tire stem blowout...

Scary!!

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Screw in stem? That suggests the stem threads gave way.. or there may have been a crack in the metal stem. Either way.. very unusual..

 

Stem valve is screwed in. Who ever changed ur tire should replace the stem as they often leak with age and then fail if loose. I have not heard of it popping out but it is possible since it just screws in

 

If it is a standard rubber push in type valve stem then someone has replaced it. These high performance cars need the metal valve stems that have a nut on the outside to lock the stem into the rim. My Ferrari indie mechanic just replaced four tires for me and I asked him if he replaced the stems. He said not necessary -- just replace the cores.
Alan

 

Bingo. Rubber is for ordinary cars. Its possible the rubber degraded or worse.. wasn't truly the right size for the hole!

 

I had the same thing happen to me on the FIRST day I owned the car. Apparently the transporter guy strapped the rim over the valve stem and damaged it. I didn't notice it at first and took the car for a spin. After about 20 miles of driving, all of a sudden it let loose! Thankfully I was only about 1 mile from my house, and I was doing only about 20 mph when it happened (I was doing about 90mph just minutes before!). I was able to quickly pull over before it fully deflated, so there was no rim damage.
I had to have my wife bring out a jack and tools to me so I could remove the tire. Unfortunately it was a Sunday on Fathers Day, so places were closing up. The only place that was open was Costco. I transported the tire there and they fixed it in minutes. They were able to replace the stem without any damage to the rim, and they did it for free!!
I got VERY lucky that it all worked out, but boy, what an adventure being that it was my first day with the car.
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I would not trust the pull in rubber type. High performance car manufacturers don't put the screw in types for no good reason. Definitely get those replaced as soon as possible.

Read this:

Tire Valve Types, Components and Uses

While there are three basic types of tire valves: rubber snap-in, high-pressure snap-in and high-pressure metal clamp-in, it's the vehicle, required tire inflation pressures, driving conditions and wheel design that dictate which type valve is appropriate for the application. The Tire and Rim Association in the United States has assigned valve design numbers for the various types and dimensions.

In order to complement wheel styling, valves can be fitted to the wheel in any position from horizontal to vertical. Nearly horizontal valve alignment is the most common and used by many wheel manufacturers to accept valve mounted tire pressure monitoring system transmitters. While tire valves will operate at any angle, valves mounted in a vertical axis used at high speeds are more likely to experience pressure loss due to centripetal forces depressing the valve core and allowing air to escape.

Tubeless Rubber Snap-In Valves

Tubeless rubber snap-in valves allow a maximum cold tire inflation pressure of 65 psi and are designed for passenger car, light-duty trailer and light truck applications, as well as are suitable for use in autocross competition. Rubber snap-in valves are available to fit either .453" or .625" diameter holes in the rim and have effective lengths ranging from 7/8" to 2-1/2". While most rubber snap-in valves use a plastic cap, some are fitted with chrome sleeves and metal caps to help complement the appearance of custom or alloy wheels.

Tubeless Snap-In Valves for High Pressure

Tubeless snap-in valves for high-pressure applications are designed for medium and heavy-duty trucks and trailers and must be used when recommended cold tire inflation pressures exceed 65 psi. High-pressure snap-in valves for .453" rim holes allow a maximum cold inflation pressure of 80 psi while those for .625" rim holes allow a maximum cold inflation pressure of 100 psi. Typically used in steel wheels, high-pressure snap-in valves combine a thicker rubber snap-in base with a metal barrel and a plastic cap. Effective lengths range from about 1-1/4" to 2".

High-Pressure Metal Clamp-In Valves

High-pressure metal clamp-in valves can be used with virtually any wheel and are highly recommended for all track activities, as well as when vehicle speeds may exceed 130 mph. Metal clamp-in valves use a rubber grommet to seal against the wheel when their retaining nut is tightened. While metal clamp-in valve design and styling can result in retaining nuts hidden inside the wheel or visible outside, those with the retaining nut on the outside offer a practical benefit of allowing retaining nut tightness to be checked and adjusted without having to remove the tire from the wheel. Metal clamp-in valves allow a maximum operating pressure of 200 psi and are available to fit either .453" or .625" rim holes, as well as specialty applications, such as 6mm (.236") or 8mm (.315") holes. Metal clamp-in valves use a metal cap and have effective lengths ranging from flush to 2" and are offered in straight or bent configurations to fit wheels with unique shapes. Low profile and lightweight alloy clamp-in valves are also available for racing applications.

