[eliseo001]

HEY NEW HERE.
I HAVE A BMW M850i XDRIVE(4dr)
I put vossens 22”. Do i have to program or something the transmission when i put theses wheels on? Car now feels like it’s glitching as i start off

[snowbimmer]

Originally Posted by eliseo001

HEY NEW HERE.
I HAVE A BMW M850i XDRIVE(4dr)
I put vossens 22”. Do i have to program or something the transmission when i put theses wheels on? Car now feels like it’s glitching as i start off

What are your tire sizes, wheel widths and offsets?

And a picture

[eliseo001]

Tires size are 295/25/22 rear
Fromt 255/30/2 front
Rim width front 9.5
Rear 10.5

[DanG]

What tires are you running?

There is no programming for tires or wheel size

[snowbimmer]

Originally Posted by eliseo001

Tires size are 295/25/22 rear
Fromt 255/30/2 front
Rim width front 9.5
Rear 10.5

Your tire diameter is about an inch more than OEM sizing. There are others on the forum running your set-up. Maybe there is an offset problem and the tire is hitting the wheel well (not enough offset) or the strut some how (too much offset).

What do you mean by glitching? Does it eventually go away? How long have you run this setup?

The Alpina B8 uses 20" and 21" tires that are about an inch taller than the M850 OEM size. I've been trying to research to see if there is any magical engineering done to the M850 as they turn it into an Alpina to account for this. I haven't found a definitive answer, but several have chimed in and said their larger tire setup has not caused any problems.

[Llarry]

Also, may I recommend posting in the 8 series forum? You are more likely to get an experienced M850i owner's input.

[eliseo001]

Thank you guys for the help.
I litter ran this 4 days ago. And yesterday i put stocks back on and it went away. Now im really going crazy i want to see how i can put that setup back.

[eliseo001]

I feel in 1st gear while starting move foward without switching to 2nd it feels like 3 hits. Then when i accelerate hard its feeling like lagging power studdering

[RED99HT]

The car may not be liking the taller setup and the new ratio of front wheels being taller than rear now
Stock fronts 245/35/20 = 26.5” tall
Your set up = 28.1” tall
1.6” difference is a lot for these vehicles and it maybe throwing the computer off
Stock Rear 275/30/20 = 26.8” tall
Your set up 27.8” tall
1” difference for the rears.
I’m not an expert here but since this is an all wheel drive car and the front tires are marginally taller than the rears now and are 1.6” taller front and 1 “ rear it may be throwing the all wheel drive system out of synchronization
Also, how heavy are your new wheels? 22’s can add a significant amount of weight over stock and again throw the system out of wack

[snowbimmer]

Originally Posted by RED99HT

The car may not be liking the taller setup and the new ratio of front wheels being taller than rear now
Stock fronts 245/35/20 = 26.5” tall
Your set up = 28.1” tall
1.6” difference is a lot for these vehicles and it maybe throwing the computer off
Stock Rear 275/30/20 = 26.8” tall
Your set up 27.8” tall
1” difference for the rears.
I’m not an expert here but since this is an all wheel drive car and the front tires are marginally taller than the rears now and are 1.6” taller front and 1 “ rear it may be throwing the all wheel drive system out of synchronization
Also, how heavy are your new wheels? 22’s can add a significant amount of weight over stock and again throw the system out of wack

I think you transposed the OEM sizes. The fronts are 26.76 going to 28.02, or Plus 1.26"


And the rears are 26.50 going to 27.80, or Plus 1.3"


Does that look right?

So OEM fronts are 0.98% taller than the rear, his set-up has the fronts 0.79% taller, a negligible difference it would seem. I've heard that if you keep the ratios real close you will be OK.

The Alpina 20" set goes Front 27.72 and Rear 27.58
Front is 0.51% taller.

The Alpina 21" set goes Front 27.76 and Rear 27.74
Front is only 0.072% taller.

And, do they make any changes to the Alpina when they upgrade it from the M850 tire and wheel size, or just slap the bigger tires on and call it a day?

Again, there are some forum members running the same new set-up as OP. There are also forum members running the Alpina wheel and tire set-up on the M850 with apparently no adverse effects. You may be on to something with the weight gain, but I've seen 22" wheels here on the M850.

[eliseo001]

Thanks. So what do you guys recomend me doing?

[RED99HT]

Unfortunately I don’t think there is much you can do. I would suggest 3 things
1. Remount the wheels and check to make sure there is ample clearance all around while the car is back down on the ground. Is the car lowered? If the wheels are a high offset you may be rubbing inside the wheel well. Do you hear any rubbing?
2. Weigh in your 22”s vs the stock wheels. If there is a huge difference in weight, 10+ lbs it may effect the all wheel drive system
3. Install new tires to get back to closer to spec height . Although I would hate to go with a smaller sidewall you already have.

Last resort would be to go back with the stockers or sell the 22’s and drop down to 21’s and get the tire hight back in sync with stock height

[snowbimmer]

Do you know your Vossen offsets?

[Dasky_spas]

I run 275/35/20, much taller than oem and no issues. Bring the car is to get scanned. If anything, maybe reset the transmission values parameters so it can relearn with the taller wheels on.