Auto Tyre Pressure regulation

[jamsbong]

Hi guys,

http://www.youtube.com/watch?v=hxmcG4xCjlE

http://www.selfinflatingtire.com/how-it-works.html

This is a great tech that should be implemented in F1. That way you can go out in stone cold tyre at the right pressure and still maintain the same inflation level when the tyres are red hot.

Or this tech is already banned?

[Jersey Tom]

Except the tires go out pre-heated, already hot.

Interesting idea though.

[jamsbong]

Of course you won't go out with cold tires with u have a choice.
When you can push hard and the tire becomes over-inflated and thus loosing grip because the contact patch between road and tire is reduced.
Moreover, when it starts to rain and safety car comes around, the tire loose pressure and thus looses structural strength.

you will have less worry about it with this tech.

I think F1 teams can debate this in terms of safety aspect.

[andylaurence]

What does it weigh? What will the difference in unsprung weight and rotational inertia do to lap times?

[jamsbong]

Thats a good question. Looking at their design, it looks simple and appears to be compatible as an add-on to existing wheel. There will be additional weight maybe 100g if you made it out of exotic materials...

I Speculate that the extra weight is worth it as a safety feature + more consistent tires behaviour.

[marekk]

Not sure how relevant to F1, but if this technology works, it could save many lives and billions of dollars on saved fuel. Know many people not checking their tyre pressure other then when switching form summer to winter and vice versa - if at all.

[nacho]

I wonder how it would work in racing with tyre loading changing very frequently and heavily?

[jamsbong]

the tire pressure should be the same. the tires would deform but the pressure won't change much, i think.

[Richied76]

This product is useless and will never work. For arguments sake a road car. U begin your journey with slightly low pressures and as you begin to to drive it begins filling your tire. Then you hit the motorway and gain speed to which your tires have TO MUCH volume of air but at a standard pressure. If you drive hard and gain alot of heat in the tire then pull up on your driveway to a stop. As your tires cool they will end up just as under inflated, if not more than when you left the first time.
Besides the valves will always be working, they will inflate a warm tire (heat generated by the under inflated tire in the sidewall) with cool air which will either expand the air inside or cool it.
If it can bleed off air it will be venting warm air then filling with cool. There would be no constant and it would be terrible for a race car.

I could see this product being of huge hinderance in very hot or cold climates.

I know your probably going to shoot me down but volume and pressure are to different things when tempature is involved
They don't say in owner manuals "inflated tires when they are at ambient temperature" for no reason

[jamsbong]

The system maintains the tire pressure. Not just inflate the tires indefinitely. When the pressure is higher than the adjusted value, the system will deflate the tire to correct the pressure.
So... I think it will work.

From the video, it seems there is no info on how to deal with over inflating tires. I would have thought they have a valve that releases on over pressure. I suppose it is not difficult to add this bit. Certainly a lot easier than self inflating system.

[Richied76]

But that's what I'm trying to say. It will be dumping warm low volume air with cold air from outside.

Think of a race start. Low volume of air in the tires but as there at 80c they are at correct pressure. They begin to cool so as the race starts they begin to fill, but by the 2nd lap temperature increases so it becomes over filled and has to dump more air. Behind a safety car the tires will cool and fill up... Then at the restart, unless they can react super fast they will be more like motorbike tires come the 1st corner.

but anyway I'm sure they will "work" prefect at the restart behind a safety car in the middle of a wet race when there full of water

[Lurk]

They say it could work with electronic valve. I don't think its difficult to measure tyre temp, tyre pressure and external temp to calculate the right mass of air to get in or out.

[Smokes]

It Peristaltic pump, One perstaltic pumps flow is plusating. the Hose occulsion will vary depending on is the tyre in under or over inflated. when the tyre is inflated to pressure any fluid in the hose needs to be vented as with positive displacement pumps the fluid need to be displaced. Flow rate is going to be affect by rpm occulsion size dimeter of the hose.

It will take energy from the wheel and it will affect sidewall flex.

If you can program a valve to open and close quick enough you may have a winner

[Richied76]

i still thing introducing a valve that can open on a tire inducing wet/humid/dirty/spent exhaust gas is a bad idea on a race car. Plus electrical?....so 100g per wheel, plus 500g ecu+ wires. soon adds up.

The risk isnt worth the reward. Say at a pit stop the valves dont pair with the ecu wirelessly especialy if its only one tire, you'll have some self regulating and some not.

Biggest problem for me is RULES. ajusting pressures in race using anything other than mechanical operation via the driver is the only system allowed..

Road cars...yes....MAY BE. Race cars....big no no