Unofficial Big-Wheel Thread: 18/18 and 18/19 - the future for NSX tire sizes

Why was it a no-go? And how much rear camber are you running?

Yeah 275/35/19 is really the size we'd need with a 225/40/18 front. If that has to be a 30 rear those ratios are definitely going to be off.

I the meantime... I've found out BC can make a 17 to clear my brakes. So I am going to for now, get a new 17/18 BC set and just sell my advans until this is sorted out. I can always keep them as a "track set" I feel I need two sets of wheels and tires anyway. So I will continue to try to contribute what I can here but at least I won't have my car immobile anymore.

I did a lot of checking tonight on this 225/40/18 front with various rear combinations. The rear is actually pretty limited when matched up to the front. The most promising size far as selection was 225/40/18 mated to 305/30/19. I went all the way up the ladder... 265, 275, 285, 295, and 305. 265 and 305 have better selections.... and I am not sure if 305 would fit under the rear fenders or... what you guys think of that large a split. A very interesting tire that showed up as a "competition tire" that seems to have exceptional grip dry and wet was this continental ContiForce Contact. It does come in 225/40/18 and 305/30/19 and could possibly be a really extreme streetable tire. That is if you are OK with a $510 rear tire with a wear rating of 80. Don't mistake it with a street tire because of its looks. This is a track tire. DOT wear rating is 80. Thoughts?

Ben at the wheels boutique has run 315's before . The issue was the coil over and spring perch cannot be too big or the hit the tire. Here is one of the threads and you can see pics and front and rear tire sizes. Also find other threads by thewb for more combinations and pics http://www.nsxprime.com/forum/showthread.php/124946-Wheels-Boutique-NSX-on-HRE-591R?p=1196576

As you know, larger rear then optimal will understear and be heavier then optimal.

This setup is conflicting in my opinion as benefits of the brakes are offset by the less then optimal tires and wheels. Personally I would stick with the stop techs and 17 / 18 wheels as it is in my opinion a better balanced compromise

But I'm really glad you are doing what your doing and trying new things for us to learn from

SocalX thanks for the post. Very helpful. Although ben listed no offsets which sucked. It is too late for me to stick with stoptechs. I own the ceramics so I must make them work.

http://www.nsxprime.com/forum/showthread.php/26611-New-wheels-crazy-tires!!?s=

Another old but good thread. No offsets here either but good pics showing the width you might try calling hre as they likely have records or

What's very important to note here... is both the 315 and 305/25/19 are 25 series. Diameter wise that would not match up well with a 225/40-18 at all. Both of these guys went with 225/35/18, ie low profile.

I believe the whole plan was to go with a 35 series 19" tire... ie 275 35 19.... 285 35 19

Chris, see post 78. 305-30-19 is a very good match for a 225/40/18. It keeps the OEM ratio.

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What's great is the overall availability of tires at this combo. While Billy has mentioned and rightly so suggest 225/40/18, the rear combinations with this size are still very limited. That is unless you go 265/35/19 or 305/30/19 both of which have many combinations with the 225/40/18.

275, 285, 295 in either 30 or 35 are pretty limited.

Yes Dave, I was pointing out both links posted were 25 series, not 30, not 35.

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By going with 305 30... the extra width depending on wheel width will then add to over diameter. Which is what you're looking to achieve.

Oh and if you talk about weight, that Conti is so damn light, the 225/305 18/19 combo weighs 4 pounds LESS than my current 235/40/17 and 275/35/18 NT01

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nsxot1c said:

Yes Dave, I was pointing out both links posted were 25 series, not 30, not 35.

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By going with 305 30... the extra width depending on wheel width will then add to over diameter. Which is what you're looking to achieve.

Click to expand...

You mean height? Sorry Chris, I am a bit confused. Yes you are right, the 305/30 is definitely larger diameter. But it matches the 225/40 we want to use and not the 35 series fronts both posts used. I guess we are saying the same thing unless I'm still not understanding you. I understand this may be more difficult to "fit" because of the diameter.

Going back to the first post, the entire thread was created due to issue of diminishing tire availability (especially top-level high performance street tires) in NSX-specific sizes.

A very popular size that will be around for a long time is a 225/40-18.

