Pilot Sport Cup 2 345 30ZR19 in the rear for ACR

[PkB2014]

I have driven both the PZero's and PSS on track for a full day each. Keep in mind the PZero's were on the Viper and the PSS were on a different smaller car. My personal assessment is that on track, the PSS to me seemed ok to decent, but the PZero's were better than I expected.
lol how's that for an objective and definitive response?

Seems reasonable. Sort of my conclusion from past experiences as well.

I ran the Pzeros in One Lap for two years on a 2015 TA 2.0. They scared the hell out of me in the rain. Hydroplaned like crazy. Now I run Michelins. Pzeros suck IMO.

I feel like the PSS would win against many performance tires in the rain. So this makes sense.

Thanks for the input guys. And sorry for the moderate thread hijack

[ek1]

Sooo....PSC2s are on.

Initial impressions from a 40-mile drive dropping off the ACR for the NVE transport. Mostly highway, 30-65 mph range:

1. Car does not dart as much as with R888Rs and DEFINITELY not as much as with R7s.
2. Ride is quieter, less tire noise.
3. You know that sensation of being hit in the back of your head with a baseball bat when driving over small bumps with rear wheels of the ACR? It's mostly gone with PSC2's

Coming up next: ~1,000 mile drive from Denver to Vegas through Arizona, followed by 1/2 track day at the Vegas speedway. We'll see what happens. In the mean time, here are some pics.

20180422_135847.jpg

20180422_140154.jpg

[kriskyk]

Can you clarify about the darting versus the r888rs?

[ek1]

Can you clarify about the darting versus the r888rs?

Most cars with wide front tires will follow grooves on pavement, which causes the car to pull to the left or right depending on direction of the groove. With stock Kumhos in the front it was not too bad, but when I put Hoosier R7s on, it felt like someone was trying to wrestle the wheel from you on a highway (I live in NYC, some of our nation's worst roads are located here). With R888Rs the darting was approximately the same as stock Kumhos, but with PSC2s it's less. I always thought that it had something to do with tread width, but it can't be because R7 has 10.4" width and PSC2 has 10.5", so something else may be at play here. Maybe someone who knows more about tires can comment.

[parabs]

How is the cold street grip of the psc2 vs the r888r?

[kriskyk]

Ahhh tramming got it thanks!

Was your alignment adjusted when you put on the psc2s?

[catwood]

How was the traction control? Did it get upset over the diameter change?

[sharmut]

Fantastic. Look forward to your feedback for their track performance.

[stradman]

Sooo....PSC2s are on.

Initial impressions from a 40-mile drive dropping off the ACR for the NVE transport. Mostly highway, 30-65 mph range:

1. Car does not dart as much as with R888Rs and DEFINITELY not as much as with R7s.
2. Ride is quieter, less tire noise.
3. You know that sensation of being hit in the back of your head with a baseball bat when driving over small bumps with rear wheels of the ACR? It's mostly gone with PSC2's

Coming up next: ~1,000 mile drive from Denver to Vegas through Arizona, followed by 1/2 track day at the Vegas speedway. We'll see what happens. In the mean time, here are some pics.

20180422_135847.jpg

20180422_140154.jpg

Its interesting Eugene looking at the rear wheel setup. Obviously because the front tire/wheel is taller you have had to jack up the rear a bit more to maintain the correct rake but damn there now seems to be a bit too much air between that rear tire and wheel arch for my liking. I understand though why it like that way.

[Jack B]

Most cars with wide front tires will follow grooves on pavement, which causes the car to pull to the left or right depending on direction of the groove. With stock Kumhos in the front it was not too bad, but when I put Hoosier R7s on, it felt like someone was trying to wrestle the wheel from you on a highway (I live in NYC, some of our nation's worst roads are located here). With R888Rs the darting was approximately the same as stock Kumhos, but with PSC2s it's less. I always thought that it had something to do with tread width, but it can't be because R7 has 10.4" width and PSC2 has 10.5", so something else may be at play here. Maybe someone who knows more about tires can comment.

It may be due to my alignment, however, I get minimal dart effect with the 888's .

[PkB2014]

How was the traction control? Did it get upset over the diameter change?

Does anyone have the actual percentage/ratio of tire diameter differences that the TC and ABS allows? I have the Hoosiers which is about 4.3% change from stock and the systems seem to work normally. I’m looking at some Autocross tires that would be slightly more than 5% difference. I’m wondering if 4.5% or 5% might be the magic threshold where things start acting up.

[ViperGeorge]

Does anyone have the actual percentage/ratio of tire diameter differences that the TC and ABS allows? I have the Hoosiers which is about 4.3% change from stock and the systems seem to work normally. I’m looking at some Autocross tires that would be slightly more than 5% difference. I’m wondering if 4.5% or 5% might be the magic threshold where things start acting up.

I've been unable to get an answer on this. I do know that running Hoosiers in 315/30/18 front and 345/30/19 rear on my on 2015 TA 2.0 caused the TC to freak the hell out.

