Anyone have Kosei K8R's?

[Keenercarguy]

I'm looking into buying a street set of wheels/tires and the plan is to either go 17x7 Kosei K4R's OR (more likely) 17x8 Kosei K8R's with a 225/45-17 tire for the best feel/sidewall stiffness (versus a 235/40-17 for all out grip). I'm looking at the K8R's because they're way better looking than the K4R's but still way lighter than stock at 16.5ish pounds, impressive for a 17x8.
Note: My track/autocross set will be 17x9 RPF-1's with 235/40-17 ZII Star Spec's, so this is only a question regarding K8R's.
DOES ANYONE HAVE K8R's? I'm looking for pictures mainly, and possibly also reviews.

[TofuJoe]

Interested in these wheels, too.

[Vracer111]

I've yet to see anyone with the K8R, it was a wheel I was looking forward to before deciding not to bother with 17x8 size anymore.

If you are looking for the best tire size on a 17x8 wheel for responsiveness and ride control then you should stick with the stock 215/45-17 size, it's the optimal size for an 8" width wheel, having a tread width of ~8.1" with most performance tires.

I had the K4R with 215/45-17 Kumho XS Extreme Performance tires for track...the +36mm offset gives nice stability and the combination of reduced unsprung mass and grippy tread compound matched to wheel width yield better agility and better overall ride quality. The K8R are +48mm offset though, so they will not give as wide a track, and thus less lateral stability.

Personally I've gone to 17x7.5 +40mm wheels and 205/45-17 tire size for DD (currently running the stock tires to save some money, but it's now time for new tires and they will be 205/45-17 size again). Makes the car even sharper and quicker in input response in addition to lowering CG for better stability and increasing acceleration resoonsiveness when both on and off the throttle. If you are looking to finely hone the reflexes to razor sharp, can't beat 17x7.5 wheels with 205/45-17 performance tires.

Old picture of my FR-S on the 17x7.5 +40mm with 205/45-17 tires, a 17x8 +48mm wheel and stock sized tire would actually not stick out as far with a slightly more narrow track...

[Keenercarguy]

Originally Posted by Vracer111

I've yet to see anyone with the K8R, it was a wheel I was looking forward to before deciding not to bother with 17x8 size anymore.

If you are looking for the best tire size on a 17x8 wheel for responsiveness and ride control then you should stick with the stock 215/45-17 size, it's the optimal size for an 8" width wheel, having a tread width of ~8.1" with most performance tires.

I had the K4R with 215/45-17 Kumho XS Extreme Performance tires for track...the +36mm offset gives nice stability and the combination of reduced unsprung mass and grippy tread compound matched to wheel width yield better agility and better overall ride quality. The K8R are +48mm offset though, so they will not give as wide a track, and thus less lateral stability.

Personally I've gone to 17x7.5 +40mm wheels and 205/45-17 tire size for DD (currently running the stock tires to save some money, but it's now time for new tires and they will be 205/45-17 size again). Makes the car even sharper and quicker in input response in addition to lowering CG for better stability and increasing acceleration resoonsiveness when both on and off the throttle. If you are looking to finely hone the reflexes to razor sharp, can't beat 17x7.5 wheels with 205/45-17 performance tires.

The two tires I generally enjoy for street use, Dunlop Direzza DZ102's and MIchelin Pilot Super Sports, have a 7.1 inch and 7.7 inch tread width (respectively) when in 215 size, I looked into that before deciding on the 225's… I don't really need a MAX performance tire that runs extra wide like with a Star Spec or RS3 on my daily set, I see rain pretty often and also lower temperatures and occasionally ice. (The DZ102's and PSS handle all those conditions just fine for summer tires though)
I'm looking at the K8R's because I dislike the stock wheels, and want a lighter and slightly wider street set for both looks and functionality, so I'm going to bother with 17x8's for that haha

[Vracer111]

Look at the Kumho Ecsta Sport LE and Continental ExtremeContact DW tires in 215/45-17... very much wide 8"+ tread width on those with really good wet and dry performance. Plus the Continental DW is one of the lightest tires you can get...the 215/45-17 is 18.7lbs, the 205/45-17 is 17.5lbs...that means the wheel/tire combo on my FR-S would come in under 35 lbs compared to the stock ~41 lbs...nice! And if I could afford to get the BBS RF forged 17x7.5 wheels it would drop down to ~32lbs a corner...

[Keenercarguy]

Originally Posted by Vracer111

Look at the Kumho Ecsta Sport LE and Continental ExtremeContact DW tires in 215/45-17... very much wide 8"+ tread width on those with really good wet and dry performance. Plus the Continental DW is one of the lightest tires you can get...the 215/45-17 is 18.7lbs, the 205/45-17 is 17.5lbs...that means the wheel/tire combo on my FR-S would come in under 35 lbs compared to the stock ~41 lbs...nice! And if I could afford to get the BBS RF forged 17x7.5 wheels it would drop down to ~32lbs a corner...

Ugh yeah tire weight is a PAIN, those Direzza DZ102's have great grip and last forever for a summer tire... But they're 22lbs a tire in a 215 wide which is just horrible. How long do the ExtremeContact DW's last in your experience? I burned through a pair of PSS on my rears in probably about 12,000-13,000 without ever actually taking them drifting (just AutoX'ing)... So that's why I've been running DZ102's back there, don't want to run into that problem again :/

[TofuJoe]

Experienced guy at the tire shop near me said the Michelin PSS will last a lot longer than the Conti ExtremeContact DW.

[Keenercarguy]

Originally Posted by TofuJoe

Experienced guy at the tire shop near me said the Michelin PSS will last a lot longer than the Conti ExtremeContact DW.

Yeah I'd heard similar but never a first person testimony. Plus tirerack actually lists the DW as 20 pounds a tire in 215 anyway, not too far below a DZ102 or PSS for that matter. But I'm always interested in (at least fairly) non-biased reviews.

[rwebber]

I just installed them 2 days back and They look amazing. I didn't see any photos of anyone running them on an FRS. I wrapped them with 245 40 conti 5s. They are so light compared to stock setup even with the fat tires.
Need to get it lowered ASAP.
I'll share some pics once I clean my car.

[rwebber]

I attached 6 images. The weight is def noticeable and i removed my spare tire today as well.

[Manic]

Did you really need to dig up three posts for this?

[Shark_Bait88]

Seriously.

Make one post.

[Kestrel]

Looks good. What does brake clearance look like with these?

Sent from my SAMSUNG-SM-G900A using Tapatalk