Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 Why is it considered clever to park with one wheel up the banking? The whole car should be on the road surely? Because it shows off the stiffness of the body, the higher the tripod without splitting the car in two the stiffer the car. If I go for it round a corner the car lifts a wheel anyway, like this - Quote Link to comment Share on other sites More sharing options...
Matthew_Gibson Posted July 15, 2012 Report Share Posted July 15, 2012 because the cars mega stiff,. even though my astra estate us to do this. it was about an inch off the floor too Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 Will be an even more impressive tripod when I pull my finger our of my arse and get all the bits I have bought on it. I had the hump with the car yesterday and wanted to sell up, but I've decided after a good thrash today I am going to keep it a bit longer. I have just done a deal for a set of seam welded box section lower arms off of an ex Cup race car which will help keep things stiff when it is lowered. I can't fit them yet though because they need new bushes Quote Link to comment Share on other sites More sharing options...
RobinJI Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) It shows sod all about the cars shells stiffness. It just shows that it's got some form of relatively stiff rear anti-roll, I'll get a shot of my Passat doing it sometime. Basically any vaguely sporty FWD hatchback will do it. My Scirocco did it in a fairly serious way, if you jacked the car from the front jacking point, the rear wheel would come off the floor before the front one would, and it would be further in the arch than it would have been when on the floor standard. In my car news, the Passat managed 57mpg the other day, a new best and I hadn't even been trying for decent economy, just drove to London at 70, 3 hours in traffic in London, 70 home again then a hundred miles or so around the local A-roads driving normally. It also didn't bat an eyelid at towing a mini (on a trailer) back from London, which I was pleased with, as the clutch bites a touch high, but it didn't show the slightest hint of slipping. The little 1.6td engine managed to pull the lot at motorway speeds fine too. The Scirocco (note that it's only jacked at the front): PS: Because it shows off the stiffness of the body, the higher the tripod without splitting the car in two the stiffer the car. That makes no sense, the higher the tripod, the steeper slope you've parked it on, it proves nothing about the car. If you can get it off the floor at all then you can get it to any height, because the force on the shell is still the same really quite minimal load. I'm kind of tempted to see if I can get my mums Skoda Fabia to do it now just for a laugh If anything the test should be, 'the shallower slope it'll tri-pod on, the stiffer the rear anti-roll.' Edited July 15, 2012 by RobinJI Quote Link to comment Share on other sites More sharing options...
Tom Booth Posted July 15, 2012 Report Share Posted July 15, 2012 Passats seem to do best when your not trying. When I'm trying I get about 43mpg, giving it a lashing I can get about 55ish. Seems much happier at 75-80mph then at 70, seems abit laboured. Went a run in the camper last night with the missus, 18-20mpg up in heeeere. Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 Do it Robin, you geek. My clio did it without a RARB no probems, it does it a lot better now though. Prawns does it going up the almost unnoticable slope to his driveway - Robin, if I gave you my old RARB could you make me a thicker one? Quote Link to comment Share on other sites More sharing options...
RobinJI Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) My clio did it without a RARB no probems I intentionally didn't say ARB, I said anti-roll, not 'bar' Your clios rear torsion beam already had a lot of built in roll resistance, the ARB just adds to it. My clio did it without a RARB no probems Robin, if I gave you my old RARB could you make me a thicker one? Maybe, it'd depend on the design and when you wanted it. Why do you want a thicker one? is it understeering? Tom, yeah, I genuinely think it's better on fuel at 70 than 60. I need to plug in my boost guage from the Scirocco sometime, but I think it's because at 60 it's not on boost, while at 70 it's just creeping into positive pressures, which means higher volumetric efficiency = higher dynamic compression ratio = higher thermal efficiency = higher fuel economy. (PS, yes Jardo, I am indeed a geek, quite a massive one infact. ) Edited July 15, 2012 by RobinJI Quote Link to comment Share on other sites More sharing options...
dann2707 Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) I don't understand the whole turbos add efficiency thing. Is that just for diesels or what? I'm mega confused. ex, a high powered car (waiting for Jardos dickheadery "its not a fast car lolol its not 200000bhp/ton lololol) such as the Ford focus st has the 2.5 turbo charged engine but has poooooor economy so obviously a turbo doesn't add efficiency in this case? What about turbo diesel cars? Would my 1.8 tdci Focus get better or worse economy if it was N/a? My dads just got one of those crappy new 1.0 3 cylinder foci' which has a turbo to add efficiency. Where is the line where it becomes more power orientated over efficient?! Shed some light please Edited July 15, 2012 by dann2707 Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 I'd shed all the light you need, but I'm a dickhead so you can f**k off and google it like every other fanny. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted July 15, 2012 Report Share Posted July 15, 2012 Good job I wasn't asking you then Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 I'm tempted to answer your question now, but I'm not sure if answering it or not will piss you off more. So I'm going to save myself the effort and let Robin do it. Bearing in mind I work in a Ford main dealer and have direct Ford training on the new Ecoboost engine I know exactly the sort of technical shit you need to know; and probably better than anybody else on the forum. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted July 15, 2012 Report Share Posted July 15, 2012 But you often bullshit your way through on here too, and everyone knows it.. I think i'd rather listen to Robin but THANKS anyway. Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 But you often bullshit your way through on here too, and everyone knows it.. I think i'd rather listen to Robin but THANKS anyway. What do I often bullshit my way through? Give me an example. Quote Link to comment Share on other sites More sharing options...
george_seamons Posted July 15, 2012 Report Share Posted July 15, 2012 almost unnoticable slope to his driveway - Are you shitting me?! That things like a f**king halfpipe! My car related news is that I smashed the silencer out of my KO4 charge pipe today, and replaced it with a piece of stainless tube. Cue lots more turbo whistle and recirc valve noise! Quote Link to comment Share on other sites More sharing options...
