Thats why I said at the concept and design phase. That's a correct statement and of course only part of achieving a fast full lap. Other than mass is different from weight and 4WD cars have different weights and performances, why are we not seeing any of this mathematical and engineering skill you seem to intimate you have? The opportunity existed. Armchair critiquing is easy.
Sure and while the Focus RS is a good car, it's a bit ugly, a 5 door bloater, seriously hyped by the media and in this forum, only now really worth a small amount of my huge metal capacity.
Excellent post about weight. Autocar has just done an excellent review of the old king of the hatchbacks, the Megane RS. Bag a bargain while you can. The light, pure and incisive drive is an enthusiasts delight: http://www.autocar.co.uk/car-review...rives/2016-renault-mégane-rs-275-cup-s-review
Mines here in a couple of weeks. Pics will be posted when I've added weight via paint protection film, some subtle wrapping and stickering!!!!!!
"Corner entry for a fast lap time is the max radial g you achieve" is actually total nonsense, not even sure what that means. Anyone who has looked at a the output from a data logger will know that the max lateral g you see will be somewhere in the middle of a turn, a perfect set up perfectly driven car will show a line which evenly shares longitudinal g and lateral g as the car enters and exist the corner. Some will refer to this as maximising the traction circle. http://www.formula1-dictionary.net/traction_circle.html
TBH I do a lot of this type of driving and its very hard to see much difference in overall performance because there are so many variables. One of my friends is an ex racing driver and is faster than us in anything, some are braver than others in corners, some know their car so well that they can always push it right to its limits, some rely on 4WD and power... In terms of BMW you mention, it isd probably more suited to such roads because it is smaller, I used to drive a supercharged Elise which seemed just about the perfect balance of sizer and speed form most driving roads. By comparison my Megane does feel a bit lardy at times!
That quote is taken out of context and was originally part of the original 2WD versus 4WD advantages. It’s still true for the lighter 2WD vehicle advantage compared to the 4WD. Of course it’s only part of the whole corner. Max radial g? Why do you have a problem with that? Same term as centrepetal accel or as some use, lateral accel and only from equations of a body (car) in circular motion, ie a corner. As a racer you will also know the corner entry is a critical phase and if you get it right it will lead to a transition to the best radial g you can achieve. Of course it’s not and instantaneous g transition from the turn-in to apex, but the turn-in starts the process. Good link to the F1 dictionary but that really refers to tyres and traction/grip. When a car is in a corner, all 4 tyres will be at different parts of the traction circle due to direction, inside tyre, outside tyre, loading etc. That is why radial g is a better measure as it defines what the whole car is achieving in a turn. Also, I do know 'peak' radial g is not the only parameter that represents perfect turn. Radial g can spike so be it needs to be analysed on the curve. There are also other assumptions that have to be satisfied as a baseline before comparison. I’m happy to have a reasonable debate about this stuff with anyone (maybe not sunnylun lol) if they wish to.
Yep. Totally agree. That's why I take little notice of these debates about how much better an rs is than a megane, golf r , CTR etc The driver is handy in the e30, but we are all regulars on track and are out around north wales once a month in the summer. That said it was still a surprise how well it went.
Radial g, there is no such thing in physics, applied maths or engineering. Centripetal force (which is what I think you mean by radial g) is not really meaningful as cars in general don't corner in circles, and worse the vehicle is not necessarily perpendicular to the centre of this circle anyway which doesn't really matter much either (most of the fastest guys in club racing or old school cars 'back it in' on corner entry). If you mean lateral g you were very wrong, it is pretty much always at a maximum at a point around the middle of a corner, as I said anyone who has looked at the output of a datalogger or been around racing will know this. Most cars do not make that much g on corner entry which is why trail braking has become such a big thing in high end racing as they are then using up the hitherto unused grip available in the tyres for braking at the same time as turning. Inertia is one big reason why cars don't make that much g on turn in, again experience looking at a data logger will show big g numbers in low speed corners as the car has much less inertia and thus can be turned very aggressively. One builds a traction circle directly from data logger recordings (as they record a g vector of lat g, long g), it tells one how well the car uses the tyres at different phases of a corner and since there is only a certain level of g available the goal of the engineer (and to some extent the driver) is to maximise the traction circle as this is gaining lap time by making the car faster at the different corner phases. The article pretty much said all that in expanded form. Its fundamental stuff really to performance engineering. None of this has much baring on the comparison of the RS Ford to the RS Megane.
