49 replies to this topic

[WhiteBlue]

http://www.racecar-e...s-10-more-fuel/

Renault blown floor uses 10% more fuel
By Sam // April 6, 2011

Renault R31
Renault Sport F1 has revealed that during the Australian Grand Prix Red Bull and Renault used 10% more fuel than normal. The blown floors prevalent in the field this year mean that engine and exhaust management is even more crucial than in previous seasons. To power a blown floor effectively and generate additional downforce, an engine must produce significant amounts of exhaust gas. Simply put, the more fuel burned, the more exhaust is produced and potentially more downforce. “Since the RS27’s fuel consumption rate is extremely good, the Renault-equipped teams were able to burn 10% more fuel than normal during the Australian Grand Prix without running out of fuel, therefore giving more exhaust flow to its partners using the blown diffuser” a Renault release revealed.

The Ferrari 056 is thought to have the highest fuel consumption in Formula 1.

I think that 10% more fuel consumption is considerable. It is not in the interest of the sport to increase fuel consumption. I expect that something will be done about it in the future.

Edited by WhiteBlue, 06 April 2011 - 14:00.

[Ross Stonefeld]

They all run in fuel conservation mode for the majority of the race anyways, almost no one starts with a completely full tank. *shrug*

[dau]

What.

[Risil]

Design an engine with better fuel consumption, like Renault have, and you'll see a benefit in terms of downforce generated? Sounds like an ideal green-racing initiative to me.

Unless 'encouraging lower fuel consumption' means that teams get extra championship points for every litre of fuel they return to at the end of the Grand Prix weekend.

Edited by Risil, 06 April 2011 - 14:08.

[arknor]

its not the fuel in the race that really counts...

its the massive amounts of fuel it takes to get everything to and from a race weekend

[Fastcake]

I hope not, that's a plain stupid idea. Tough if you don't like it, if you want to have a lower fuel consumption then design your car better, the way it should be.

[hotstickyslick]

http://www.racecar-e...s-10-more-fuel/


I think that 10% more fuel consumption is considerable. It is not in the interest of the FIA to increase fuel consumption. I expect that something will be done about it in the future.

Fixed.

[undersquare]

That's quite interesting.

Suppose Lewis' floor stay hadn't broken in Oz and he'd been able to pressure Sebi all race and make it hard for him to save fuel?

This issue is presumably why we saw Vettel sit on quite a small lead.

Edited by undersquare, 06 April 2011 - 14:36.

[F.M.]

Interesting that they get more performance when running with 15-20 kg additional fuel to generate extra downforce than to run 15-20kg lighter.

[Ferrari2183]

No, who cares.

[MadYarpen]

[Scotracer]

No. They wont ban something - if it increases the performance by a greater margin than the cost of carrying extra fuel then it's not a waste.

[Requiem84]

Interesting that they get more performance when running with 15-20 kg additional fuel to generate extra downforce than to run 15-20kg lighter.

My thoughts exactly. 10 kgs of fuel equals about 0,1-0,2. They must get a huge amount of downforce from the FEE to make this work.

[MadYarpen]

Hey, why don't we ban Ferrari engine? It is more thirsty I think!

[Ross Stonefeld]

My thoughts exactly. 10 kgs of fuel equals about 0,1-0,2. They must get a huge amount of downforce from the FEE to make this work.

You'll get a hell of a lot more than .250 a lap from better aero.

[FNG]

its the massive amounts of fuel it takes to get everything to and from a race weekend

This is why I will never ever take F1 and green seriously. Who cares what the cars are doing on track, it's a pittance compared to the energy used to transport everything. In the years that we had the US GP they never ran it back to back with the Canadian GP. They would fly back to Europe in between. Talk about a waste of energy!!!

