The Fastest Tire Stagger? (for a BMW M2)

*Timestamps in Description!*
There's a pretty big diversity of tire sizes run on the BMW F8x platform for the track: square, stock 20mm stagger, 30mm stagger, ect. I wanted to find out how various tire staggers compared to each other and which was fastest around the track! To perform this test I used the same tire model (Hankook RS4) for all combinations, and with the stock springs/dampers on my BMW M2 Competition.
Index:
-0:00 Intro
-0:25 Test Overview
-1:36 The Slowest Stagger
-2:46 The Middle Fastest Stagger
-4:11 The Fastest Stagger
-5:39 Conclusion

[@clarusfish]

Great work here FaRKle ! Thanks a lot for this quality analysis backed up by practical experience on the track...

[@tractioncontroldelete]

Very helpful. Thanks for the thorough breakdown.

[@cryalowicki]

Facinating. Not what I would have guessed. Thanks for doing Science!

[@shouldigetit]

You’re doing it for science!Very cool

[@m2comp369]

This is brilliant! I've always wondered about the effect of staggered set ups. Whilst your focus was more on track times, I have gone with 255 F and a 285 R for grip in mind given the car is tuned. It is very interesting how the various combinations affect the car's overall balance. Thank you.

[@LdtEntertainment]

Love the intro 🤣

[@uncleben4536]

Great video, not the outcome that I expected at all.

[@oficina_moomoo]

Happy wife happy life but gotta do it for science. Thank you for this, very informative. I have been running 20, 265 -285 on stock daily wheels and 275-295 on apex track wheels. Would love to try something else just to feel how different it is really but so far been happy with 20, I am a newbie but this car just makes driving so easy and predictable, I don't want a oh shit moment like you had on that turn lol

[@FaRKle0079]

You've got it set up excellently.

[@carsstuff9914]

Good video! I definitely like the 20mm stagger, and can set good lap time with them easily. I do believe the bigger tire size should net you a faster time theoretically, the driver just have to spend time to adapt the different balance of the car, to squeeze out the mechanical grip. It might be super difficult on the stock geometry

[@johnungvarsky8875]

Another great FaRKle video! Always interesting, full of detail and with real data to support conclusions. Such a pleasure to watch. I wish you had had the opportunity to test a square setup with the same conditions. Can you speculate where square might have fallen in your tested list? I’m running square 245/40-18 on my 335ix and am considering 255/40-18. Regular front/rear rotation has really kept even wear for optimal performance on 245/40’s during their lifespan. Guys are quick to throw spacers on their car. But changing front/rear track widths can effect understeer/oversteer. Have you ever tested to what degree? Is it mild/hardly noticeable, or perhaps as much as changing diameters on a sway bar? There’s always theory but actually doing a well designed test usually yields a surprise or a confirmation. Again, great video!

[@FaRKle0079]

I think square would've been more difficult to drive with the rear wanting to come around more on turn in. The optimal stagger is going to differ a lot for xDrive and I run square on my xDrive wagon.

[@zw7191]

Nice video! I’ve been running 285 squares and it actually balances really well (with coilovers and track alignment )

[@FaRKle0079]

Depending on the coilovers, I can definitely see where square would be faster. A lot of coilovers have much stiffer front springs compared to the rear, so going slimmer in the rear allows it to slip a little and get some rotation.

[@LdtEntertainment]

Thats wide! How much camber do you need to run 285 squared for the M2? and what wheel offsets are you using?

[@zw7191]

@@LdtEntertainment I’m running-3 front camber with stock sway bar. The wheel is 18x10, ET25 for the front. My coilover has less inner clearance compared to stock shock so I need an 10mm spacer as well.

[@luciengutierrez431]

@@zw7191 I’m considering a sq set up on w 285x35 on my 18x10x25 apexes but currently have a 9.5 upfront and am running 255/40 and 275/40. Alternately I’m considering a staggered set up w a wider front like 265/35 and 285/35 rear. My 1M is fully tuned and built w Ohlin suspension and upgraded bushings. What tire and wheel sizes set up do you recommend for track?

[@USMC_LAterZ]

Good

[@malinoisnation9392]

Wish you were my neighbor. Great video.

