I would like to upgrade my 14" bottlecaps to 15" basketweaves (4-bolt). Is there any fit concern with this switch? Thanks.
I don't think so as long as the wheels have the proper offset. If your car is lowered and you do driver's schools or auto-x, if you run 225/50/15 tires, you'll likely rub the inside of the fender lip and have to roll it for clearance (which is difficult to accomplish without cracking and losing the paint on the fender lip). Not sure if 225/45/15's might clear. Tire Rack shows wheels for E30's up to 17".
225/50x15 can fit OK on lowered car Moving from 14" to 15" on an E30 should not be too big a deal, unless, as MGarrison pointed out, the offset is much off spec. The biggest potential problem is rubbing on the front suspension if your offset number is bigger than stock. On my E30 track car, I went to 15" wheels, and used wheels meant for FWD Japanese cars in order to save big on cost and wheel weight. Their offset of ET39 also allowed me to use spacers to get the proper clearances to suspension parts and brake calipers.
I've used both MSW & BBS 7x15 baskets as track wheels for my E30, w/ 205-50/15 tires - and never had any probs w/ rubbing, even when I was using the rediculously low Alpina front springs. It's dark & cold in my garage right now, but I could give you their part #s and measure the offsets for you, if you need the info. My current street rims are Alpina E30 7x16s, w/ 205-45/16 tires. They've never rubbed, either, but my front ride-height is a bit higher now w/ the Racing Dynamics springs, & that the anti-sway bars are maxed out. I'd be confident to wear a 7x15 rim (w/ the proper offset) on a stock-suspension E30 for street use and they'll look great. But if you'll be doing any auto-cross or track events, you'll need a (much-) stiffer front anti-sway bar to keep your front fender-lip away from the outside tire in a high-performance turn. Also note, that when you graduate to wider wheels, you'll also be looking at higher-performance tires that'll have much more 'stick' than your stock tire/wheel combination. These wider, stickier tires will permit much greater lateral g-force, your car will experience greater body-roll as a result, which will reduce tire-clearance, unless you stiffen the suspension to compensate. Heh, once you've done the +1 rim / tire thing, you'll completely change the handling characteristics of your car & increase its performance limits, now you'll have to do some driving events to improve your skills - before you know it, you'll be talkin' inflation-pressures & spring-rates to your buds in the club, & spending (lots) more money chasing additional changes! Seriously, though - when you wear +1 rims & wider / stickier / lower-profile tires, you'll be driving a different automobile that will require you to improve your driving skills. I had a lot of fun driftin' my stock E30 & OEM tires around the track at sensible rates of speed - when you change your car's 'feel', you might not be entirely comfortable w/ its new capabilites.
Great info. I don't anticipate spending time on the track, just looking to up the fun-factor and a better look than the bottle caps. Bilsteins and possible a subtle lowering will come first. Thanks.
I agree that 'fun-factor' is a pert' good reason to be drivin' around, also that the 'look' of the car is an important part of one's owner-pride. But as I remember my experience, the salient fact is that my car was easier to drive & more forgiving to my mistakes in its 'showroom' wheel/tire/suspension configuration - that is, the BMW engineering team did their job exactly right! Once I started up the 'aftermarket upgrades' ladder, I think I lost something - the sense of 'balanced ease' at its traction-limits started to occur at higher & higher speeds, 'til I realized that I'd modified the car beyond the point where my driving skills could cope w/ its capacities - I needed to bring more precision & greater concentration to my driving. So I'd just like to repeat, if you go for a +1 wheel, w/ a higher-performance tire, that your car will behave v. differently from what you're used to, it might take 1 or 2 track-schools, or several thousand miles street-miles, before you'll become accustomed to its new capabilities.