Ah buddy, I've tried that route, but unfortunately you can't use logic and reasoning with someone who simply doesn't understand what they're saying, let alone what someone else is saying Aside from the occasional "hit" of saying a stock phrase in the right context, which is probably a repetition of something likely to have been read elsewhere, he genuinely doesn't say anything meaningful Kinda pointless replying, as you can't hold a conversation with someone who doesn't understand the principles of what they're talking about and seems to create sentences made up of words that don't have any meaning when strung together If we want to chat about cornering speeds then we need to do some basics around friction and forces, but that's A-level mechanics and I get the feeling we're dealing with someone who took GCSE foundation papers (assuming they have done their GCSEs...) Just as an example, this also doesn't mean anything: "There are also other assumptions that have to be satisfied as a baseline before comparison." It's like dealing with David Brent on cars - buzzword bonanza. The kind of person that likes to say, "let's take this offline, kick it around the office for a while before we run it up the flag pole and get a steer from the powers that be, before we hit the ground running. After all guys, we don't want to score an own goal" btw either the Focus or the Megane are unlikely to have their max potential for cornering speed reached by anyone on here, as someone's correctly stated above, so until we're all on slicks and cannot corner any faster, probably just as well saying both are pretty good cars and as time goes on, technology will improve, and will no doubt get better, faster, and safer.
Armchair critic mode again....... Another reply that actually doesn't add anything or input anything technical or mathematically relevant. A sort of non-committed criticism of other peoples inputs with brief references to an incisive depth of personal knowledge we never actually see whilst drifting off into obscure references. Let’s see something relevant to the subject; otherwise we will have to conclude it's just all bluff. At least NJH is prepared to have a technical dialogue.
Just a few comments and corrections for you: Centrepetal force isn’t radial g, its Centrepetal acceleration. I know you like nitpicking.... Force and Acceleration are different. Don’t worry, you don’t need to explain. Of course cars don’t go round in perfect circles, that’s why the g (or do you prefer force or lateral acceleration?) transitions from turn-in to apex. Why do you assume I think it’s constant? I covered that in my previous reply. The initial turn in, if you get it right is part of defines what the peak g might be. The analysis and vehicle path is not pure and steady state. Pretty obvious. Being perpendicular or not at the centre of the circle is irrelevant as the car acts as one body and unless you have more than one set of X/Y axis g sensors and unless you are stabilising your car g sensors in space you will always have latent errors anyway. Remember most car data logging g sensors are not ‘space stabilised’, they are strapped down. A horizontally mounted g sensor will record latent g in the vertical plane. Not good for sloping circuits. A single datalogging g sensor set only records what the car is doing at that point, it isnt sensing understeer, oversteer or any degree of slip about the vehicle centroid. Just a point on your data logging, a traction circle in many respects is fairly irrelevant as it’s down in the detail of performance as g is only part of the data analysis required to analyse a corner or overall circuit performance. You need several feeds because you can hit a peak g on corner but it’s still not the most efficient path. That why speed and ground track are just as important. Other data feeds are also useful. Good to chat.
Waiting for you to actually say something that can be responded to first Try a single sentence that's a statement of fact, and then an application of that fact to make a point that reinforces an opinion If it helps you, quote your reference for the fact, as it'll then stop you making stuff up and going astray
Come on, you can do better than this surely. The topic is clear. Cornering, data logging, traction, measuring acceleration, analysing performance. Have an input rather than just criticising other people's.
My stance is this - you're so ignorant of the number of factors involved before you can make such sweeping claims as you do, that your opinions are worthless because they're not founded upon any logic and you haven't demonstrated any understanding of the complexities involved Here's what I think about the new Megane... As a species, we are evolving. The technology we have at our disposal to make things is improving. Our understanding of the world around us is improving. Equally, businesses need to survive and to do so they need to make profit. We don't know what Renault's aims are for the new car, but it's fair to assume they will want to maintain profitability of their business. For the car... If they want it to be faster, it will be If they want it to be safer, it will be If they want to produce the car more cheaply, they will In fact, anything from a design and engineering perspective that they want to do, they can do, because it's all within their internal control and technology will enable them to do so On the flip side, making it faster/safer/more efficient etc doesn't necessarily translate to more unit sales or more profit, as costs may change and/or the improvements made may not be aligned to consumer demands If they want to sell more or make more profit, based on data they have about consumer demands, then they will design it with those demands in mind and they may conflict any of the other factors involved Thus any claims you, or anyone else makes about the car being "better" or "worse" are irrelevant opinions, because you have no idea what Renault's objectives were So either buy one, or don't buy one, but don't go spouting BS claims about things you don't know and expect to engage anyone in sensible conversation. Example being, "adding weight will <insert BS claim here>" is nonsense, because the new car isn't a complete replica of the last one except adding a massive ballast for no reason, so taking one attribute in isolation just shows a complete lack of understanding and appreciation of what else is involved
Strange reply. We were discussing car handling on circuit, data logging, cornering, traction and you are now covering the new megane, new car marketing, what Renault might do and profit. Total disconnect.