RobinJI Posted July 15, 2012 Report Share Posted July 15, 2012 I'm tempted to answer your question now, but I'm not sure if answering it or not will piss you off more. So I'm going to save myself the effort and let Robin do it. Bearing in mind I work in a Ford main dealer and have direct Ford training on the new Ecoboost engine I know exactly the sort of technical shit you need to know; and probably better than anybody else on the forum. I think you should answer it , because I'm curious as to just how in depth/biased/marketing based their training was. (PS, I have an answer mostly written, but I'm curious to see Jardos side of the story, as it may well be good info.) Quote Link to comment Share on other sites More sharing options...
dann2707 Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) What do I often bullshit my way through? Give me an example. In here, if someone pulls you up on something you claim you didn't put the " " smiley on as "it was a joke". Shit like that. It gets tedious. Same with the fitness thread last week when everyone proved you wrong. I'll be honest, we have 2 people like you in my group at Uni who claim to know everything, and are obnoxious to f**k. Needless to say me and the rest don't get along with them. Edited July 15, 2012 by dann2707 Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) The way Ford have marketed the Ecoboost is pretty clever, they've basically left ALL of the technical information out and just gone "here's a brochure about our new car which does X MPG and costs X amount a year to tax." Until we did our online e-learning on them I didn't have a scooby doo about how they'd done it. The Ecoboost engines were designed to be driven like a diesel with a huge torque spread from 1500RPM to about 4500RPM IIRC. They are direct injection and have tiiiiiny little turbo's which spool up almost instantly. Because the 3 cylinder is a really lumpy idle they've used an intentionally unbalanced flywheel, they also used an iron block to aid warm up time, the exhaust manifold is also cast into the head to try and keep it cool too. They've got an internal timing belt which runs through an oil bath to make it last longer and the turbo bearings and seals have a special coating which I cannot remember the name of which basically makes them spool up instantly. You can hear them whistle down if you rev it and then shut the engine of too which is pretty cool. I could go into the "how's" of why the Ecoboost is so economical, but that'd be boring and isn't what you actually want to know. The long and short of it is that some turbo cars are designed and tuned for economy and some for power, adding a turbo increases the efficiency as by basically drawing the burnt charge out and using that energy to force the fresh charge back in quicker, meaning that the engine can "do it's job" quicker and also getting more "charge" into the cylinders through forced induction. The increased thermal efficiency that this offers also lowers the c02 emmissions of the car which is why turbo'd cars are always much cheaper to tax than their NA alternative. By adjusting the amount of boost, the timing of the engine and the amount of fuel which goes through the injectors you can make any car more efficient or more powerful with a turbo. The turbo itself is only a small part of what makes the engine either powerful or fuel efficient. It depends what you ask it to do. A lot of the time the turbo also changes the torque curve, so with a turbo car you tend to keep the revs lower than you would on an NA car because that's where the power is. Higher RPM = the air/fuel charges being drawn in and out much more frequently so it is obviously using more fuel. As far as I know it that is how and why small turbo engines are being used to increase fuel economy and lower tax. It's probably not as an in depth reply as Robin will have written but I hope it covers the basics. Edited July 15, 2012 by Pashley26 Quote Link to comment Share on other sites More sharing options...
Revolver Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) Think about how much bigger displacement the engine needs to be to match the power of the turbo. More fuel going in. A turbo makes higher pressure air too that raises the power per cc of mixture. That's my understanding, sombody correct me, lol Looks like I was snaked. Edited July 15, 2012 by Revolver Quote Link to comment Share on other sites More sharing options...
forteh Posted July 15, 2012 Report Share Posted July 15, 2012 I could be wrong but turbos do not pull the exhaust charge out faster, completely the opposite infact, the exhaust gasses feed through the low pressure side of the turbo which then forces the intake charge into the cylinder at a higher pressure/volume/density. Also an iron block to aid engine warm up? Aluminium blocks heat up faster so Im not sure what theyre trying to tell you there. Quote Link to comment Share on other sites More sharing options...
