[will.c]

Originally Posted by N8N

Hmmm, I was leaning towards the 245 PSS's already, so you're really just kind of validating my choices. However, I didn't really know what the "hot" wheels were, sounds like everyone is saying whether I go 17 or 18 that I should primarily be looking at ARC-8s and F14s.

What would be the advantages of the staggered setup? I really don't see the upside, honestly, other than built-in understeer for those who didn't grow up driving RWD pickup trucks in snow

Correct; understeer. In other words, high-speed stability.

I didn't think it would be THAT important, until I tried putting my 189s reverse-staggered. It was hard to keep the car in the middle of the lane at merely normal highway speeds, to say the least. Try that yourself if you can w/ your 230s.

And also for our cars, slight stagger MAY provide faster lap times, but we'd be talking about splitting hairs here.

But overall I agree; square seems to be the generally preferred choice for many other reasons.

[N8N]

I thought that highway stability was primarily a function of alignment, e.g. for hands off tracking you'd want as much caster as you could get and a touch of toe in. I also find it odd that scrub radius seems to be pretty much ignored but then again i used to drive a 944 and that car tracked fine (but i may have a warped perspective as one of the vehicles i learned to drive on was an old IH Scout with a tiny steering wheel and super sloppy steering box...)

[will.c]

no you're right, but only to a certain extent. And without camber/caster plate, they can't even be changed much, and I assumed a slight toe-in would be applied regardless of what setup because we're talking about daily driving. I was trying to keep it less technical, and isolate the topic to just wheels and tires, but it seems you're savvy in all.

I think alignment is crucial in handling for lower tier of handling limit, e.g. highway driving, and can only go so far. But the overall balance from sheer contact patch area bias at the car's traction limit (at the track) are mostly affected by staggering of the tires.

I dont know what the scrub radius on our cars is, but changing it less than 20mm I don't think will have too much effect on handling. Im assuming that our cars come with slightly neg SR, thus widening the track should make it more neu. Or even if it was pos/neu to begin with, making it more positive would ultimately give more steering feedback with higher steering effort, which IMO are good. I've tried my car with and without 10mm spacers at the track, but honestly, the feedback and inputs are at such high levels that the SR effects are not really significant. maybe just a taaad bit of increase steering effort.

Edit: I read your comment again; you said "highway stability" which I agree with you that alignment is the primary variable.

[N8N]

Well, I wouldn't call myself "savvy" but I know enough to be dangerous

My background is (sadly) not racing or HPDE type driving but I do have an engineering degree and briefly worked for an OEM supplier of brakes so I have a little "book larnin'" but not as much actual behind the wheel test experience as I'd like. As generally I need to select wheels/tires without having the opportunity to test them first, I tend to ask lots of questions and overthink things

The main thing that I remember about scrub radius is that if you had too much the vehicle would pull to the high-mu side when braking with the front wheels on different surfaces - that is the one thing that was really dramatically evident even to the "un-sensitive" - the difference between an average passenger car and a typical 4WD truck was astonishing in this respect. Now it's not a problem if you're ready for it and know how to handle it, but it seems that most people who drive vehicles where this is an issue would say "scrub what?" if you tried to explain it to them... But usually such vehicles have ABS now and it's tuned to mitigate that effect, but at the expense of ultimate stopping distance.

So caster/camber aren't easily adjustable on a BMW? I ASSumed caster wouldn't be but I also ASSumed that camber would be... but I haven't really been underneath the car much at all yet mostly because I need to buy myself a good low profile floor jack that will fit underneath it! Even my little cheap Chinese portable one won't fit under the side skirts :/ I just had a local shop give me an alignment after I swapped my winter wheels/tires on, and they were able to get everything within spec somehow.

[will.c]

yea.. caster, no. but camber, a little bit in the front, but not much at all. BTW highly recommend a steel jack 2.5ton+. I've already seen 2 cases where a typical aluminum jack collapsed under our heavy cars.

[Expert@ApexWheels]

Here are a few more photos of the e92 335i with 17x9.5" ET35 ARC-8s that is used for the race track:









These are the 17x9.5" ET35 Satin Black ARC-8s wrapped in 255/40/17 Nitto NT01 R-compound tires with 5mm spacers in the front to clear the front strut. It is lowered on TC Kline coilovers with camber plates, dialing in about -2.8 degrees in front and -2 in the rear.

