What brands and sizes are you guys running for spacers?

I am currently on wheels that are 19 x 8.5 ET35 with tires that are 245/35ZR-19 on both the front and rear. What would you guys recommend for spacer fitment? Is it okay to have it slightly staggered? What is the power distribution on the "x-drive" system? Or should I just order the same sizes for the front and rear?

The wheels are a bit wider than the stock set-up, but I am looking to achieve a wider stance.

 

Beautiful car!

 

I recommend that you try out different thickness spacers to reach your desired result. See how the car looks with spacers mounted. Experience how it drives.

I run Turner Motorsport spacers, because I like how they're made (back-cut and drilled for lightness... chamfered at back ID and front collar OD, etc). Turner and ECS sell spacer test kits if you just want to test fitment.

You have to run longer wheel bolts when you run spacers, or install studs and lug nuts, which is a fairly big commitment.

Spacer kits are available with a batch of correct length wheel bolts, which makes for a simple way to land with the correct extra bolt length. Depending on your budget you could purchase 5mm, 7.5mm, and a 10mm with wheel bolts included, and then try them out. Flip what you don't keep, with a little resale loss (Turner and ECS will not let you return opened spacer packs). If it turns out that you want even spacing, get the additional set you need.

Slightly staggered is okay, so long as everything clears/doesn't rub. Be sure to fully articulate your steering and front/rear suspension, and then check for visual rubbing when you're testing. You may not hear every rub, but stuff can still wear if there is rubbing.

As for X-drive, with all the various wheel/tire/spacer/KW adjusted height that I have run, I see more impacts resulting from tire diameter and size, then track (although I do feel the influence of offset and track width at higher HP levels).

A discussion I had a long while ago about offset and track impacting X-drive had me landing with the mindset that BMW engineers opted for certain pairings of track width and offset on X-drive equipped cars to have ideal yaw control for X-drive and DSC systems. They want a system that provides good feedback and response for the typical driver to remain in control when various systems kick in.

When we modify our cars and change offset and track, it impacts the whole X-drive system, even if there are no warnings lit on the dash. I have certainly felt the difference under hard acceleration and corning (and there are quite a lot of things happening in code related to braking and engine performance that relate to X-drive and DSC... things that take a lot of coding to turn off). So I measure the hub track and wheel track on my project cars before I start modifying, in order to track how changes impact handling.

Power distribution is stated in various places to be 40:60 (60% rear), which is continuously variable, mostly changing upon detection of wheel slip, although there are other factors being monitored that can trigger the servo in the transfer case and also vary the ECU.

 

Thank you for the wealth of information! I think I will be purchasing Burger Tuning spacers because of the lifetime warranty and high quality materials. Plus they include the right size bolts.

Based on your experience, how has a wider set-up effected the yaw control? Should I be worried about the differential when going wider?

 

I'd run a 5 or 10mm up front and a 15 or 17.5mm in the rear. But if you really want to dial in the fitment aggressively check out the spacer fit kit ECS sells, they have a rent and return deal on it.

As for space brands I run ECS 17.5mm spacers up front on my summer wheels (style 232s 19x9 et48/et18 w/ 255/40/19) and Turner 15mm up front 20mm out back on my winter wheels (style 123s 18x8 et43). Both come with options for proper bolts and I'd highly suggest either of them.

 

Thanks for the reply! I went with Turner Motorsports 10mm up front and 17.5mm in the rear. The front looks great and is flush with the curves of the fender but the rear may need to be a little further out so I may go with 20mm or slightly larger in the future. Cheers!