Valve Cores

Regardless of the valve type, the valve core is the fundamental sealing device and should be snugly screwed into the valve core chamber. Valve cores come in short and long lengths, with the short length being preferred for high performance applications.

Both nickel-plated and brass valve cores are available. The nickel-plated valve cores must be used in the aluminum valve stems of tire pressure monitoring sensors because using a standard brass valve core in an aluminum tire pressure sensor valve stem will experience galvanic corrosion and the brass valve core will eventually seize in the valve's aluminum barrel.

All valve cores feature a seal attached to a movable, spring-loaded pin that allows pressurized air to pass when inflating a tire, as well as air to escape when the pin is depressed to unseat the seal. While valve cores themselves can accept a working pressure of 300 psi, it is important to protect them from grit, sand and moisture. Grit and sand might prevent valve cores from sealing completely, and moisture can freeze in cold temperatures and defeat the seal.

Valve Caps

High-speed pressure loss and core contamination are several of the reasons why valve caps should always be used. In case anything disrupts the valve core's seal, the valve cap provides a backup seal that prevents air from escaping. And while using valve caps will make it take longer to check tire pressures in the pits at a racetrack, the consequence of having a tire lose pressure is much worse.

Three types of valve caps are available: plastic dome, metal dome or a metal "screwdriver" design used to tighten and loosen valve cores. The plastic dome caps are fine for normal driving and autocrossing, however they should be replaced with metal valve caps to withstand the high temperatures experienced during racetrack driving. Valve caps are knurled to make it easier to tighten or loosen them, while some metal caps feature hex head designs. Metal caps use a rubber washer or o-ring to seal the valve completely.

If the valve cap is missing, it is best to press the valve core momentarily to release a little air before checking or adding air pressure. This will allow the compressed air inside the tire to blow debris out of the valve. Avoiding moisture is more difficult to address, because it is often hard to find a consistent source of dry air. Checking or adding air tire inflation pressure outside in the middle of a snowstorm is not recommended unless absolutely necessary.

1st -- Tubeless Rubber Snap-In Valves
2nd -- Tubeless Snap-In Valves for High Pressure
3rd. -- High-Pressure Metal Clamp-In Valves
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Here is the Ferrari one:

174166 VALVE/TIRE : Ricambi America

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Thanks Daniel. It would be almost impossible for this to blow out.
Alan

 

^ I'm not sure which wheels are on your car. If you can email us ([email protected]) or call us (336-499-2500) we can help further.

 

My BBS modular wheels also came from the factory with rubber stems.

 

The metals ones should fit the BBS modular w/o any problem.

 

Are you sure?
The reason I say that is because the base of the stem is recessed through the spokes. I can't see the base of the stem. I'm not sure that there would be enough room for the stems mounting bolt collar to fit in the hole of the spoke, especially not enough to tighten the collar down. I think the spokes on those rims can be separated from the outer rim without losing air, that's why it's deep in there...
I attached a photo, you can see what I'm talking about. I have no experience trying to fit metal stems, I'm just throwing it out there as a possible issue.
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I was incorrect. 184240 is correct for the modular wheel.

184240 BBS TIRE VALVE : Ricambi America

I'll get a picture later today.

 

Here's a couple (yes, pretty bad) pictures from when I had to buy one (because of stolen valve cap). It is a rubber snap-in valve.
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So BBS are recommending a rubber valve stem for a car that can achieve 170MPH which is contrary to the tire manufacturers recommendations -- metal screw type where the vehicle can exceed 120MPH.
Alan

 

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Interesting, my 184240 replacement valve didn't have BBS logos on the silver plastic caps. Nor do my OEM valves.