Using the DL1 Datalogger to police power
Discussion
Hi Guys,
We're currently evaluating the Race Technology DL1 Datalogger as a method of enforcing maximum power in our racing series (MR2 Championship). Since Britcar uses this method and has done for a while now, can anyone offer any feedback on how effective - or otherwise - the system is?
Thanks in advance!
Patrick
We're currently evaluating the Race Technology DL1 Datalogger as a method of enforcing maximum power in our racing series (MR2 Championship). Since Britcar uses this method and has done for a while now, can anyone offer any feedback on how effective - or otherwise - the system is?
Thanks in advance!
Patrick
RogueMotorsport said:
Hi Guys,
We're currently evaluating the Race Technology DL1 Datalogger as a method of enforcing maximum power in our racing series (MR2 Championship). Since Britcar uses this method and has done for a while now, can anyone offer any feedback on how effective - or otherwise - the system is?
Thanks in advance!
Patrick
Opinions on here will vary drastically with the axes that people posting will have to grind.We're currently evaluating the Race Technology DL1 Datalogger as a method of enforcing maximum power in our racing series (MR2 Championship). Since Britcar uses this method and has done for a while now, can anyone offer any feedback on how effective - or otherwise - the system is?
Thanks in advance!
Patrick
You'd be better off phoning JT and discussing it with him as he sees the system from the organisers point of view.
If all the cars arer identical, which presumably yours will be (assume all MR2's) or are very close to identical, and you have a standard ENFORCED mounting arrangement, it should be fine. The actual numbers may be off, but it will show up cars with more power than the others, which I assume is the point!
Thanks guys, and David - I'll be in touch.
I've only just realised that if this method of policing is not universally liked then I may be stirring up trouble which is not my intention. I am particularly keen to hear of any criticisms though (perhaps via email?), since these will be levelled at me as series co-ordinator!
I have got some big advantages over Britcar in that I've only got three MR2 chassis' to worry about and the location and fitment of the DL1 will be controlled - possibly even with a mandatory bracket. I do intend to make aero modifications free (within a virtual envelope around the vehicle) and I'm wondering how you guys deal with things like changing the angles on spoilers and canards etc, or do you just assume it's not going to make that much difference from the initial reading.
Cheers,
Patrick
I've only just realised that if this method of policing is not universally liked then I may be stirring up trouble which is not my intention. I am particularly keen to hear of any criticisms though (perhaps via email?), since these will be levelled at me as series co-ordinator!
I have got some big advantages over Britcar in that I've only got three MR2 chassis' to worry about and the location and fitment of the DL1 will be controlled - possibly even with a mandatory bracket. I do intend to make aero modifications free (within a virtual envelope around the vehicle) and I'm wondering how you guys deal with things like changing the angles on spoilers and canards etc, or do you just assume it's not going to make that much difference from the initial reading.
Cheers,
Patrick
The DL1 calculates power, CALCULATES is the key word here, through knowledge of the aero, cda. If you change wing angles, or indeed allow any aero change you are obviously changing this cda, or what you actually need is drag, factor. If you dont then remeasure the drag, the power figure will be out massivly! And here lies the problem of this form of tool. Remember also that, as not all the cars are the same aero wise, the actual VALUE of power now becomes important, whereas if all the cars are identical absolute values become irrelivant and you can just search for those with a higher figure than the rest. But as now the actual value has become important you need to measure other atmospheric factors, such as temp and pressure as these also have a bearing. Not hard to do at all, but just another thing that needs to be done!
Assuming that not EVERY car has been in a wind tunnel, EVERY car will need to do a coast down test. You need to be consistent here as some may have been in a tunnel, but you should use the value calculated by the device, or at least the SAME method for all cars. Now anyone can cheat a coast down test, but if policed it can be done reasonably well. Also remember that this needs to be done for EVERYONE at the SAME time, as again atmospheric condtions will change the outcome, and obviously if people change the aero on the car...
It depends on how accurate you want to be. If you are going to allow discrepencies of a reasonably large amounts, then it doesnt really matter what you do, but if you want to have an actual tool for policing the rules then you need to cover all your bases or you will have LOADS of complaints/issues on the day!