[Alen E90]

^^

[N8N]

I'm trying to avoid wheel/tire packages that require adding camber to fit... but that does look fantastic!

[Amini77]

Originally Posted by Alen E90

^^

+1....so sick

[DallasBoosted]

David, what front lip is that? Looks like a 1M...

[jbass524]

Originally Posted by N8N

I'm trying to avoid wheel/tire packages that require adding camber to fit... but that does look fantastic!

I've done extensive modification and tracking with an E92 so I have some experience. I hope it's good.

APEX makes an 18X8.5" wheel for the E9X. If you want track wheels go square and as wide as possible. Camber is probably the single best handling upgrade you could do and besides wheels, would be my first.

Not sure if this is the case, but tire wear on the inside has a lot to do with the toe than and with adjustable camber plates you can easily (5 minutes) adjust them for street use after a track day.

BTW, 17s out perform 18s in some cases and at the level of driver here, me included, 17s would never be why you're not as fast as you think you should be. Add that wheel and tire cost is a lot less and I would always opt for them unless I was sure 18s we're better.

[Expert@ApexWheels]

Originally Posted by DallasBoosted

David, what front lip is that? Looks like a 1M...

That would be the Slek 1M front CF lip with a custom fitted 1M front bumper.

[tinnsoldaten]

where do I get that front bumper ?

[jbass524]

Originally Posted by tinnsoldaten

where do I get that front bumper ?

That's the LTBMW 1M Bumper conversion. Call them.

[DallasBoosted]

Fitment confirmed... 17x9.5 ET35 Arc8's on the front of my car, with 5mm spacers. Looks like about 3-3.5mm of clearance to my ground control strut with the spacer on. I'll confirm the tire fitment (255/40-17 NT01's) when I get them mounted next week.

Also confirmed the 17" Arc8's clear 355mm stop-techs.

[UltraRacer13]

Originally Posted by DallasBoosted

Fitment confirmed... 17x9.5 ET35 Arc8's on the front of my car, with 5mm spacers. Looks like about 3-3.5mm of clearance to my ground control strut with the spacer on. I'll confirm the tire fitment (255/40-17 NT01's) when I get them mounted next week.

Also confirmed the 17" Arc8's clear 355mm stop-techs.

I bought the exact same wheels as you. But my AST 4100s have an adjustable endlink with a collar that threads up and down the strut. The collar added just enough width to the strut to make clearance an issue. I tried modify but was unable. The guys at APEX were awesome and summarily shipped me some 17x9's to solve the issue. I have yet to mount them (I am out of town) but will this week.

[DallasBoosted]

Originally Posted by UltraRacer13

I bought the exact same wheels as you. But my AST 4100s have an adjustable endlink with a collar that threads up and down the strut. The collar added just enough width to the strut to make clearance an issue. I tried modify but was unable. The guys at APEX were awesome and summarily shipped me some 17x9's to solve the issue. I have yet to mount them (I am out of town) but will this week.

That was nice of them. I probably would have gotten 17x9 et30's for my fronts if they had been available, I'd prefer to run without the spacers. Oh well! Apex seems to have great customer service and a great product at a great price... no wonder everyone seems to be buying them.

[DallasBoosted]

275/40 rears and 255/40 fronts NT01's on 17x9.5 square Arc 8's. Fits great with 5mm spacers up front. Should be some pretty massive front end grip with the ~34mm wider front track... Thanks to the guys at Apex, very reputable and excellent vendor.

[neilvosko]

Lowered wide and no rubbing?

[DallasBoosted]

Originally Posted by neilvosko

Lowered wide and no rubbing?

Just went around the block to check fitment so far, then put my street wheels back on. But seems good so far.

[Mavus]

Originally Posted by DallasBoosted

Fitment confirmed... 17x9.5 ET35 Arc8's on the front of my car, with 5mm spacers. Looks like about 3-3.5mm of clearance to my ground control strut with the spacer on. I'll confirm the tire fitment (255/40-17 NT01's) when I get them mounted next week.

Also confirmed the 17" Arc8's clear 355mm stop-techs.

This is great info - thanks!

What is the camber in front and rear?

Are you concerned about 275s "bubbling" on rear rims?

[demontwinz]

Dallas you BBK clear the 17"??? wow