire change once in 3 years sounds like it's your daily driver.

I'm very curious about the poke, if any, with your new wheel/tire setup. Can you please post photos looking down the front and rear sides to see how flush they look. Again congratulations on your project. Great result!

The previous Will They Fit link compares my existing fit to the 18x8 stock. But I don't fully understand "poke" so I'm attaching a few pictures here for you to maybe visually answer the question?

[alohasurftoad]

255/40/18 on 8.5" at ET38 does not need a spacer. however if the rim was 9.5" then it would because the inner rim lip will touch the strut.

here is Polo08816 with the same specs, except on on Arc-8
https://f30.bimmerpost.com/forums/sh...0&postcount=85

regarding 704M weight, i could not locate it anywhere. however since 442M and 403M weights are known and the 704M is a cast 19" as well, my speculation they weigh 29lbs front, 29.5lbs rear. you could also weight the whole wheel/tire and subtract the weight of the tires, if known.
.

[f30bmw340i]

255/40/18 on 8.5" at ET38 does not need a spacer. however if the rim was 9.5" then it would because the inner rim lip will touch the strut.

Thank the lord for that. I can't spend one more day looking at tire+wheel posts, I want to put it behind me for years now.

regarding 704M weight, i could not locate it anywhere. however since 442M and 403M weights are known and the 704M is a cast 19" as well, my speculation they weigh 29lbs front, 29.5lbs rear. you could also weight the whole wheel/tire and subtract the weight of the tires, if known.

I have them sitting in the garage but am lazy to weigh them. In the name of science and helping my brethren, I shall weigh them one day in the future. Hopefully. (I'm lazy )

[pauli18c]

Looks great man, glad we could help you out some!

[johnung]

Originally Posted by f30bmw340i

Crap, a spacer at the front or at the back? But there's no rubbing in the front.
This is my current setup's comparison to the 18" stock setup. Makes my tire 10.4mm closer to the suspension strut.
Also, I checked with alohasurftoad on this thread and he said I won't need a spacer. Not trying to point fingers or anything, just want to make sure I didn't misunderstand anything.

And you're right, it's 38, I'll edit the original post. Been a minute since I made the swap. I also made a mistake with my stock tire name I think (S001).

Yes, per my calculation the weight savings should be around 5 to 6lbs per wheel+tire.

Enkei Raijin weight - 21lbs (per Tirerack's site). I read somewhere the 704M 19" were ~25 to 26lbs. I spent 2 months researching these and would find random info in YT videos or links, but I can't find this particular link for the life of me right now.

Conti DWS 06+ are 23lbs (some sites quote it at 22 and some at 23, so I'm taking the 23 to be conservative about my weight saving calculations) and the Potenza S001 (19x8) were 25lbs.

Couple of posts in the forum (post from mh24), Tirerack employee asked Enkei customer care (although I wouldn't really bank on it), but also visually, there's a ton of space in the back (pictures attached).
Enkei's won't clear the front. The above link answers that as well.
In all honesty, even if I don't make the upgrade, I am not too bothered about it. I have no intention of upgrading the front brakes. My upgrade path will be to first change the brake pads and see if that makes a difference. I'll upgrade the rear brakes only if that isn't satisfactory.

Best of luck man, looking forward to hearing from you. Do you track the car or is this for daily driving? Tire change once in 3 years sounds like it's your daily driver.

The previous Will They Fit link compares my existing fit to the 18x8 stock. But I don't fully understand "poke" so I'm attaching a few pictures here for you to maybe visually answer the question?

Alohasurftoad is the guru. Listen to him. Taught me everything I know.

Tremendous unsprung weight savings. You should be able to feel a difference.

Yes, my car is a daily driver and family trip car. No more long commuting, so miles stay low. And winter tires are on for 4 months which also reduces miles on my summer tires.

Your photos look great. Nice and flush as expected, especially with ET38 vs ET35 which pushes them into the wheel well by 3mm more.

Below is a link to a good video to visually see various levels of flush with the fender and poking out of the fender. It's a subjective thing. I just don't like poke but some people do.

