[Swiss-Maserati]

My question is : what is the pressure you put on your front and rear tires when they are at temperature? with 19" wheels? with 18" wheels? with standard road tires? with semi-slicks like PZero Corsa?

Why? Some days ago, I went to the track. My tires was perfect on a grip point of view BUT, the side of the left front tires seems damaged... my tire vendor said me the front tires are dead and I must change them...

Left front tire, the side is not more readable:

 

[Swiss-Maserati]

Right front tire, to compare:



I just received some professional pics from the organizer, and I discover the left front tire roll over a lot !

FYI I used 2.4 / 2.0 bars on front / rear tires (at hot temp, after 20min on the track)

 

[willie]

OH MY GOD MAN,

you really, but really need to add air into that rubber, What was the tire pressure at the beginning of the session?

did you take the tire pressure at the end?

it really looks like you had no air in them and as a result this happened. a common mistake it to lower the pressure of your tires before you start on the track. always start with more than the usual and work your way down from that point.

remember that you can take air out as the session goes on, but it is really a bad idea to add cool air into a tire warm of the track. i use nitrogen when i go to the track and it works great, you can get it at almost any new tire shop and it controls the temperature far better.

remember to take the tire pressure after you have ended the laps, in an ideal world all of the tires would be at the same pressure. if one is higher that the other then you can take air out to match the rest. this will give you a more even balance and you will see that the car handles better.


of course everything that i tell you is subjective, this is just my experience as a races car driver and i know everyone has there own opinion, but in street cars this has worked for me... also this is advised based on the assumption that the cars suspension is in stock condition and that you haven't been playing with camber or toe setting.

hope this helps,

Willie

P.S. use shoe polish to mark your tires before you enter the track, and see at the end if the marks are still intact or how far are they gone.

 

[thebimbo]

Not very interesting.

 

[Swiss-Maserati]

@willie: I only remove (hot) air after a few laps... I begin with 2.2 (cold)... How much you put on your tires for track usage (front / rear, after a few laps so hot)?

@thebimbo: how much you put on your tires for road usage (cold, front / rear)?

 

[thebimbo]

I put in what it says in the GS handbook. I think it's 50 water melons to the front / 20.4 squeezed ants for the Pirellis but maybe not. Ask me again if u need this and I'll dig out the manual.

 

[Swiss-Maserati]

I will be pleased if you can open your handbook again, I have one for my Coupé GT but I have the GranSport 19" wheels with Michelin PS2 tires... Thanks in advance !

 

[CCPotenza]

The tip about painting a stripe across the tread with white shoe polish is a good one. Make sure you paint it onto the inside and outside siewalls, too. When the stripe wears out evenly, you're in good shape.

Ultimately, the best way to optimize tire pressures is to use a pyrometer ..... come off the track, jump out and measure the temperature of the tire across the treads and sidewalls. Getting the temps to be equal across the tread width is ideal.

 

[squid]

PUT AIR IN IT!! Yipes!!! I imagine you were getting a ton of understeer?

And you've got some cracks in the bead, not sure if it's related but I'd bet it is. I wouldn't be doing top speed runs on those tires in that condition...

 

[Swiss-Maserati]

PUT AIR IN IT!! Yipes!!! I imagine you were getting a ton of understeer?

No understeer, no oversteer... At limits, the car skid on the 4 tires, very balanced !

And you've got some cracks in the bead, not sure if it's related but I'd bet it is. I wouldn't be doing top speed runs on those tires in that condition...

"Craks in the bead"? I dont understand, english is not my mother language!
FYI I changed the front tires today...

 

[demoe]

this American think you are loco en la cabeza!

) but since I often travel at 250+km/h speeds on German autobahns (these days to reach these speeds it means travelling thru the night!*) it gives piece of mind that all is OK and I would add that every time there are at least some minor adjustments made on the alignment. * Zurich to before Frankfurt (420km) by night in 3 hours, early afternoon return took over 5 hours @#$!

250kmh!!!!! that is over 150 mph??.....Here in the States if I am lucky, will get an opportunity to hit 110 mph for a brief second.....Not sure if I would have the Cajones to sustain speeds over 150 mph on public roads.

 

[Swiss-Maserati]

250kmh!!!!! that is over 150 mph??.....Here in the States if I am lucky, will get an opportunity to hit 110 mph for a brief second.....Not sure if I would have the Cajones to sustain speeds over 150 mph on public roads.

California have "sea, sex and sun", Europa have German Autobahn... that's life!

 

[CCPotenza]

The Autobahn

About 15 years ago I picked up a new Mercedes E-Class at the factory. One day while on the Frankfort-Munich Autobahn I was blissfully humming along in the 3rd lane at 145 mph. I'm thinking this is GREAT, but I'm also brainlessly assuming that because I'm passing everything in sight that I'm the fastest guy on the road.

Suddenly something catches my eye ...... it's the frantic flashing of ...... OMG! .... a car that is bearing down on me like a missile. I only have time to look over my right shoulder and yank the car into the middle lane. The Lamborghini Countach must have been going 195 when he went by, then over the horizon and out of sight in just moments. Most indelibly, I will NEVER forget the sound of that car when it flew by.

Ahhhhh, the Autobahn. What a wonderful place.

 

[thebimbo]

.....Not sure if I would have the Cajones to sustain speeds over 150 mph on public roads.

No way Jose!

 

[Swiss-Maserati]

Some other pictures if you are interested :

 

[Swiss-Maserati]

 

[bundas]

highway high

would be nice to open up car without being locked up forever, old euro. does things nicely.

 

[Steeldream]

Coming home from Denver after picking up the new Spyder I hit 165 indicated on a couple of flat, straight stretches in Utah. The car felt like there was still some go left, my resolve said there wasn't.

Car hasn't been lowered and the front end was pretty light at that speed. I don't know I'd want to drive at that rate for very long, not to mention topping it out!

On the other hand, Marlene, my co driver, noted after a stint that "120 feels like 90".

 

[bundas]

is the president watching

these days any hint of,, Beeep, might trip a signal, how about that. 163 in fifth, with power to go. can top out at pocono coming out of turn before pit and hold down thru two turns, banked, befor standing on brakes.