[kbsilver]

We've owned several BMWs over the years. And one common characteristic was that very secure initial bite when applying the brakes. That good bite was usually associated with lots of brake dust.

On our new 340i GT (currently less than 1K miles), it does not seem to have that strong initial bite. Stops well enough but needs much more pressure on the pedal. This is what low dusting pads would act like except the car is generating plenty of dust. Does this get better as the brakes bed in?

One exception to this rule has been our 2011 335D. It has the typical great initial bite, but does NOT produce lots of brake dust. We're at 85K miles and still on the original pads. This is what I would like to see in the GT. And because of the heavy diesel engine, the D does not weigh that much less than the GT.

[Billfitz]

Bite isn't affected all that much by the pad density. The main reason for soft pads is that they're a lot cheaper and easier to replace than rotors, and the harder the pad the faster the rotors wear.
I don't have another BMW as a frame of reference, but my GT creates a lot more dust than any other car I've ever had. It still brakes better as well.
Put this on your wheels and the dust will easily rinse off:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

For that matter it doesn't accumulate near as much either. It works so well that when I pulled my wheels to rotate the tires I put it on the inside of the rims.

[Richbot]

Owned/driven any other BMW's with fixed front calipers? My thought is they had to use a different set of priorities to keep noise down when they decided to put fixed calipers on many of their cars. The brake feel on our 335xiGT is considerably spongier than all of our previous bmw'/ we've owned everything from E36 on. It is similar though to other F30's I've driven with the 4pot front calipers

[GTBrandon]

Did your previous BMW have slotted rotors? These can increase the "bite" feel, just watched a good video on it actually haha. Maybe this would be interesting to you:

[kbsilver]

Originally Posted by GTBrandon

Did your previous BMW have slotted rotors? These can increase the "bite" feel, ...

All cars in my comparison are factory stock (and not M's) which means plain rotors. Our 2011 335D has great initial bite, and little dust. The 2017 340iGT has less initial bite and moderate dust. The 2 cars weigh about the same (diesel engine is heavy). Seems as BMW is going backwards in brake pad technology.

I will say with more miles on the GT the bite is improving, but still not like the E90. Also on the E90 it appears we will get 100K miles or more out of the factory pads. A contributing factor is due to the compression on the diesel, it slows down pretty quickly when you take your foot off the throttle.

On the other hand, the GT, especially in economy mode, coasts forever. Plus because the radar cruse control only looks at the car in front, it does not anticipate slowing down in advance which also tends to use the brakes a lot. On the GT I'm already expecting short brake pad life.

[Richbot]

Agree.

E90M front rotors and pads were good to keep going for many more miles when I went to a Stoptech front kit at 60,000 miles, with a lot of autocross and hard street use in their history. Same story on the E90M as the diesel, 8cyl with 12:1 compression and short gearing means lots of engine braking

But a more apples-to-apples example is our E90 335xi on which front rotors and pads made it to 75k, rears to 62k, both changed before they were strictly necessary but within about 5k of the light going off and had great brake feel down to the last drop. THe F34's feel has always been squishy and now has picked up a bit of pad-transfer or "warp" under braking which I've never had in any of my previous BMs. Our F34 currently has 44k on it and the fronts will be lucky to make it past 50k; most of the bevel is gone from the front pads. The F34 is a 335xi and sees identical driving conditions to our E90 335xi.

[Billfitz]

Originally Posted by Richbot

Our F34 currently has 44k on it and the fronts will be lucky to make it past 50k.

I'll take that. I've never had a set of front pads on previous cars last past 30k.

[Richbot]

it's looking like 30-40% less life with worse feel than the E90 on a purportedly better brake system with fixed four pot front calipers. one of many reasons this will be our last new bmw

[CaboM4]

Originally Posted by kbsilver

We've owned several BMWs over the years. And one common characteristic was that very secure initial bite when applying the brakes. That good bite was usually associated with lots of brake dust.

On our new 340i GT (currently less than 1K miles), it does not seem to have that strong initial bite. Stops well enough but needs much more pressure on the pedal. This is what low dusting pads would act like except the car is generating plenty of dust. Does this get better as the brakes bed in?

One exception to this rule has been our 2011 335D. It has the typical great initial bite, but does NOT produce lots of brake dust. We're at 85K miles and still on the original pads. This is what I would like to see in the GT. And because of the heavy diesel engine, the D does not weigh that much less than the GT.

I have had several BMWs to-date and these are the worst brakes I have had. Felt uncomfortable stopping in certain situations, as I expected better performance.

My previous F10s (535 and 550) and my current F85 (X5M) stop exellent. I dont expect the F34 340i to stop as well as my ///M, however i expected performance on-par with the F10s.

Has this gotten better over time? I was very upset that the F30 M-Sport brakes are not available as an option on the F34. I plan to ask my dealership about upgrading to these.

[SCMike]

Not sure if the same holds for the F34, but for the standard F30 brakes with "poor bite" issues, Turner Motorsports recommends replacing the standard pads with M-Sport pads. Apparently a direct pad swap, with better bite, at the cost of more dust:
https://www.turnermotorsport.com/t-b...ke-Differences
Upon further searching, looks like the M-Sport pad substitution works only on the 4-cyl F34, not the 6-cyl F34 - different design on the latter? step backwards?

And even further searching reveals (this is confusing) an OK fit on the 6-cyl F34 -
stock on front: https://www.turnermotorsport.com/c-2...pads-stock-oem
M Sport on rear: https://www.turnermotorsport.com/p-3...335i-f32-435i/

[CaboM4]

I plan on testing coding just "SPBR" under the HO_WORT to see if that gives a better feel. If not, we are going to upgrade to the ///M-Performance Big Brake Kit Accessory Upgrade and hope that makes things better. Its 4-piston front and 2-piston rear with larger rotors as well. Since it isn't officially offered for the 2017 340i GT, I will need to make sure it will fit with the 19" style 598M wheels ... will then also ned to spec a winter set appropriately after the brake upgrade.

you laugh, but on my F10, the 19" 3451M wheels cleared the stock F10 550i calipers, but the 20" 343Ms from the M5 did not clear the stock F10 550i Calipers without spacers ... go figure.

[Old-School]

Thanks for posting about this.

I'm driving a '15 328iGT and seriously considering an '18 340iGT when my lease is up late this Summer. Since I'm wanting something higher performance with my next car, & as someone who loves driving hard, (but needs the size/utility of the GT) this brake feel situation is not good to hear..

Would be great if they offered a M performance package with bigger brakes (AND a version of the 340i/440i M-Performance power & sound kit too) for our GT's

I guess I can dream.

[CaboM4]

Originally Posted by CaboM4

I plan on testing coding just "SPBR" under the HO_WORT to see if that gives a better feel. If not, we are going to upgrade to the ///M-Performance Big Brake Kit Accessory Upgrade and hope that makes things better. Its 4-piston front and 2-piston rear with larger rotors as well. Since it isn't officially offered for the 2017 340i GT, I will need to make sure it will fit with the 19" style 598M wheels ... will then also ned to spec a winter set appropriately after the brake upgrade.

you laugh, but on my F10, the 19" 3451M wheels cleared the stock F10 550i calipers, but the 20" 343Ms from the M5 did not clear the stock F10 550i Calipers without spacers ... go figure.

SPBR coding gives a better overall brake feel. Still within break-in period so not going heavy on the car now ... but I think as-is with SPBR coding will be acceptable for us long-term with the F34 ... if I want to have a ton of fun I'll take out the F85