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

[ek1]

I am trying to decide on what tires I am going to use for the trip to NVE3 and a track day there. I am driving from Denver to Vegas and will do what looks like a 1/2 day track day in Vegas. I usually only drive the car to/on/from the track and use 295/30/19 Hoosier R7 in the front and stock 355/30-19 Kumho in the back, but obviously driving with R7s through the Rockies is a no go. In the past I also tried Toyo Proxes R888R 295/30-19 in the front for the road and light track duty, but they howl at 70+ mph on a highway, so it's a no go for me for long drives.

Since Michelin already makes Sport Cup 2 in my front size (295/30-19), I figured maybe I should try the 345/30ZR19 Sport Cup 2 in the back as well. Looking at specs side by side with a stock Kumho 355/30-19, the Sport Cup blows the Kumho out of the water - it has a 562 Lbs higher max load, it weights 8 Lbs LESS, and has a 0.2" wider tread. I also do not see any issues with alignment and/or traction control since since the diameter of the Sport Cup 2 is only 0.3" less than the Kumho. Every single person I spoke to that uses PSC2 is very satisfied with them, on road and track.

What do you guys think?

[cashcorn]

It sounds like you have already decided on the Michelin's and I agree.. I've been looking at the Proxes, outstanding grip for the street, however reviews always complain about road noise on the frwy.. good luck on your choice!

[catwood]

I'm in San Diego and I'll probably tow just the 300 miles. good on you for driving it

[Arizona Vipers]

Cup 2's all the way if you are driving there. They are fast as hell for a street tire, barely off R7 times.
The track will be packed full of newbs so you wont be breaking any track records anyway.

[stradman]

Ever thought of going to 18's in the front Eugene?

[ek1]

Ever thought of going to 18's in the front Eugene?

Yeah, many times. The clearance between the caliper and the rim scares me, although my calipers are already beat up a bit even with stock 19" wheels. Then there is the cost and effort of buying an extra set of rims, re-doing alignment, etc. I'll do it some day, but not this season.

[ayousef]

Well the only problem would be the difference between the rear diameter and front diameter on the new tires. I was looking at the Cup2's and decided to get the R888R, I know they do howl. I was wondering how those two tires would differ in performance and if you had any issues with ABS or traction control using the Toyos?

[ViperGeorge]

I have steel TA brakes on my ACR-E and can therefor run 18" front wheels without a problem. For the One Lap of America I run Michelin PS2s in the front (295/30/18) and Michelin PSSs in the rear (345/30/19). They do not make the PSS in a 295/30/18 and they don't make the PS2 any longer in a 345/30/19 hence the mixed models. No issues though and I prefer them to the Pzeros. They are virtually the same diameters as the stock Kumhos so car setup is the same.

However, the 295/30/19 tire you want to run in the front will be taller than the Kumho 295/25/19 by more than 1 inch. This will effect the rake of the car and probably the ESC and ABS systems. You might not notice the effect on the ESC or ABS but I did in my old 15 TA. The ESC on that car would constantly try to interfere while just driving around. The diameter difference was enough to make it think one axle was slipping. The ACR is sensitive to rake though and you might want to raise the rear to maintain the proper rake. Good luck and we'll see you there.

[ayousef]

I have steel TA brakes on my ACR-E and can therefor run 18" front wheels without a problem. For the One Lap of America I run Michelin PS2s in the front (295/30/18) and Michelin PSSs in the rear (345/30/19). They do not make the PSS in a 295/30/18 and they don't make the PS2 any longer in a 345/30/19 hence the mixed models. No issues though and I prefer them to the Pzeros. They are virtually the same diameters as the stock Kumhos so car setup is the same.

However, the 295/30/19 tire you want to run in the front will be taller than the Kumho 295/25/19 by more than 1 inch. This will effect the rake of the car and probably the ESC and ABS systems. You might not notice the effect on the ESC or ABS but I did in my old 15 TA. The ESC on that car would constantly try to interfere while just driving around. The diameter difference was enough to make it think one axle was slipping. The ACR is sensitive to rake though and you might want to raise the rear to maintain the proper rake. Good luck and we'll see you there.