[@michaelnyden8056]

Agreed with other comments, square needed to be compared same day, but nice video and data anyway.

[@usernamealreadytaken770]

I just got some BMW 763M wheels for my M2. I was curious if you stuck with the stock 245/265 setup or if you went with a wider setup with your 763M wheels.

[@FaRKle0079]

I kept the stock PSS 245/265 for my 763m wheels. That's my "street" wheel set.

[@JohnDoe-so9oy]

Nice video! How do you even fit a 305 on there? I put a 275/30 michelline ps4s in the rear, seemed tight already when lowered. Is it possible to go wider w my rim now? BBS FI-R 138BS - 19 x 10.5 5-120 et35

[@FaRKle0079]

You can see how I fit it in this video (jump through the time stamps): kzbin.info/www/bejne/q4eQgGimiq-aj9U You can also use the below site to compare the fitment. You should be able to fit a 285 and maybe 295 depending on how low you are. willtheyfit.com/index.php?width=295&aspect=30&diameter=19&wheelwidth=10.5&offset=35&width2=305&aspect2=30&wheel_size=19&wheel_width=11&offset2=44

[@kktorado]

How does the 265/285 compare to the stock 245/265?

[@DinanEX]

Have you thought about how the rear tire affects the e-diff? I’ve tried a few variations on my F82 and found that getting it as close to the diameter of the OEM tire produces the best results.

[@FaRKle0079]

I really haven't. I try to keep my tire sizes close to OE. The diff should work based off of the wheel speed sensors and their relative motion to each other, and my rear tire sizes have been within 1.5% of OE, so I'd be surprised if there was much difference in the behavior. Which tire sizes did you play around with on your F82 to see the diff behavior?

[@briyun519]

Did you have issues with the traction light coming on during turns? I’m running 265/35/18 295/30/18 and having the issue

[@FaRKle0079]

I haven't had any traction lights come on, but I also run DSC off, haha. It wouldn't surprise me if you can still get it to flicker on in some turns with 30mm stagger.

[@fer1306]

Retest with 275-285 combo pls, if possible with 275-295 too. Would be interested to compare it to the 265-285 time

[@FaRKle0079]

I need a tire sponsor! 🤑

[@fer1306]

@@FaRKle0079i feel you. 275-285 combo can be done as you already have these tyres in this video. I currently have 265/35r18n square setup with nankang crs, and this type of tyre has 275/35 and 295/35 too, i will try to fit them and compare at my local track for next season

[@dogshit9870]

Looking for a tire setup for the m2c. What is the largest wheel size the front will take without rubbing? Can i do a 285F and 305R with stock suspension? Thank you

[@FaRKle0079]

It's pretty easy to fit a 275 front, but 285 and higher gets really tricky. You typically have to size down in diameter significantly and will need a good amount of camber for sure.

[@dogshit9870]

Thank you so much for the reply!

[@project9s888]

Great video. Are these 18s or 19s, I know you have the upgraded brake kit. Also, have you heard about comparing the width stagger by ratio and not directly # in mm's? Saw somewhere on bimmerpost a while back. It stated 20mm 255/275 is not the same as 265/285 as the ratio is going away from BMW intended ratio. Interesting although I think for most this analysis is simpler & tremendous. I run 255/275 PS4S street and rides great. I am drag racing 295/30/18s rear and the car handles terribly with 40mm double stagger (19s front). Of course this is not streetable just swap for track and back off. Really do think the 20mm is the perfect setup for these cars. Wondering if I could go 265/285 19s for daily but doubt it I'm close to rubbing in rears.

[@FaRKle0079]

All wheels except the 305 are 18s. The 305s are on 19s. I haven't heard of of altering the stagger ratiometrically, probably because keeping the magnitude delta is the closest you'll get to the stock ratio. The stock stagger ratio with 245/265 is 8.2%, and 265/285 is 7.6%, only 0.6% difference from the stock stagger ratio. Going to 265/295 is 11.3%, much larger. Let's assume I can go to 285/305, the stagger ratio is 7%, so only a bit over 1% different from stock.

[@project9s888]

@@FaRKle0079 You explain things so damn well! Agree it makes sense. 20mm stagger on 18s I think would ride better than 20mm stagger on 19s. Any input? I can't run 18s front because of the NH kit.

