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missed that - why would anyone want to "tune" a derv?!
Same reason as any other car. The people I rang about it said my 140 would go to 190bhp, and still do 50+mpg. Hard to argue with figures like that
It's just figures though. The 190bhp (if they got it) will be peaky as hell. Reached clattering at 4000rpm and gone by 4002!
It's your car and cash at the end of the day. But having your cake (200bhp) and eating it (50mpg) rarely happens without massive compromises.
Look I'm not saying it's a good thing - the question was, why tune a diesel? So I answered it.
But having your cake (200bhp) and eating it (50mpg) rarely happens without massive compromises
I quite fancy the 170bhp Passat TDi...
It's just figures though. The 190bhp (if they got it) will be peaky as hell. Reached clattering at 4000rpm and gone by 4002!
It's generally not that bad though.
So noisy and heavy are your specific compromises then! Have you heard the new Passat when deploying those ponies? It would make your ears bleed in tunnels. My aircooled camper sounds refined next to it 😀
It's just figures though. The 190bhp (if they got it) will be peaky as hell. Reached clattering at 4000rpm and gone by 4002!
It's generally not that bad though.
O.K I admit, I'm a derv hater. Possibly because none of my 3 motors does better than 28mpg. But then I didn't buy them for economy..
if its a diesel specific chip, it does work.
mass produced Diesels are designed and tuned to run on supermarket watered down fuel in countries where its pish
if you get the "bolt on" chip, it tunes it back up as if its being run on quality stuff (shell).
running super market fuel in it, it will be better on all counts, but knacker it quicker too as its trying to burn more efficiently than the fuel will allow.
running it on nicer fuel only, and you will get better speed, torque and mpg, with little in the way of penaltys.
these chips (boxes of toys, not simple resistors) plug onto the ecu connector, not under the bonnet, and mess with the computers calculations (admittedly in a pretty blunt, and generalised way)
...as far as i understand it anyway!
if you get the "bolt on" chip, it tunes it back up as if its being run on quality stuff (shell)
Not really sure I agree with that. If you are talking about injection timing, then it should adjust the timing as it goes along anyway I reckon.
Molgrips, CO2 is inversely proportional to MPG. But a car optimised very precisely for the best performance in a complex lab test will not give you the best MPG or lowest CO2 output in the real world.
Gotcha.
Chiefgrooveguru, you speak the truth.
gwj72, have you actually got any eperience of a good modern diesel engine? Something like the Jaguar/Landrover/Peugeot/Citroen 3.0 ltr V6. In standard form gives 280 bhp & 400lbs/ft of torque and from the outside you'll have trouble telling it from a petrol at idle.
His car maybe (missed that - why would anyone want to "tune" a derv?!).
Audi seem to be having moderate success at Le Mans with a diesel.
The point is to get an increase in torques, especially at lower revs, to improve overtaking. My Octi is 110bhp, or thereabouts, and I don't notice much difference from my Puma which was 129bhp when overtaking, but there's certainly a hell of a difference in fuel economy. I was lucky to get 300 miles from a tank on the Puma, I estimated approx 25-30/gallon, compared to between 45-60, around 500-550/tank with the Octi, and that's the difference between a lower revving torquey oil burner and the very revvy Yamaha designed Zetec in the Puma. Fabulous fun to drive though, I wish I could still afford to run it. :0(
Jeez, these threads.
Ignoring for a minute the "you'll break it arguements (because you won't), the economuy gains (you won't see) and the modest power gains (which can be had).
What's the point? The last time I drove in the UK all the much, much, more powerful vehicles than the one I was driving seemed to achieve was a zap of gratuitous acceleration before braking as the gap to the vehicle in fornt diminished. A sort of "I'm a frustrated prisoner of this metal box and this trafic saturated road" statement.
I actually agree with you 100% there Edukator. Fast cars on British roads are a mug's game. The best fun you can have is swoopy open country roads, and any reasonably decent handling car will do you just fine 🙂
Pretty much all of the current 'eco' versions of diesels out there are at the limit of fuel consumption for what you can get out of the technology they use. To get further increases you will have to wait until the next gen engine models start to be used.
