458 not stable at high speeds

Tyres are the obvious start, old or small cracks

 

Indeed, but first tell us more about the car ... (and yourself too please, f.i. your name)

 

My 458 spider at 150 was as solid as a rock. The steering wheel felt a little loose and not real confidence inspiring up there. But it was fine. No idea where l would go faster so l haven't.

I recommend good tires properly warmed up for any car.

 

Wheel alignment or something loose.

 

Did you check to see if your tire pressures are off. It sounds like either your tire pressures are set too high, or your tires need replacing.

 

I've done 165 and it was stable as can be

 

My F430 and SCUD is stable at 130mph. Havent done it with my Special.

But my 3 series is stable at 130, start with tires. makes a big difference at high speed.

 

Atta boy!

 

These cars can be taken to 200 mph without serious stability issues. I know cases first hand where friends have crossed 200 mph and myself have come pretty close to 200 (yes i get scared a bit more easily and let off the accelerator). It's not so much fun going that fast in a straight line though, vs doing the twisties at lesser speeds.

Get your car checked. It may have some issues perhaps even minor like tires etc...

 

Get it checked out! Vibration issues can be caused by tires etc but a side to side movement like you are describing with steering wheel is not something you should have unless something like heavy wind or road issues. Sounds like something is loose or worn.

 

I've had mine at 185 mph, no stability issues at all, but as expected the front end does feel a little "lighter." Also have to remember to keep steering movements very, very small and gradual. (not sure if I was excited or scared, but it was awesome!)




Jim

 

What tire pressures are you running cold?

Also, which mode was the car in and did you have the bumpy road suspension decouple on or off?

Ray

 

Here we have all sorts of Ferrari drivers admitting open that they proceed at speeds illegal in many jurisdictions, but the police never come here and listen?

Hmmmm???

 

All on tracks.

Iwas parked today with my top down in front of my house. A local cop drove up, smiled and said: lt would be fun to chase this car on the open road. How fast will it go?

I replied: about 200 mph. He said: l'd never catch you. Beautiful car. Have a great day...and drove off.

 

How many miles on the current tires?

Some years ago, I had some strange vibration problems on my motorcycle. I had a heck of a time figuring out what it was. In the end, it turned out to be worn tires. Another time, I started having this really bizarre handling issue; turned out to be tire pressure.

What you might consider is to increase the tire pressure up to maybe 32 psi at all four corners (cold) and then quickly do a run and see if the car is smooth at speed - before the tires get completely up to temp. Obviously, be very careful and keep it to a straight line on private roads or a run way or something.

I would also jack the car up and check for play in the suspension members at all four corners. Check to make sure all lugs are torqued also.

Having uneven tire pressure in the rear might not be a good idea; I wonder if that might throw off the e-diff or something?

Also, personally I would not trust the tire pressures on the Ferrari display. It's an okay guide but I set my tire pressures when cold using a very accurate analog pressure gauge and then just use the TPMS as a indication of if anything has changed or if I have picked up a nail or something.

Ray

 

Did you watch Le Mans? A 458 won the Am class. That's a pretty nice statement about the speed agility and reliability of the car.

Maybe watch the race to see if the 458 was unstable.

Since you want to run your car at the limit, you will need to be sure everything is tuned for this. Get better tires, check your suspension set up, and then work with professionals who know about racing at these speeds.

You bought a fantastic sports car. With some work, you will have a race car optimized for track racing.

 

The steering wheel moving back and forth sounds like unbalanced wheels to me. Check to see if a wheel weight is missing or maybe consider having the balance checked.

I've never balanced car tires myself. But like anything else, it's usually difficult to find people who are losing as much sleep over how everything is done on your car as you are. I do balance my own motorcycle tires and in that area I spend a lot of time getting it done right (usually 45 minutes to an hour per tire) because it can make a huge difference. I also have carbon fiber wheels, so that magnifies errors.

Just to give you an idea of the motorcycle tires, I balance them to around a 1/4 of a gram. That's about the weight of a coffee bean or maybe a 1 inch strip of scotch tape. The method I use is to find the heaviest section of the wheel (without the tire) then mount the tire so that its heaviest part of the rubber is offsetting the heaviest area of the wheel. Once the tire is mounted in the correct orientation, then I static balance it to about a 1/4 of a gram in all locations. I also take into consideration the rotors and titanium fixing bolts, which I balance on the wheel, but then have to remove and replace while mounting the tires.

And don't forget the weight of the plastic valve stem cap...

I've thought about making my own static balancer for car tires, but haven't gotten around to it just yet.

Since vibration appears to be involved, I'd definitely inspect the wheels to see if all the weights are present.

Ray

 

Oh I also meant to post this.. It shows the suspension mode settings relative to the manettino.

I have noticed the handling isn't quite as sharp in sport mode or with the bumpy road on. I drive my car almost always in the CT OFF mode (the click above race). I don't know about anyone else, but I personally wouldn't be going over 125 in any mode below race - although the car should be able to go fast and feel stable in any mode. The fastest I went in my 360 was 155 and it felt very stable and smooth. I would think the 458 should be even better.

Ray
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All good advice. I'll never use anything other than a quality pressure gauge to adjust the pressure.

To the OP. Which tyres are you running? Bridgestones, Pirellis or Michelins? What time of day did you measure the 30, 30, 28, 27 pressures?

 

Having been to 195+ in my 458 coupe and 180+ in my Speciale Aperta
I can confirm they are all inherently light on the front end above 150
No matter what tyres, or settings.
Just my 2 cents.

 

First, as noted by others, most of us are on tracks when we run at those speeds, I don't put others on the road at risk when I'm driving. Second, it wouldn't matter at all even if some folks were on the street and their post was seen by the police. Being a recovering lawyer, and former Prosecutor, you cannot be ticketed for admitting to speeding "after the fact." You must be caught during the act (by the police, or camera device). Even a neighbor saying they saw you speeding is not enough. So...thanks for the concern, but we're all good here.



Jim

 

Yup, that's what I found as well, but certainly controllable with proper high speed driving skills.




Jim