Just remember it works on sound laws of physics that do indeed work BUT crap in crap out!
Assuming that not EVERY car has been in a wind tunnel, EVERY car will need to do a coast down test. You need to be consistent here as some may have been in a tunnel, but you should use the value calculated by the device, or at least the SAME method for all cars. Now anyone can cheat a coast down test, but if policed it can be done reasonably well. Also remember that this needs to be done for EVERYONE at the SAME time, as again atmospheric condtions will change the outcome, and obviously if people change the aero on the car...
It depends on how accurate you want to be. If you are going to allow discrepencies of a reasonably large amounts, then it doesnt really matter what you do, but if you want to have an actual tool for policing the rules then you need to cover all your bases or you will have LOADS of complaints/issues on the day!
Just remember it works on sound laws of physics that do indeed work BUT crap in crap out!
Edited by CTR Arachnid on Thursday 11th June 18:50
we've run them in the TVR challenge for about 5years now.. orginally a lot of people didnt like them, but if you use them properly with the correct setup data for each car ( i.e. coast down tests etc) they do a good job. the software gets better and better too.. we've spent a fair bit of time with the guy that runs it for us taking the drivers through their data to show them what it can tell them... one of the original biggest skeptics is now one of the biggest fans..
if you dont do coast downs etc the figures will be out, and some feel there are issues with basic p/w classes however you police them but for your application same model cars and same weights etc it should be very simple... if you do it though sell the idea of the data feedback as well as the rule enforcing...
if your building a new car the cost of the logger and the dash you can plug into it is less than a decent set of guages !!!
cheers
Graham
if you dont do coast downs etc the figures will be out, and some feel there are issues with basic p/w classes however you police them but for your application same model cars and same weights etc it should be very simple... if you do it though sell the idea of the data feedback as well as the rule enforcing...
if your building a new car the cost of the logger and the dash you can plug into it is less than a decent set of guages !!!
cheers
Graham
There are a number of ways that I'm looking to play this. I'm hoping to allow a large amount of freedom in what people can do with their cars whilst still being able to keep a lid on the costs. The method currently used by Britcar and others is plan B - we know it works and we can fall back on it if the method I'm about to describe doesn't.
Performance Index:
Classes will be arranged by (what we will refer to at the moment as) power to weight - 150bhp/ton, 200bhp/ton and 250bhp/ton. There will be no minimum weight limit, which will allow people to make their cars heavier or lighter to meet the class that they want to be in. I'm making an assumption here that taking rolling resistance and CDa out of the equation for the moment, entering a weight of 1000kgs into the RT analysis software will return the cars power to weight, rather than the car's actual power. With me so far? To illustrate this, if we had two identical vehicles - one weighing 1000kgs and running 200bhp, and one weighing 500kgs and running 100bhp - both would give the same power reading in the RT analysis software (of 200bhp) if you entered a figure of 1000kgs as the weight.
Take that one step further and bring Drag into the equation. We know the baseline CDa ratings for each version of the MR2 which we can enter into the RT analysis software. From this point, if someone made their car more aerodynamically efficient (ie more slippery) then the RT analysis software would show a higher power figure in the above example. It is my intention to introduce the concept of a Performance Index (PI) that essentially incorporates power, weight and aerodynamic efficiency to arrive at a comparative figure for all of the cars. I believe that if the concept is sound then the PI figure will actually be a closer method of establishing equivalence than simply power and weight alone.
The only potential issue I can foresee is that a car could have aerodynamic devices that increase it's CDa - and therefore allow it to run more power to compensate - but that those devices in turn would create more downforce giving the car a handling advantage. I think I can legislate around this with the regulations governing size, type and location of aerodynamic devices. Rolling resistance shouldn't figure largely as all cars will be on the same controlled tyres, and sizes will be within certain parameters.
I'd be really keen to get some feedback about this idea - even if it's just to shoot me down in flames for my faulty understanding of physics!