In order for this 225/40-18 front to work and to keep the F-R outer diameters in check for ABS & TCS, we need to use the following rear sizes:


275/40-18: (good diameter) - 45/55 % distribution

-Nitto NT05
-Bridgestone RE-11
-Michelin PS2
-Pirelli P-Zero

-Nitto NT01
-Toyo R888

295/35-18: (on edge of acceptable diameter) - 43/57 % distribution

-Hankook RS3
-Nitto NT05
-Michelin PS2
-Continental DW

265/35-19: (good diameter) - 46/54 % distribution

-Advan AD08R
-Bridgestone RE-11
-Michelin PSS
-Michelin PS2
-Continental DW
-Pirelli P-Zero
-BFG Sport Comp-2

-Hoosier A6 & R6
-Toyo R888

275/35-19: (good diameter) - 45/55 % distribution

-Hankook RS3
-Nitto NT05
-Michelin PSS
-Michelin PS2
-Bridgestone S04
-Continental DW
-Pirelli P-Zero
-BFG Sport Comp-2

285/35-19: (good diameter) - 44/56 % distribution

-Bridgestone RE-11
-Michelin PSS
-Michelin PS2
-Bridgestone S04
-Continental DW
-Pirelli P-Zero
-BFG Sport Comp-2

295/35-19: (good diameter) - 43/57 % distribution

-Michelin PSS

-Hoosier A6 & R6

295/30-19: (just outside diameter range but may be ok) - 43/57 % distribution

-Advan AD08R
-Michelin PSS
-Michelin PS2
-Bridgestone S04
-Pirelli P-Zero

-Hoosier A6 & R6
-Toyo R888

305/30-19: (on edge of acceptable diameter) - 43/58 % distribution

-Advan AD08R
-Hankook RS3
-Bridgestone RE-11
-Michelin PSS
-Michelin PS2
-Pirelli P-Zero

-Toyo R888



The stock NSX tire sizes ended at 215/255 which equates to 46% front 54% rear distribution to which is interesting given the car's 40/60 % weight distribution.

The popular 235/275 track setup = 46/54 % distribution.


***With the above, the idea is to choose a rear tire brand/model/list of various options, decide on a width, then decide your wheel width and offsets. If you stretch a 295, you probably won't be able to put a 275 on. But if you size your wheel widths to say 10.5" wide, then you have the flexibility to go down to a 275 or up to a 305.

For the widths, many supercars (458 & MP4-12C) use a 44/56 % tire distribution for their 42/58% weight distributions. Since the NSX is more rear-weighted than these cars, they could probably use proportionally more rear tire distribution. However, from the factory the NSX was tuned for 46/54% -probably mostly due to the commonly available tires at the time.

I havn't driven too many NSXs that understeered, and feel that the rear tires are burned off quicker than the front on track. Adding more rear volume will make the rear tires not wear or overheat as fast and I suspect could make the car handle better.

I agree that adding a much larger diameter wheel could have negative attributes, but for people who are FI, this is not really an issue, and for those who are NA, I intend on datalogging the 17/18 combo vs. 18/19 combo to see its effect on track.


For fitment:

This thread was intended for people who drive their cars in a sporty manner and track their cars. Because of this, an ideal alignment will require LESS rear camber especially as rear tire widths increase. Less camber and a larger sidewall will give you less clearance than people who run small sidewalls and a lot of rear camber (which also wears tires out quickly).

RYU and I came up with 19x10 +35 and 19x10.5 + 42 will fit under factory fenders.

With the FXMD wide F&R fenders, the goal is to have another 15-20mm of clearance on top of the above, to allow for a more common 19x10.5 +25 offset.


-Billy

Billy do you realize all the rear tires you have listed aren't all available in the combo with a 225/40 front but as individual sizes?

What do you mean? Every tire I listed has a 225/40-18 option available.

Does anyone have a photo of a 225/40-18 on a wheel or better yet on an nsx?

jcbadcura said:

Does anyone have a photo of a 225/40-18 on a wheel or better yet on an nsx?

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Post #38

Edit: Here's another angle:

Billy I am suspicious of some of those, I will check later but the first one that came to my mind was nitto NT05 you've listed under 275/35/19, I don't see a 225/40/18 nitto NT05 listed on their site.

TURBO2GO said:

Billy I am suspicious of some of those, I will check later but the first one that came to my mind was nitto NT05 you've listed under 275/35/19, I don't see a 225/40/18 nitto NT05 listed on their site.

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Thanks for your confidence in me. I've just spent days calculating all of these wheel/tire/size/offset combinations.

225/40-18 NT05 is on their website:

http://www.nittotire.com/Tire/Street/nt05#size

All the rear tires I listed above have a 225/40-18 front option for it.

LOL I have confidence in you, I don't know maybe it's because I am on a mobile device? Just so you know I am not BS'ing, it's not showing up for me:



I spent 6+ hours last night looking at combinations. I dismissed anything but extreme performance summer and track tires, perhaps that is why my list was much more narrow.

