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Actually air is 78% nitrogen (http://www.webelemen...text/N/key.html) , so my replies were somewhat tongue in cheek ;-)
Chairs
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'Filling tyres with nitrogen' - big scam or what?
#2
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Posted 03 April 2003 - 12:31 PM
and mine... :twisted:
just goes to show you what bull$hit some people come up with...
just goes to show you what bull$hit some people come up with...
#3 Guest_Matt and Tiggr_*
Posted 03 April 2003 - 01:56 PM
Non bulshot reply now.
If a gas could be discovered that did not expand with heat, then that would be usefull, as it would mean that the tyre pressure would remain constant.
Problem is that this would in effect controvene Charles Law which states that as temp goes up, the volume must also increase ;-)
Bet Ferrari would put it in their F1 cars if it existed ;-)
If a gas could be discovered that did not expand with heat, then that would be usefull, as it would mean that the tyre pressure would remain constant.
Problem is that this would in effect controvene Charles Law which states that as temp goes up, the volume must also increase ;-)
Bet Ferrari would put it in their F1 cars if it existed ;-)
#4
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Posted 04 April 2003 - 09:11 AM
You can buy some things called "tyrelief" values which bleed air pressure from the tyre as tyre temp goes up... for some reason these are banned in a lot of motorsport rule books.
When rallying cold pressure would be set to around 26 psi and at the end of a 6 mile stage they would rise to over 35 psi...
If you want economy - try blowing your tyres up to 40 psi... the reduced contact patch would reduce rolling resistance (and also grip)
)
Using increased tyre pressures is also a trick used on rolling roads to show higher readings... as more power runs are performed the tryres get nice and hot (remember they are two contact patches per tyre on a rolling road). The power at flywheel is calculated during coast down - the lower the resistance the lower the losses and higher the BHP shown.
When rallying cold pressure would be set to around 26 psi and at the end of a 6 mile stage they would rise to over 35 psi...
If you want economy - try blowing your tyres up to 40 psi... the reduced contact patch would reduce rolling resistance (and also grip)
)
Using increased tyre pressures is also a trick used on rolling roads to show higher readings... as more power runs are performed the tryres get nice and hot (remember they are two contact patches per tyre on a rolling road). The power at flywheel is calculated during coast down - the lower the resistance the lower the losses and higher the BHP shown.
#5
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Posted 04 April 2003 - 09:57 AM
QUOTE
If you want economy - try blowing your tyres up to 40 psi... the reduced contact patch would reduce rolling resistance (and also grip) )
)I used to play around with tyre pressures to get cars to handle more to your taste...balance out understeer/oversteer...was an article in one tuning mag about 'free tuning mods' and this was one of them.
Ran my previous modded Puma 1.7 on 17s with front/rear pressures at 28/36...gave relatively tail-happy handling and little/no understeer :wink:
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