Need help fitting wide wheels on an e30.

[seven-57]

So I just picked up a crazy set of BBS RS131's, but the price was killer so I couldn't resist.

I'll start with the car.
Right now I'm driving a 1987 BMW 325e. The car is currently on custom coilovers made by a company called Broadway Static. I found them here on Stanceworks and Jaze, the guy I worked with, is awesome and helped me out every step of the way. I definitely recommend checking them out if you're looking for high quality coilovers. I'm currently running 5" swift springs.

So the wheels I just picked up are BBS RS131's. They're Porsche fitment so they're 5x130 and I currently have a set of 4x100-5x130 20mm adapters.

So these are the original specs of the wheels. They came from a Porsche 928S.
16x8.5 et56
Centerbore: 71.6

Now the wheels have been rebuilt at some point so the wheels are now:
Front: 16x9 (1" lip, 8" barrel)
Rear: 16x10.5 (2.5" lip, 8" barrel)

I currently have brand new Falken 512's mounted on the front (205/40/R16).

My real issue is finding a tire that will fit the rear wheels and still allow me to be low while sitting properly in the rear fender well.

I still want to run stretched tires, so I was thinking of putting 225/40's on the rears, but again, I'm not sure what size tire to run.

My next question is making the wheels sit well with the fender. I want the typical low stance with my lips poking just outside or a little flush with my rolled fenders. I'm not sure what size spacer to run considering the wheels have been rebuilt and now I'm not sure what the new offsets are.

Sorry this was such a long story. Thanks for any help!

[Byron]

Your new offsets are et50 on the 9's and et30.5 on the 10.5's, assuming they kept the stock barrels and just got bigger lips. The front is easy, a 40mm adapter and they'll fit great with about a half inch of poke. The 10.5's are a real tight fit in the back, if you use the 20mm adapters you have now they'll poke about 3/4". It will be slightly easier for you to fit since you have an early model, but you're still going to need a hefty roll/pull. You don't have much space on the inside either. I'm not up to date on 4x100-5x130 adapters, but the highest offset you can run and still clear the trailing arm is et14, which would be a 16mm adapter.

As for tires, run the 205/40's up front and get some 215/40's for the back. Realize you're going to need to go very low to pull off such a short tire.

[Zic]

If the 8" barrel is stock. than your current specs are like this.

changing the width x amount only changes the centerline x/2 which is where offset is measured from. all you ever need to know:

+1" lip = -12.7mm offset
+.5" lip = -6.35mm offset
-.5" lip = +6.35mm offset
-1" lip = +12.7mm offset

+1" barrel = +12.7mm offset
+.5" barrel = +6.35mm offset
-.5" barrel = -6.35mm offset
-1" barrel = -12.7mm offset

Fronts will be at 16x9 et49,65.ish.
and rears will be at 16x10.5 et30,6ish.

I would personally want a setup of 16x9et10ish and 16x10.5et20ish. So I would go for a 40mm adapter up front and a 10~15mm adapter on the rear. *edit, Byron knows more about E30 stuff than i do, seems like my rear adapter advice ain't gonna cut it, so you will need bigger ones. and thus needing a good pull on the rear fenders.

[seven-57]

Your new offsets are et50 on the 9's and et30.5 on the 10.5's, assuming they kept the stock barrels and just got bigger lips. The front is easy, a 40mm adapter and they'll fit great with about a half inch of poke. The 10.5's are a real tight fit in the back, if you use the 20mm adapters you have now they'll poke about 3/4". It will be slightly easier for you to fit since you have an early model, but you're still going to need a hefty roll/pull. You don't have much space on the inside either. I'm not up to date on 4x100-5x130 adapters, but the highest offset you can run and still clear the trailing arm is et14, which would be a 16mm adapter.

As for tires, run the 205/40's up front and get some 215/40's for the back. Realize you're going to need to go very low to pull off such a short tire.

I'm pretty sure the barrels aren't stock, but I'm not sure. Do you know the original size? Off the top of my head, I think that the stock barrels were 7.5" with 1" lips, but I could be making that up. My fenders are rolled but not pulled. You're sure 215's aren't too small?

[seven-57]

If the 8" barrel is stock. than your current specs are like this.

changing the width x amount only changes the centerline x/2 which is where offset is measured from. all you ever need to know:

+1" lip = -12.7mm offset
+.5" lip = -6.35mm offset
-.5" lip = +6.35mm offset
-1" lip = +12.7mm offset

+1" barrel = +12.7mm offset
+.5" barrel = +6.35mm offset
-.5" barrel = -6.35mm offset
-1" barrel = -12.7mm offset

Fronts will be at 16x9 et49,65.ish.
and rears will be at 16x10.5 et30,6ish.