I am a bit confused, previously you had mentioned you wanted to get close to the weight distribution of the NSX and so it sounded like you liked the extra wide rears... 295, 305, etc. now it sounds like no so much? I mean what is your thought on the continental I posted above? It also comes in 265/35/19

TURBO2GO said:

LOL I have confidence in you, I don't know maybe it's because I am on a mobile device? Just so you know I am not BS'ing, it's not showing up for me:

I spent 6+ hours last night looking at combinations. I dismissed anything but extreme performance summer and track tires, perhaps that is why my list was much more narrow.

I am a bit confused, previously you had mentioned you wanted to get close to the weight distribution of the NSX and so it sounded like you liked the extra wide rears... 295, 305, etc. now it sounds like no so much? I mean what is your thought on the continental I posted above?

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Hmm, so there are only 3 sizes of 18" Nittos?

(FYI - that's NT05R, not the NT05 )

Yes i'm leaning towards 295/305 width tires as potentially 'ideal' for the NSX on 225 fronts. I've never tried the continental and talked to them about getting a set for my M3, but they are R-comp tires, equivalent to Michelin PSC, NT01, R888s, so probably not ideal for my M3 street car but might be good for a non daily driven car. But there are many tires that are known to be amazing for both street and track which I already listed as available.

On mobile the only choice I get is NT05R.

So both shalylorD and I have to make some decisions. I can say with some fair amount of certainty a 225/40/18 can fit the front. So now the decision is the rear for us. A non-daily driven car is exactly what we have, me especially, I pretty much drive to the track and back and on rare occasion of a nice day drive the car on a weekend. I've been caught in several monsoons from and to the track on NT01 on the highway, standing water, kind of sucked going 35-40 MPH. so this Conti seems very interesting. The two sizes to choose from are 265/35 and 305/30, but that requires such vastly different wheel sizing I think I have to make a bit of a decision. 305/30 and 265/35 both seem to offer the best selection. I mean what do you think I should do? I have to do something because of my brakes. We are both FI.

Did you decide on 18" rears?
What rear wheel width?
DF front fenders?
Stock Rear Fenders?
What tire do you want?

For rain, the PSS, RE-11, and Conti DW are probably your best bet. Probably in that order for dry performance as well.

stuntman said:

Did you decide on 18" rears?
What rear wheel width?
DF front fenders?
Stock Rear Fenders?
What tire do you want?

For rain, the PSS, RE-11, and Conti DW are probably your best bet. Probably in that order for dry performance as well.

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1) 18/19. Don't really want to do 18/18.

2) He has downforce front fenders, I do not but I am not sure I need them with a 225/40. I'd like to at least try. I have finally managed to fit the 235 NT01 in with no rubbing even at full lock.

3) stock rear fenders

4) a streetable track tire. I, also carefully watching weight. The RE11 is very heavy. I love that contisport because its a super lightweight.

Not necessarily looking for a rain tire. I just like that Conti over my NT01 because its much lighter and because of its increased rain capability might be easier to drive around all summer. I put very few miles on the car. It's still an R comp track tire.

I have the Conti DW street tire on my cars. I do not have the ContiFORCE Contact R-comp. No one knows for sure the ContiFORCE's wet or dry grip and IMO the NT01 is one of the best R-comps in the rain that's out there.

For your 18" front, you are going to need a wheel the clears your caliper (spoke wise) in either a 18x8 +36 or higher or 18x8.5 +42 or higher.

If you run a DF front fender, you can run an 18x8+28 (preferably +30) or higher or 18x8.5 +34 (preferably +36) or higher.

If you run a FXMD front fender, you can tack on another 7-10mm above the DF in clearance.

For the rear, you're going to need a 19x10 +30 (preferably +35) or 19x10.5 +37 (preferably +42) to clear the rear fender.

Tire wise, I'd look at 275/35-19 or 285/35-19 to be conservative in a RS3, NT05, PSS, or DW.

Looking at a volk. Here is the sizing available. Ignore the numbers in parentheses:



19:



I'm thinking 18x8.5 front et 42? Worried about 50 not clearing the caliper. And the 19x9.5 rear et 31? I'd really like to get face 3 rear if possible instead of face 2. It's a curved spoke style... Like the RSII but it is forged. So lots of caliper clearance.

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8.5 front 9.5 rear would have the front 225 stretched a bit and the rear 275 bulging a bit. Not terrible though, but you couldn't go too much wider on the rear tire.

Unless you get a wheel to test, I personally would do the +50 front and space it accordingly since at +50 and a 8mm spacer, while having the same offset as a +42, it will give you more spoke-caliper clearance than a +42 with no spacer. I wouldn't discount the RSii just because it's not forged.