ZPOST - View Single Post - M and non-M: custom offset die forged wheels

MBan · 08-21-2022, 02:25 AM

On my Z4 M Coupe I'm running 8,000 tonne die forged Advan RS-DF in 18 x 8.5 +35 and 18 x 9.5 +22. These are really light (I measured them at 7.9kg/17.4lb at the front and 8.3kg/18.3lb at the rear) and super strong due to the forging process. However, I think the front offset could do with being a few mm lower to push the wheel further out. There are pretty much no options for die forged wheels in an 8.5 width (or a 9 inch) with an offset lower than +35 but not too crazy low. The only one I am aware of is the BBS RG-R which comes in a +30, but they are relatively heavy (9.2kg according to BBS and I'd wager they're actually heavier) and for the M you need to get the 10 inch rear which weighs 9.6kg. And, the BBS wheels require hub rings.

Through an Australian company that imports car parts from Japan I found out about a company called TWS Forged (not TSW!). These guys do proper die forged wheels and one of their models (the T66-F) is super lightweight and can be made in custom offsets if you buy a certain number of sets (I've been told 5 sets is enough). For reference the T66-F in an 18 x 8.5 +35 weighs 6.99kg/15.4lb and an 18 x 9.5 +22 weighs 7.97kg/17.6lb. Hub-centric, so no need for hub rings.

So, I'm wondering if anyone else would be interested in ordering a set? Prices are about 91,000 yen per wheel.

Since the Z4 M and non-M take the same wheel at the front, this is open to all Zs, but it would mean we would have to agree to a front wheel specification and then pick the rears from the standard sizes TWS do. If five M owners are keen, we could get custom rears as well, but to be honest, 9.5 +22 fits pretty well. The TWS T66-F custom menu has some really nice custom colours, but if we pick an off the shelf rear wheel (colour and offset), we would have to pick the same standard colour for the custom offset fronts.

Over the last couple of months I have been testing a bunch of different front offsets using spacers. Effectively, I've tried 8.5 +23, +25, +27.5 and +30. I've done some heavy cornering and got quite a bit of rubbing on the arch liner (to the front of the wheel, where that little round push clip joins the liner to the guard) with the +23, a bit with the +25 but was fine with the other two offsets. For reference, I'm on KW V3s, 10mm lower than stock at the front, -2 degrees of camber, 235 40 R18 tyres and I used a heat gun on the arch liner to free up a couple more mm. Based on this, I'd be happy with an offset of +28 or 2mm either side.

Here is the T66-F page (sorry - it's in Japanese):
https://www.tws-forged.com/tws_t66-f.html

And here is the 'custom' page:
https://www.tws-forged.com/tws_t66-f_custom.html

Finally, here is a Youtube review:
https://www.youtube.com/watch?v=ge8QjcaqpP8

08-21-2022, 02:25 AM	#1
MBan First Lieutenant 170 Rep 362 Posts Drives: BMW Z4M Coupe Join Date: Jul 2014 Location: Perth, Western Australia iTrader: (0)	M and non-M: custom offset die forged wheels On my Z4 M Coupe I'm running 8,000 tonne die forged Advan RS-DF in 18 x 8.5 +35 and 18 x 9.5 +22. These are really light (I measured them at 7.9kg/17.4lb at the front and 8.3kg/18.3lb at the rear) and super strong due to the forging process. However, I think the front offset could do with being a few mm lower to push the wheel further out. There are pretty much no options for die forged wheels in an 8.5 width (or a 9 inch) with an offset lower than +35 but not too crazy low. The only one I am aware of is the BBS RG-R which comes in a +30, but they are relatively heavy (9.2kg according to BBS and I'd wager they're actually heavier) and for the M you need to get the 10 inch rear which weighs 9.6kg. And, the BBS wheels require hub rings. Through an Australian company that imports car parts from Japan I found out about a company called TWS Forged (not TSW!). These guys do proper die forged wheels and one of their models (the T66-F) is super lightweight and can be made in custom offsets if you buy a certain number of sets (I've been told 5 sets is enough). For reference the T66-F in an 18 x 8.5 +35 weighs 6.99kg/15.4lb and an 18 x 9.5 +22 weighs 7.97kg/17.6lb. Hub-centric, so no need for hub rings. So, I'm wondering if anyone else would be interested in ordering a set? Prices are about 91,000 yen per wheel. Since the Z4 M and non-M take the same wheel at the front, this is open to all Zs, but it would mean we would have to agree to a front wheel specification and then pick the rears from the standard sizes TWS do. If five M owners are keen, we could get custom rears as well, but to be honest, 9.5 +22 fits pretty well. The TWS T66-F custom menu has some really nice custom colours, but if we pick an off the shelf rear wheel (colour and offset), we would have to pick the same standard colour for the custom offset fronts. Over the last couple of months I have been testing a bunch of different front offsets using spacers. Effectively, I've tried 8.5 +23, +25, +27.5 and +30. I've done some heavy cornering and got quite a bit of rubbing on the arch liner (to the front of the wheel, where that little round push clip joins the liner to the guard) with the +23, a bit with the +25 but was fine with the other two offsets. For reference, I'm on KW V3s, 10mm lower than stock at the front, -2 degrees of camber, 235 40 R18 tyres and I used a heat gun on the arch liner to free up a couple more mm. Based on this, I'd be happy with an offset of +28 or 2mm either side. Here is the T66-F page (sorry - it's in Japanese): https://www.tws-forged.com/tws_t66-f.html And here is the 'custom' page: https://www.tws-forged.com/tws_t66-f_custom.html Finally, here is a Youtube review: https://www.youtube.com/watch?v=ge8QjcaqpP8
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