Patrick
Performance Index:
Classes will be arranged by (what we will refer to at the moment as) power to weight - 150bhp/ton, 200bhp/ton and 250bhp/ton. There will be no minimum weight limit, which will allow people to make their cars heavier or lighter to meet the class that they want to be in. I'm making an assumption here that taking rolling resistance and CDa out of the equation for the moment, entering a weight of 1000kgs into the RT analysis software will return the cars power to weight, rather than the car's actual power. With me so far? To illustrate this, if we had two identical vehicles - one weighing 1000kgs and running 200bhp, and one weighing 500kgs and running 100bhp - both would give the same power reading in the RT analysis software (of 200bhp) if you entered a figure of 1000kgs as the weight.
Take that one step further and bring Drag into the equation. We know the baseline CDa ratings for each version of the MR2 which we can enter into the RT analysis software. From this point, if someone made their car more aerodynamically efficient (ie more slippery) then the RT analysis software would show a higher power figure in the above example. It is my intention to introduce the concept of a Performance Index (PI) that essentially incorporates power, weight and aerodynamic efficiency to arrive at a comparative figure for all of the cars. I believe that if the concept is sound then the PI figure will actually be a closer method of establishing equivalence than simply power and weight alone.
The only potential issue I can foresee is that a car could have aerodynamic devices that increase it's CDa - and therefore allow it to run more power to compensate - but that those devices in turn would create more downforce giving the car a handling advantage. I think I can legislate around this with the regulations governing size, type and location of aerodynamic devices. Rolling resistance shouldn't figure largely as all cars will be on the same controlled tyres, and sizes will be within certain parameters.
I'd be really keen to get some feedback about this idea - even if it's just to shoot me down in flames for my faulty understanding of physics!
Patrick
the dl1 will not give you the p/w it will give you the power figure.. you'll then need to divide that by the weight yourself.. iirc
the weight is used on the dl1 to allow it to calculate the power.. as you know the power is actaually the work required to accelerate a given mass. this is then refined using the drag and cda figures..
if someone makes a car slipper then if you used the same drag figure as someone else ( assuming same weight) it would show more power that the other car, as acceleration would be greater for the same mass. as the resistance to a draggier car is higher it needs more power.
I think you'd find it difficult to balance aerodynamic efficiency as all you can measure really is the drag... and an aerodynamic efficient car would have low drag and high downforce, but another car could generate the same downforce but have more drag, and a standard car could easily have more or less drag than one with a wing...
might be possible though... have you got a logger? you can download the software and play with it from the RT site for free. they also run trg courses for free, and im sure if your considering them for the series they would loan you a logger.
G
the weight is used on the dl1 to allow it to calculate the power.. as you know the power is actaually the work required to accelerate a given mass. this is then refined using the drag and cda figures..
if someone makes a car slipper then if you used the same drag figure as someone else ( assuming same weight) it would show more power that the other car, as acceleration would be greater for the same mass. as the resistance to a draggier car is higher it needs more power.
I think you'd find it difficult to balance aerodynamic efficiency as all you can measure really is the drag... and an aerodynamic efficient car would have low drag and high downforce, but another car could generate the same downforce but have more drag, and a standard car could easily have more or less drag than one with a wing...
might be possible though... have you got a logger? you can download the software and play with it from the RT site for free. they also run trg courses for free, and im sure if your considering them for the series they would loan you a logger.
G
In simple terms the powerlogger measures the speed at point 'a', the speed at point 'b', the time it took to get from 'a' to 'b' and the rate of acceleration during this time. If the analysis software knows how hard it was for that object to move (weight, rolling and aero drag) it can then calculate the power output at the wheels. It's those 3 values you need for it to perform the calculation. As you mentioned the Crr will be pretty much the same for all your cars and actually has very little impact on the result. The CdA will make a differance from car to car but altering the rake of a wing for example doesn't make as much differance to the final result as most people think it will. If you have a percentage window to make allowances for this then this will give you accurate enough results to give you an indication if anyone is cheating or not.
The system allows you to go into great detail with determining the power output by compensating for weather, gradients etc. so you can be as detailed as you like in your analysis.
the system has it's detractors and it's champions but it will give you accurate results if you feed it with the correct data and you have the advantage of a full datalogging system in the car as well which will be of massive benefit to your drivers. A definate plus point of the system is that the driver can't cheat it, on a rolling road there is always the risk of the 'second' ecu being used which gives a differant power output to that used in the race. With the DL1 the system is recording data all the time so any time the driver finds the boost button it will show up in the analysis software.