Another top article about the Cup S. Performance, value, handling. Nothing touches it. Keep it simple, keep off the options (even if you can still get a new one to order) or even better, pick one up used. Don't get tempted by lardy rivals: http://www.autoexpress.co.uk/renault/megane/95551/renault-megane-rs-275-cup-s-2016-review
So you didn't deal at all with what I posted just made up some more random stuff unrelated to what I said mixed in with some reasonable but entirely irrelevant digressions to divert from the fact you stated a load of "facts" that were nonsense. That is what people do when they have lost the argument. https://en.wikipedia.org/wiki/Centripetal_force 7 years at university doing a degree and PhD in Physics btw, I have posted a video on here before of me racing in one of the UKs most prestigious club championships. I was also named and thanked by Hartech Porsche in a half page advert as part of their team when I did race simulation and data analysis for them as they successfully took on that Championship from 2011 onwards (Paul Follett in particular who I continued to help through his time with Sorg Rennsport racing an M3 GT4 in VLN and European endurance). I have no idea who you are but I am not bothering any more as thankfully there is enough posting on this forum for any casual reader to pick up on and filter you're contributions.
Utter utter utter bollocks. Just go and state that to anybody doing serious race car data analysis. I'm out as its clear from both your fine details and the wider view of your postings that you are a BS merchant.
To get back to the topic at hand. I think that it'll be the greatest for what it has been and for its lifespan. It's not many car manufacturers who have, what is essentially, a 5/6 year old design that can still keep its head up there with the new releases of other car manufacturers. It's still beloved by the press but time is marching on and progress is needed. I'll have my 275 Trophy for years to come yet. I have hope for the mk4 but I don't believe the early versions will be the best. I think it'll need revisions like the mk4 Clio has needed. Will it be as praised as its predecessors remains to be seen.
Really.... Reference data logging and telemetry, and the ‘Traction Circle’, it isn’t a direct output used for analysis. What you are referring to is of course is just ‘g’ in a variety of scenarios with relevant g vectors and the Traction Circle is only a summation of individual outputs and is presented as a series of fused data g outputs. When you look at a cars performance in a corner, under braking, accelerating you are only really interested in how it behaves, how to improve it during that phase of the analysis. The Traction Circle is a bit of summarized overall detail.
Right from the first post though, you felt the need to challenge any statement. For example, going back to Radial g, you said it doesn’t even exist as a relevant term. Completely wrong of course and if you really had a depth of understanding on vehicle dynamics, (not just physics) you will appreciate a car rolls, pitches and can yaw in a turn. All your references to lateral g, which by definition is actually 90 deg to the longitudinal axis, needs, of course, to be broken into its component vectors. A simple single paired accelerometer system introduces errors in that turning scenario. Take a moment and have a look in aerodynamics, where the true component vector for turning after eliminating pitch, roll etc is called Radial g. Why is it important, because the output of a simple vehicle data logger drifts into error with pitch, roll and possible yaw. Radial g, although a term you might not be familiar with, is the actual turn rate. It’s all about sensing and measuring accuracies which is a critical element of vehicle dynamics. Maybe it’s just a case of appreciating and discussing another level of detail and knowledge in vehicle dynamics. If Wikipedia references to Force is your thing, then fine. We both know you can flip between Force and g as required and they are both relevant to the subject and applied as required. In racing you can measure a wide range of parameters and you know that includes g, so why challenge it? I suspect you just want to be a bit pedantic, a bit on the pure side. So here’s one for Centripetal acceleration: https://en.wikipedia.org/w/index.php?title=Centripetal_acceleration&redirect=no We can all just trade basic definitions and I thought we might get into some interesting handling stuff, data logging detail, yaw rate sensors, GPS and modern accelerometer accuracies, what sort of GPS FOM you need for a decent track reference and just how many sensors you need for a good data logging/telemetry system. Even maybe some of those handling references to handling and trail braking, which isn’t an advantage on every corner anyway. C’est le Vie.
Sure is. Here is EVO's take on it and their comments on price? Well anyone that pays list for one has been mugged. Discounts and great used buys are what make it extra special. VFM: http://www.evo.co.uk/renault/megane...p-s-review-still-exciting-despite-its-old-age
My next car won't be a hot hatch because it won't compete to a mapped mk3 RS Megane. That said I can't afford to run an M/Amg/porsche either so not quite sure what I will do!