[H2H]

Let us try to collect the important facts:

a) The exhaust blown into the diffusor can significantly increase the overall volume and speed of air in this critical aero, thus increasing downforce greatly.

b) The exhaust only increases downforce significantly when fuel gets ignited

c) Downforce is of most importance in corners to obtain higher cornering speeds, but those are the places where full throttle can be counterproductive

So far this is "free" downforce, as "free" as a turbo, meaning that of course you have to invest a lot into this solution and that you suffer in other regards, but that you gain afterwards a premium in downforce. But possibly the whole investment is only worth it when you can do also something about c) even if you have to make additional investments and sacrificies. So what?

d) In some ways (engine mapping) you can keep up the ignition of fuel to increase the downforce of the diffusor without (fully) powering the rear wheels. In this case a very considerable amount of fuel has been used that way.

I suspect that Red Bull and Renault have designed their cars from the start up with the intent to use those considerable amounts of fuel to provide that "extra" amount of downforce in slower, non-full throttle corners. If we consider that some circuits need less amount of fuel it is clear that such tracks, just as Oz will be the prime targets of heavy "exhaust boosting". This aspect among others made KERS for RBR also less important, as they had not to rely on fuel saving achieved by it.

P.S: This might one of the reasons why the initial pace of RBR was not so superior to McLaren during the first phase of the race as in Q3, where their weight was of course surly almost indentical. If RBR carried at the start, let us say, 20 kg more than the KERS-powered McLaren than the close gap would make much more sense. The quick heating of the tyres and the quicker degradation of them would fit neatly into this picture, although it can not explained only by that.

Edited by H2H, 06 April 2011 - 18:00.

[Ali_G]

Let us try to collect the important facts:

a) The exhaust blown into the diffusor can significantly increase the overall volume and speed of air in this critical aero, thus increasing downforce greatly.

b) The exhaust only increases downforce significantly when fuel gets ignited

c) Downforce is of most importance in corners to obtain higher cornering speeds, but those are the places where full throttle can be counterproductive

So far this is "free" downforce, as "free" as a turbo, meaning that of course you have to invest a lot into this solution and that you suffer in other regards, but that you gain afterwards a premium in downforce. But possibly the whole investment is only worth it when you can do also something about c) even if you have to make additional investments and sacrificies. So what?

d) In some ways (engine mapping) you can keep up the ignition of fuel to increase the downforce of the diffusor without (fully) powering the rear wheels. In this case a very considerable amount of fuel has been used that way.

I suspect that Red Bull and Renault have designed their cars from the start up with the intent to use those considerable amounts of fuel to provide that "extra" amount of downforce in slower, non-full throttle corners. If we consider that some circuits need less amount of fuel it is clear that such tracks, just as Oz will be the prime targets of heavy "exhaust boosting". This aspect among others made KERS for RBR also less important, as they had not to rely on fuel saving achieved by it.

P.S: This might one of the reasons why the initial pace of RBR was not so superior to McLaren during the first phase of the race as in Q3, where their weight was of course surly almost indentical. If RBR carried at the start, let us say, 20 kg more than the KERS-powered McLaren than the close gap would make much more sense. The quick heating of the tyres and the quicker degradation of them would fit neatly into this picture, although it can not explained only by that.

But weren't McLaren also using a blown diffuser, although not via the crazy design they originally wanted to go with ?

[Villes Gilleneuve]

Let us try to collect the important facts:

The underscoring was not condescending enough, please draw us a stick figure.

[Bunchies]

They are using engine energy to create downforce using underfloor aero. They are moving to ground effects soon. Craig Scarborough asserted on the latest episode of Peter Windsor's "The Flying Lap," that the turbocharged engines from the 1980s were able to use the EBD twice as effectively because of the increased exhaust gases that come with turbocharged engines. The Exhaust blown diffuser and the blown floor, then, seem to be natural evolution of the aerodynamics away from wings and towards ground effects. It would be difficult to believe that these devices would be banned when they could be crucial to the development of GE technology. Rotary engines output huge amounts of exhaust gases, and can drive huge turbines for their tiny size. These would be ideal for continued aero and GE exhaust scavenging.

[Ali_G]

The underscoring was not condescending enough, please draw us a stick figure.

H2H comes out with one of the most insightful posts in the thread and you come out with this crap ?

