Re-71 vs Falken RT660

[Code Monkey]

Originally Posted by NoHaveMSG

No, I was just going by feel. I broke my temp probe and haven't bought a new one. There were 4 of us running these chasing the same issues.

Thanks, just wondering. Not the same tire obviously but I usually run between 26-28 hot on the Falken Azenis RT615K+.

[jflogerzi]

Originally Posted by Code Monkey

Thanks, just wondering. Not the same tire obviously but I usually run between 26-28 hot on the Falken Azenis RT615K+.

Wow that's pretty low for hot. What do you start a session at cold?

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[Code Monkey]

Usually between 19-22 cold.

[NoHaveMSG]

Originally Posted by steverife

Those tires look about how I'd expect them to look.

I guess if I was used to running RE's or Yok's I'd be happy with them at this stage. I am really a bit underwhelmed by them.

[ZDan]

Originally Posted by Code Monkey

Thanks, just wondering. Not the same tire obviously but I usually run between 26-28 hot on the Falken Azenis RT615K+.

Originally Posted by Code Monkey

Usually between 19-22 cold.

Is this for AutoX or track work?

I wouldn't get caught up trying to see how low you can go either way! Additional adhesive grip from greater contact area running low pressures is to some degree offset by greater rolling resistance and slower transitions. Also if tire overheating is a concern, lower pressures will build more heat more quickly.

Most radial track tires have a very broad range of pressures over which they'll develop close to their max grip. Here's some GRM skidpad data vs. pressures:
https://grassrootsmotorsports.com/ar...oss-and-track/


I would bet that for autoX you'd want pressures higher than what's "optimal" for skidpad, and for track work you would want to go higher still. I usually aim for 34-36psi hot at the track. I do not have nearly enough track time available during events to scientifically determine "optimal" pressures but I'd rather err on the high side for greater tire life and less heat buildup (a real concern even over 3-lap time trials on A052s).

My 0.02...

[Code Monkey]

Track exclusively.

[N_Raged]

I had my RT660's since May and they've seen four parking lot AutoX events and one school lapping day at Mosport GP. Very happy with them compared to my previous RT615K+. I'm competitive in my AutoX class up there with my peers on RE-71R's, even won my class on the last event. Steering inputs with the RT660 is not darty as I would expect from a performance tire, so that's probably why experts who have compared them say that the RE-71R are the sharper tire.
With that said, the RT660's grip at the limit is still phenomenal.

My specs:
225/45R17 on 17x8" ET45 wheels.
Hot tire pressures: F=32PSI, R=30PSI
BRZ tS with Bilstein B6's.
-1.9deg front camber, -1.0deg rear camber.
Front 22mm Perrin Sway bar on Soft setting.

On a side note, I also have the issue with the cut across the entire width of my tire. I only inspected them after my first AutoX event and at first I thought this cut was created by the terrible broken pavement at the venue. The cut is pretty shallow fortunately and should wear away eventually.

[conehead]

I ran two seasons of autox on my RT660s without ever rotating them and also some dd in between (just did not have the time to keep swapping them out). The have nearly perfectly even wear and plenty of life left. Won my last event in them so they are still performing well. Overall I'd say they have the same grip with a touch less feel than my Re71r, but much lower running cost (cheaper to buy and longer lasting). I'm glad SSC is protecting me from the expensive yokohamas.


All of these tires are specifically designed for autox. They would be excellent for time attack, but for longer track use you need to use track tires that are designed to hold up to the heat. These will wear out rapidly.

[jflogerzi]

Originally Posted by conehead

I ran two seasons of autox on my RT660s without ever rotating them and also some dd in between (just did not have the time to keep swapping them out). The have nearly perfectly even wear and plenty of life left. Won my last event in them so they are still performing well. Overall I'd say they have the same grip with a touch less feel than my Re71r, but much lower running cost (cheaper to buy and longer lasting). I'm glad SSC is protecting me from the expensive yokohamas.


All of these tires are specifically designed for autox. They would be excellent for time attack, but for longer track use you need to use track tires that are designed to hold up to the heat. These will wear out rapidly.

that's why our cars can bring an extra set of wheels. DD+ a durable track tire and a Time attack set when you trying to set PBs in short 2-3 lap stents

[NoHaveMSG]

Originally Posted by jflogerzi

that's why our cars can bring an extra set of wheels. DD+ a durable track tire and a Time attack set when you trying to set PBs in short 2-3 lap stents

That’s what I have been doing. SX2’s most of the time for me.

[racingfool]

Originally Posted by N_Raged

issue with the cut across the entire width of my tire

Looks like a seam where the tread was glued onto the carcass.
I seem to remember reading that that can happen with summer tires in cold weather.

[Icecreamtruk]

So update on my part. Grip is ok on the RT660, around the same as the RE71R and a touch below A052. "Feel" is numb, a bit like the yokos. So its basically a inferior tire to both of those in pure laptimes or ability to extract time out of them. I will say that the very first lap out on them (straight into attack mode), that very first heat cycle, they are easily half a second per minute faster. I've never had a tire with such a marked drop off in grip after the first cycle. In that one first cycle, they blew the yokos and stones out of the water by a mile, but it only lasted 2 laps, then it was back to "normal" 200TW auto/time attack grip levels.

Edit: didnt compare directly to either of those tires (as I had no mounted set) but did compared them to Maxxis RC1 (r1 compound), which are around the same speed as nittos, or about 0.5 per minute slower than the yokos. Falkens were about .3 to .5 seconds per minute faster. So pretty much there, a touch slower but a bit numb in the steering feel.

[NoHaveMSG]

Originally Posted by Icecreamtruk

So update on my part. Grip is ok on the RT660, around the same as the RE71R and a touch below A052. "Feel" is numb, a bit like the yokos. So its basically a inferior tire to both of those in pure laptimes or ability to extract time out of them. I will say that the very first lap out on them (straight into attack mode), that very first heat cycle, they are easily half a second per minute faster. I've never had a tire with such a marked drop off in grip after the first cycle. In that one first cycle, they blew the yokos and stones out of the water by a mile, but it only lasted 2 laps, then it was back to "normal" 200TW auto/time attack grip levels.

Edit: didnt compare directly to either of those tires (as I had no mounted set) but did compared them to Maxxis RC1 (r1 compound), which are around the same speed as nittos, or about 0.5 per minute slower than the yokos. Falkens were about .3 to .5 seconds per minute faster. So pretty much there, a touch slower but a bit numb in the steering feel.

Out of curiosity, what size are you running and what are your alignment specs? Where did you settle on hot pressures?

[dreamwonder]

Datapoint, maxxis rc1 r2 is pretty much the same as re71r in terms of grip, maybe a hair faster. But it can last a good 3 laps before it starts greasing out compare to 1 lap of the re71r. Corded the maxxis in 6 days, 550f/600r spring rate. Stock bars. Camber is -4.1f and -3f, zero toe. This is with rotation after each day.