[G30M]

Originally Posted by haru69

The rear slides enough already for me
For my skill that's enough 🤣

fair enough

[G30M]

Originally Posted by haru69

I also heard that after 180kmh the front axle will totally disconnect and you only drive in rwd
Since I also tried already a 50% acceleration from 200kmh and this issue also appears I think there is just some issue with the rear tires
Unless im wrong about the front being disabled after 180kmh

Oh I also forgot to say if I partially turn off DSC or fully off the car has no issues

the front axle is disconnected most of the time

front axle is only activated when accelerating

at least in my M340i it was, not sure about yours.

[haru69]

Originally Posted by G30M

the front axle is disconnected most of the time

front axle is only activated when accelerating

at least in my M340i it was, not sure about yours.

well mechanically all the G2* series pretty much share everything

[tracer bullet]

Originally Posted by haru69

Well I will stick to OEM I see no reason to do that

I want to agree and say stay with the stick size. But - a square setup is an idea to consider, if the car wants the tires to have the same rolling diameter at all 4 wheels, that would certainly accomplish it.

[haru69]

Originally Posted by tracer bullet

I want to agree and say stay with the stick size. But - a square setup is an idea to consider, if the car wants the tires to have the same rolling diameter at all 4 wheels, that would certainly accomplish it.

well the original post was about having issue with continental tires

[CSBM5]

Originally Posted by rcsummers

Upload a picture of the door sticker.....

I'm not accusing you of anything but 245/255 doesn't seem like any OEM combo I've seen before. They'd either be a square setup, or usually a 245 would be paired with a 275 in OEM BMW specs on the f10 and a 225 would be paired with a 255 on the f32 in OEM BMW specs.

I'd be happy to admit I'm wrong though.

The hankooks could have different rolling diameters than the conti's. a 245 hankook isnt always the same exact size as a 245 continental even though they're both 245's.

It's the standard G22/G26 M-sport or M440i sizing with that slight stagger in width and diameter. You see something similar with the X3M and X4M that use 255/45-20 front and 265/45-20 rear (or 255/40-21, 265/40-21).

[RockCrusher]

Originally Posted by G30M

the front axle is disconnected most of the time

front axle is only activated when accelerating

at least in my M340i it was, not sure about yours.

My info is xDrive under normal conditions splits power 60/40 rear axle/front axle.

But under extreme conditions can send all power to either axle.

With some models -- M8 -- one can set the AWD system to rear wheel drive only.

[G30M]

Originally Posted by RockCrusher

My info is xDrive under normal conditions splits power 60/40 rear axle/front axle.

But under extreme conditions can send all power to either axle.

With some models -- M8 -- one can set the AWD system to rear wheel drive only.

the Audi is 40/60 FR AWD 100% of the time. not BMW.

there is an app called Protool it reads the torque to the front wheels at all times. other than accelerating my car is 0% torque to front wheels.

my M340i will be full mustang mode driving in a straight line in the rain. very scary the back will just suddenly come loose.

as far as i know the transfer case clutch pack generates a lot of heat every time it is engaged. even if your car has more AWD it will not be 40/60 all the time or your TC will explode in 1 year. it's not an Audi (it has a differential so full time !00% 40/60 AWD, we have a clutch pack)

[RockCrusher]

Originally Posted by G30M

the Audi is 40/60 FR AWD 100% of the time. not BMW.

there is an app called Protool it reads the torque to the front wheels at all times. other than accelerating my car is 0% torque to front wheels.

my M340i will be full mustang mode driving in a straight line in the rain. very scary the back will just suddenly come loose.

as far as i know the transfer case clutch pack generates a lot of heat every time it is engaged. even if your car has more AWD it will not be 40/60 all the time or your TC will explode in 1 year. it's not an Audi (it has a differential so full time !00% 40/60 AWD, we have a clutch pack)

Well, the power flow graphic in my M8 shows power to the rear wheels and front wheels 100% of the time unless I remove pressure from the gas pedal then after a moment or so it shows power flowing from the front and rear axles to the transfer case and to the battery.

Added: Forget to mention regarding transfer case heating...

My 2003 Porsche 996 Turbo had an AWD system that had a viscous coupling to the front diff. The fluid used had a working temperature of 300F. This system worked just fine and was stilling working fine at 161K miles. 'course, I had the front diff (and rear diff) and transmission (6-speed manual) fluid changed on schedule.

[tracer bullet]

Originally Posted by haru69

well the original post was about having issue with continental tires

I'm aware of that. Just thinking of ways to keep it from happening again, or that you might consider making it work (could keep 2 of the existing tires).

You knew you'd get opinions and ideas, right?

[haru69]

Originally Posted by tracer bullet

I'm aware of that. Just thinking of ways to keep it from happening again, or that you might consider making it work (could keep 2 of the existing tires).

You knew you'd get opinions and ideas, right?

I'm quite sure the rear tires are defective because the problem only occurs during acceleration. Since I don't want to risk this annoying issue again, I'm just going to buy a set of Goodyear Asymmetric 6. Continental took no responsibility, and they even admitted their manufacturing standards can result in varied tire quality. Honestly, I've never liked Continental, and this was my first and last time trying their brand

[shawnhayes]

Originally Posted by haru69

Then why there is no problem with the OEM tires (same size)
And there is also other people with this same continental tire and had no issue with my same size
That's just a defective tire

Being absolutely transparent, many brands vary WILDLY in the exact outer diameter from brand to brand labeled EXACLY the same size.