I've done several F30 brake upgrades. The quickest improvement that you can make is to install Hawk 5.0 brake pads with a brake fluid replacement (if it hasn't been done within two years). Part numbers in attached photo. Your brakes are Front 340x30, Rear 330x20.

Replacing stock brake hose with stainless steel brake lines eliminates mushy brake pedal. See photo.

Replacing your rear single piston Bosch calipers over 330x20 rotors with rear dual piston Brembo over 245x24 rotors is a very good mod. The 340/330 configuration tends to nose dive under heavy braking while the 340/345 will squat very controllably.

The front Brembo 340 and 370 calipers are essentially the same except the 370 body casting is stretched by 15mm to fit the larger diameter rotor. They even take identical pads. So there isn't any dramatic difference in braking feel. There is a difference in repetitive braking, like on a track. The larger 370 rotor has more mass to handle more heat before brakes start to fade.

Congratulations again. Wheels look great!

[lens]

Originally Posted by f30bmw340i

Thank the lord for that. I can't spend one more day looking at tire+wheel posts, I want to put it behind me for years now.



I have them sitting in the garage but am lazy to weigh them. In the name of science and helping my brethren, I shall weigh them one day in the future. Hopefully. (I'm lazy )

Originally Posted by alohasurftoad

255/40/18 on 8.5" at ET38 does not need a spacer. however if the rim was 9.5" then it would because the inner rim lip will touch the strut.

here is Polo08816 with the same specs, except on on Arc-8
https://f30.bimmerpost.com/forums/sh...0&postcount=85

regarding 704M weight, i could not locate it anywhere. however since 442M and 403M weights are known and the 704M is a cast 19" as well, my speculation they weigh 29lbs front, 29.5lbs rear. you could also weight the whole wheel/tire and subtract the weight of the tires, if known.
.

I have the weight.

704M front wheels
8JX19 ET:36
12.5KG (27.5lbs)

704M rear wheels
8,5JX19 ET:47
12.8KG (28.2lbs)

they're pretty damn heavy.

For reference, I bought flowformed 18s on my old 335i, and they weighed 18.1lbs each wheel.

[f30bmw340i]

chaungo - That's amazing, oddly I never found a thread with the weight for it. Thanks, helps the laziness in me. So yeah, tremendous weight savings.

I've done several F30 brake upgrades. The quickest improvement that you can make is to install Hawk 5.0 brake pads with a brake fluid replacement (if it hasn't been done within two years). Part numbers in attached photo. Your brakes are Front 340x30, Rear 330x20.

Replacing stock brake hose with stainless steel brake lines eliminates mushy brake pedal. See photo.

Replacing your rear single piston Bosch calipers over 330x20 rotors with rear dual piston Brembo over 245x24 rotors is a very good mod. The 340/330 configuration tends to nose dive under heavy braking while the 340/345 will squat very controllably.

The front Brembo 340 and 370 calipers are essentially the same except the 370 body casting is stretched by 15mm to fit the larger diameter rotor. They even take identical pads. So there isn't any dramatic difference in braking feel. There is a difference in repetitive braking, like on a track. The larger 370 rotor has more mass to handle more heat before brakes start to fade.

It was actually your post (on a different thread) that inspired to me add it to my future list of mods. Esp the part where you mentioned, it helps the car squat more comfortably.
And yes the 2y duration (I have that in mind). CPO inspection happened early 2022, which ends by 2023, when it'll be perfect time for me to change the rear rotors (330 to 345), calipers and brake fluid replacement. Maybe even paint the calipers

pauli18c Thanks man. Your car's color (Alphine white) was what I was ideally looking for, but rolled the dice on what I could find. Jealous! What's the interior color?

[johnung]

Originally Posted by f30bmw340i

chaungo - That's amazing, oddly I never found a thread with the weight for it. Thanks, helps the laziness in me. So yeah, tremendous weight savings.

It was actually your post (on a different thread) that inspired to me add it to my future list of mods. Esp the part where you mentioned, it helps the car squat more comfortably.
And yes the 2y duration (I have that in mind). CPO inspection happened early 2022, which ends by 2023, when it'll be perfect time for me to change the rear rotors (330 to 345), calipers and brake fluid replacement. Maybe even paint the calipers

pauli18c Thanks man. Your car's color (Alphine white) was what I was ideally looking for, but rolled the dice on what I could find. Jealous! What's the interior color?

