Tyre size for occasional track days.

Red_Bullet · Postby **Red_Bullet** » Mon Jul 15, 2019 12:17 pm

I have enkei RPF1 15*7 +41 currently with Nitto NT01's fitted but they are stuffed.

Car is rotrex supercharged NA8 with 140 RWKW

so, time for new tyres, considering Nankang AR-1's in either 205/50/15 or 225/45/15.

The 225 is the maximum width that can be fitted to a 7 inch wheel. Should I do that, or is it bad idea to put a 225 on a 7 inch wheel? Circumference is very similar, not sure about weight. Is there anything else I need to know?

Magpie · Postby **Magpie** » Mon Jul 15, 2019 3:23 pm

I have not run 225 on 7” rims, 205’s on 8” yes.

In AR-1’s the 205’s are lighter than 225’s, I do not have the info on me but can confirm tonight.

Red_Bullet · Postby **Red_Bullet** » Mon Jul 15, 2019 3:45 pm

Thanks Magpie, gotta pull the pin on a decision this week. Was thinking about getting some RPF1 15*8 +28, but figure I would likely get horrible clearance issues.

The AR's in 205/50/15 are $188, 225/45/15 are $217 each, not a great difference in price but weight is a consideration as is running a wide tyre on a skinny wheel.

Magpie · Postby **Magpie** » Mon Jul 15, 2019 4:00 pm

I'll post some carcass weights tonight.

15x8 +25 Advanti Storm's would get my money, and they did...! You can get away with a small guard roll, nothing drastic.

I have some 15x8 +20 as well but did some serious guard rolling as was thinking about going to 0 offset...

Red_Bullet · Postby **Red_Bullet** » Mon Jul 15, 2019 11:23 pm

Yes the Advanti Storms do look interesting, thanks for the tip.

Magpie · Postby **Magpie** » Tue Jul 16, 2019 10:37 am

AR-1 205/50/15 - 9.07 kg
AR-1 225/45/15 - 9.77 kg
AD08R 205/50/15 - 8.55 kg
Dunlop Slick 200/580R15 - 6.46 kg

Advanti Storm 15x8 +25 - 4.23 kg
6UL 15x7 +36 - 5.29 kg
AV1D - AV12 15x8 +20 - 7.26 kg

Red_Bullet · Postby **Red_Bullet** » Tue Jul 16, 2019 7:44 pm

Magpie wrote:AR-1 205/50/15 - 9.07 kg
AR-1 225/45/15 - 9.77 kg
AD08R 205/50/15 - 8.55 kg
Dunlop Slick 200/580R15 - 6.46 kg

Advanti Storm 15x8 +25 - 4.23 kg
6UL 15x7 +36 - 5.29 kg
AV1D - AV12 15x8 +20 - 7.26 kg

Enkei RPF1 15*7 +41 4.38 kg
Enkei RPF1 15*7 +35 4.47 kg
Enkei RPF1 15*8 +28 5.15 kg

Red_Bullet · Postby **Red_Bullet** » Tue Jul 16, 2019 7:45 pm

The 225 isn't much heavier than the 205 in the Nankang AR1

plohl · Postby **plohl** » Tue Jul 16, 2019 8:53 pm

It honestly won't make too difference hey. Especially given you're only occasionally going to the track, so just buy the cheaper 205s and put the saved coins towards another track day.

Red_Bullet · Postby **Red_Bullet** » Tue Jul 16, 2019 9:38 pm

plohl wrote:It honestly won't make too difference hey. Especially given you're only occasionally going to the track, so just buy the cheaper 205s and put the saved coins towards another track day.

Yep, I've been think that too Shane. Throwing money at something doesn't necessarily make it more fun. But it is interesting looking at options, ya know. You learn stuff by pondering ideas. :idea:

I now know more about it all. Thanks.

Roadrunner · Postby **Roadrunner** » Tue Jul 16, 2019 9:45 pm

Any reason you’re changing from NT01 to AR1? Cost or just trying something new?

Also worth considering is rolling resistance of the wider 225, but maybe that’s splitting hairs too finely...

Red_Bullet · Postby **Red_Bullet** » Wed Jul 17, 2019 10:01 am

Roadrunner wrote:Any reason you’re changing from NT01 to AR1? Cost or just trying something new?

Yes both of those things and AR-1 is road legal as I drive to and from the track. The NTO1 that isn't so clear with the sidewall marked "Recommended for competion use only" or words very close to that. Not sure I'd like to argue the point if I got pulled over.

Red_Bullet · Postby **Red_Bullet** » Wed Jul 17, 2019 12:28 pm

I took the easy and cheapest option 205/50/15 Nankang AR1's. done.

Custardtart · Postby **Custardtart** » Fri Jul 19, 2019 1:35 pm

Red_Bullet wrote:I took the easy and cheapest option 205/50/15 Nankang AR1's. done.

My friend has tried both on his NA Clubman which is heavily tracked and he’s a top driver. They both produced very similar times. I drove his car with AR1’s back to back with my NC on Toyo r888r’s and also found them very similar in grip and feel. A really nice tyre.