Installed a new set of Pilot Sport 4S on GT350R - completely lost that "sharp" feeling. Car does not feel stable anymore

[IainD90]

Try 32psi and a few more miles on them before giving up hope. I have 20" GT500-spec PS4S on my 350R and they still feel very sharp and crisp in terms of turn-in. But don't forget you are going from worn down near-slicks to fully treaded brand new street tires so there will definitely be a loss of sharpness.

They are currently at 32PSI. I will put some more miles on it and see what happens. I have a track day coming up in a few weeks, nothing crazy, giving ride alongs to kids for charity. But we'll see what happens when they heat up and increase pressure.

Like Champale said, give them a few miles to wear off the mold release compound. That's likely contributing to some of the undesirable behavior you're experiencing. I understand that the PS4 has softer sidewalls, so you may also need to add a pound or two of pressure to sharpen up the reflexes. What pressures are you currently running?

Currently running 32. I assumed it was the treadblock design. Although I had brand spanking new Pilot Superports on my old 2018 GT350 and they were very precise and not anything like what I'm experiencing with these PS4S. Also worth mentioning, these PS4S in OE GT350R sizes run much wider than the Cup2's. They are noticeable bulkier than their factory counterpart. I'm going to try 35PSI I think, but I don't want increased wear in the centre of the tire.

The PS4S is a tire I whole heartedly dislike. Yes, you need to scrub them in. Then, you need to find the least bad tire pressure. The sidewalls are shockingly soft on PS4S. This is surely a component of your feelings driving the tire. If you are really pushing the car, changes in swaybars or alignment might be needed to regain confidence.

Interesting that you don't like them - I actually have them on my VW Golf R and absolutely love them - it's why I wanted them so bad for the Mustang.

Time for some burnouts


I can't comment on the SC2s but I switched from PSS to PS4S last year (when I couldn't find PSS anywhere) and had the same thought: they are noticeably less "grippy". You're definitely not imagining things, pretty sure many here would agree.

I still like the PS4S tires though, they work for me... I just drive on the street, only ever going the speed limit, always obeying all the rules of the road

They are WONDERFUL street tires. I like to take it up to the cottage once or twice a year, and the Cup2's made that journey a handful. The PS4S is so much more relaxing and enjoyable to drive.

next time buy Supercar 3 or 3R and save money to boot. Michelin isn't the best tire.

Your observations are not unusual. Switching from corsas (somewhat similar to Cup2) to PS4S the latter are quite vague by comparison.

I almost bought the SC3R's. But I wanted more of a street tire. I have PS4S on my Golf R and I had supersports on my old GT350; I love both, so I figured PS4S on the 350R would be perfect. But it's not!

Recommended pressure for the street on my GT350 that originally came with PSS is 32 PSI, just FYI.

Yeah, I actually can't recall what pressure I had. I took that car to a track day like 3 days after I bought it, and after one session I came off track and reduced the pressure to about 32. Then I put it back to 35. It seemed fine afterwards.

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[Weather756]

I changed my cup2s to PS4S 295/35/19 all around. Not as precise as the cup2s but 9.5/32 on tread as opposed to 5/32 on cup2s. Just made a 1,000 mile trip to VT and the PS4S performed just fine. Less of a "pucker factor" in the wet. Nothing but street driving. Running 35 psi all around.

 

[Mustangford289]

 

[Mustangford289]

 

[Threebanger]

I think most of what you're feeling is the loss of feedback from the PS4s. I recently switched to SS from the SC2s and it's about the same. You give up that 'connection' to the road. Give it a few miles and you'll get accustomed to it again.

edit: just saw you've run SS before. I did read in comparisons that the SS outperformed the PS4s in every way. This is why I chose them (+ they worked extremely well @ Trak Attack).

https://comparethetire.com/michelin-pilot-sport-4-vs-supersport/

 

[brokenblinker]

I think most of what you're feeling is the loss of feedback from the PS4s. I recently switched to SS from the SC2s and it's about the same. You give up that 'connection' to the road. Give it a few miles and you'll get accustomed to it again.

edit: just saw you've run SS before. I did read in comparisons that the SS outperformed the PS4s in every way. This is why I chose them (+ they worked extremely well @ Trak Attack).

https://comparethetire.com/michelin-pilot-sport-4-vs-supersport/

Just wanted to highlight quickly that Pilot Sport 4 (abbreviated PS4 or PS4s for plural) is a different tire than Pilot Sport 4 S (frequently abbreviated PS4S for singular or plural). I wonder if that is creating some confusion in this thread....

I've been incredibly happy with my PS4S, but admittedly haven't tried the Cup 2s yet (sitting on my other wheels to mount as soon as car comes back from dealer).

 

[Weather756]

More info...