Tirerack has the 345-30-19 Cup 2's but it says limited quantity, are you sure they stopped making this tire?

[ViperGeorge]

Tirerack has the 345-30-19 Cup 2's but it says limited quantity, are you sure they stopped making this tire?

No my post was for the more streetable Pilot Sport 2s (PS2) and the Pilot Super Sports (PSS). If the OP wants a street tire I wouldn't go with the Cup 2. They are still not as good in the rain and they won't wear as well. Michelin does make the PSS, the PS2, and the PS4 in 295/30/19 and Tirerack has them all. So if I were going with the sizes the OP discussed for the street I would go with the PSS in 295/30/19 and 345/30/19. Remember though the front tire in that size WILL BE taller.

[ek1]

Well the only problem would be the difference between the rear diameter and front diameter on the new tires. I was looking at the Cup2's and decided to get the R888R, I know they do howl. I was wondering how those two tires would differ in performance and if you had any issues with ABS or traction control using the Toyos?

When I switched from the stock 295/25-19 to the 295/30-19 R7s, I had to readjust the ride height and had to redo the wheel alignment (because the R7 295/30-19 is about 1" taller than the 295/25-19 Kumho)). I never had any issues with abs or traction control. The R888Rs in 295/30-19 are almost exactly the same height as the 295/30-19 R7, so I dont have to do anything when I swap R888Rs and R7s. I also cannot go back to stock Kumhos in the front without readjusting ride height and redoing alignment again (which is OK since I have no intention of ever doing so).

[SharpMan]

Can people with 295/30-19 on the front post up some pics. Thanks.

[ayousef]

When I switched from the stock 295/25-19 to the 295/30-19 R7s, I had to readjust the ride height and had to redo the wheel alignment (because the R7 295/30-19 is about 1" taller than the 295/25-19 Kumho)). I never had any issues with abs or traction control. The R888Rs in 295/30-19 are almost exactly the same height as the 295/30-19 R7, so I dont have to do anything when I swap R888Rs and R7s. I also cannot go back to stock Kumhos in the front without readjusting ride height and redoing alignment again (which is OK since I have no intention of ever doing so).

Another advantage I see with the larger diameter front tire is the fact that you will be forced to lower the front of the car, this would reduce the amount of preload on the front spring and as a result "soften" it, and aid in reducing unwanted front end push. Lets see how this goes.

[ek1]

Can people with 295/30-19 on the front post up some pics. Thanks.

Here we go. Sorry if it's too close, my garage is tiny.

20180331_170854.jpg
20180331_170952.jpg
20180331_171003.jpg

[SharpMan]

Thanks...looks like a more sensible aspect to me.

Any issue with trac or stability control on?

Here we go. Sorry if it's too close, my garage is tiny.

20180331_170854.jpg
20180331_170952.jpg
20180331_171003.jpg

[ek1]

Thanks...looks like a more sensible aspect to me.

Any issue with trac or stability control on?

Zero issues with traction or stability control. I did have the ride height readjusted properly and had a wheel alignment done.

[ForTehNguyen]

not an ACR but Im running taller front tires 285/35/18 instead of 295/30/18 to have matching PSS tires for the rear. No issues with traction control, performed great at the track during an HPDE weekend.

[SilveRT8]

I also just installed a new set of street tires on my spare set of SW2 wheels, Mich PSS 285-35-18 fronts and 345-30-19 rears.
I only drove the car on 3 occasions with this set-up so far, but a few times when in first or second gear, the car would not want to accelerate and the Traction control light would come on, even on moderate acceleration. One gear up to third or fourth and all is fine again. Could it be the taller fronts 25.9'' vs 25'' and slightly lower rears 27.2'' vs 27.4'' ? I also went with a change to 3.91 gears, but did not have an issue with the stock Corsa's set-up ?
This does not happen all the time, but it did it at least 3 or 4 times, enough to make me worry about it .
Car is a '16 GTC group TA2.0 with Arrow PCM, Belanger Headers ww/ HF cats, AR mufflers, 3.91 rear gears, Ipsco UD pulley, K&N drop-in filter and smooth tubes, lower spring caps. All recently installed.