Ye but savings can be made elsewhere. Underbody aero panels, aero wheels, start/stop engine, high gearing, turbo ... kinetic energy recovery... some of these would obviously push the price of the car up significantly
One of the vehicles I most enjoyed driving didn't even have good handling, thankfully it lhad lots of steering lock to compensate (my Welsh Water Marina van). Having a set of forestry commission keys to go with it was more important.
Ye but savings can be made elsewhere. Underbody aero panels, aero wheels, start/stop engine, high gearing, turbo ... kinetic energy recovery.
Apart from the turbo, Toyota are already there 🙂
Just get a TVR .. no remap needed... family friendly.. not many things to go wrong..
they even emit a safety warning to other motorists as you are heading toward them
Apart from the turbo, Toyota are already there
what model?
The Volvo C30 has all that.. except the kinetic energy recovery
Prius. Recovers kinetic energy to the batterry. The most aerodynamic production car in the world. Transmission has the effect of a CVT but with an enormous gear range, and it also shuts off when going down hills or just lifting off slightly. Asymmetric piston stroke giving greater expansion than compression. Coolant circuit in the exhaust to warm it up super quickly. Electric power for slow speed traffic and manoevring. Fuel tank bladder to stop harmful hydrocarbons escaping when you fill up.. and so on.
Ye but savings can be made elsewhere. Underbody aero panels, aero wheels, start/stop engine, high gearing, turbo ... kinetic energy recovery... some of these would obviously push the price of the car up significantly
Sorry, yes absolutely, I was talking more of benefits purely from engine calibration. Aero and weight are the biggest ones. Unfortunately these are the easiest ones to 'fiddle' for the official emissions test and so gain quite a large chunk of CO2/fuel consumption. Not that any vehicles specifically mentioned on this thread fall foul of that of course.......
I'm interested in the technical aspects if you care to share?
Can't share a huge amount unfortunately as, although our involvement in the project is public knowledge, the calibration strategy itself is definitely not!
I've worked on both the latest Volvo DRIVe vehicles and also the Zafira Ecoflex. Both involved a huge amount of re-calibration of the engine in order to meet client CO2 targets whilst staying within EU emissions limits. I have to say, as a company we also endeavour to greatly improve real-world fuel consumption performance as well and indeed we did a lot of work with the Volvo's in that respect. Ditto with driveability and noise - they shouldn't be any different to drive than the other diesels in the range.
Presumably the 'next gen' is what, solenoid valves? Variable compression/expansion ratios?
Not really that 'high-tech', more just that the current engines being used in eco-models are three or four years old and probably based on blocks older than that. Main benefits in the next few years will come from higher pressure fuel systems and piezo injectors, better combustion chamber design, variable geometry turbos and the use of other aftertreatment such as SCR (which will cut the amount of EGR required). Most of the technology is there, it's just waiting for manufacturers to design engines with it in!
Prius. Recovers kinetic energy to the batterry. The most aerodynamic production car in the world. Transmission has the effect of a CVT but with an enormous gear range, and it also shuts off when going down hills or just lifting off slightly. Asymmetric piston stroke giving greater expansion than compression. Coolant circuit in the exhaust to warm it up super quickly. Electric power for slow speed traffic and manoevring. Fuel tank bladder to stop harmful hydrocarbons escaping when you fill up.. and so on
Yeah it is impressive... the one problem with it though is the battery... expensive to manufacture in environmental terms IIRC
I've worked on both the latest Volvo DRIVe vehicles
May I congratulate you on a job well done then, because if the stats are close to the real world they are excellent.
Are certain manufacturers further from the stats than others then?
My ideas for more efficient engines include small displacement V6s where you can switch off one bank (like big American trucks) thereby reducing the amount of air you're needlessly compressing; and a two stroke two cylinder design with high pressure air supplied by an external compressor and accumulator.
expensive to manufacture in environmental terms IIRC
Yeah that's what the haterz say but there's no real evidence that I've been able to find. Lots of recycled nickel goes into batteries for example. Plus the factory Toyota make the cars in is pretty eco friendly too, something that gets overlooked.
Audi seem to be having moderate success at Le Mans with a diesel.
Go on then, name another diesel race car. 🙂
I can think of one, off the top of my head.....
Le Mans is a pretty special case though!
Your two-stroke sounds like a ship engine, Molgrips.
Go on then, name another diesel race car.I can think of one, off the top of my head.....