In the GT-R world where I spent 10 years, significant differences would blow the center diff. We just got to the point that AFTER installation we'd have to chalk the tires and do a ten rotation roll and make sure the chalk mark was the same.

This problem is NOT new and very variable.

My best, and only solution, has been to go to a square setup. It's what I prefer so I can rotate the tires anyway.

Shawn

[Drv4fun]

Originally Posted by haru69

Hey everyone,

I've got a BMW G26, and after putting on Continental Sport Contact 7 tires, I'm getting an odd issue. When I hit around 150 km/h and give it about 50% throttle, the traction control light flashes and the engine power cuts out. It doesn't happen every time, but I'm thinking it might be tire-related. Any ideas what's going on?

new tires are the exact same spec of the previus tires i had
i already have put my old tires and there is no issues

this is the response from continental (outrageous):

Good morning.

We have examined the information provided and can confirm that the reported phenomenon is not attributable to manufacturing defects of the tires, but rather to incorrect equipment.

Since this is a BMW Xdrive vehicle with different sizes between the two axles, it is practically mandatory to install BMW-approved tires, i.e. "starred" tires, as recommended by BMW itself.

These tires have lower manufacturing tolerances than the ETRTO standard ones, to adapt to the characteristics of the Xdrive transmission, which in turn has limited tolerances.

Installing non-approved tires can lead to malfunctions of the vehicle's traction/stability control systems and, potentially, damage the mechanical parts of the transmission.

We attach a technical sheet that deals with the topic and we recommend that you only install BMW-approved tires on the vehicle.

I didnt see anyone ask, did you verify the tires were mounted properly, they look to have inside/outside?

[haru69]

Originally Posted by Drv4fun

I didnt see anyone ask, did you verify the tires were mounted properly, they look to have inside/outside?

yes i mounted these tires twice to make sure it was not a mounting issue

[haru69]

Originally Posted by shawnhayes

Being absolutely transparent, many brands vary WILDLY in the exact outer diameter from brand to brand labeled EXACLY the same size.

In the GT-R world where I spent 10 years, significant differences would blow the center diff. We just got to the point that AFTER installation we'd have to chalk the tires and do a ten rotation roll and make sure the chalk mark was the same.

This problem is NOT new and very variable.

My best, and only solution, has been to go to a square setup. It's what I prefer so I can rotate the tires anyway.

Shawn

i must be very very unlucky
because literally no one have ever heard of this problem
i guess im gonna buy a lottery ticket maybe luck will balance out

[shawnhayes]

Originally Posted by haru69

i must be very very unlucky
because literally no one have ever heard of this problem
i guess im gonna buy a lottery ticket maybe luck will balance out

Lost knowledge, I guess

https://www.gtrlife.com/threads/tire...issues.322300/

We had this issue on the street. Nowhere near as hard/high speed as you are having. It would overheat the diff.

Shawn

[G30M]

Originally Posted by haru69

I'm quite sure the rear tires are defective because the problem only occurs during acceleration.:

i am telling you, that BMW X Drive is only AWD in acceleration, that is why. when not accelerating, it is RWD, no problem.

there is an App called ProTool, it reads the front axle torque in real time, you can see that.

[G30M]

Originally Posted by RockCrusher

Well, the power flow graphic in my M8 shows power to the rear wheels and front wheels 100% of the time unless I remove pressure from the gas pedal then after a moment or so it shows power flowing from the front and rear axles to the transfer case and to the battery.
.

i don't think the graphics is accurate, but I do know BMW is clutch pack and it cannot do full time AWD. Audis with the mechanical diff and Subaru with the mechanical diff for example, are full time AWD.

[haru69]

Originally Posted by G30M

i am telling you, that BMW X Drive is only AWD in acceleration, that is why. when not accelerating, it is RWD, no problem.

there is an App called ProTool, it reads the front axle torque in real time, you can see that.

yeah thats why i rather just change all 4 tires and hope i dont get unlucky again

[rcsummers]

Originally Posted by CSBM5

It's the standard G22/G26 M-sport or M440i sizing with that slight stagger in width and diameter. You see something similar with the X3M and X4M that use 255/45-20 front and 265/45-20 rear (or 255/40-21, 265/40-21).

Had no clue, I guess another reason why Modern BMWs don't make all that much sense to me.

Curious to the engineering logic behind the minimal stagger.

[haru69]

I give you guys an update I have cleared all the errors from bimmerlink
And right now the car became basically undrivable
The traction control has became like crazy is cutting power after 50kmh during straight and during corner
Witch 50-80% power

[egparson202]

I’ve put almost no thought at all into exact matching (<1%) the tire sizes on my AWD Audi. Over 50K miles I’ve treated it as if it were RWD, purchasing same size or occasionally larger tires for the rear. Never feeling any particular loyalty to the OE specs. Zero problems. I’d be very curious to learn exactly how much the difference is in rollout on the troubled Conti’s.