[parabs]

I also just installed a new set of street tires on my spare set of SW2 wheels, Mich PSS 285-35-18 fronts and 345-30-19 rears.
I only drove the car on 3 occasions with this set-up so far, but a few times when in first or second gear, the car would not want to accelerate and the Traction control light would come on, even on moderate acceleration. One gear up to third or fourth and all is fine again. Could it be the taller fronts 25.9'' vs 25'' and slightly lower rears 27.2'' vs 27.4'' ? I also went with a change to 3.91 gears, but did not have an issue with the stock Corsa's set-up ?
This does not happen all the time, but it did it at least 3 or 4 times, enough to make me worry about it .
Car is a '16 GTC group TA2.0 with Arrow PCM, Belanger Headers ww/ HF cats, AR mufflers, 3.91 rear gears, Ipsco UD pulley, K&N drop-in filter and smooth tubes, lower spring caps. All recently installed.

I just installed 295/30/19 and 345/30/19 r888’s on my srt and I have once experienced the exact same issue you just detailed. It was immediately after I installed the tires and observed at mid to 3/4 throttle. Although since then I haven’t been able to replicate the issue with similar throttle inputs.

[ViperGeorge]

I just installed 295/30/19 and 345/30/19 r888’s on my srt and I have once experienced the exact same issue you just detailed. It was immediately after I installed the tires and observed at mid to 3/4 throttle. Although since then I haven’t been able to replicate the issue with similar throttle inputs.

Yup, this is exactly what happened when I ran taller front tires on my 2015 TA 2.0. I was at Motorsports Park Hastings running Hoosiers. Unless I turned ESC off completely the car could not really be driven. I couldn't even drive to the gas station less than a mile away without turning the system off. The SRT engineer that designed the ESC/Traction system for the Gen 5 told me that this was due to the taller front tires. The system compares wheel speed of each axle against what is expected and if it detects a difference it intervenes. Because of the taller front tire the system thought one axle was slipping relative to the other and hence tried to correct it.

He also said that the taller tires would change the way the ABS worked for the same reason. This would be harder to feel but the effect would still be there. I couldn't get a real answer on how much of a difference in tire height the system would tolerate because he said they never tested it with anything but the stock tires. He doesn't like to comment on anything non-stock for this reason.

Since then I've tried to keep tire heights the same or nearly the same as stock. Fortunately my ACR has steel brakes and I can run 18" wheels in the front. With 18" wheels I run the 295/30/18 which is virtually the same diameter as the stock 295/25/19 Kumho. The rears at 345/30/19 are only 0.2 inches different in diameter, an amount apparently too small to matter.

[SilveRT8]

I just installed 295/30/19 and 345/30/19 r888’s on my srt and I have once experienced the exact same issue you just detailed. It was immediately after I installed the tires and observed at mid to 3/4 throttle. Although since then I haven’t been able to replicate the issue with similar throttle inputs.

I just went for a Sunday drive and happy to report that Traction control did not act up today. Hopefully the Arrow PCM is learning or adapting to the new tire combo. Can that be the case ?

[ViperGeorge]

I just went for a Sunday drive and happy to report that Traction control did not act up today. Hopefully the Arrow PCM is learning or adapting to the new tire combo. Can that be the case ?

Not positive but I do not believe that traction and stability are controlled by the PCM. By the way, I also had an Arrow controller on my TA 2.0 and it didn't make any difference.

[ek1]

BTW, my car is 100% stock.

[Jack B]

I just went for a Sunday drive and happy to report that Traction control did not act up today. Hopefully the Arrow PCM is learning or adapting to the new tire combo. Can that be the case ?

There is not a lot of learning going on. Traction control and stability control are implemented by the pcm. The input to the pcm comes from the wheel speed sensors.

[SilveRT8]

There is not a lot of learning going on. Traction control and stability control are implemented by the pcm. The input to the pcm comes from the wheel speed sensors.

Thanks Jack, I wonder if Arrow /Prefix could alter the PCM with revised values for the wheel speed sensors, as I feel it's right on the verge of acting up when accelerating strongly ?