Realistic Maximum Tire/Wheel Size on Track
02-15-2017, 02:48 PM
#11
...Ive been running a 255/295 stagger for quite a lot of miles now 100k?, and knock on wood am still on the factory hubs/bearings with about 220k miles now. This is with some hard track time as well on a big 2.5 mile course, not auto X. But this is on a track/street car where I'm trying to get the most grip possible wile running an extreme summer 200 compound...
02-15-2017, 03:02 PM
#12
Then you start to get heavier wheels and tires. I believe its a balance of weight / grip. Recall rolling resistance and aerodynamics. The wider, the worse, so yes, depending on your power, there would be a point of diminishing return. Along with rotational mass...
A 245 Hoosier will stick more than a 275 setup and will be much lighter. Heck, a 275 Hoosier would be lighter than a 200TW tire...Keep it in mind, if you do switch to hoosier... you're screwed, you'll be hooked.
I think the suspension stress issue would be so minimal that tracking your car alone would deterioate that argument. Besides, I am sure a 255 Hoosier would put more stress on components than a 275 200TW tire..
I have a hard time justifying a 315 width tire on a 230-240whp tops(?) N/A S2k...
Its still a lot more weight than needed. You could run a 275 Hoosier on a 10'' wheel and it would be under 40lbs...
A 245 Hoosier will stick more than a 275 setup and will be much lighter. Heck, a 275 Hoosier would be lighter than a 200TW tire...Keep it in mind, if you do switch to hoosier... you're screwed, you'll be hooked.
I think the suspension stress issue would be so minimal that tracking your car alone would deterioate that argument. Besides, I am sure a 255 Hoosier would put more stress on components than a 275 200TW tire..
I have a hard time justifying a 315 width tire on a 230-240whp tops(?) N/A S2k...
Its still a lot more weight than needed. You could run a 275 Hoosier on a 10'' wheel and it would be under 40lbs...
The S2k is a momentum car on the big track anyway, its got plenty of power to maintain a faster cornering speed from the added tire width over a similar compound tire in a conventional 245/255 size. Im not saying its batter then a 275 Hoosier on the track, but I would argue its about the best summer tire combo for the track that I also get to enjoy on the street. Im still having fun setting street tire time records at my 2.5 mile track. When I get bored with that, I might think about investing in a whole other wheel set with track compound tires in more conventional sizes, or in more ridiculous sizes maybe
I will likely no matter what still run no wing and top down though 
This will be a test year though, as mentioned moving from 255/295 to 275/315 this year. Im curious of course to see my total lap times, and where I fair at what parts of the track. The gearing change is likely going to have more bearing help or hurt then the 2lb increase in rotational weight moving up to 315. I consistently hit 124-125mph at the end of the strait with old tires, so I will be be monitoring that. My guess is I will lose a couple mph, but will more then make up for it in the rest of the track with higher cornering speeds. That's my hope anyway. Then i suppose I can confirm the quandary for the OP, for at least my track at the Ridge.
Last edited by s2000Junky; 02-15-2017 at 03:36 PM.
02-15-2017, 03:27 PM
#13
There isn't a ton of guys NA that run larger than a 255 square.
I just mounted some 275 RC1's and I'll be hitting CVR this weekend. I'm SC and my buddy is NA and we will compare our AIM data and get a feel for corner speed vs top speed.
I just mounted some 275 RC1's and I'll be hitting CVR this weekend. I'm SC and my buddy is NA and we will compare our AIM data and get a feel for corner speed vs top speed.
02-15-2017, 06:03 PM
#14
A 275 or 285 or 295 200tw tire can be faster than a 245 or even a 225 Hoosier on a track or surface that rewards mechanical grip. I think you're asking a very subjective question(s). The quick answer is, it just depends.
When it comes to road courses, I've ran tires sizes from 225 to 295s. I've also ran wheel widths ranging from 8.5, 9, 9.5, 10, 11 and 11.5.
My fastest times have been on 225s on a 9.5 and 245s on a 10. These are Hoosier A6, R7, and A7. Remember with Hoosiers, the 225 is really a 245 and the 245 is really a 260-265. 285 hoosiers run wider than 295 hoosiers. Again, it all depends.
There is more grip with a wider tire but you sacrifice aero and unsprung weight for the grip so it's almost null. But if you're AXing or running a short course, the wider wheel and tire combo should be faster. Aero comes into play on tracks that reward having aero. Those would be the time that a smaller tire may be faster as you don't need the mechanical grip as much as well as benefiting from lighter unprung weight along with less drag.
The fast setup currently is a Hoosier 225 on a 10. There are many 10" options currently that fit on stock body work. 949, Forgestar, Advan RZII, even Rota.
It all depends.
When it comes to road courses, I've ran tires sizes from 225 to 295s. I've also ran wheel widths ranging from 8.5, 9, 9.5, 10, 11 and 11.5.
My fastest times have been on 225s on a 9.5 and 245s on a 10. These are Hoosier A6, R7, and A7. Remember with Hoosiers, the 225 is really a 245 and the 245 is really a 260-265. 285 hoosiers run wider than 295 hoosiers. Again, it all depends.
There is more grip with a wider tire but you sacrifice aero and unsprung weight for the grip so it's almost null. But if you're AXing or running a short course, the wider wheel and tire combo should be faster. Aero comes into play on tracks that reward having aero. Those would be the time that a smaller tire may be faster as you don't need the mechanical grip as much as well as benefiting from lighter unprung weight along with less drag.
The fast setup currently is a Hoosier 225 on a 10. There are many 10" options currently that fit on stock body work. 949, Forgestar, Advan RZII, even Rota.
It all depends.
