In a bit of a pinch needing some tires quick for upcoming track days and it seems the HANKOOK C51 that I've been running are in limited supply.

Wanted to try these Toyos in sizes 255/35R18 and 275/35R18 but strangely the 275 is rated LL for Light Load.

Has anyone run these tire in this size. Is this an issue ?

 

I've used the C51 Hankook extensively and have also used the Toyo RR this season in a pinch, in place of the C51. The Toyo is not even close to the performance of the z214 C51. Several seconds slower in my experience.

The Toyo sizing worked fine with my 987 cayman, no issues that I experienced.

This isn't to say the RR is garbage. But don't expect C51 levels of grip from them.

 

Thanks. Since you have extensive experience with the C51's I wanted to ask what your alignment settings are and how long they typically last?

I'm running -3.0F/-2.5R camber with -.04 toe out in Front and .32 toe in on the rear.

I just went through 2 sets of C51's what I feel is fairly quick.

I am getting like a chamfered wear on the inside shoulders of all the tires. The outside shoulders have a nice rounded wear. I run them for about 8 sessions and then flip them on the rims and switch sides.

Then within another 4 to 8 sessions the R/F inside shoulder cords.

The rest of the tire is worn fairly even down to the wear bars?

Too much camber?

I'm running pressures around 34 - 35 hot.

 

The RR is a very good tire but the available sizes you listed are incorrect for the Cayman and in particular will be a very over-stuffed fit on the front wheel.

The RS1 is a terrible piece of **** and best avoided (that's likely the tire Chris was referring to).

Your use/wear of the Hankook Z214 C51 is appropriate.

Your alignment specs are reasonable. If you lean on the tire more and/or reach higher mid-corner Vmin speeds then a bit more camber would be helpful.

 

My theory is the inside shoulders are getting hammered under straight line braking. It's confusing because the tracks are mostly right hand turns so the R/F tire is getting worked the least.

I was thinking maybe I should reduce negative camber to maybe -2.8/2.3.

Thoughts ?

 

Tire temps in the usual inner/middle/outer zones would help (a bit).

The rest depends on spring rates, sway bar settings, how you drive (hard to sort out on the internet), and testing.

Reducing camber further is going to reduce mid-corner speed and increase outer 1/3 wear unless you are driving miss daisy.

Bottom line - if you want tires to last longer, switch to something like the Hankook RS4. And accept less grip/speed.

 

Thank you. Looks like it's time to invest in a proper pyrometer.

 

Used both the RR r-comps and the RS1 slick this year. Indeed the RS1 slick should be avoided at all cost. The RR, considering it's an r-comp in same category as the C51 and virtually identical price point, is OK but the Hankook C51 is objectively a better tire on the 987 cayman.

Agree on the wear characteristics. Every set I've used, I've corded the inside edge of the tires, typically fronts first. My first few sets I targeted 32psi hot and corded them in 6x 30min sessions. Two sets in a row.

All sets after (probably 8-10 at this point), I set at 36psi hot and get ~15 sessions out of them including flipping on rim halfway through. In my experience, they are still very fast even near the end. I set my Mosport PB time of 1:28.1 on the very last lap of the 15th heat cycle of C51's, and found the tires just starting to cord on inside edges when I came off track. Tremendous tire in my experience.

Toyo RR I could only get into the low 1:31's. Good consistent tire but very obviously lacked the grip of the C51.

 

I've run both RR's and C51's- my experience is the C51 has quite a bit more grip and lasts longer than the RR, tires run a 3200 lb E36 M3.

 

Thanks again fellas. I managed to get 1 set of C51's shipped. I'm gonna get a pyrometer so I can really dial them in.

 

Check the date codes on them when you get them to ensure they're fresh tires. See a few threads down re: a lot of people in the past month receiving tires manufactured in 2015, which are being replaced upon request with fresh tires.

 

Will do. I had seen those threads. Good looking out.

 

Could be too much positive caster. The more positive caster in the setup, the more tire lean (negative camber) as steering angle is increased. Thus the inside RF tire is dragged around the corner causing excessive wear. I had this issue on my 981.

 

Thanks lemming, interesting note. In my readings I know I read something somewhere that said "as much positive caster as possible."

I can't remember where I read it or if it even pertains so this car lol.

So I ended up trying a set of RR's. So far I like the tire. To me they feel a bit less grippy laterally but the same in braking. That may also be because the front size is wider than the C51 so the understeer/oversteer balance is different.

After a half assed attempt to heat cycle them my brother and I put 15 heat cycles into them over 2 days.

We flipped the fronts on the rims and switched sides after the first day.

So far wear seems good.

I would definitely recommend these for HPDE if the Hankook is not avail. Depending on how much more wear we get out of these, I may switch to them permanently.

 

How many heat cycles were you getting out of the C51's, just curious.