[Ali_G]

They are using engine energy to create downforce using underfloor aero. They are moving to ground effects soon. Craig Scarborough asserted on the latest episode of Peter Windsor's "The Flying Lap," that the turbocharged engines from the 1980s were able to use the EBD twice as effectively because of the increased exhaust gases that come with turbocharged engines. The Exhaust blown diffuser and the blown floor, then, seem to be natural evolution of the aerodynamics away from wings and towards ground effects. It would be difficult to believe that these devices would be banned when they could be crucial to the development of GE technology. Rotary engines output huge amounts of exhaust gases, and can drive huge turbines for their tiny size. These would be ideal for continued aero and GE exhaust scavenging.

There will be a fuel flow limit with the 2013 engine formula so the teams will have a play off between power and downforce, if diffusers are still allowed.

There's always the chance that with running two underfloor venturi's that diffusers may be banned at the rear.

[TURU]

There will be a fuel flow limit with the 2013 engine formula so the teams will have a play off between power and downforce, if diffusers are still allowed.

There's always the chance that with running two underfloor venturi's that diffusers may be banned at the rear.

LOL WUT

Have you ever and I mean ever, seen a F1 car without a diffuser?

[Scotracer]

LOL WUT

Have you ever and I mean ever, seen a F1 car without a diffuser?

Yes. In the late 70s/early 80s.

[Ali_G]

LOL WUT

Have you ever and I mean ever, seen a F1 car without a diffuser?

Yes. Cars that have venturi's generally don't run with rear diffusers as they don't compliment each other.

Edited by Ali_G, 06 April 2011 - 18:40.

[Ali_G]

Yes. In the late 70s/early 80s.

I doubt before the Lotus 78 if any car ran with diffusers.

I'd say they first appeared on cars for the 83 season ?

[Scotracer]

I doubt before the Lotus 78 if any car ran with diffusers.

I'd say they first appeared on cars for the 83 season ?

I 'unno, I didn't follow F1 that far back

[H2H]

But weren't McLaren also using a blown diffuser, although not via the crazy design they originally wanted to go with ?

IIRC Scarb wrote somewhere that McLaren (Mercedes) might have trouble with the exhaust management. In any case RBR (Renault) came up with this idea first, or better, evolved it first into the modern concept, so they could still have an advantage in this regard. It is also quite important to note that the Lotus Renault is now pretty much built around the forward exhaust and might rely potentially the most on the additional downforce created by the "extra" ignition of fuel. As other teams are going towards the RB7 solution, Renault covers propably the two most effective approaches of using that "extra" fuel consumption.

So if we consider the central role in planning of those two solutions I am convinced more than ever that getting the most out of those two exhaust designs was considered key. So both teams and Renault might had very similar goals.

P.S: It is pretty much impossible to say how much more fuel, if at all the RB7 or the R31 carried at the start. While the Renault engine is said to consume less then the Mercedes and the thirsty Ferrari, those two and the R31 had all, if different, KERS systems - while the RB7 had none.

Edited by H2H, 06 April 2011 - 19:12.

[Bunchies]

There will be a fuel flow limit with the 2013 engine formula so the teams will have a play off between power and downforce, if diffusers are still allowed.

There's always the chance that with running two underfloor venturi's that diffusers may be banned at the rear.

Certainly! The turbos, though, should help with the efficiency in this respect, as they should move much more exhaust gas while providing minimal losses in fuel economy. The negative byproduct will be heat, which could see numerous engine blows from tight packaging.

[FranDaMan]

Doesn't turbo anti-lag also produce increased exhaust flow?

[Scotracer]

Doesn't turbo anti-lag also produce increased exhaust flow?

Not necessarily - only if you put another fuel injector in the exhaust flow. Most racing engines have massive valve overlap so you get fuel in to the exhaust even on 0% throttle and then with the air injected you get combustion, ergo turbo spooling.

[pingu666]

one method is injecting fuel to get antilag, you cant do that on a f1 car (a seporate injector)

[FranDaMan]

I hope we see that. F1 needs cars that spit two foot long sheets of flame on the overrun

[Scotracer]

I hope we see that. F1 needs cars that spit two foot long sheets of flame on the overrun

Without a Turbo, anti-lag is irrelevant

[FranDaMan]

Without a Turbo, anti-lag is irrelevant

But they're coming in 2013, right? That's what I was getting at.

