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McLaren have chosen some interesting design routes on their new competitor. In addition to our own technical analysis, McLaren's Tim Goss and Paddy Lowe explain why some decisions have been made in light of the regulation changes.
I don´t get the reasoning why a big diffusser does starve of air at bigger ride heights...raymondu999 wrote:Yes, but look at their barn-door diffuser. That thing is just so big it starves at high ride heights, and that's a big reason why in qualy (when the fuel isn't weighing the car down and letting it go lower) McLaren have been generally weaker than in the race
Yes, diffuser can only "choke" at very low ride heights.marcush. wrote:I always thought it was the other way round...small ride heights -shallower difusser ramps needed to avoid separation?
It will be a balance between the amount of floor (I'm assuming a longer wheelbase car has a longer floor <- is it true???), and (induced) diffuser angle from raising the rear of the car. Both will give more down force, but I don't know which is better.marcush. wrote:I suspect the long wheelbase indeed does hamper the exploitation of rake to gain downforce...as you will of course need more rideheight at the rear to hold the car at similar rake angles compared to a shorter car.
First of all the cars are so stiffly sprung that the ride heights don't change due to fuel consumption as much as you think they do, less than a centimeter max. The reason why you might see an f1 car high off the ground is mostly to account for the weight of down force at speed. Secondly the purpose of a diffuser is to create a low pressure as air flows out from behind the car. Which means that bigger is better... You cant starve a diffuser by making it too big because the whole point of the diffuser is to allow air to flow as fast as possible under the car by creating a huge exit point.raymondu999 wrote:Yes, but look at their barn-door diffuser. That thing is just so big it starves at high ride heights, and that's a big reason why in qualy (when the fuel isn't weighing the car down and letting it go lower) McLaren have been generally weaker than in the race
Flow velocity will decrease as the volume increases. Of course, the constraint at the other end is choking it by making it too small.AbbaleRacing77 wrote:You cant starve a diffuser by making it too big because the whole point of the diffuser is to allow air to flow as fast as possible under the car by creating a huge exit point.
Exhaust flames indicate unburnt fuel being passed through the exhaust. As this energy is being wasted, it must play avoc with the fuel consumption.wrcsti wrote:I didn't hear the ignition but it was clearly used as exhaust flames lasted the whole way through braking and not just on downshifts as usual. Same thing on rbr and Ferrari.
This is what i hoped people would gather from my post in their heads without having to write so much.JMN wrote:Indeed, but it also improves throttle response and feeds the diffuser. Both of these effects allows you to get back on the gas faster, which is very noticeable on tracks such as Singapore. Furthermore you have the the increased cornering speed as the rear is less likely to slide. It is however perfectly possible they turned it down for the race compared to FP2 due to fuel consumption considerations. While retarded ignition does increase fuel consumption, I think it's fair to say it doesn't exactly waste the energy - it uses it in a maner that is less efficient, but has a critical impact on the way the car behaves while coming on and off the throttle.