I would personally want a setup of 16x9et10ish and 16x10.5et20ish. So I would go for a 40mm adapter up front and a 10~15mm adapter on the rear. *edit, Byron knows more about E30 stuff than i do, seems like my rear adapter advice ain't gonna cut it, so you will need bigger ones. and thus needing a good pull on the rear fenders.

Comparatively, yours and Byron's calculations are only about 1mm off so I'm gonna play it safe around both your estimates. I have the 20mm adapters, but idk if I wanna buy new bigger ones. I might just try to buy spacers to mount on top. I've never done that, but does that seem like a bad idea?

[seven-57]

So I guess what I'm really seeing here is that I should just purchase new adapters all together. Do you guys have any recommendations on someone to purchase from?

[Byron]

Keep the rear adapters, it's not worth spending money on new ones to get only 4mm of space. You need new ones for the front, don't put a 20mm spacer on an adapter. I just re-looked at the sizes you posted, and something's off with all the measurements. RS's are center mount, so if you really do have 8" barrels and 1" and 2.5" lips, your wheels woul be 9.5's and 11's. I'm gonna guess and say they have and had 7.5" barrels.

215's will work fine, get something other then a 512 though; they run so narrow they probably won't mount.

[seven-57]

Keep the rear adapters, it's not worth spending money on new ones to get only 4mm of space. You need new ones for the front, don't put a 20mm spacer on an adapter. I just re-looked at the sizes you posted, and something's off with all the measurements. RS's are center mount, so if you really do have 8" barrels and 1" and 2.5" lips, your wheels woul be 9.5's and 11's. I'm gonna guess and say they have and had 7.5" barrels.

215's will work fine, get something other then a 512 though; they run so narrow they probably won't mount.

Well they don't even make 512's anymore so it's not like it matters lol Possibly. I'm going off of what I was told by the PO before I bought them. I'll measure them when I get a chance though. Any recommendations for a tire brand?

[1badg35]

i would personally redrill the set to 4x100 and then you will have much more room to work with. you sure they are 8" barrels? I dont think those came originally with 8" barrels

[seven-57]

i would personally redrill the set to 4x100 and then you will have much more room to work with. you sure they are 8" barrels? I dont think those came originally with 8" barrels

I "was" pretty sure they were 8" barrels but now I don't know. You're the guy who refinishes all those gorgeous sets right? You work is killer. Every time I'm in the classifieds I hit your thread to look at your work hahaha You think a redrill is really worth it? It would certainly cost me a lot more. I only need to buy 2 adapters to do it this way.

[Byron]

I'd stay away from a redrill, there's no cars that those would just bolt up to if they were 4x100, and the cost of the redrill+spacers+extended bolts+hubrings is going to be way more then the cost of 2 new adapters.

As for tires, just get a tire that runs true to size and you'll be fine.

[seven-57]

I'd stay away from a redrill, there's no cars that those would just bolt up to if they were 4x100, and the cost of the redrill+spacers+extended bolts+hubrings is going to be way more then the cost of 2 new adapters.

As for tires, just get a tire that runs true to size and you'll be fine.

Thanks man. Right now I'm looking between:
1. Yokohama S-Drives in 215/40R16
or
2. Falken Azenis RT-615K in 215/45/16

If it's really coming down to a 5% difference in sidewall then I'm just going with what I can find cheaper.

[Byron]

Both of those run wide. And the visual difference between a 40 and a 45 is actually quite large. You would notice it for sure. If I'm not mistaken, BFG makes a g-force sport in 215/40 for around $80 a tire. Short tires for 16's are getting hard to find though.

You could also do a 205/45 all around, but I personally think a 45 sidewall is too much to look good stretched.

[seven-57]

Both of those run wide. And the visual difference between a 40 and a 45 is actually quite large. You would notice it for sure. If I'm not mistaken, BFG makes a g-force sport in 215/40 for around $80 a tire. Short tires for 16's are getting hard to find though.

You could also do a 205/45 all around, but I personally think a 45 sidewall is too much to look good stretched.

I've run G-force tires before. Awesome tires, but loud as hell. I'll try it. I am looking for budget. The previous owner had 205/40's on the rear and the tires are destroyed. Looks like the bead popped right off.