R compound tires.

[mossaidis]

Thanks Will!

Hopefully, the unmouned hankooks are still in the trunk of the Jeep. I say hopefully, since the Jeep is in NYC, and though in a garage, still up for "grabs".

I'll have them mounted tomorrow morning and I'll drive them around town for 20 minutes or so. I am not taking them to full temps or to a full cooldown, but I assume 18 hours is better than overnight. certainly not ideal. Thanks for the advice.

On other news, the way my schedule has been looking, I don't think I'll see you guys until July at NHIS.

Make sure you provide lots of video content of all the tracks for me to view at work!

[tmak26b]

tmak: Then be sure to watch your tires *very* carefully, and flip them on the rims as I suggested, and you'll halve your tire budget.

already did that. I am debating if i should flip this one after 140 miles or if I can squeeze one more day out of it. It gets expensive to pay $30 each time to flip

[Subw00er]

This is sort of off-topic, but does anyone know how many heat cycles Hoosier R6's are good for?

[boltonite]

If you don't heat cycle them (or buy them heat cycled), they will be super fast for 1-2 cycles, fast for 3-5 more, then lose from .2 - .5 second on an average track (NHIS, LRP) for the next 3-5 cycles. By then my tires are corded but you could get more cycles at .5 - 1.0 second slower still. The R6s wear out pretty fast - much faster than Kumhos - and you can kill a set in a couple hours of hard racing (i.e, one enduro or a few sprints).

If you do a good heat cycle (i.e., scrub 5-10 minutes w/ 1-2 hard laps, inflate to ~50 lbs and let sit for ~ a week), the R6s will last considerably longer but lap times will fall off at about the same rate. For DE or lapping events that is okay; if you are trying to set track records or qualify on poll you won't be doing that on older R6s... the only tire that I know of that can get faster as it ages and wears is a toyo.

At ~$200+ a pop, I'd take a hard look at a Kumho or Toyo before splurging on R6s, you will be giving up a few tenths (maybe more) but saving a ton on tires over the course of a season.

FF

[tmak26b]

Trying not to go off topic, but

I just got back on the Azenis after riding a month on the RA1s. Boy these tires suck in comparsion. They don't grip as well, they are extremely noisy and they are extremely bumpy. I can hardly go 80mph without going crazy in the car due to noise. Also these tires tend to track all over the place too, I really need to get back on the RA-1. Full tread RA1 would make excellent street tires if you have a short commute

[ryanthieme]

I'm going to assume you're talking abut the Azenis Sports. Are you using up an old set of 215's or the newer 216's?

From my experience, the 215's got pretty noisy after about 8k miles and I ditched them after 12k miles. By then all the grip was basically gone and they were way too loud for my tastes.

This is my first summer on the 615's and so far I like them. I've yet to autocross them so I don't have much in the way of comparable notes as my daily commute up and down 128 is way too crowded to see what they are like out around 80 mph. They do seem quieter, although the last time I put a new set of the 215's on the wheels was 2 summers ago.

I did, briefly, run around on a full tread set of RA-1's last summer and would agree that they are head and shoulders above the Azenis, but the price tag is just too much for me to use them as an everyday tire.

[chaos4NH]

I have had quite good luck with the RT 615s as street tires. Around 2500 miles and not noisey that I can tell (wife says I am deaf, so......). I will continue to use them as my street tires and mount up the RA1s for the track.

[tmak26b]

I have both sets of tires, didnt like them both. The only thing that is noisier than the 615s are the 215s. I just got home from Boston, my ear is still ringing from the piece of crap tires. If I have to use them for long trips again, I am going to ahve to bring my ear muffs. Once these tires wear out, I am going to get more RA-1s. Believe it or not, RA1s can last just as long for me because I dont spin them as easy. My normal street tire wear 2x as fast in the rear. With the RA1s, i would say 1.5x faster

[mossaidis]

Hey Mickey,

I ran a set of the 214's (205/50-15) for the first time at the Glen. This was the first outing for my "new" car, and I was pretty busy at the event, so I didn't really push them much.

Compared the the RA-1, the construction seems much different. The Hankook is a slightly heavier tire, with significantly sitffer sidewalls. Construction seems more inline with Hoosiers.

