18/19 concave wheel questions/reccomendations

[chiefsfan]

Purchasing an nsx this weekend and want to get new 18/19 wheels. I've been following the nsx wheel guide:

18"/19" -

Front wheels:
70.1 center bore

- 18X7.5, +45 (very inset) to +30 (very flush and depending on tire choice, possibly risky)

- 18X8, +48 (again very inset) to +33 (again very flush, use caution - and narow tire)

- 18X8.5, +48 (yes very inset but the rim is wider) to +42 ( it should be noted that the tire will be very, very stretched and this is not for everyone)

Rear wheels:
64.1 center bore
*** It MUST be noted that the NSX suspension geometry is such that when lowering the car, the rear will pull the tire inwards significantly, allowing a lower offset - lower number means wheel sticks out more - thus your wheel that was "flush" at stock height will no longer be flush, keep this in mind and know that the lower offset REAR wheels listed here will only work with lowered cars*** - wheels marked (*) are for lowered cars -

- 19X9 (very narrow wheel but can work, not "optimal") +40 to +30*

- 19X9.5 +45 to +28*

- 19X10 +45 to +28*

- 19X10.5 +45 to +29* ( at the lower offsets your car will need to be quite low and use a stretched tire (265/30/19) to clear fenders)

- 19X11 +45 to +36*

I understand offset, and understand the wider the wheel/the higher offset the more flush and the potential to get more concave wheels. But what determines concave? Backspacing? I think Jhae Pfenning has some of the most beautiful wheels I've ever seen on an nsx. I want something similar, just not wheels that cost as much as an accord. He has the following:

[FONT=&quot]WHEEL DESIGN : HCA163
FRONT WHEEL SIZE : 18X8.5″
REAR WHEEL SIZE : 19X10.0″
CENTER FINISH : MATTE BRONZE
LIP FINISH : BRUSHED BRONZE
HARDWARE FINISH : HIDDEN[/FONT]
[FONT=&quot]TIRE BRAND : MICHELIN
TIRE MODEL : PILOT SUPER SPORT
FRONT TIRE SIZE : 225/35/18
REAR TIRE SIZE : 275/30/19

Here is a link to his bcforged wheels: http://www.bcforged-na.com/project/jhaes-acura-nsx-1819-hca163/

and a pic:

Is there a formula that makes a wheel concave so that I can better understand? Or do you just have to shop around....

I've been looking at TSW geneva's,

(18 X8 5-114.30 +35

&

19 X9.5 5-114.30 +39)

but I don't know if those will come concave and I don't want to spend money on wheels that I'm not happy with. Someone help :witless:

[/FONT]

 

[mwagner10702]

One other thing to consider is wheel fitment that is compatible with a BBK. Those 18/19 wheels will make your OEM brakes look teeny tiny behind the wheels. Next thing you know you'll be shopping for a BBK and if you don't account for clearance issues you will either have to live with tiny looking brakes or be buying new wheels.

 

[chiefsfan]

One other thing to consider is wheel fitment that is compatible with a BBK. Those 18/19 wheels will make your OEM brakes look teeny tiny behind the wheels. Next thing you know you'll be shopping for a BBK and if you don't account for clearance issues you will either have to live with tiny looking brakes or be buying new wheels.

Ya, definitely planning on getting a BBK as well. I just don't want to go to the trouble of doing all this if I don't have concave wheels.

 

[Senninha]

Hi chiefsfan,

Thank you for the helpful post. Ive been looking at aftermarket wheels for a while. The set up in the photo highlights the issue I’m trying to overcome. The fronts look OK, firewall looks upright, outside edge to arch looks great. However, the rears look aftermarket ... the stretched tire is a no no for me, exceeding the bodywork is also not good. would reducing rim width and adjusting offset be possible to (in my opinion) correct the above look?

Regards and happy hunting ...

 

[Hapa88]

Here's my car with the TSW Geneva in the 17x8 +40 and 18x9.5 +39. The rear is concave.


The thing that determines concaveness is primarily design. It comes down to the designer whether they want it or not. The amount of concaveness that a designer could potentially make is relative to the amount of backspace and the spoke design (curved vs straight spokes).
Other TSW wheels that don't come in concave (flat face) with similar sizes and offsets are the Interlagos and Nurburgring.

 

[Jinks]

View attachment 155695
Advan RG3 are concave both front and rear. Clears any bbk too.

 

[davidf]

I ran a set of these for years. Perfect fitment, clears most any BBK. Very light weight. Still on my favorite list.
http://www.nsxprime.com/forum/showthread.php/206522-Advan-rs2-18-19?p=1979674#post1979674