When a rear caliper upgrade is done you typically end up with front grey and rear blue calipers.

The best solution is painting with G2USA Caliper Paint. It's a two part epoxy paint that doesn't fade and wears like iron. It's much more resistant to chipping than the blue paint that BMW uses. It brushes on and as it dries the brush strokes disappear as it levels out to a sprayed on like finish.

It's very important to clean and prep the surface. And especially important to only paint with the air temperature in the prescribed range so that the paint flows properly off the brush. I was able to paint my front grey calipers on the car and the new blue calipers on the bench.

My buddy bought a complete set of blue calipers and used a G2USA custom Ferrari Red to change their color. Photos attached. G2USA comes in stock colors or you can pay extra for color matching. They already have a library of custom colors that they've matched which is where he found Ferrari Red.

Later I bought a complete set of Blue F370/R345 calipers that were really beat up from tracking. The blue color had turned green from the excess heat and most of the piston caps were torn. The pistons were in good shape but they had to be rebuilt with all new seals, caps, pins, clips, and fittings.

Powder coating requires all of the rubber bits and pistons to be removed so it was the perfect time to try powder coating. They get disassembled, media blasted, powder coated, baked and then reassembled with new parts. The results are excellent. The downsides are the expense, and that the brakes are off the car for a few weeks. I had the time because I was doing a complete caliper swap.

Hope this helps!

[pauli18c]

Originally Posted by f30bmw340i

pauli18c Thanks man. Your car's color (Alphine white) was what I was ideally looking for, but rolled the dice on what I could find. Jealous! What's the interior color?

Interior color is red. I wasn't sure about it at first but I've always had the normal standard interior colors (black, grey, tan) so I wanted to just try something new. I wound up really digging it and glad I got it. Get a lot of compliments on it surprisingly that I wasn't expecting at all

[f30bmw340i]

johnung I totally forgot that if I do the rear caliper upgrade, the caliper will be blue in color. In your car, did you scrape off all the blue-turned-green before you sprayed on the red?
I haven't decided on the color yet honestly, was thinking porsche acid green for the calipers but now seeing the red on your grey, getting swayed.

pauli18c - Even the youtuber Justin Buice has that combo I think. Curious about how the red interior looks like in-person. The combo I was looking for myself was white with tan interior.

[johnung]

Originally Posted by f30bmw340i

johnung I totally forgot that if I do the rear caliper upgrade, the caliper will be blue in color. In your car, did you scrape off all the blue-turned-green before you sprayed on the red?
I haven't decided on the color yet honestly, was thinking porsche acid green for the calipers but now seeing the red on your grey, getting swayed.

pauli18c - Even the youtuber Justin Buice has that combo I think. Curious about how the red interior looks like in-person. The combo I was looking for myself was white with tan interior.

Here's the G2USA link so that you can see the process and potential stock and custom colors.

https://www.g2usa.com/

Preparation:
They make it seem like you just spray the caliper down with a can of brake cleaner and then paint. But any type of quality paint job requires more preparation than that.

You can easily do the front grey calipers still on the car and the purchased set of blue rear calipers outside. Obviously you don't need to paint the rear of the caliper on the car. No one can see the back. Make sure to put a cheap plastic open oil catch pan underneath to catch the crud.

Lots of Formula 409 spray works the best for deep cleaning off dirt and brake dust. I use stiff nylon brushes and a tooth brush. Then spray it all down with brake cleaner. No need for scraping. Sand down any rough spots or chipped areas with increasingly finer sheets of sandpaper. Spray it all down with brake cleaner prior to painting.

G2USA Caliper Paint goes on with a small brush provided. It levels out as it dries so brush marks disappear. Once you mix the two epoxy parts there is a limited time before it hardens. So have all four calipers prepped and ready to be painted all at once. Always paint when air temperature is with the range given in the instructions.

Hope this helps!

