Hey guys! So I've been kicking around the idea of a dedicated track day wheel/tire setup since the summer. The only way to sell the idea to the pregnant wife was if I got a really good deal on the setup...that, and get rid of the extra car **** in the garage.

I've been looking at a non-staggered setup specifically for the track, that way I can rotate wheels and (hopefully) extend tire life. I found a really good deal on a set of silver Q1S 18X9.5's, so I finally pulled the trigger. All reports indicate they are a decent track wheel: not heavy (that's relative) and they're strong. I wanted the 9.5's so I can fit a wider tire all the way around but not have them too wide in the front, plus I'm a sucker for anything that's dished (even slightly) and not flush.

Honestly, I really don't know what "best"-size tire I should run. Since it's the same tire on all four corners, are 295-35-18's out of the question? I really don't know what would be the widest tire that would fit on a Q1S and 1) not rub, and 2) only enhance performance, not decrease it. And I don't want a short tire, either...so would a 35 be too short if I had to go to a 275?

Anyway, although it's still relatively nice here in DC, I'm about to park the car and be in full-on mod mode here soon to get ready for next season:

1. Dedicated track day wheels/tires.
2. Finally finish installing my water-meth injection.
3. Relocate my heat exchanger so I can finally get my brake-cooling ducts mounted.
4. New sway bars (that's right, Strano: I'll be calling you soon ).

Any input is much appreciated!

PS. I don't know what tire I'm going with, yet. I know what I would LIKE to go with, but my better half would likely shoot me if I dropped the dolares on them.

 

The 275/35/18 seems to be a popular track size and what I run now (NT01s). The wheels are Enkei PF01s 18 x 9.5 x 45 mm offset.

Last year I ran the 275/40/18 which is about 0.9" larger diameter.

 

Sleeper, thanks dude. The Q1S's are a 45mm offset, too. What made you step it down to the 35s? How is track traction with the NT01s when they're cold, warm up and towards the end of a 20 minute run when things start to get mushy?

 

Hey Greg,

You can fit anything from a 235/40 to 285/35 on those rims so that leaves you quite a few options. So really the question should not be 'what tire size' but rather 'what tire' to run.

But the real question is what kind of money do you want to spend. Are you ready to spend $300 per tire? In general thats what new R-comps in the sizes we are talking about cost. $1200 for a set of tires that only last about 10 track days give or take is pretty hard to swallow.

I've used the following psuedo R-comp tires and enjoyed them all (some more than others): RT-615, NT01, R888 and 555RII. The trouble is they are all in the $1200 per set range. As are the Hoosier A6 and R6, which probably won't even last 10 track days. Kind of makes your head spin.

I've never used true R-comps like the A6, R6 or V710, so can't really speak to them. But of the tires I've tried and if spending that kind of money is in your plans than I'd recommend the NT01. Its a good, solid all around tire. They have excellent grip given a warm up lap or 2. They are generally quiet but will squeal when pushed past their limit. They will get "greasy" at the end of 20 minutes on a hot day, but they all do this in my experience.

Another option is to buy used 'scrubs'. This may be an excellent choice for you. Its easy to get the Continental (rebadged Hoosiers) scrubs from the 'Continental Tire Sports Car Challenge' series. They are full slicks and ususally have a couple heat cycles on them. Generally cost in the 100-150 per tire range. Scrubs from other series are also to be found. There are several ways to find scrubs: you can search Google or Ebay (search for Hoosier or Continental Challenge). There are people who make a business out of selling scrubs: jbracingtires.net is one. You can look on RacingJunk.com. You can go to the AX & RoadRacing section of corvette forum dot com (lots of used tires fort sale pop up on there). Last year I usd the R888 exclusively but in years prior to that I used several sets of Hoosier scrubs from what was then called the Grand Am Koni Challenge. They worked great. The bang for buck was huge.

HTH, Brad

 

You can also go as narrow as 255 or 265 on a dedicated open-track wheel, to improve your turn-in and clearance a bit. I know the early S197 Cobras ran a 255 on a 9.5" wheel, so will likely avoid rubbing (the OEM off-set is about +50mm) Since you are +45mm, I don't see an issue, as your fenders are factory rolled.

The NT01 is a nice tire, although I have not driven them.

Jazzer

 

What made you step it down to the 35s? - a 1/2 lower center of gravity and higher effective gear ratio

How is track traction with the NT01s when they're cold, warm up and towards the end of a 20 minute run when things start to get mushy? - pretty well what Argonaut said. I got 10 track days out of my first set and obviously I liked them enough to buy a second set. They were flipped on the rims after a while to even out the wear.

 

Further to me post above I often find that when the NT01s feel "greasy" this is because the hot pressures get too high. I run 39 lb hot at both ends and if they get into the 41 + range after a long session then they tend to slide more. Bringing them back down to 39 solves the problem.

As Argonaut said the NT01s squeal at the limit and this is a good thing. They also have better characteristics when at the limit and don't just say all of I've sudden "I've had enough" and send you into the weeds.

 

Hey fellas, thanks! I really appreciate the feedback.

Brad, that was some really good advice. Other than the back country/mountain "road course" plan you laid out for me when I head up to Carlisle and go for some spirited driving, that was probably the best knowledge you bestowed upon me, homie.

Matter of fact, guys, I pulled the trigger on some rebadged Hoosier race tires. After some looking around and speaking with different businesses, I went with a set of 275-35-18's from bimmerworld at what I feel is a steal of a price. Speaking with the rep, he explained that their tires only have about 2 heat cycles on them which means I'm hoping they should last at least 2 full track weekends next year, but you get what you pay for. The website read that they are made from a CTC compound that actually lasts a little bit longer. Any experience with this?

I'm pretty excited about giving these a shot. I'm probably only going to make a MAX of 2 events next year. However, I'm under the impression that when these tires start to go, they don't provide much in the way of any feedback whatsoever. How did Sleeper put it, "sudden "I've had enough" and send you into the weeds." This is a fairly accurate assumption? So, the only real way to tell they are starting to go is by the car not turning in/out the way you want, correct? No noise?

While I'm thinking about it, a buddy of mine with a miata mentioned to me at an event earlier in the year that he was running "scrubs", but I didn't know what he was talking about until reading Brad's feedback. Towards the end of this run (about 13:00-ish)...

http://www.youtube.com/watch?v=jHbARrPjP-s

...you can see him almost lose it and take a ride completely OUT of the bowl. After the run he mentioned that he was running scrubs and they were about done. Mentioned that they lasted a few events, but whatever because they were cheap and he's just going to get more.

Any more advice regarding race tires please let me know. I'm sure I'm in for a handful with these...but looking forward to it.

Anyway, thanks again!

 

Good purchase. Yea, those tires from Bimmerworld are the same rebadged Hoosiers I mentioned above, i.e. the ones from the Continental Challenge series which some Bimmerworld cars run in.

I have not tried these tires specifically but did use their predecessors a lot. In general you can expect them to have grip which far exceeds that which you are use to. Its really amazing the difference. They will be very quiet, you won't hear much if any tire squeal when they start sliding. But they will slide. I think its kind of a misnomer to describe them by saying "they grip, grip, grip and then suddenly break loose". The difference is, with a street tire they give you lots of audible feedback. With a racing slick you don't get that. Also with a slick you are potentially going faster and thus things happen faster - like a spin for example.

They suck in rain and wet and they suck in cold if you can't get heat in them. They take a bit more effort to warm up as well, you can't just hammer on them the first lap. They will last way longer than two weekends. Don't be surprised to get 4 or 5 weekends out of them.

 

What's the widest tire we can fit up front for this car? I want to run a square set up for the track