Did I say slow break ins ONLY happen with turbodiesels? I'm just mentioned that it does happen remarkably often for turbodiesels. Not to mention 300,000km overhaul intervals for some hard working units (towing, off road racing, etc). Tristan and his wild assumptions...

I'm not saying gears change power levels. I'm saying narrow power bands need tight ratios to keep them in their usable rpm range. Maybe tristan is simply too mentally lazy to think about what I mean...

With wide powerbands, you can achieve similiar or superior overall performance with less gears. This is very obvious on the exits of tight turns. No need to shift so often and loose time to gearsifts.

I was just saying for a given peak power, wider powerband is superior overall, irrspective of engine type. BTW, most quantify the width of a powerband via absolute rpm numbers alone. This is VERY wrong.

Lets say a 7000rpm redline engine has a 3000rpm powerband (4000-7000rpm). An engine with a 5000 rpm redline has a 2800rpm powerband (2000-4800rpm), peak power at say 4600rpm and peak torque at 2000rpm, all the while keeping a relatively flat torque curve. Given they both produce the same peak power, the 2nd unit actually has a superiory powerband. Why? Because a larger proportion of the usable revs (idle to redline, assuming both engines have enough torque to idle of in a smooth start) is usable for good acceleration. The 2nd unit could also make do with say 5 instead of the other's 6 gears and still perform similiarly or even better. Of course, I'm saying this is true for all engine types, though tristan might just come up with some wild excuse or assumption just to try to piss off someone he doesn't personally like. And of course, this is rather simplistic, though of course to really understand this needs numerical and graphical data.

This all assumes that aall else is closely matched, of course. Or tristan is again too mnetally lazy to deduce such an obvious assumption.

Multitasking a "new" buzzword? Wow, didn't know that. That word has existed since computer geeks and the idea of concurrency in computers existed, so how?!? If I'm just another join anything new bandwagon guy, then why do hate Windows vitsa so much? It's new, right? Well, it's basically nothing more than a resource hog with no real benefit to date, that's why. I tried and found nothing particluar good about it. Does a great job of turning your multicore Ferrari into a stegosaurus. Again, tristan and his fanboy accusations...

I'll let you in on something about me. I used to be somewhat like you, believing RWD and petrol engines are the only way to go for race and general perfomane applications. Petrol engines eem the best not because they are truely fundamnetally superior to all other enigines. It's the result of having enjoyed a seriusly overprivaledged level of development. The more one delves into technological history and scinece, the more apparent it gets. Remmeber flame, ignition, killer exhaust fumes that spew out sulphur clouds, etc? Then again, tristan might not be a student of technological history...

But when alternatives are allowed to develop as well as that particular narrow category of vehicles, any reasonable and logical person is forced to reevaluate things. There's more than one way to achieve a given requirement.

Wind power is good for the environment? What made you think I'll say such a thing? Fact is, they could cause all sorts of trouble, from spoiling the scenery to disrupting wind patterns in undesirable ways. Conservation of energy is always applicable as far as physics can knows, so power form the wind is NOT free.

Solar power? Hmmm, Unreliable, inefficient (best cells typically used are just over 10% efficient!) and HIDEOUSLY expensive. Solution? Not until solar cell efficency goes WAY up. Could take quite a while...

Besides, those reflective surfaces could cause major problems for types that use concave reflectors to concentrate liht onto a tube of fluid...

Geothermal, a great idea if you live in say, Iceland? Your not going to cause much extra change. It's just the use of heat that the earth already spews out itself. Reliable too, since the earths core won't cool down any soon...

All this based on engineering/scientific literature, personal experience of working with them and field expereince from field experiments and real life users.

Anyway, gotta go for now. Work, work, work...

As I did read solar panels never make more energy that is needed to make them, something along those lines it was, don't know how closely true with wind power plants.

We have some wind power plants in LFS, are they disturbing wind pattern in Blackwood so that you will get less speed from diesel or what was point with those here ?
I guess, I'm lost again, but could you two just agree to disagree?