Peugeot 908 (also in LeMans)
Ricardo-Judd engined LMP from a few years ago
Seat Leon (one of the most successful touring cars of modern times)
JCB Dieselmax (not a race car, but has the land speed record for a wheel driven vehicle)
I think there are a few more but those are the main ones!
May I congratulate you on a job well done then, because if the stats are close to the real world they are excellent.Are certain manufacturers further from the stats than others then?
I'm not going to lie and say they are exactly the same as you have to make compromises to hit the CO2 target in the NEDC test zone - but they are as close as you are probably going to get. Volvo made a big deal about getting real world fuel economy good as in the home market they would get shredded if people replaced their current Volvos and didnt get at least the same or better fuel economy.
The NEDC test is defined around a set of coastdown terms which are notoriously simple to fudge. Some manufacturers fudge them a lot more than others. Unfortunately that is one area we don't have control over when we calibrate an engine and so have to go with what we are given. The Volvo ones were certainly realistic though - they are easily the most honest company I have worked with.
Your two-stroke sounds like a ship engine, Molgrips
Hmm, interesting, not familiar with those. I forsee that the issue with this design would be a suitable compressor.
One day I'll buy old cars and bodge these crazy ideas into them, see how I get on 🙂
Some manufacturers fudge them a lot more than others.
I don't suppose you can tell us which ones? Anecdotally, BMW are bad for this - but that could be because BMW drivers like to boot their cars about - and also Fiat are getting slammed for the real world economy of their Twin Air 500.
I don't suppose you can tell us which ones?
I could, but then I'd have to kill you......
In all serious, it's probably best not to just in case.... Some we have 'evidence' for and others you can just tell that something is a bit dodgy when you look at all the numbers. I'm sure a slightly less unscrupulous engineer has put them somewhere up on the big wide web!
Well I should let you all know that I can get the govt figures from both the Prius and the Passat in summertime, whilst sticking to the speed limit 🙂
Diesels.......Take as mentioned as a good modern example - the jag 3.0 diesel. Only 271bhp from 3 litres with 2 turbo's. Peak power at 4k. That's good? My 1996 petrol car mullers it for power with lower displacement, half as many blowers and another 3k before I hit my redline.
That's not progress chaps. It does 48mpg while I average 24. Definitely an advantage on that front I guess.
Some good points and discussion there chaps.
In summary my plan is to run this 20p resistor for the next tank of fuel, (i put in 50 litres at 136.9 totalling £68.45) thats just so i remember when i tap the figures into fuel economy calculator.com.
Im running it with miller diesel plus stuff in as apparently it reduces the unburnt fuel and black smoke emmisions you can get.
Im not after power, however if it will return 75mpg then your talking, especially at todays prices.
I will get back to you when the fuel light comes on and let you know the results (on mpg, when i want a faster car ill buy one)
The jag diesel also has around 500Nm of torque - which is more than an F1 car produces. That is what 3 litres an two turbos gives you (as well as the good mpg).
Torque is generally what you want in a road car, not outright power (only available at full throttle and very high rpms), so in that case the jag engine is a pretty good bit of kit.
The jag diesel also has around 500Nm of torque - which is more than an F1 car produces. That is what 3 litres an two turbos gives you (as well as the good mpg).
F1 cars spin to 20k revs, they don't need a high torque figure. My car has way more torque than a f1 car too. Hot hatches do these days. Meaningless stat that.
Martin does vans - www.vantuner.com
and does not over estimate your power increase.
Anyway, big downside is insurance - I declared it and my premium doubled and most insurers will no longer touch a modified car - so it gets harder and harder each year to find anyone who will quote (other than specialists who charge a small fortune).
You aren't looking hard enough. Difference between my old standard car (~225bhp) and after I'd tuned it (~290bhp) ended up being a big fat £0. And it wasn't a small fortune either. Maybe £500 fully comp.
What's the point? The last time I drove in the UK all the much, much, more powerful vehicles than the one I was driving seemed to achieve was a zap of gratuitous acceleration before braking as the gap to the vehicle in fornt diminished. A sort of "I'm a frustrated prisoner of this metal box and this trafic saturated road" statement.
Or, there's the thrill of booting a car from standstill up to 60 in 4.8 seconds. It's fun. I'm a frustrated prisoner in a metal box when I'm in the missus' Ka.
