a small brake upgrade

[dark_knight]

wider tire is NOT = more girp? hmmmm...

Change the tyres then to something softer. Or run 15x7 and a 205 tyre. Wider tyre doesn't give more grip, it just produces more drag due to the extra rotational mass.

AdamB.. really now..? wider tires don't give more grip..? really..? i guess i must have really dozed off in physics class about surface area and coefficients of friction then.. lol

 

[Rev]

- I think Adam is refering to the reduced pressure on the road effecting grip due to the greater tyre surface area. You may have cancelled the effect with the extra mass of your brake rotors , rims and wheels ?

- with 205/40/17 I rarely if ever wheel spin even in the wet .

- It takes a while to get going with 17's but the rolling momentum is tremedous useful on the open road not so in the city , I find stopping is the problem.

 

[dark_knight]

true Rev, although there's two ways to look at the grip issue, acceleration grip (given this is a fwd) and will lurch upward on launch.. &.. deceleration grip. i'd say wider tires may only affect you slightly on acceleration but will be a lifesaver when braking..

 

[Rev]

I didn't want to mention that as I know you are still in the testing stage but in a straight line dynamic loading sitaution should be good fun. It can also effect the handling dynamics and drive technique for curved roads but having driven outback myself and had a herd on cows come in front at 150kph in half light not to mention the kangaroos, I can see the bigger kit could be very useful for you locale.

 

[dark_knight]

the plan for these was originally to run cooler brakes for longer because the stock ones cooked way too quickly, esp after the td04.. so yeah, let's see how the test phase goes..

 

[AdamB]

AdamB.. really now..? wider tires don't give more grip..? really..? i guess i must have really dozed off in physics class about surface area and coefficients of friction then.. lol

I thought exactly the same as you mate, until a coversation cropped up on here and I learnt about it during chassis engineering lol.

The wider tyre only allows more heat to escape faster than a smaller tyre. Having a 900kg car on say 195 or 215 tyre's doesn't change the contact patch against the road surface. The only thing to change the contact patch is the mass of the car, or lowering the tyre pressures so that it spreads across the surface. However lowering the tyre pressures increases the frictional force and therefore temperature increases, so the need for a wider tyre is needed. F1 racers don't run wide tyres because they need grip, they run wide tyres because they have so much aero load pushing the car into the ground the tyres would overheat if they ran like 225 tyres.

 

[dark_knight]

so anyway, back to my brake build, the brembo kit brings in quite a bit of weight to the steering knuckle and despite it being unsprung weight, i think it will work in my favor to keeping the wheel planted. a road test and actual use in real life on the road will be the best judge.. so let's see..