I found that the Hankooks like a bit more pressure than the RA-1s. Probably about 2 pounds or so, cold. I normally start the day on RA-1s with pressures around 31-33, depending on the weather and track conditions. The Hankooks needed a couple of extra pounds (about 34 cold) to get into the "zone". Whereas the RA-1 tops off at 40PSI hot, it seems the Hankooks could go to 41-42°F before they start to drop off. The 2nd day at WGI was a little on the overcast/chilly side, and my temps maxed out just shy of 40°F. I used a pyrometer to check the temps, and am thinking a little higher would have provided more even temps across the tire's tread. This is all very preliminary though.

Before you get to Lime Rock, I would suggest you scrub in the Hankooks. Take them out and bring them up to temp, then immediately jack the car, dismount the tires, and stack them for 24 hours. Some will say that the Hankooks will be good to go as soon as they have cooled to ambient, but this is the minimal cool-down time. I would suggest 24 hours. Not "one day", "over night", etc., but at least 24 hours. This would be a good break-in / scuffing / heat-cycling procedure for the Toyos and Kumhos as well.

The Hankooks seem promising, and though I expect they will offer more ultimate grip, I do not expect them to be as well-suited for COM duty as the RA-1s. Typical COM weekends involve 7 or more heat-cycles, which the RA-1s seem to handle with ease. Other tires, as Borat might say, "not so much".

- Will

Hankook update. Got back from LRP yesterday from a Patroon BMW event where I ran 4 15-20 minute sessions at 50-68 degrees. Rears looked great with minimal wear, right front looked about 80%, but the front left looked about 65-70%, the inside edge of the tread had just touched the 2/32 wear indicators. All in all, incredible traction at 40 psi -3 front and -2 rear chamber. I was able to carry good speed through corners with little or no control issues. I would estimate that the tires will last 8-10 track days with basic corner and inside-out rotation.

[slomotorsports]

I used to run with COM back in the late 70's and early 80's (back when Dave Sherman and Dave Burden created the "Japanese" and "German" Cup trophies). My little 1974 Spitfire and my little budget never allowed me to run any exotic tires.

Fast forward 20+ years; now my son and I co-drive an 88 Mazda RX7 Turbo (13BT) in SCCA NER Solo autox events.

We just joined COM and registered for the upcoming NHIS school and time trial in July. Based on the class rules, I've put us in Street Prepared A (we run in SM2 in SCCA Solo)

We've been running on Kumho V710's at the autox events (yes, our racing budget is bigger now). It seems like some of you run these for time trials too. Is there another tire that we should consider or will we be OK on our V710's? It would be great if we didn't have to get yet another set of tires.

~Shawn

[mossaidis]

(I speak as a semi-noob that has driven with used Kumho 710's)

The Kumho 710 will work fine as a track tire. Of course, there is the general wear believe on the 710's... that is during the first 4-5 heat cycles the tires are AWESOME... after which the traction slowly degrades. Though the tires itself seemingly never wears out, traction begins resembling a Toyo, then a 700, and then a used Falken Azenis after 3-4 track days or 20 some heat cycles.

In the end, it's still a R compound and will do fine as a track tire. Also, the 710 usually has a larger cir. than other r-compounds in the same tire size. Depending on your torque curve (which is probably as small as my little Honda beep beep!) the size increase will NOT help accel. But... this is not a F1 race, just go out and have fun!

[slomotorsports]

We've been pretty happy with the tire on autox courses. They heat up quickly and provide us with ample traction/grip. My worry is that I wouldn't want them to heat to the point where they start to be really gummy. I don't want to get up close and personal with any walls at NHIS (nor do I want my son to either).

[WillM]

I've only run the V710's once, and they were borrowed, so my practical experience with them is limited.

That said, there are plenty of guys that run them on the track. I believe they are touted as being slightly stickier than the Toyos, but not as long-lasting. Pretty much exactly what Mickey said. As long as there is enough tread on them (no cord), you should be fine.

You obviously have experience heating up the tires and know what to look for. Just check the temps and pressures regularly. Not sure what heat and pressure range those tires like to be in, so you might want to check with Tirerack or Kumho. Mid 30's to 40psi (hot) seems about right for most DOT R tires.

Cheers,

Will

[Mick]

They'll be great, you don't have to worry about overheating them. I've been running only v710's for the past 2+ seasons with good results. My car is ~2500lbs.

[slomotorsports]

We run at 28 psi front and 26 psi rear. On hot days, we spray the tires after each run and we always re-adjust pressures to stay at the 28/26.

It seems that these particular tires don't need to be run at higher pressures. Of course, that just might be autox. We're new to R compounds.

What do you run for pressures, Mick? At last years Tire Rack National Tour at Devens we weighed in around 2800 lbs.