Forum Replies Created
3rd February 2015, 23:29 at 11:29 pm #291627
To be honest horsepower is a bit of a meaningless figure since it doesn’t really translate into the actual power that the engine uses to turn the wheels, it’s rather a figure to measure the peak efficiency of the engine at its maximum output. The key issue is the fuel flow rate. If you think about the current F1 engines, they are allowed, within the rules, to rev to 16,000rpm. But again, this is a meaningless figure without the context of the fuel flow rate.
Fuel burns at its peak power when mixed with a specific amount of air, which is why on a small capacity engine, you need to hit high rpm to generate power, because the amount of ait going into the engine is determined solely by the movement of the pistons. We don’t know precisely what the ideal air:fuel ratio is for F1 fuel but let’s say was 13:1 (13 parts air to 1 part fuel). We know the maximum peak fuel flow allowed is 100kg/h then the maximum peak airflow is 1200kg/h. The displacement (cc) of an engine is the total volume of the swept area of all of the cylinders, so each rotation of the crankshaft sucks in a specific amount of air through the inlets.
On a naturally aspirated engine the peak rpm is the point where the engine is turning fast enough to draw in air at the rate required to achieve the correct air:fuel ratio for the maximum fuel flow rate (in our example, 1300gk/h). If the cylinders are large, each rotation of the crankshaft draws in a lot of air, so that peak airflow is achieved at a low RPM, whereas on a smaller engine, it will need to be turning faster in order to suck in enough air. So if you had a limit on the rpm of 20,000rpm in the technical regulations, but the peak airflow was achieved at 18,000rpm, then there would be no point in revving the engine much higher than that – you can’t physically burn more fuel than the maximum allowed flow rate, and otherwise you’re simply sucking in more air and screwing up the air:fuel mix and losing power.
Of course, here we’re talking about turbocharged engines, so it’s not just the movement of the cylinders drawing air in, it’s being pumped in at a rate much higher than that. But the result is still the same – peak power is achieved when the air is going into the engine at the rate of 1300kg/h, regardless of rpm.
Sorry, this is a really long and rambling way of saying that if they’re only revving to 13,000rpm, it’s because that’s the point where they’re making peak power, and revving any higher than that would not create any more power, because the maximum fuel flow rate has already been passed.
Obviously, fuel flow and rpm aren’t the only factors in how much actual power is generated. It’s a pretty inefficient system, so a lot of the potential energy created by burning the fuel is lost and not turned into actual twisting force at the output shaft. Specifically talking about F1, the faster the engine is turning, the more loss there is through friction, so it’s in their interests to generate the power at a lower rpm by using more boost from the turbo, than using lower boost at a higher rpm.
This really is the key to an energy-efficiency formula, because the level of actual power generated is determined by how effectively the engineers can minimise the amount of power that is lost through inefficiency. Or in the case of ERS, taking some of that lost energy and turning it into a form that can then be recycled back into the system. It’s the real reason why manufacturers are so interested in the engine formulas in F1 and WEC, because the technology designed to minimise inefficiency in their race engines can then filter down to their road car engines, making their road cars more powerful and more efficient.
Sorry for the massive, very boring and probably highly inaccurate post.3rd February 2015, 12:37 at 12:37 pm #291603
The regs are a bit hard to understand, but from what I gather, there’s a limit on the amount of energy which can be discharged through each lap, but no specifics on exactly how quickly that energy has to be discharged. So basically the restriction is on the max fuel flow rate to the ICE, and then how much energy can be used per lap. I think there are a few other rules regarding energy use over a stint etc. But basically what it boils down to is that you can either take a massive speed boost for a short space of time (like 1000hp for a few seconds) or take a smaller boost throughout the course of the lap. Being in the 8mj class, it means they have the biggest restriction on the amount of fuel they can use, but the biggest allowance of harvested power that they can use.
The reason they’ll have gone for the (seemingly baffling) FWD option for the ICE is actually pretty simple. The way that energy is harvested under braking is by using a recovery system attached to the driven wheels to slow the car down rather than the brakes. The more of the braking that can be done by the energy recovery system, the less power is lost, and the more energy is harvested. Most hybrid race cars are rear wheel drive, so only harvest from the rear wheels. This is not ideal really, as most of the braking is done by the front wheels – if you had a 50/50 brake bias you’d have a car that was pretty unstable under braking. So if you have a FWD car, you can harvest a lot more energy through the driven wheels than on a RWD car. Clearly Nissan’s thinking here is all around maximising usable power and efficiency for the best possible top speed, possibly at the expense of a little bit of driveability at the corner exit, and also probably as a bit of a compromise to the chassis layout.
It really is a very cool concept, and great to see them really thinking about the rules without making any assumptions about the kind of layout that’ll work best. As I said above, it’s abolutely consistent with Ben Bowlby’s ‘blue sky thinking’ approach that we saw with the DeltaWing and the ZEOD. Throwing ‘conventional wisdom’ in the bin, and thinking logically about an engineering problem with a blank sheet of paper, to come up with the best possible solution.
Actually, in answer to your question, I think that probably the 1250hp figure is a little bit conservative. I reckon at full tilt, the combination of the ERS and the ICE would be able to produce well over 1500hp’s worth, but only for a very short burst of two or three seconds. I suspect they’ll have a number of different harvesting and discharge options that they can use both in qualifying and throughout the race.2nd February 2015, 12:18 at 12:18 pm #291446
Well the car was finally officially launched yesterday. Looks like the rumours were true – not only is it front engined, but it’s actually front wheel drive (at least using the ICE). Looks a lot better with some paint on it, but it’s still a weird looking thing to my eyes. Kudos to Nissan though for thinking outside of the box, though that shouldn’t come as much of a surprise considering it is the brainchild of Ben Bowlby, designer of the mad DeltaWing.