Also with rolling roads they need to be very correctly operated to get consistant figures and from my experience they mostly only perform static state tests which do not necessarily give a true representation of the cars power delivery under acceleration (Thanks Rod
) which is subjected to constant variations in CdA, Crr, and drivetrain inertia. Because the DL1 is recording the acceleration of the car as it happens it automatically has these influences in the data it has recorded to give you a true record of the power at the wheels.
As with any equipment based sport there is no right or wrong answer to how to police it, there will just be a way of doing it which will suit your objectives better. Good luck and remember to keep it simple. The simpler it is the easier it should be to police.
The system allows you to go into great detail with determining the power output by compensating for weather, gradients etc. so you can be as detailed as you like in your analysis.
the system has it's detractors and it's champions but it will give you accurate results if you feed it with the correct data and you have the advantage of a full datalogging system in the car as well which will be of massive benefit to your drivers. A definate plus point of the system is that the driver can't cheat it, on a rolling road there is always the risk of the 'second' ecu being used which gives a differant power output to that used in the race. With the DL1 the system is recording data all the time so any time the driver finds the boost button it will show up in the analysis software.
Also with rolling roads they need to be very correctly operated to get consistant figures and from my experience they mostly only perform static state tests which do not necessarily give a true representation of the cars power delivery under acceleration (Thanks Rod
) which is subjected to constant variations in CdA, Crr, and drivetrain inertia. Because the DL1 is recording the acceleration of the car as it happens it automatically has these influences in the data it has recorded to give you a true record of the power at the wheels.As with any equipment based sport there is no right or wrong answer to how to police it, there will just be a way of doing it which will suit your objectives better. Good luck and remember to keep it simple. The simpler it is the easier it should be to police.
Patrick, I think this is a bad idea because the money man will find a way of giving the car as much torque a possible without going over the given power to weight ratio so gives them a much bigger advantage over the budget team than if the level of modification is strictly nailed down.
I always favor the route of nailing the guys to specific parts and specific specifications....mostly standard i.e. cheap!!!
This is a good solution for Britcar because of the diverse selection of cars allowable in each class, but in a one make series its much easier/cheaper to set a spec and stick to it.
I always favor the route of nailing the guys to specific parts and specific specifications....mostly standard i.e. cheap!!!
This is a good solution for Britcar because of the diverse selection of cars allowable in each class, but in a one make series its much easier/cheaper to set a spec and stick to it.
trouble is standard doesnt always mean cheap... i.e. was it formula fords that had to have standard heads... ok so the little guy buys a standard head and bolts it on.. guy with money buys 30 heads and has them all flow tested uses the best... etc
when we ran the v6's there were some mods that were simple and cheap that gave power and performance boosts. they were outside the rules, so anything legal became difficult and very expensive and buggered reliability.. not a problem if you've got an endless supply..
like most things im a fan of a compromise between the two.. a p/w baseline with some specifics outlawed..
if someone has s
t loads of money though they are always going to find a way round things..
when we ran the v6's there were some mods that were simple and cheap that gave power and performance boosts. they were outside the rules, so anything legal became difficult and very expensive and buggered reliability.. not a problem if you've got an endless supply..
like most things im a fan of a compromise between the two.. a p/w baseline with some specifics outlawed..
if someone has s
t loads of money though they are always going to find a way round things..Ian Carvell said:
Patrick, I think this is a bad idea because the money man will find a way of giving the car as much torque a possible without going over the given power to weight ratio so gives them a much bigger advantage over the budget team than if the level of modification is strictly nailed down.
that's a failing of using power/weight, not for using a datalogger.this is not to say you don;t have a valid point, if you compare the output's of a turbo engine vs. an NA one both running to the same P/W, then it becomes obvious that there are going to be issues, for example, look here, both these cars run to the same P/W (turbo car is heavier), which do you think has the advantage?
james tucker said:
It works !
James,never suggested it didn't.
