Please Explain This: Fuel Flow Restrictions

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JAA17
JAA17
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Joined: 25 Aug 2017, 20:34

Please Explain This: Fuel Flow Restrictions

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I do not know what this means. I read somewhere that the fuel flow restriction (that was talked about this weekend) is bad. The person said the grid would totally be upside down with Honda having the best car.

Could someone explain as I have not got a clue what this all means? And why would Honda be number 1?
[Alonso Fan]

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subcritical71
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Joined: 17 Jul 2018, 20:04
Location: USA-Florida

Re: Please Explain This: Fuel Flow Restrictions

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I can hit on what fuel flow restrictions exist, the part about Honda being no 1 if there were no restrictions is complete speculation in my opinion.

The rules stipulate the maximum fuel flow allowed according to section 5.1 in the 2019 technical regulations. In a nut shell, above 10,500rpm it is limited to 100kg/h and below 10,500rpm it is dictated by a formula in relation to engine rpm. Exceed either of these and risk disqualification. Watching the on board videos it seems most teams run between 11,000 and 13,500rpm under acceleration.
5.1 Engine Specification :
5.1.4  Fuel mass flow must not exceed 100kg/h. 
5.1.5  Below 10500rpm the fuel mass flow must not exceed Q (kg/h) = 0.009 N(rpm)+ 5.5.

JAA17
JAA17
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Joined: 25 Aug 2017, 20:34

Re: Please Explain This: Fuel Flow Restrictions

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subcritical71 wrote:
30 Apr 2019, 15:18
I can hit on what fuel flow restrictions exist, the part about Honda being no 1 if there were no restrictions is complete speculation in my opinion.

The rules stipulate the maximum fuel flow allowed according to section 5.1 in the 2019 technical regulations. In a nut shell, above 10,500rpm it is limited to 100kg/h and below 10,500rpm it is dictated by a formula in relation to engine rpm. Exceed either of these and risk disqualification. Watching the on board videos it seems most teams run between 11,000 and 13,500rpm under acceleration.
5.1 Engine Specification :
5.1.4  Fuel mass flow must not exceed 100kg/h. 
5.1.5  Below 10500rpm the fuel mass flow must not exceed Q (kg/h) = 0.009 N(rpm)+ 5.5.
Thanks for the explination. But why do some people think that is bad? Why do others think it is good? Why is it even needed? Is it some sort of 'save the planet' kind of thing?
[Alonso Fan]

Jolle
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Re: Please Explain This: Fuel Flow Restrictions

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JAA17 wrote:
30 Apr 2019, 15:10
I do not know what this means. I read somewhere that the fuel flow restriction (that was talked about this weekend) is bad. The person said the grid would totally be upside down with Honda having the best car.

Could someone explain as I have not got a clue what this all means? And why would Honda be number 1?
Honda number one? I think you've read an article of someone that hasn't much real knowledge of the technical side of F1.

The background is maybe more important to understand the why. F1 is a sport where everything is restricted to don't let things get out of hand too much, just like any autosport. For instance, the width of the car, the minimum weight, etc etc and also the power output. In the past with natural aspirated engines this was done with the amount of air that could be used (the maximum capacity of the engine) combined later with a rev limiter. Because turbo engines aren't influenced directly by the capacity of the engine but more by the combination of boost pressure and capacity, they opted to limit the other side of the equation: fuel. This has a few advantages over an air restrictor or boost limit as we've seen in other series (like WRC and Indycar); there is no sudden boost fall when you pop the restrictor (As we've seen in Indycar in the past, it was almost a game to challenge the pop-up valve instead of fair racing) and it's more high-tech, going towards lean burn engines as we see on the road.

Without some kind of limiter, fuel or air, power output would be in theory, limitless. We've seen this in the early eighties where, in the few years there were no limits, teams melting their BMW engine in one hot qualifying lap with outputs of supposedly in exces of 1200 hp (mounted in a bendy aluminium frame). With current technology this would be even more extreme and has little to do with racing.