Oh… and 1250bhp when it’s all turned up to 11…17th January 2015, 8:39 at 8:39 am #290369
My own interpretation which may or may not be in line with how the FIA will apply the rules, is that there is no ‘new power unit’ each time it is upgraded. The homologated power unit is he one they started with in 2014, and the development tokens will be applied against that, but won’t be considered part of the homologated baseline. So they can run any combination of upgrades at any point during the season, as long as the same spec is applied to every one of their PUs on the grid. There does not appear to be anything within the sporting or technical regs which defines at what point during the year any of the tokens need to be applied, nor that they need to be applied at the same time, or even that they need to remain applied for the entire season.15th January 2015, 10:58 at 10:58 am #290315
I could be up for this, if the races are weeknights. I can’t really do weekends unfortunately.
It’s worth noting that there have been a couple of similar championships run with people from here on the PRL forum, and there have been a few lessons learned – some of the performance factors on the LMP cars are a bit broken, giving certain cars a pretty hefy performance advantage. I think David-A probably knows the ins and outs, and would have some useful input on performance balancing (if you wanted to go down that route).
Might be an idea to set up a FB group or something?5th December 2014, 9:20 at 9:20 am #288129
I really wish they would get rid of the big gap after Le Mans. It’s the premier event of the season, and the race people are most likely to bother watching. It seems incredibly short sighted not to want to capitalise on all the excitement generated by the 24h by having a succession of races shortly afterwards.
I guess there is a need for a short break as the teams will need time to go back and repair/rebuild the cars after they battering they take, but I would have thought three weeks should be enough time, at the most. By the time the Nurburgring rolls around, people will have forgotten about it.27th November 2014, 17:16 at 5:16 pm #287555
I wonder how many other WEC/F1 rumours will come true.17th November 2014, 9:56 at 9:56 am #285908
The thing I just can’t get past is how much money has been wasted by the team’s management. The team have underperformed, and remained glued to the back of the grid. They bemoan a lack of budget, but how much money has been thrown down the toilet? How much money did it cost chasing the rights to the Team Lotus branding, not to mention the cost of uniforms, signwriting, vehicle wrapping etc? And then how much money was spent on legal fees in a futile attempt to keep hold onto that name? How much did they spend on buying a new factory in Leafield? And then how much was spent buying the Caterham car company? And also funding feeder series teams running the same branding? Think about how many tens or even hundreds of millions were spent by the team’s owners, all because their egos demanded that they had a recognisable brand name on their cars. Imagine what the F1 team might have been capable of had all of that money been ploughed solely into the development of the cars. They could have had the budget and performance of a solid midfield team, but instead the money was flushed down the toilet.
Companies and individuals have been left out of pocket for services they were never paid for. Hundreds of people are now facing unemployment right before Christmas. And while it’s really easy to bemoan the unfair distribution of prize money and commercial agreements in F1, the fact is that there should have been plenty of money to secure the future of this team for years to come, but was instead spent on pointless ventures. I feel sorry for the staff made redundant, and I feel terrible for the companies who have been swindled out of money by this bunch of cowboys. But the reason Caterham are in the mess they’re in is because they were run by people who thought it was more important to spend most of the money on the paintscheme of the car, rather than how fast it goes. People like that frankly do not have any business being in F1.16th November 2014, 10:10 at 10:10 am #285674
Unfortunately Caterham’s crowd funding has nothing to do with saving the team, and everything to do with securing the 10th place prize money for the administrators to pay off the creditors before the team is shut down. They’ve already laid off all the backroom staff (in addition o those they already made redundant earlier in the year) so the remaining ‘team’ is nothing more than the skeleton crew needed to make two cars appear on the grid at Abu Dhabi.
Nobody has saved anything.6th November 2014, 9:28 at 9:28 am #284120
I think it would be interesting to compare the overall race durations to try and work out an average lapspeed this year compared to last. While I think the ultimate outright laptime may be slower, but I have a feeling that over the duration of a race, the cars in 2014 are faster. With more durable tyres and less fuel saving, it feels like drivers are able to consistently push for more of a race, with less dropoff in tyre performance compared to last year.
Obviously there are other factors – track resurfacing, slight layout modifications, atmospheric conditions, etc etc. But I have a feeling that a 2014 car on 2014 tyres would now beat a 2013 car on 2013 tyres over a race duration.5th November 2014, 22:42 at 10:42 pm #283565
Hasn’t Intrlagos been resurfaced and had a bit of reprofiling of the corners?26th October 2014, 9:32 at 9:32 am #28030625th October 2014, 21:23 at 9:23 pm #280305
Audi have confirmed on their twitter feed that it’s all baseless rumours and they fully intend to proceed with their DTM and Le Mans programmes.13th October 2014, 16:39 at 4:39 pm #278692
I imagine that during the days of unlimited track testing, tyres were regularly pushed well past this sort of distance. But it may well be a record for the longest distance covered in a single stint during a GP.6th October 2014, 21:25 at 9:25 pm #277351
That is an absolutely horrific impact. Nearly lifts the truck into the air. At least having the weight of Sutil’s car off the front meant it did lift up. Without the weight of Sutil’s car hanging off the front it might not have lifted at all, and just totally flattned the Marussia.
It’s hard to see how anyone can survive that. Hoping for the best, but fearing the worst. :(