[Supr3me]

Car and mods are in my sig. I love my 20's and Michelin PS4S for cruising but I need a more serious wheel and tire combo for track and drag. I'm putting down a little over 500 AWHP right now and need more sidewall.

I'm thinking APEX Arc-8s for a lightweight wheel but am open to other suggestions.

17s or 18s?

I know square setup is recommended for track, but I feel like that really reduces my rear tire width. I'm running 225/35/20 on the front and I get a fair amount of rub at even a moderate drop so I definitely couldn't go much wider. I'm running 265/30/20 on the rear and on a 10" rim it's a bit stretched. I think I could go a bit wider, especially if I raised the car a bit. 225 square setup feels way too narrow for the rear. Who's running square setup on a 340i xDrive?

Finally tires. R888's? RE-71R? I'm AWD so it seems like I could stay with extreme summer performance instead of an r compound. Any extreme performance summer tires you'd recommend besides the Michelin PS4S?


Thanks in advance for your opinions.

[Expert@ApexWheels]

Originally Posted by Sµpreme

Car and mods are in my sig. I love my 20's and Michelin PS4S for cruising but I need a more serious wheel and tire combo for track and drag. I'm putting down a little over 500 AWHP right now and need more sidewall.

I'm thinking APEX Arc-8s for a lightweight wheel but am open to other suggestions.

17s or 18s?

I know square setup is recommended for track, but I feel like that really reduces my rear tire width. I'm running 225/35/20 on the front and I get a fair amount of rub at even a moderate drop so I definitely couldn't go much wider. I'm running 265/30/20 on the rear and on a 10" rim it's a bit stretched. I think I could go a bit wider, especially if I raised the car a bit. 225 square setup feels way too narrow for the rear. Who's running square setup on a 340i xDrive?

Finally tires. R888's? RE-71R? I'm AWD so it seems like I could stay with extreme summer performance instead of an r compound. Any extreme performance summer tires you'd recommend besides the Michelin PS4S?


Thanks in advance for your opinions.

Hi there,

For a 18" square setup, I would recommend something along the lines of the following fitment:

Front & Rear: 18x9” ET30 or ET31 with 245/40-18 tires
-Direct fit
-255/35-18 tires can also be used but may require additional front negative camber and potentially a rear fender roll depending on ride height and tire selection.

With a 18x9" ET30 wrapped in a 245/40-18 tire at all four corners, this setup will be a complete direct fit. Wider 255/35-18 tires can also be used but with more aggressive track-focused compounds, we suggest dialing-in some front negative camber to help with fitment (and performance).

If you have any questions, please let me know!

-Geirsen

[Supr3me]

Thank you Geirsen. I think we're also corresponding via email on this topic and your suggestions have been terrific.

[andino]

I would opt for 255/40/18 rather than 255/35/18 (if you go the 255 route). 255/35 is a fair bit shorter than stock (about 4%) which may have other issues than just speedo being off. I've run 255/40/18 on stock xdrive suspension as well as lowered without issues needing extra camber.

[thejeremyman9]

For tires, i have heard that RE-71R have better grip on a circuit despite the higher treadwear than R888. Not sure about straight line grip though.

If you want a 1/4 dedicated setup, consider a drag radial? Do you really spin that much with xdrive from a launch?

[Supr3me]

Originally Posted by thejeremyman9

For tires, i have heard that RE-71R have better grip on a circuit despite the higher treadwear than R888. Not sure about straight line grip though.

If you want a 1/4 dedicated setup, consider a drag radial? Do you really spin that much with xdrive from a launch?

I'm leaning towards the RE-71r right now.
As for wheelslip, I'm using xHP to limit torque on the shifts to minimize TC intervention but would like to get stickier so I can put more torque down.
Honestly, I have more issues with downshift launches on a roll.- sometimes I punch it and it downshifts and TC kicks in and I just end up popping like crazy but not going anywhere lol

[thejeremyman9]

Originally Posted by Sµpreme

I'm leaning towards the RE-71r right now.
As for wheelslip, I'm using xHP to limit torque on the shifts to minimize TC intervention but would like to get stickier so I can put more torque down.
Honestly, I have more issues with downshift launches on a roll.- sometimes I punch it and it downshifts and TC kicks in and I just end up popping like crazy but not going anywhere lol

Why would you downshift on a roll and not just preselect the correct gear? You could brake boost if you needed but honestly not even necessary on stock turbo (if you are). And if you really want to be in auto, you can downshift in D to M then slap the trans over to S once you start the roll.

Also why do you have TC on? You should be in DSC off or at least sport + where TC typically will not kick in as long as you are going straight (and the steering wheel is pointed the same direction as the car).

[andino]

If you only care about straight line, you may consider something more specific for the task. Something like the Nitto NT05R in the rear and NT05 up front.