dann2707 Posted July 15, 2012 Report Share Posted July 15, 2012 Jardo in "doing it considerably more right than usual" shocker Only after a subtle hint... Nice one, i'll have a read of this properly later. Just finishing off enhancing poppa bears paintwork on his new car. Turned out niacccce so far though Covered in SO much sap though for a 30 mile old car haha. Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) Just to add on, because the edit button isn't there. I know you asked about diesels too, well I also do Mazda who currently have the best diesel engine in the world. It is a 2.2 diesel with 150bhp, it is a 4 cylinder twin turbo and in a 1500kg compact crossover it averages 61.4MPG and produces only 119G/km of C02 so it is as cheap to tax as a Fiat 500. With the diesels the lower the compression ratio the better, it used to be that diesels ran with 20.1 compression ratios and some people still don't believe a diesel can run below 17.1 compression ration. But the new Mazda has a 14.1 compression ratio which is the lowest production compression ratio in ever made. What that does is mean that they can make the internals of the engine MUCH lighter, which makes the engine more efficient and also makes it drive like a petrol. The twin turbo just makes it smooth, but the main benefit to diesels is to make them lighter and have less restriction. The other alternative is just to up the boost and cram more into them, but most diesels are so unrefined internally that most manufacturers are looking at new ways to make them more efficient without just upping the boost and fuel. - Forteh, you are right. What I've said is a bit misleading, it is as you say and that is what I was trying to get at but worded it terribly. I know a lot of people don't understand how a turbo can effect the intake, I was just trying to point out that the power STARTS from the exhaust stroke. The resistance of the back pressure the turbo gives does cause a small reduction in power on the exhaust stroke which in turn effects the other cylinders. I think the use of the iron block is with regards to head disapation and the way that effects warm up time. You know if you leave an engine just ticking over from cold it takes ages to get up to running temperature without being driven? Well an Ecoboost warms up just as quick as if you drove the car. Edited July 15, 2012 by Pashley26 Quote Link to comment Share on other sites More sharing options...
RobinJI Posted July 15, 2012 Report Share Posted July 15, 2012 (edited) Pretty decent answer Jardo, and actually answering a different side of the question to the side I was. Everything makes sense and isn't BS from where I'm standing (You might be interested to know that actually intentionally miss-balancing the rotating mass is nothing new, it's often done on the crankshaft in order to partially counteract the acceleration forces of the recipricating mass, basically making the engine vibrate in 2 planes instead of 1, but with half the peak forces.) My answer: A turbo basically adds power to an engine by increasing its volumetric efficiency, by increasing the intake pressure. Volumetric efficiency is the engines ability to cram as much air into the cylinder as possible (it's the %age of air that actually goes through the engine compared to the amount that would go through it if the cylinder was filled with air at atmospheric pressure at BDC each power stroke, and none leaked). This is probably stuff you already know (you're studying automotive engineering aren't you?), but yeah, this is what gives you more power, because as we all know more air = more fuel = more power. The increase in economy comes from the increase in the volumetric efficiency, which increases the engines dynamic compression ratio. (the ratio of air actually in the cylinder at BDC compared to the air actually in it at TDC (by mass).) This in tern directly increases the engines thermal efficiency (it's ability to transfer the heat energy released through combustion into kinetic energy.) And as a result, it manages to get more power from the same amount of fuel when compared to a larger engine of the same power, which would be running at a lower volumetric efficiency. There's also the reduction in energy lost to mechanical drag from the larger contact area of bigger pistons against larger diameter cylinder walls, and in some cases actually a lower number of cylinders, as well as the energy lost to accelerating the heavier/larger number of reciprocating components in a bigger engine. None of this is necessarily a trait of turbo-charged engines, it's just a trait of engines with a high specific power output, hence why v-tecs manage good economy for their performance too, the difference is you can take the specific power output to a whole new level with forced induction, and importantly, they let you achieve high volumetric efficiency at low RPM, where mechanical losses are lower, which is much more difficult with a naturally aspirated engine. Supercharged engines would be similar, but they waste energy driving the charger, while turbos use effectively 'free' energy from the exhaust heat/velocity to drive it. A good concept to get your head around in terms of engine economy/efficiency is turbo-compounding. This is where as well as using the turbo to pressurise the intake, it's mechanically linked to the crankshaft, in order to add the rotational force of the turbos shaft to the engines power. This is basically using the turbo as a mini gas-turbine engine, using the exhaust energy that would otherwise be a waste product to add to the engine power. Clever stuff, the trouble comes when you try and get power from a shaft that wants to spin at a constant speed in the region of 100000rpm into a shaft that varies speed all the time anywhere between 1000 and 7000rpm, you need a CVT or many ratios, and these tend to be prohibitively expensive, or melt, or are just hugely inefficient/heavy/unreliable. Edited July 15, 2012 by RobinJI 2 Quote Link to comment Share on other sites More sharing options...
011001000110010101110010 Posted July 16, 2012 Report Share Posted July 16, 2012 New car Dirty Clean Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 16, 2012 Report Share Posted July 16, 2012 Just bought a BMW. 90,000 miles, one owner from new, full BMW service history, TOTALLY mint. Literally the cleanest car I've seen for a long time. £400 Clio is up for sale, so a total turn around from yesterdays post haha! 2 Quote Link to comment Share on other sites More sharing options...
Pashley26 Posted July 16, 2012 Report Share Posted July 16, 2012 Clio is sold. - What the f**k Fred?! Last time I knew you were driving a 106 lol Quote Link to comment Share on other sites More sharing options...
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