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Discussion Starter · #1 · (Edited)
Michelin PS2 owners how much PSI F/R?

I ask because when I picked up my car from the alignment shop today (tires mounted and full alignment), they were running almost 43 psi in all tires.

On my F1s, I ran 30/30 cold and it felt pretty good for me.

I almost immediately brougt the tires tires down to 30/30, but the sidewalls felt pretty soft to me overall.

Also, does anyone know if my dropping the tires down this much (43psi-30psi) adversly effect the alignment? I can only assume that they aligned at 43.

Thanks for your input!

-7
 

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Discussion Starter · #2 ·
Update:

I spent some time yesterday/evening playing around with pressure settings and found that the best overall in general was (as others have mentioned in the past) + 2psi to the front.

Although trying to give them as much time to cool off as possible, I settled on 34F/32R (semi-warm).

This morning before dirving I re-checked the pressure and found that I was more like 30F/28R. I went ahead and brought them up to 32F/30R and took it for a spin. So far so good.

Observations: (note also impacted by a new alignment which I'm still getting used to.)

-The fronts are very direct/positve and turn in very quickly. Do not feel soft in the sidewalls nor do they tend to plow. I suspect that the alignment has something to do with this as well. So far, very impressed with these tires on the front, yet to show me any bad habits. Very sticky tire.

-The rears are also very sticky. They lock in nicely behind the fronts and haven't stepped out yet. Overall, they do not feel as direct as the fronts though and I'm trying to figure out if this is my alignment or if I simply need to put more air in there. You can feel them settle a bit before the really lock in, but once they do, they really, really grab. One other note, the rears do screech when pushed...again not sure if this is the alignment.

So, far I'm very happy with these tires...

I will post my alignment details in my next post, perhaps some one can provide some input.

-7
 

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Discussion Starter · #3 ·
Requested an aggressive street aligment that would not completely tear up my tires.

Alignment Details:
Front Left:
Caster: 6.2
Camber: -0.3
Toe: 1/32"
SAI: 9.0
Included Angle: 8.4

Front Right:
Caster: 6.4
Camber: -0.3
Toe: 1/32"
SAI: 9.4
Included Angle: 8.7

Total Toe Front: 1/16"

Rear Left:
Camber: -0.3
Toe: 1/32"

Right Rear:
Camber: -0.3
Toe: 5/32"

Total Toe Rear: 1/32"

How does this seem?

-7
 

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Discussion Starter · #5 ·
OneQuickCoupe said:
Did you go with the stock sizes?

D.J.
Yes 265 front 295 rear on stock wheels.

The more I drive the car the more concerned I'm becoming. It does feel pretty lose back there compared to the previous alignment and F1s. I do not think that it is the tires though.

Obviously, there would be a compromise of straight line stability vs. cornering, but it feels almost like the cambered the rear to increase front turn in, but it just doesn't feel right. You can actually feel the rear shift over into a grip state and that's when the noise begins.

-7
 

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se7en said:
Yes 265 front 295 rear on stock wheels.

The more I drive the car the more concerned I'm becoming. It does feel pretty lose back there compared to the previous alignment and F1s. I do not think that it is the tires though.

Obviously, there would be a compromise of straight line stability vs. cornering, but it feels almost like the cambered the rear to increase front turn in, but it just doesn't feel right. You can actually feel the rear shift over into a grip state and that's when the noise begins.

-7
I'm sure you have already thought of this but when you filled your tires to make up for the low cold pressure you now may be 2 pounds to high when they are warm. This is good data on these tires as mine are on order and haven't mounted them on my car yet. I have a new set of PS2's stock size coming any day now.

D.J.
 

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Ya, good info on the tires. Mine should be coming any day as well.
 

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Discussion Starter · #8 · (Edited)
OneQuickCoupe said:
I'm sure you have already thought of this but when you filled your tires to make up for the low cold pressure you now may be 2 pounds to high when they are warm. This is good data on these tires as mine are on order and haven't mounted them on my car yet. I have a new set of PS2's stock size coming any day now.

D.J.
I had thought of that, hence the question in the original post. Not sure what to do just yet. I'm sure that you'll be happy with these tires, they've got a mountain of grip and then some more, they're quiet (I felt like I was driving a hummer for the last few weeks that I had the F1s on), and very smooth as well.

I have no regrets regarding the purchase, but feel that I haven't quite found my way just yet regarding alignment or pressure.

I'd be curious to hear your thoughts after your have come in.

BTW: they rate max pressure on these things @51psi.
 

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se7en said:
Yes 265 front 295 rear on stock wheels.

The more I drive the car the more concerned I'm becoming. It does feel pretty lose back there compared to the previous alignment and F1s. I do not think that it is the tires though.

Obviously, there would be a compromise of straight line stability vs. cornering, but it feels almost like the cambered the rear to increase front turn in, but it just doesn't feel right. You can actually feel the rear shift over into a grip state and that's when the noise begins.

-7
I wonder if the shop that aligned your car would let you put it back on to see if something has changed. I think I would give it a shot. They may charge a small fee to check or do it free.
You will be at what you believe is the correct tire pressure vs the extremely high pressure they aligned it at. It may not make any difference but would be a good reason to check it, and would give you the opportunity to see if some of the spec's have changed.