[f30bmw340i]

johnung Thanks for the detailed info. I'll refer back to this next year when I kickstart the project.

[f30bmw340i]

johnung

I am scoping out parts for the rear brake upgrade (later in the year) for my 2018 BMW 340i. I had a few questions

1. Stainless steel brake lining: What's the advantage of these over the existing brake lines? I was under the impression that the rubber lining has a bit of play and stainless steel is more for track usage. I maybe wrong, but just want to understand the logic before adding this to the parts list.
2. Rotors & pistons: I noticed that you'd recommended the Hawk brake pads for the rear but didn't see the recommendation for the rotors & pistons (brand/make). What would you recommend?
3. Insurance: Do you know if any of these modifications will void the car insurance?
4. Brake pads: Any idea if the Hawk brake pads squeak or have increased brake dust?

Thanks

Originally Posted by johnung

Alohasurftoad is the guru. Listen to him. Taught me everything I know.

Tremendous unsprung weight savings. You should be able to feel a difference.

Yes, my car is a daily driver and family trip car. No more long commuting, so miles stay low. And winter tires are on for 4 months which also reduces miles on my summer tires.

Your photos look great. Nice and flush as expected, especially with ET38 vs ET35 which pushes them into the wheel well by 3mm more.

Below is a link to a good video to visually see various levels of flush with the fender and poking out of the fender. It's a subjective thing. I just don't like poke but some people do.

I've done several F30 brake upgrades. The quickest improvement that you can make is to install Hawk 5.0 brake pads with a brake fluid replacement (if it hasn't been done within two years). Part numbers in attached photo. Your brakes are Front 340x30, Rear 330x20.

Replacing stock brake hose with stainless steel brake lines eliminates mushy brake pedal. See photo.

Replacing your rear single piston Bosch calipers over 330x20 rotors with rear dual piston Brembo over 245x24 rotors is a very good mod. The 340/330 configuration tends to nose dive under heavy braking while the 340/345 will squat very controllably.

The front Brembo 340 and 370 calipers are essentially the same except the 370 body casting is stretched by 15mm to fit the larger diameter rotor. They even take identical pads. So there isn't any dramatic difference in braking feel. There is a difference in repetitive braking, like on a track. The larger 370 rotor has more mass to handle more heat before brakes start to fade.

Congratulations again. Wheels look great!

[johnung]

Originally Posted by f30bmw340i

johnung

I am scoping out parts for the rear brake upgrade (later in the year) for my 2018 BMW 340i. I had a few questions

Stainless steel brake lining: What's the advantage of these over the existing brake lines? I was under the impression that the rubber lining has a bit of play and stainless steel is more for track usage. I maybe wrong, but just want to understand the logic before adding this to the parts list.
Rotors & pistons: I noticed that you'd recommended the Hawk brake pads for the rear but didn't see the recommendation for the rotors & pistons (brand/make). What would you recommend?
Insurance: Do you know if any of these modifications will void the car insurance?
Brake pads: Any idea if the Hawk brake pads squeak or have increased brake dust?


Thanks

Rubber brake hoses balloon when brake pedal is first pressed, then the hydraulic force is finally transmitted to the brakes. This causes a mushy brake pedal feel that is eliminated with stainless steel brake lines that can’t balloon. Also used in racing because less risk of being cut by road debris.

Hawk 5.0 brake pads (not talking about other models of Hawk pads) Brake pads don’t make noise if they are installed correctly with brake paste. Hawk 5.0 pads have less dust than stock pads. It’s light in both volume and color, and not sticky like stock pads so it washes away easily.

These are bolt on replacement parts. Never heard of any auto insurance issues.

Have no idea why you are referring to pistons which are internal to brake calipers and rarely replaced.

Rear F30 Brembo 2-piston calipers fit over 345mm x 24mm rotors. Your 340i has the larger 185mm emergency brake machines inside the rear rotor hats. I recommend either plain German made Zimmermann rotors. Or for an upgrade full crossdrilled StopTech rotors. See photo. They have best bite and are best in rain. That’s why BMW M3/M4 have full crossdrilled rotors.

Avoid dimpled and slotted rotors which are noisy and not much of an improvement at all.



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