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imstimpy (02-16-2017)
02-16-2017, 04:32 AM
#15
Agreed, and I'd be skeptical as well. If I'm not mistaken, the 225 Hoosier measures very close to a 200TW 245/255 widthwise anyways.
02-16-2017, 07:14 AM
#16
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My question is not "can I run a 275+ tire and what does it take to do so?". My question is "if I ran a 275+ tire, is it 'better' than a 245 r-tire or less reliable?". "Better" being faster, obviously, but also without dramatically affecting reliability. Being faster takes into account rotational mass, rolling resistance and aerodynamics, and unsprung weight.
Can a 275+ fit under the car? Sure, with the right amount of time and money. Is it faster than a 245, though, and will it break proportionally more? That is what I am after. I understand this is also an "it depends" question. For a little track like Driveway Austin or Harris Hill Road, a wider tire would likely be faster given the low straight speeds. On a track like Texas World Speedway or Circuit of the Americas, pushing a 315 for 2/3 mile at 100+MPH with 240whp would probably hurt. In fact, I think I noticed an effect on end of straight speeds just going from a Hankook RS-3 to a Bridgestone RE-71R.
I'm fairly confident going from 9" to 10" on a 255 200TW would be faster. I'm skeptical it would be faster than a 245 Hoosier or even a 225 Hoosier. Cheaper in the long run, maybe. From what I'm seeing a 295+ 200 TW might be necessary to keep up with a 245 Hoosier and at that point I'd say an 18x11 200 TW setup is not worth the investment.
Thanks for the discussion so far.
Can a 275+ fit under the car? Sure, with the right amount of time and money. Is it faster than a 245, though, and will it break proportionally more? That is what I am after. I understand this is also an "it depends" question. For a little track like Driveway Austin or Harris Hill Road, a wider tire would likely be faster given the low straight speeds. On a track like Texas World Speedway or Circuit of the Americas, pushing a 315 for 2/3 mile at 100+MPH with 240whp would probably hurt. In fact, I think I noticed an effect on end of straight speeds just going from a Hankook RS-3 to a Bridgestone RE-71R.
I'm fairly confident going from 9" to 10" on a 255 200TW would be faster. I'm skeptical it would be faster than a 245 Hoosier or even a 225 Hoosier. Cheaper in the long run, maybe. From what I'm seeing a 295+ 200 TW might be necessary to keep up with a 245 Hoosier and at that point I'd say an 18x11 200 TW setup is not worth the investment.
Thanks for the discussion so far.
245 Hoosier
225 Hoosier
275 200TW
255 200TW
There is no reason to consider any other wider tire or option if you are purely looking to go fast in an NA S2000. All it takes to fit a 275 under the car is a wheel with the correct size and offset and some massaging of the OEM fenders. I have run the Maxxis RC1 in 275/35/17 with OEM fenders and no rubbing on a 17x10 +55 wheel. I will add that the general rule for going fast in NASA TT is to maximize compound before width ALWAYS. If you want to go fast and there is no rule that says you can't, just buy the Hoosiers.
Last edited by King Tut; 02-16-2017 at 07:18 AM.
02-16-2017, 07:36 AM
#17
Here you go fastest to slowest:
245 Hoosier
225 Hoosier
275 200TW
255 200TW
There is no reason to consider any other wider tire or option if you are purely looking to go fast in an NA S2000. All it takes to fit a 275 under the car is a wheel with the correct size and offset and some massaging of the OEM fenders. I have run the Maxxis RC1 in 275/35/17 with OEM fenders and no rubbing on a 17x10 +55 wheel. I will add that the general rule for going fast in NASA TT is to maximize compound before width ALWAYS. If you want to go fast and there is no rule that says you can't, just buy the Hoosiers.
245 Hoosier
225 Hoosier
275 200TW
255 200TW
There is no reason to consider any other wider tire or option if you are purely looking to go fast in an NA S2000. All it takes to fit a 275 under the car is a wheel with the correct size and offset and some massaging of the OEM fenders. I have run the Maxxis RC1 in 275/35/17 with OEM fenders and no rubbing on a 17x10 +55 wheel. I will add that the general rule for going fast in NASA TT is to maximize compound before width ALWAYS. If you want to go fast and there is no rule that says you can't, just buy the Hoosiers.
02-16-2017, 09:02 AM
#18
My guess is a 295 Hoosier A7 setup would still outperform a 225 or 245 Hoosier A7 setup, especially if you've tweaked aero to minimize the impact of the wide tires (spats under and in front of fenders). My understanding is that in Miatas, which have far less power than we do, they still haven't found an upper limit where going wider has reduced lap times. Every time they go wider, they go faster. Peak straight speed is less important than the other 90% of the track where speed is dependent on grip or corner exit speed.
02-16-2017, 10:16 AM
#19
My guess is a 295 Hoosier A7 setup would still outperform a 225 or 245 Hoosier A7 setup, especially if you've tweaked aero to minimize the impact of the wide tires (spats under and in front of fenders). My understanding is that in Miatas, which have far less power than we do, they still haven't found an upper limit where going wider has reduced lap times. Every time they go wider, they go faster. Peak straight speed is less important than the other 90% of the track where speed is dependent on grip or corner exit speed.
02-16-2017, 10:53 AM
#20
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My guess is a 295 Hoosier A7 setup would still outperform a 225 or 245 Hoosier A7 setup, especially if you've tweaked aero to minimize the impact of the wide tires (spats under and in front of fenders). My understanding is that in Miatas, which have far less power than we do, they still haven't found an upper limit where going wider has reduced lap times. Every time they go wider, they go faster. Peak straight speed is less important than the other 90% of the track where speed is dependent on grip or corner exit speed.