seems like this ones opened up a can of worms.
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seems like this ones opened up a can of worms.
Less time spent on the internet and more time spent on Ste's car please :thumb:Quote:
Originally Posted by blacktopcustomsuk
With the wheels what was the original idea with having wheels wider at the back than front? How would it have affected the handling??
Crackin work :cool:
lol
The idea of wider back than fronts was mine and has been scrapped due to not really giving any advantages lol
After a bit of reading wider doesnt always = better grip so 7j are being used all round.
dont really know how to put this but .
wow !!!!!!
hat off to ya dude !
thanks kevin
lol not that im shooting you down, but surly more rubber on the floor always = more grip.
it would give more advantages in a RWD drive car as all the power is in the rears.
on a flip note, does that mean FWD cars should have wider fronts lol
awaits the fook off comments lol
Yes it does, that's why wider wheels don't always give you more grip. There's an optimum width for a set vehicle weight, obviously things like sidewall stiffness come into it, but basically the wider a wheel, the wider side to side, and the thinner front to back the contact patch becomes due to the fact the weight of the vehicle squashes the tyre against the floor.Quote:
Originally Posted by bmw156
a wide track has it's up's and down's but dont hold me to it ! lol
anyway this build is just as good as nick's , keith's,
and the fabrication is neer on par to the god austin ,:)
track width is the distance between the 2 wheels, not the width of either? Not sure which you meant. Pretty much anything you can change on a car has it's ups and downs, as they say you never get something for nothing.
just googled, and got this. seems interesting.
quoted
"We race a Formula car (Reynard) with 6 inch front and 8 inch rear..here is a recap of discussions about going to 8 inch front and 10 inch rear.
Downside of larger tires
More rolling resistance.
Harder to get heat in them.
More aero drag.
More unsprung weight.
Bigger wheels = heavier wheels and more rolling mass = equal or even slower lap times. The wider wheels (tires) have no proven advantage at all.
1 - The cars will accelerate slightly slower because of the greater MOI of the heavier wheels and tires.
2 - The cars will be a bit slower in a straight line because of the extra drag.
3 - Assuming that there is a diameter difference ( I honestly don't know - never looked at the spec comparisons), geometry may be adversely affected - camber curves may need to be VERY different.
4 - If the car was at max width with the smaller tires, with the wider tires offset inwards to match the max width, scrub radiuses will be adversely affected. Without making major changes to the upright geometry, this will necessitate caster changes that may be out of the range of available adjustment
5 - If the wider tires are used on a car that wasn't already at max width, the above doesn't apply, assuming that the center of the contact patch can be placed at the same widths, though caster changes may still be necessary for decent steering effort.
6 - If the tires have to place all their extra width inboard, suspension interference can become an issue, especially front lock availability. Front wing interference might also become an issue on many cars.
7 - Differences in lateral and vertical tire spring rate will necessitate different springs and shock valving ( already necessary because of the greater unsprung weight). These differences might also necessitate changes to the RC heights.
There's a lot more, but you should get the gist of what I'm saying : Just throwing on a wider set of tires proves NOTHING one way or the other. It is ONLY when the car gets optimized (which might necessitate cutting and welding) for the wider tires that you can start to get legitimate answers.
Aero footprint-wise, one of the biggest factors is the width of the contact patch, and therefore the width of the high pressure wedge of air that is being pushed just ahead of it. Wider = more drag (and lift). Some old SAE papers actually show that both ( drag and lift) can be decreased almost linearly with grooves in the tread, but obviously at the expense of contact patch area. Overall width played a larger role than height, but the percentage differences were small. The shape of the shoulder ( how square or round) played a major role.
The wheel design also will play a major role in aero drag - try a spin coast down test with different designs and you'll be in for a surprise.
The next big factor will be getting heat in the rubber - generally a bit harder to do with the bigger tires as the unit loading of the contact patch is decreased - but this can be overcome quite a lot with the right shock valving, and gets helped big time when the track temps are sky-high - when the skinny tires are more prone to over-heating unless you go to harder compounds. Fat tires will generally allow the use of much softer compounds, even in the high heat situations. Under these conditions, the fat tires will almost assuredly have a big advantage at tight, twisty tracks."
IIRC there comes a point were increased surface area does not equal increased grip, i'm sure there is an equation. Something to do with pressure per square inch, as the contact area increases past a certain point the grip actually decreases or something like that lolQuote:
Originally Posted by bmw156