[Supr3me]

Originally Posted by thejeremyman9

Why would you downshift on a roll and not just preselect the correct gear? You could brake boost if you needed but honestly not even necessary on stock turbo (if you are). And if you really want to be in auto, you can downshift in D to M then slap the trans over to S once you start the roll.

Also why do you have TC on? You should be in DSC off or at least sport + where TC typically will not kick in as long as you are going straight (and the steering wheel is pointed the same direction as the car).

I'm not on stock turbo, I'm on Pure800. And the specific instances I'm referencing aren't street racing or serious pulls, just dicking around in Sport drive, Sport+.
Punch it and the transmission downshifts and I get serious traction intervention. But on launches I get it on upshifts as well. I can send you logs if you're interested, but honestly just looking for tire suggestions rn.

[weehe126]

I definitely like the RE71r as mentioned before. They get into temp range very quick so they are good on the street without needing to push them hard to get fraction. One issue you will have with R888 or NT05r is getting the tires warmed up, because cold they have worse traction than your current tires. Only issue with RE71r is that they have limited sizes for 17 and 18" rims. For 19" they have wider sizes.

[thejeremyman9]

Originally Posted by Sµpreme

I'm not on stock turbo, I'm on Pure800. And the specific instances I'm referencing aren't street racing or serious pulls, just dicking around in Sport drive, Sport+.
Punch it and the transmission downshifts and I get serious traction intervention. But on launches I get it on upshifts as well. I can send you logs if you're interested, but honestly just looking for tire suggestions rn.

Ah i see. I figured based on your OP you would only be swapping these tires on for running times, then swapping back to 20s for everything else, so the situation you described wouldnt apply.

Back on track (no pun intended ), i think the others above gave some good suggestions. I think weehe's temperature consideration is a major point IF you plan to use them on the street without preparation as you suggested. The RE-71R will be more streetable in that sense than some more drag focused tires.

[Supr3me]

Thanks all, really good specific suggestions here.
I think I do need to make an absolutely final decision whether this new setup will truly be a track day setup only or whether I want it to be my new double duty summer setup/track setup.

There's just something about buying brand new wheels and then putting them in the garage that my brain is rejecting lol. I want to drive them and enjoy them. And honestly, the 20" AGs are starting to show their age.

Decisions decisions.....

[Supr3me]

OK I've narrowed this down some and definitely will use my new wheels/tires combo as my summer street/track setup.

Unfortunately when I looked at most of the 18" wheel offerings that are square or nearly square, I don't love the way they look. I concluded that the narrower wheel combined with higher offset robs most of the concavity and I'm a sucker for a concave wheel.

So if I do an Enkei RS05RR 18x9.5 front, 18x10.5 rear, it sounds like 35 front offset and 45 rear offset will work. Does that sound right? Will I still get decent concavity with that offset?
I'm willing to increase ride height and do a small amount of camber, but I'm on KW V1 and so I'm limited in how high I can go in the rear. I'm thinking 255/40/18 and 285/35/18 for tire. Will those be stretched on those rim sizes, in PS4S? I know those run a little wider.

And follow up, how much performance for track and drag do you think I'm sacrificing with this setup?

Thanks in advance for the assistance on this.

[weehe126]

I would step down at least the front to a 9" as 255 on a 9" is already a little stretched. 285 would also be fine on a 10" rear. Wider rims just means more weight. What tire are you looking to run as the RE71r doesn't come in those sizes.

[Supr3me]

Originally Posted by weehe126

I would step down at least the front to a 9" as 255 on a 9" is already a little stretched. 285 would also be fine on a 10" rear. Wider rims just means more weight. What tire are you looking to run as the RE71r doesn't come in those sizes.

Thinking about PS4S. I'll need to double check tire sizes they offer.

[weehe126]

So I just want to state that I originally wanted to get the 18" M513 rims to run more sidewall, for more traction. I love the RE71r tires as I ran them on my E90 335i (275/35/18) that was at ~475whp. However, 275 rears are the widest option for an 18" rim, and only a 275/35/18. So you would be losing the sidewall benefit of an 18" rim. The RE11 has a 275/40 and 245/45 combo you can run, but isn't as good of a tire wet or dry. Again, 275 is as wide a tire as you can get, unless you want 285/30 which would be dumb.

I decided to get the 19" M3/4 equivalents, m437 rims because of everything I stated above. In addition, there is no significant increase in weight when you consider both rim and tires (513 vs 437 and RE11 vs RE71r), I think the 19" rims and tires were actually lighter. I am currently running a 275/35/19 MP4S in the rear (because they came with the rims) and am at 460-480whp in my 340i. So very similar power and sidewall comparison between the 335 and 340. These MP4S can't come close to the dry traction I had with the RE71r on my 335. 3rd gear is almost useless unless it is new asphalt. I could basically dead hook in 2nd gear with the RE71r with the 335.

I know it is hard comparing awd vs rwd for traction, but I would strongly consider looking at 19" rim options. 9" et 30-35 front, 10" et 40-45 rear and you can run 245/40 and 285/35 RE71r.