 

[JR369]

The PS4S is a tire I whole heartedly dislike. Yes, you need to scrub them in. Then, you need to find the least bad tire pressure. The sidewalls are shockingly soft on PS4S. This is surely a component of your feelings driving the tire. If you are really pushing the car, changes in swaybars or alignment might be needed to regain confidence.

OP has an R. So I seriously doubt changes to swaybars or any suspension components need or should happen.

OP,
I swapped out my Cup2 R tires for PS4's on my 18 R. 99% of my driving was local and street driving. I found the MP4S's to be very street compliant with soaking up bumps and pavement cracks and very little of the notorious tramline that is present from 15-18 GT350R's. That is what I personally wanted. A more daily friendly R to drive around in. If I were to push the R on a track the PS4's wouldn't be my tire of choice. Yes they don't grip and corner like the Cup2's. They are street friendly tire for sure.

 

[WItoTX]

The only thing not covered about the loss in feel going to the PS4 and PS4S is that the PSS is a garbage tires after a few heat cycles. I had them on mine with plenty of tread on them, and I might as well have had 500 TW tires. I ditched them for a real autox tire, but honestly anything would be better than those PSS. Good enough for street tires, but garbage if you use your 350 for its intended purpose.

 

[jmn444]

The only thing not covered about the loss in feel going to the PS4 and PS4S is that the PSS is a garbage tires after a few heat cycles. I had them on mine with plenty of tread on them, and I might as well have had 500 TW tires. I ditched them for a real autox tire, but honestly anything would be better than those PSS. Good enough for street tires, but garbage if you use your 350 for its intended purpose.

they are far from a competitive autox tire, but they are also very far from garbage as a track/street tire IMO. A cup 2 is slower than a new pss for me by day 3, so bang for buck the pss is better than a cup 2 aside from the 1st 2 days on track lol

 

[WItoTX]

they are far from a competitive autox tire, but they are also very far from garbage as a track/street tire IMO. A cup 2 is slower than a new pss for me by day 3, so bang for buck the pss is better than a cup 2 aside from the 1st 2 days on track lol

I think we agree LOL. Once they get some heat cycles, they turn rock hard. They work just fine on the road though.

 

[cmxPPL219]

Lots of great points above.
What I'd add to help answer OPs original question, is tire characteristics like ultimate dry grip, wet grip, breakaway, treadwear, etc., are always looked at, but often forgotten about sidewall stiffness.

In addition to what's been talked about here, a large part of what OP is describing as loss of "sharp" feeling, is due to the relative soft sidewalls of tires like PSS and PS4S, compared to SC2. The SC2, obviously it doesn't have to be said what it surrenders for greater ultimate dry performance-related characteristics at limit handling; sidewall stiffness (in conjunction with tread block design and compound type(s) of course) has a lot to do with initial turn-in response and how it translates to the feel in the steering wheel when adding steering angle.

I don't take mine to the track as often as I like, but even though I do more street driving, I've opted to keep the SC2s, because I also like razor-sharp steering response and have no qualms about some of the downsides of SC2s on the street. Having had tires in the class of PS4S/PSS and Conti ECS - really great all rounder street tires, great grip, and add a level of comfort back, but initial turn-in feel/response is too soft for my preferences, due to the relatively soft sidewalls - again, compared to something like the SC2. OPs reaction to the switch to PS4S is the same sort of reaction I had years ago, when experimenting with different tires, and resulted in me having certain non-negotiables and how I rate my tire characteristics preferences.

Hope that helps.

 

[Threebanger]

The only thing not covered about the loss in feel going to the PS4 and PS4S is that the PSS is a garbage tires after a few heat cycles. I had them on mine with plenty of tread on them, and I might as well have had 500 TW tires. I ditched them for a real autox tire, but honestly anything would be better than those PSS. Good enough for street tires, but garbage if you use your 350 for its intended purpose.

PSS is what they used @ Trak Attack. Worked great on the roval after a full day of drag, brake, and slalom class.

 

[SRT]

I will never buy a Michelin tire after two sidewalls blew out on potholes Pirellis would laugh at.

Had opposite experience, Pirelli p-zero grip was absolute shit. Had them in my 13 GT and 15 Viper. The Viper when it came time to taking them out and putting in PS4S, the debeading machine punctured all 4 tires of the sidewall on the pirelli. Absolute shit tire and well documented all over the internet.

 

[Mikepol2]

I took the Cup 2's off the Mach and replaced them with 305/30 and 315/30 PS4S, and must admit I too was expecting a little more sharpness with turn-in. I bought a set of 2000 mile OEM 2016 GT350 wheels and tires for the 2018 GT and seem to remember a much more noticeable handling improvement, although those tires weren't Cup 2's, and also I was coming from OEM PP1 wheels and tires. But yeah, thought these PS4S might handle a little better than this. Also noticed they get a little squirrelly feeling at the limits, not very confidence inspiring. But I don't really have anything to compare them to on this car.

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