Colin McRae Rally 2005 objecively gets my pulse higher than any real car I've even driven in a straight line and produces micrograms of CO2 (the computer is solar powered). Your 4.8 seconds of tyre-smoking, look-at-me-I'm-macho, anti-social "thrill" belongs to a more superficial age when Yanks had 400bhp big blocks and a 55mph speed limit.
If you really want thrills then having found an appropriate place something like a basic Seven on skinny tyres won't do your 4.8 seconds but will provide hours of entertainment. Choosing from the cars I've driven this one rewarded skills with thrills.
Colin McRae Rally 2005 objecively gets my pulse higher than any real car I've even driven in a straight line
😯
I get the skill/thrill ratio thing. I've had an immense amount of fun ragging an old Sierra round Knockhill. But there's a lot to be said for sheer brute force acceleration.
EDIT: and what's antisocial about it, anyway? Antisocial is pissing through someone's letterbox, not giving it beans off the lights.
Antisocial is driving too fast (which may well be within the speed limit), or "giving it beans off the lights", in a built up area increasing the danger to pedestrians, cyclists and other road users, and damaging people's quality of life with increased noise and pollution.
If you want to be a racing driver, please go to a race track.
271bhp from 3 litres with 2 turbo's. Peak power at 4k. That's good?
Yes. You already said it's twice as efficient! And who cares about the redline? I honestly don't care what the max rpm of the engine is. If it bothers you that much why not cross out the numbers 1-5 on your dial and replace them with 1-8 instead? Cos that's all the difference it makes.
Likewise specific power. Utterly pointless to compare two different engine technologies. Utterly. What matters is driveability, torque distribution, and power. And efficieny, too. A big V8 petrol might be lovely to drive, and have slightly better characteristics than that V6 diesel, but in the real world where we have to drive to the supermarket and pay for our own fuel, that diesel would win hands down for me.
Progress? Absolutely.
Im running it with miller diesel plus stuff in as apparently it reduces the unburnt fuel and black smoke emmisions you can get.
That stuff should increase mpg on its own, so if you are going to contrast and compare make sure the fuel is the same each time.
Re antisocial driving - a lot of people really don't like it when other drivers f*ck about on the roads that we all have to share. that's why it's antisocial.
Imagine me riding my bike around Tescos at full pelt. That would be antisocial for the same reasons.
Well that's me told.
🙄
F1 cars spin to 20k revs, they don't need a high torque figure. My car has way more torque than a f1 car too. Hot hatches do these days. Meaningless stat that.
For comparison, the average cyclist.......
~1000N @ 0.175m = 175Nm
The downside is you wont do that much past 85rpm, or for very long.
Righty ho, the results are in.
604 miles from 50litre tank so its a load of shite and its out.
Average worked out at 54mpg however it was saying that each journey was averaging over 70mpg so it clearly kids something.
However on a more serious note when removing the said resistor(which the clip broke on and was a t$%t to remove) i noticed a bung sat in the engine bay...............then saw gear box teeth!! uh oh
put some oil in and it came straight out the bottom.
Now the last time i noticed a change was about 18 months ago when i thought the clutch may have been getting rough so it could have happened then, there is no oil anywhere on the engine bay and its been running fine with no drones or whines etc.
So in short the 20p resistor has saved me breaking down somewhere random, how long i have had a dry gear box for i havent a clue but fair play to VW.
Next question, how much for a new gearbox, or recon one, any ideas
I was lucky to get 300 miles from a tank on the Puma, I estimated approx 25-30/gallon
Count-zero I thought it was just me. 270 and its running on the limit of the tank. Mind you that engine seems to go up the rev range waaaay too easily 😀
I recently bought a vw box from a breakers for 450. recon was looking over 1000. the box came with warranty and had done only 40k, have a look on ebay. another tip is if you find out what the box code is it will likely be fitted to lots of other vag group cars so i found its cheaper to buy the same box from a skoda or seat than it is for an audi, even though the box is utterly identical.
However on a more serious note when removing the said resistor(which the clip broke on and was a t$%t to remove) i noticed a bung sat in the engine bay...............then saw gear box teeth!! uh oh
Missed this earlier - good spot though!
Used gearbox.. £2-300 I suppose if it's an old car.