mini roundabouts and 355's

I would definately say that the tires are suspect. As many have already pointed out (which is why I asked how old your tires were in the first place), they will degrade over time regardless of use. I personally haven't had a set of tires last long enough to find out (especially on the Ferrari) but the compound will tend to harden. When this does, the tire essentially loses its grip and it is entirely likely that when you added throttle the lack of grip was the result of bad tires.

How did you determine that they were 7 years old, based on the date stamp, or have they been on the car for 7 years? (In which case they are probably a bit older than 7 years).

 

I had Expedias on on my car (348). When I went to buy a replacement set found out that they had been discontinued. Found out through a tire supplier that they had a set that was sitting in a warehouse somewhere. I decided against it as I figured there was a good possibility that they had been sitting for a while.

I have yokas on it now (acquired the tires when I bought a set of rims). I haven't put many miles on the car since the new tires and wheels went on, but so far very happy with them. If you do a little searching on here, there are many threads with reviews for tires. Good luck! Post pics!

 

Nobody thinks it might be the LS differential?

 

No, unless only in combination with the tires that don't have adequate grip. I've added throttle during many tight turns at more than 25% throttle (granted, I'm talking 348 with less power, but I have to imagine that 50% throttle or better would be a reasonable comparison and have not had the rear end kick out on me when I didn't want it to. Now when others have been driving my car, that is a different story all together!!

I guess to get a better picture of what happened, about how much steering input, what gear were you in, and approximately how fast were you going?

If the steering input was extreme, and you were at a slow rate in first gear, I would say it would be more likely than if you had moderate steering input, at a moderate clip, and in 2nd or 3rd gear.

 

Not that there is a problem with the diff, just that the diff would be LS or Limited Slip.

 

Okay, second gear with a fairly hard left, and I'm assuming the throttle input was fairly sudden?

If I were a betting man, I'd say its the tires.

 

Try it again. I bet there was something on the road, sideways at 15mph with a touch of the throttle, the tyres would have to be as hard as plastic.

 

Michelin PS2 is what I put on my car. Nice ride, good grip, low noise. So far I love them.

John

 

I'm using the same (owner's manual) numbers for tire pressure as before with the Pirellis. Can't recall the #s, but nothing remarkable. Perhaps some of the guys with lots of track use could shed light on pressure adjustments and effects on handling at the limit on the 355, but in normal "street use" the OM pressures seem to be just fine.

John

 

This happened in my 348.....completely fishtailed in a round about....very scary but fun!! I needed TIRES!!

There is no problem with your car other than TIRES...