D.J.
 

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I run 32 on the street and 35 on the road course.

265X35X18 front and 335X30X18 rear.

Several thousand miles and showing a good wear pattern.

These are Michelin Pilot Sports and not the 2s I'll replace them with but I'm sure the pressures are in the ball park.

Pat
 

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Discussion Starter · #12 ·
OneQuickCoupe said:
I wonder if the shop that aligned your car would let you put it back on to see if something has changed. I think I would give it a shot. They may charge a small fee to check or do it free.
You will be at what you believe is the correct tire pressure vs the extremely high pressure they aligned it at. It may not make any difference but would be a good reason to check it, and would give you the opportunity to see if some of the spec's have changed.

D.J.
I have no problem taking the car back to them nor paying for a new alignment for that matter.

What I don't want to do is go in there whining about how it doesn't feel quite right without a bit more specific direction and perhaps a bit more knowledge from one of the forum in-house alignment gurus.

Anyone?

-7
 

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se7en said:
I have no problem taking the car back to them nor paying for a new alignment for that matter.

What I don't want to do is go in there whining about how it doesn't feel quite right without a bit more specific direction and perhaps a bit more knowledge from one of the forum in-house alignment gurus.

Anyone?

-7
Sounds like a plan. No whining here. I haven't tried anything other than a stock alignment and that was after I lowered the car. Still waiting on my tires. Maybe I'll have news today.

D.J.
 

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Discussion Starter · #15 ·
Update:

So, I brought the car back into the alignment shop yesterday and they were very cool.

The shop owner was pissed that they had filled the tires as much as they had. Appsrently had warned them in the past...

I brought in some of the past alignment settings threads from Z06 (thanks forum & Subdriver!). He also had someone else (much more experienced) perform the alignment.

Prior to bringing the car in, I brought the psi down to 30/30 cold.

At the shop, the guy doing the work said that he felt that I might be happier with 34-36F and 32-34R on these particular tires. So we went with 34/32 for starts.

Let me just say that the new alignment makes a world of difference! The car is still quicker to turn in than stock, and I can really feel the rears lock in. Lots of fun to drive.

Overall, the sidewalls on the ps2 do not feel as stiff as the F1, so even though the rears really hold the car down, it doesn't feel like I'm holding as sharp a line. I will continue to play with the pressure from this point until I find the right mix.

Thanks for all of the input folks, and if you'e interested, I can post my current alignment specs.

:z:
 

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se7en said:
Update:

So, I brought the car back into the alignment shop yesterday and they were very cool.

The shop owner was pissed that they had filled the tires as much as they had. Appsrently had warned them in the past...

I brought in some of the past alignment settings threads from Z06 (thanks forum & Subdriver!). He also had someone else (much more experienced) perform the alignment.

Prior to bringing the car in, I brought the psi down to 30/30 cold.

At the shop, the guy doing the work said that he felt that I might be happier with 34-36F and 32-34R on these particular tires. So we went with 34/32 for starts.

Let me just say that the new alignment makes a world of difference! The car is still quicker to turn in than stock, and I can really feel the rears lock in. Lots of fun to drive.

Overall, the sidewalls on the ps2 do not feel as stiff as the F1, so even though the rears really hold the car down, it doesn't feel like I'm holding as sharp a line. I will continue to play with the pressure from this point until I find the right mix.

Thanks for all of the input folks, and if you'e interested, I can post my current alignment specs.

:z:
Thank you for posting an update. Looks like you may have the problem resolved.

Ha, lets get the less experienced guy to align a Z06? I guess the guy has to learn sometime. Just not on my car.

Good Luck
 

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Discussion Starter · #17 · (Edited)
OneQuickCoupe said:
Thank you for posting an update. Looks like you may have the problem resolved.

Ha, lets get the less experienced guy to align a Z06? I guess the guy has to learn sometime. Just not on my car.

Good Luck
Stuff happens I suppose. They came strongly recommended from a corvette specialist but I guess were not necessarily corvette specialists themselves. At the end of the day I suppose the only thing that really matters is that they did their level best to make things right and in my mind they did.

The car drives great now, even though I'm still playing with tire pressures a bit. I will say that the more I drive on them the more I love the PS2s!

I would restate what I have mentioned earlier in this thread, they do seem to work better (for me) with more pressure than the F1s. Right now I'm running 34/34 and I swear I could do a u-turn @ 65 (okay maybe a little exaggerated).

:guiness:
 

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se7en said:
Stuff happens I suppose. They came strongly recommended from a corvette specialist but I guess were not necessarily corvette specialists themselves. At the end of the day I suppose the only thing that really matters is that they did their level best to make things right and in my mind they did.

The car drives great now, even though I'm still playing with tire pressures a bit. I will say that the more I drive on them the more I love the PS2s!

I would restate what I have mentioned earlier in this thread, they do seem to work better (for me) with more pressure than the F1s. Right now I'm running 34/34 and I swear I could do a u-turn @ 65 (okay maybe a little exaggerated).

:guiness:
I almost did that at the track going into second gear one night. I had my head hanging pretty low after that episode. I could see down the track out of the passenger window. Not Cool.

D.J. :eek: :eek:
 
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