Kosei K8R and K5R...

[Vracer111]

Don't know the offsets, but these will be available from tire rack within the next month. I like the looks of them and they are lightweight (17x8 @ 15.4lbs, 17x9 @ 16.5lbs but size is not shown on tire rack...)

Finally, a very inexpensive formula/mesh wheel that doesn't weight a ton...

K8R:



Tire Rack K8R page with actual pictures of the real wheel (4 bolt pattern though...)





K5R:



Tire Rack K5R page with actual pictures of the real wheel (4 bolt pattern though...)





the limited Kosei K8R and K5R info...

[DuMa]

i like the mesh wheel. what are the offsets for 17x8 and 17x9?

[Pat]

I just chatted with Jared at TR. He said the 8" wheel will have a +48 offset. Meh.
He said they have not weighed the wheel, but expects 16 to 18 pounds.

[Vracer111]

Originally Posted by Pat

I just chatted with Jared at TR. He said the 8" wheel will have a +48 offset. Meh.
He said they have not weighed the wheel, but expects 16 to 18 pounds.

Thanks for the info. +48mm offset actually is a positive point to me - would be ever so slightly wider than my current 17x7.5 +40mm Enkei Fujins. I had 17x8 K4R's in +36mm offset and I didn't like the change in agility and balance with the wider track. Pretty sure the weight will come in under 16lbs, these are Kosei Racing wheels we are talking about...and the official weight from Kosei is 15.43lbs. The 17x8 +36mm K4R's were 15.4lbs bare wheel.

[Pat]

Originally Posted by Vracer111

Thanks for the info. +48mm offset actually is a positive point to me - would be ever so slightly wider than my current 17x7.5 +40mm Enkei Fujins. I had 17x8 K4R's in +36mm offset and I didn't like the change in agility and balance with the wider track. Pretty sure the weight will come in under 16lbs, these are Kosei Racing wheels we are talking about...and the official weight from Kosei is 15.43lbs. The 17x8 +36mm K4R's were 15.4lbs bare wheel.

Great, thank you. It sounds like you and I have very similar priorities. But I'm surprised to hear you didn't like the wider track, all else equal. I don't think I've ever hear anyone complain about that from a functional or performance perspective on any car. Are you able to tell us more about how the car felt with the wider track while eliminating other factors that the difference in feel could possibly be attributed to?

[Vracer111]

Originally Posted by Pat

Great, thank you. It sounds like you and I have very similar priorities. But I'm surprised to hear you didn't like the wider track, all else equal. I don't think I've ever hear anyone complain about that from a functional or performance perspective on any car. Are you able to tell us more about how the car felt with the wider track while eliminating other factors that the difference in feel could possibly be attributed to?

I talk about my feelings here: http://www.ft86club.com/forums/showp...6&postcount=32

[Pat]

Originally Posted by Vracer111

I talk about my feelings here: http://www.ft86club.com/forums/showp...6&postcount=32

Right...so I guess you can't speak to only the difference in track width, as you had other tires on there that were very likely the majority of the difference you felt in the comparison between the LE Sport and the XS.

[Vracer111]

Originally Posted by Pat

Right...so I guess you can't speak to only the difference in track width, as you had other tires on there that were very likely the majority of the difference you felt in the comparison between the LE Sport and the XS.

Yes i'ts not apples to apples - would need the same tire (both model and size) on both wheel sets to do a direct comparison of just wheel offset changes, but then a tire size that is optimal for one rim width is not optimal for another and you are biasing the results some as well. There is no way to do it correctly unless you have two sets of the same wheels and identical tires with just the offset being different or alternately you use spacers on a set of wheels.

As it is though, no matter how the end result is achieved, the 1lb lighter 205/45-17 Max Performance tires with 7.7" tread width on a heavier 17x7.5 +40mm offset wheel definitely are an improvement in agility over 215/45-17 Extreme performance tires with 8.1" tread width on a nearly 1.5lb lighter 17x8 +36mm offset wheel. Both those tire sizes are optimal in regards to the respective rim width for the selected tires. Agility and suitable grip both dry and wet is my main concern for daily driver handling.

[Pat]

I appreciate your detailed response. I wonder how one could scientifically explain how a car with narrower, less-sticky tires, riding on a narrower track with a heavier (or similar) whee/tire combo could feel more agile that another car. I am having trouble explaining how that could be possible. Is it possible it just FEELS more agile, but quantifiable tests it is not?

[Vracer111]

You could get an accelerometer/DAQ system and see which setup gives the higher deg/sec rotational rate for the chassis in a slalom course...

Don't forget that the 205/45-17 tire has a 24.4" diameter new while 215/45-17 is a 24.7" diameter new. This gives a little better acceleration and ~.15" lower CG compared to stock.

[Gunman]

Why is the K8R not available in silver in 17"? I have been looking for a light mesh wheel in a bright silver.

[Vracer111]

Originally Posted by Gunman

Why is the K8R not available in silver in 17"? I have been looking for a light mesh wheel in a bright silver.

Yeah, that's the one thing about Kosei wheels other than the K1's: seem to only come in the light grey color for the larger sizes, though it is a nice color. Would be nice to have a silver option, though the grey is not too bad and does really well with matching brake dust/and dust making them look better longer...

[Keenercarguy]

I'm going to bump this thread... Has anyone bought a set of K8R's? I'm looking for pictures and can't find any

[rwebber]

you can check mine out here:
http://www.ft86club.com/forums/showt...93#post2792993