What I was getting at is the question raised above:
Ian Carvell said:
Patrick, I think this is a bad idea because the money man will find a way of giving the car as much torque a possible without going over the given power to weight ratio so gives them a much bigger advantage over the budget team than if the level of modification is strictly nailed down.
this is nothing to do with how good/bad datalogging enforcement is per say, it's about the validity of using P/W as the only tool.No problem Simon, the DL1 datalogger when used as it is in Britcar only calculates rates of acceleration (via GPS and 'G' sensors) and speed as I understand it...the software then uses the rolling resistance and aerodynamic drag to work out the power at the wheels. Used in this way there is no way of determining what the spread of power is.
So the point is, in Britcar it is a perfect tool to level performance because there is such a wide spread of differing machinery out there, and budgets aren't all that limited. As James says it works very well indeed.
However, my belief is that in a budget formula like the MR2 series, it's not really appropriate to use the DL1 unit as the sole method of restricting performance. The DL1 can only police power to weight ratios. The guys with less restrictions on budget will engineer solutions to give much better spread of power....not to mention the initial outlay of purchasing the unit.
I believe that in these one make championships we need to have the level of allowable modifications firmly nailed down in the black and white of the regulations. I believe there is then scope to have DL1 units which are placed in random cars (even across championship) to highlighs cars that may not be sticking to those allowable modifications.
Don't get me wrong, these units are very good bits of kit and very useful, but not in my opinion as a sole purpose of limiting performance in a budget one make/marque series.
So the point is, in Britcar it is a perfect tool to level performance because there is such a wide spread of differing machinery out there, and budgets aren't all that limited. As James says it works very well indeed.
However, my belief is that in a budget formula like the MR2 series, it's not really appropriate to use the DL1 unit as the sole method of restricting performance. The DL1 can only police power to weight ratios. The guys with less restrictions on budget will engineer solutions to give much better spread of power....not to mention the initial outlay of purchasing the unit.
I believe that in these one make championships we need to have the level of allowable modifications firmly nailed down in the black and white of the regulations. I believe there is then scope to have DL1 units which are placed in random cars (even across championship) to highlighs cars that may not be sticking to those allowable modifications.
Don't get me wrong, these units are very good bits of kit and very useful, but not in my opinion as a sole purpose of limiting performance in a budget one make/marque series.
James had the idea of using inlet restrictors in the nascent V8 Supercar series.
Couple those up with the minimum weight, and you can get your desired answer.
It would be easier for you to go down this route as you only have three chassis to worry about, where Bricar has the joy of a multitude of machinery.
It's a case of calculating the size of the inlet restrictor. You need to work out where it's going to go, but it'll peg back the power - for example, you may calculate that a 60mm restrictor will only permit an engine to produce 150hp (hypothetical figure) and a 70mm restrictor allows 200hp, with a 80mm restrictor allowing 300hp.
Set your classes based on restrictor size, and have a minimum weight (somewhere above the weight where the structural integrity of the chassis may be compromised) for each class.
There will be arguments, but put it this way, if the small restrictor allows an engine to produce 150hp, and someone's engine only produces 140hp, it won't affect them at all. It will affect the person who's tweaked theirs to 170hp.
You could mandate rev limiters too.
Bits of ally in a donut shape, rev limiters, and min weights would make it easier and cheaper to police/control than the more technically advanced DL1 method.
I've said my bit, I'll get back on the fence again.
Rob.
Couple those up with the minimum weight, and you can get your desired answer.
It would be easier for you to go down this route as you only have three chassis to worry about, where Bricar has the joy of a multitude of machinery.
It's a case of calculating the size of the inlet restrictor. You need to work out where it's going to go, but it'll peg back the power - for example, you may calculate that a 60mm restrictor will only permit an engine to produce 150hp (hypothetical figure) and a 70mm restrictor allows 200hp, with a 80mm restrictor allowing 300hp.
Set your classes based on restrictor size, and have a minimum weight (somewhere above the weight where the structural integrity of the chassis may be compromised) for each class.
There will be arguments, but put it this way, if the small restrictor allows an engine to produce 150hp, and someone's engine only produces 140hp, it won't affect them at all. It will affect the person who's tweaked theirs to 170hp.
You could mandate rev limiters too.
Bits of ally in a donut shape, rev limiters, and min weights would make it easier and cheaper to police/control than the more technically advanced DL1 method.
I've said my bit, I'll get back on the fence again.
Rob.
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