[ionutz2oo0]

armchair engineering.

[seahawk]

I think it should be used as a reason to forbid those EBDs. The exhaust should be 2 round openings 20 cm above the reference plane and 40 cm back from the end of the diffusor.

[zztopless1]

I think it should be used as a reason to forbid those EBDs. The exhaust should be 2 round openings 20 cm above the reference plane and 40 cm back from the end of the diffusor.

Oh I agree! Innovation, creativity and improvements in general have no place in a sport like Formula 1...

[Ross Stonefeld]

That assumes that EBD are the only form of innovation, creativity, and improvement in modern grand prix racing.

[Lazy]

I think it should be used as a reason to forbid those EBDs. The exhaust should be 2 round openings 20 cm above the reference plane and 40 cm back from the end of the diffusor.

I disagree, the exhaust is wasted energy. If they can use it efficiently to get dragless df they will need less wing so in the long run efficiency should be increased. With the added bonus of causing less turbulence for the following to deal with.

Using exhaust for df should be encouraged maybe with restrictions on overun but, with the disadvantages of carrying extra fuel around, the teams will be highly motivated to minimize fuel used for this so regulation should be unnecessary.

[H2H]

In any case RBR (Renault) came up with this idea first, or better, evolved it first into the modern concept, so they could still have an advantage in this regard. It is also quite important to note that the Lotus Renault is now pretty much built around the forward exhaust and might rely potentially the most on the additional downforce created by the "extra" ignition of fuel. As other teams are going towards the RB7 solution, Renault covers propably the two most effective approaches of using that "extra" fuel consumption.

So if we consider the central role in planning of those two solutions I am convinced more than ever that getting the most out of those two exhaust designs was considered key. So both teams and Renault might had very similar goals.

P.S: It is pretty much impossible to say how much more fuel, if at all the RB7 or the R31 carried at the start. While the Renault engine is said to consume less then the Mercedes and the thirsty Ferrari, those two and the R31 had all, if different, KERS systems - while the RB7 had none.

The really interesting part about that 10% increase in fuel consumption over "normal" levels is that it is only the overall increase. Why?

In Oz you are going full throttle about 65% of the time. The intrinsic value of the EBD and the highly efficient aero of the RB7 increase that somewhat, but for the sake of simplicity let us keep that number and keep other things like KERS, fuel saving etc out. This means in very simple terms that for 2/3 of the time the car is already consuming as much as it can. So the overall increase of 10% falls entirely into the remaining 1/3 of the time (spent in breaking zones, some corners), meaning that in those areas roughly 30% more fuel is consumed than normal.

Quite a number, to be sure and a hefty investment in fuel, but one which allocated the money right in downforce where it counted...

Edit: I do think now that a 30% increase in fuel consumption in that 1/3 is far too conservative. The 2/3 part on full throttle should of course have a far higher share in overall fuel consumption then the 1/3 with none or part throttle. So, if for example the car consumes in those 2/3 of lap time 9/10 of the overall fuel, than the fuel consumption of that critical 1/3 might well be doubled by the use of the retarted ignition to power the EBD.

Edited by H2H, 07 April 2011 - 09:24.

[Ross Stonefeld]

In any case RBR (Renault) came up with this idea first, or better, evolved it first into the modern concept,...

Didn't Benettons have this feature in the mid 90s?

[One]

make a smart design to use less fuel and waste in exhaust power? Then the system as total is not smart at all. Ban it, as idea is to shout for efficiency. Or else, there will be more pressure from Green Peace.

[Sukhoi]

i can't understand how anyone could say a word about banning it , better take care about F1 shipment , one airplane flying from europe to asia , carrying F1 cars , drivers , parts , whatever else , burns more fuel than whole F1 during one season.

also , some people here looks simply pathetic , "thier" teams haven't came up with similar idea so they want it banned.. that's how i see it atleast in one case..

Edited by Sukhoi, 07 April 2011 - 11:29.

[Risil]

Didn't Benettons have this feature in the mid 90s?

According to Scarbs it was introduced by Renault in 1983. Seem to remember that one of the Mclaren designs of the late 1980s used the technique to great effect as well, possibly Gordon Murray's one.