[@FaRKle0079]

@@project9s888 The 18s should have better ride quality than the 19's because the more sidewall you have it can soak up some of the bumps.

[@MrScottpeterson2112]

For a second there I was about to order a Chick-fil-A Grilled Chicken Club Sandwich. 🐔 52

[@FaRKle0079]

😂 Dang, now I want one too (and a milkshake)!

[@ruleslawyer]

I really would have loved to see a square setup in comparison. So many people reccomend them that it would be nice to see how much you're leaving on the table. Also if you can fit a 275 up front are you getting a pair of 295 rears next?

[@FaRKle0079]

I need to get some sponsors to fund another permutation! My wife might tolerate me taking up the garage space, but I'll probably get some dirty looks if she sees an additional two tires and the bill for them and track time, haha. My next tire sizes will depend on what model tire I choose. I can't do a 275/295 with RS4 unfortunately.

[@ruleslawyer]

@@FaRKle0079 They make a 295/40ZR18 but I haven’t done the calculations to see if the diameter is anywhere reasonable.

[@FaRKle0079]

@@ruleslawyer unfortunately that tire is a lot bigger in diameter 😔.

[@ruleslawyer]

@@FaRKle0079 🪚

[@carsstuff9914]

I have been running square setup. I think it’s a touch more oversteer than my like, and the throttle application have to be very precise. 20mm you can put the power down at the exit while have a relatively neutral balance. Not ideal but square tires are rotatable and you can get slicks…

[@yehiazakaria203]

Any reason why you don't run/test 285/305?

[@FaRKle0079]

It's very difficult to fit a 285 in the front of an M2C. It shouldn't be a different trend from 265/285.

[@MrScottpeterson2112]

When is your next track day? Mine, T-Hill 8/27 and Laguna 9/14. I run 1:54's at Sonoma 275f 295r on 19's Stay classy 👌

[@FaRKle0079]

I'll be at Thunderhill West this weekend with Audi Club! Haven't signed up for anything else yet. I'll take a look at your Laguna date.

[@MrScottpeterson2112]

NCRC on 9/14

[@FaRKle0079]

@@MrScottpeterson2112 Ah dang, just checked and saw that's a Wednesday. It's pretty difficult for me to take week days off. I'm eyeing the 10/15 Sonoma day that LightSpeed has.

[@1bmw_Clubsport]

you are starting to be on the limit of the mechanical grip the car produces, unless you mount a drexler diff that will be a huge improvement, but also some good suspension, like nitron r3, kw clubsports or even öhlins ttx, when you should be able to finetune your car for better rotating.. alignment you could run 1mm toe in on the rear and 1mm toe out on the front.. that is also a pretty good alignment for the track for our BMW's..

[@FaRKle0079]

Shhhh, you're giving away one of my next tests! 😁

[@1bmw_Clubsport]

@@FaRKle0079 haha sry mate 😜 it is though, very cool research you are doing here. I my self run 265/295 setup on a m135i widebody car..

[@anthonyisgro7185]

Kinda wish 295s were also a part of this testing 😢

[@FaRKle0079]

Me too, but I'd need a tire/track day sponsor to to make that testing worth the cost, haha.

[@andrewthompson6893]

The stock stagger is only 20mm in name. In reality it's 15mm because the front star spec tire runs wide, and the rear runs skinny. You're such a detailed person, you really should have included the true staggers, ie the treadwidths. That would give people a better understanding of the true stagger when they don't use the exact tire you're using. Great video though, as always.

[@FaRKle0079]

That's a sharp observation. I'm going to say "it depends" though. You're right that the stock M2C 246/265 tread width difference is 15mm, but the M2CS with its Cup 2 tires is either 23 or 25mm (both star spec) depending on which ones you get. The M3/4 star spec tires (19 and 20s) are also 25mm. Since it can be pretty difficult to match 15mm and 25mm stagger exactly with non-star spec tires I'll just keep it simple to 20/30/40.

[@lucyferr5571]

Are the those 18” or 19”?

[@FaRKle0079]

All the wheels except for the 11" wide one (to run 305s) are 18". The 305 tires are on a 19" wheel.