[catwood]

I've been unable to get an answer on this. I do know that running Hoosiers in 315/30/18 front and 345/30/19 rear on my on 2015 TA 2.0 caused the TC to freak the hell out.

Yeah, that's my concern though I want to go with a different tire also. Potentially one for street and another setn (racetires) for the track. If I ever go to the track with the ACR but that's a whole nother discussion.

[ViperGeorge]

Yeah, that's my concern though I want to go with a different tire also. Potentially one for street and another setn (racetires) for the track. If I ever go to the track with the ACR but that's a whole nother discussion.

Of course you'll know when the TC is acting up. The light on the dash flashes and the car won't go. Turning off ESC/TC fully eliminates the interference but I don't know how you would know the ABS isn't happy.

[CNU_Physics]

I heard something about the GT3 RS having a new version of the Cup 2...called the Cup 2 R? Is that tire out yet?

[stradman]

I heard something about the GT3 RS having a new version of the Cup 2...called the Cup 2 R? Is that tire out yet?

Worth around 8 seconds around the Ring. But don't count on it lasting too long! Very similar to Kumhos in that respect.

[Jack B]

I've been unable to get an answer on this. I do know that running Hoosiers in 315/30/18 front and 345/30/19 rear on my on 2015 TA 2.0 caused the TC to freak the hell out.

I run the same combo for autoX without issue, but, it is the SRT

[PkB2014]

I run the same combo for autoX without issue, but, it is the SRT

Yes I run this exact same setup without issue. This is about 4.2% difference from stock ratio. My feeling is it’s right on the limit of what TC and ABS allows. But no one seems to know the exact numbers

[catwood]

Of course you'll know when the TC is acting up. The light on the dash flashes and the car won't go. Turning off ESC/TC fully eliminates the interference but I don't know how you would know the ABS isn't happy.

I ran Hoosiers on the GTS (315 fronts) on the track and it acted up on occasion on the street though it didn't see much street time with those tires. I typically turned everything off at the track (unless I forgot) and no issues. But in this case I'm going the opposite with the weird size on the street.

[ek1]

Ahhh tramming got it thanks!

Was your alignment adjusted when you put on the psc2s?

No, I didnt have the time to do it. However, my car was aligned with Hoosier R7 295/30/19 in the front and they are 26.1" in diameter vs. 26" for PSC2. In the rear, the tire diameter changed from 12.5" for stock Kumos to 12.7" for PSC2s. So I know my alignment is slightly off, but not by much. I doubt that .1" in the front and .2" in the rear has a major affect.

[ek1]

Worth around 8 seconds around the Ring. But don't count on it lasting too long! Very similar to Kumhos in that respect.

I would not be so sure. Kumho set the bar so low that pretty much any tire will exceed it. It's a brand new tire and I can't wait to try it. Few issues may be that it won't come in Viper-compatible sizes and will cost $600 per tire.

[ek1]

How is the cold street grip of the psc2 vs the r888r?

Didnt get a chance to push the car yet. Hopefully next week. Then again, its freaking 97F in Arizona now so cold tires are probably not going to happen for a while.

[ViperGTS14]

FWIW, I’m on 295/30-19 front and 345/30-20 rear. Michelin Pilot Sport 4S.
Car is lowered on MCS WNR1 coilovers. I get a slight amount of rubbing in the front. Since these are street tires I’m going to experiment with a 285 wide front.

No issues with traction or grip. I went up 1” all around in wheel diameter.
They grip on cold roads too. Car feels way more planted than the pzero grip tires.

Damn good thread, needs a bump. Currently looking for new rubber but really like the idea of going 19's for front and 20's for rear (I don't road coarse race) and running my favorite tire which is the PS4S. Just love love love these tires and it seems as though it would work, would love to see a rim and tire setup for these.

It would be nice if all Gen 5 could run 19's all around, how come the 16-17 ACR only came with 19's all around?

[serpent]

Damn good thread, needs a bump. Currently looking for new rubber but really like the idea of going 19's for front and 20's for rear (I don't road coarse race) and running my favorite tire which is the PS4S. Just love love love these tires and it seems as though it would work, would love to see a rim and tire setup for these.

It would be nice if all Gen 5 could run 19's all around, how come the 16-17 ACR only came with 19's all around?

I recently sold my 19/20 setup. Not sure about going with big tires again. Its more weight and adds to the firm ride when going larger diameter wheels. Only issue now is michelin does not like 30 aspect ratio tires, they do not have any in 18s, 19s are rare too.
Would love some ps4s 295/30 18 and 345/30 19, but michelin fucking sucks in tire selection.

[ViperGTS14]

Thanks for getting back to me serpent on that. I do believe you 20's are big for this type of car especially for a better drive. I've driven a lot of different tire setups on the street and ps4s's are just amazing. Cup 2 would be my second favorite.