Jean-Claude Migeot:

Exhaust blowing was on my menu of aero development during the first year of the flat bottom era (1983) as one possibility to recover some downforce. I was in Renault at the time in charge of aero and, after some checks on the engine bench as we were terrified to face another lag time (!) between throttle movement and downforce creation, I was given the green light to experiment in the tunnel. Exhaust blowing to create a fluid skirt on the side of the car (also tested early 1983) did not worked but blowing the rear diffuser was quite powerful (I remember something like 50 kg on the rear axle at full throttle whatever the speed).

I don't think F1 car design has really fundamentally moved on since exhaust blowing was the fashion in the '80s: perhaps normally aspirated engines make the exhaust gases less useful for generating downforce, and in general there have been more efficient ways of getting the aerodynamic characteristics your car needs. But as these more efficient ways have been gradually outlawed, I suppose it's inevitable that designers will turn to the more arcane ones. After all there are no new ideas, only inappropriate ones.

Edited by Risil, 07 April 2011 - 12:28.

[STRFerrari4Ever]

No, No, No they don't need to be banned all this green bull needs to go away seriously.

[boldhakka]

The really interesting part about that 10% increase in fuel consumption over "normal" levels is that it is only the overall increase. Why?

In Oz you are going full throttle about 65% of the time. The intrinsic value of the EBD and the highly efficient aero of the RB7 increase that somewhat, but for the sake of simplicity let us keep that number and keep other things like KERS, fuel saving etc out. This means in very simple terms that for 2/3 of the time the car is already consuming as much as it can. So the overall increase of 10% falls entirely into the remaining 1/3 of the time (spent in breaking zones, some corners), meaning that in those areas roughly 30% more fuel is consumed than normal.

Quite a number, to be sure and a hefty investment in fuel, but one which allocated the money right in downforce where it counted...

Edit: I do think now that a 30% increase in fuel consumption in that 1/3 is far too conservative. The 2/3 part on full throttle should of course have a far higher share in overall fuel consumption then the 1/3 with none or part throttle. So, if for example the car consumes in those 2/3 of lap time 9/10 of the overall fuel, than the fuel consumption of that critical 1/3 might well be doubled by the use of the retarted ignition to power the EBD.

Great post. This would imply medium-speed corners are the worst offenders in terms of fuel efficiency. Slow-speed corners mostly rely on mechanical grip, so there's no need to blow the diffuser as much, while high-speed ones already have the throttle open most of the way so there's enough exhaust gases blowing the diffuser already.

[Kimiraikkonen]

Then... if RB run with KERS in Malaysia, will must be carry and 10% more of fuel?

Mclaren could be very near in terms of race pace and not far on qualy!!!

Go go go!!!

[MikeTekRacing]

you forget that kers will also bring a better lap time

[H2H]

Great post. This would imply medium-speed corners are the worst offenders in terms of fuel efficiency. Slow-speed corners mostly rely on mechanical grip, so there's no need to blow the diffuser as much, while high-speed ones already have the throttle open most of the way so there's enough exhaust gases blowing the diffuser already.

I agree mostly. Of course we don't have any way to know just how much fuel is spent to blow the diffusor without fully powering the wheels, but it seems that it can be a very considerable amount. 60% more for those turns might very well be too low. I don't know just how easy it is to fine-tune the extra diffusor blowing, but they might very well be able to fit the amount of extra-blowing to the specific circuit and track condition. In the simpliest case the extra blowing is activated by the lifting of the throttle, but the amount could get regulated before the race or by setting the fuel mix. So slower turns might also get their fair share of blowing or they might not.

Both cars have been partly built among the EBD, so they must also packaged them to allow for intensive use of the ******** ignition, meaning tanks, cooling etc. As the tank designed for the most fuel consuming track most other circuits would surly allow for a lot of extra fuel for this RIEBD.

Red Bull could be shock everybody on Saturday if they get KERS to work. KERS impacts the laps of Q3 more than once and allows RBR to carry a bit less fuel or to boost more. Maybe they will still shock them without KERS.

Edited by H2H, 07 April 2011 - 18:06.