Quote from Jamexing :

Did I say slow break ins ONLY happen with turbodiesels? I'm just mentioned that it does happen remarkably often for turbodiesels. Not to mention 300,000km overhaul intervals for some hard working units (towing, off road racing, etc). Tristan and his wild assumptions...

You implied it was specific to turbodiesels. Read your post again and you'll see.

Quote from Jamexing :

I'm not saying gears change power levels. I'm saying narrow power bands need tight ratios to keep them in their usable rpm range. Maybe tristan is simply too mentally lazy to think about what I mean...

No, I am sufficiently unlazy to realise that what you originally said wasn't technically accurate. Your new sentence, above, is better laid out, and makes sense.

Quote from Jamexing :

With wide powerbands, you can achieve similiar or superior overall performance with less gears. This is very obvious on the exits of tight turns. No need to shift so often and loose time to gearsifts.

Indeed you can, but so many diesels now have 6 gears, and very narrow powerbands, even though they have flat torque curves, so it's not always so simple. Our Audi, for example, would be awful to drive with 4 gears because it's power band is so narrow, but without being peaky.

Quote from Jamexing :

I was just saying for a given peak power, wider powerband is superior overall, irrspective of engine type. BTW, most quantify the width of a powerband via absolute rpm numbers alone. This is VERY wrong.

I love your little asides - 'by the way, did you know...' Yes thanks, we did.

Quote from Jamexing :

Lets say a 7000rpm redline engine has a 3000rpm powerband (4000-7000rpm). An engine with a 5000 rpm redline has a 2800rpm powerband (2000-4800rpm), peak power at say 4600rpm and peak torque at 2000rpm, all the while keeping a relatively flat torque curve. Given they both produce the same peak power, the 2nd unit actually has a superiory powerband. Why? Because a larger proportion of the usable revs (idle to redline, assuming both engines have enough torque to idle of in a smooth start) is usable for good acceleration. The 2nd unit could also make do with say 5 instead of the other's 6 gears and still perform similiarly or even better. Of course, I'm saying this is true for all engine types, though tristan might just come up with some wild excuse or assumption just to try to piss off someone he doesn't personally like. And of course, this is rather simplistic, though of course to really understand this needs numerical and graphical data.

Actually, you haven't over simplified this at all. It's already an incredibly basic concept that I think every car nut with a vague understanding of gearing and torque will have worked out on their own.

Quote from Jamexing :

This all assumes that aall else is closely matched, of course. Or tristan is again too mnetally lazy to deduce such an obvious assumption.

No shit Sherlock? You mean for any comparison to hold water you have to change just one variable at a time, and keep the others consistent? Blimey....

Quote from Jamexing :

Multitasking a "new" buzzword? Wow, didn't know that. That word has existed since computer geeks and the idea of concurrency in computers existed, so how?!? If I'm just another join anything new bandwagon guy, then why do hate Windows vitsa so much? It's new, right? Well, it's basically nothing more than a resource hog with no real benefit to date, that's why. I tried and found nothing particluar good about it. Does a great job of turning your multicore Ferrari into a stegosaurus. Again, tristan and his fanboy accusations...

Fanboy? Of what exactly? I agree about Vista. But, unfortunately, 'multitasking' IS a new buzzword outside of computer speak. As your reference was to my non-computer life, I assume you meant that I should multitask or something. Only in the last four or five years has the term 'multitasking' been used in such social contexts. Or maybe you think computers aren't a modern invention as well?

Quote from Jamexing :

I'll let you in on something about me. I used to be somewhat like you, believing RWD and petrol engines are the only way to go for race and general perfomane applications. Petrol engines eem the best not because they are truely fundamnetally superior to all other enigines. It's the result of having enjoyed a seriusly overprivaledged level of development. The more one delves into technological history and scinece, the more apparent it gets. Remmeber flame, ignition, killer exhaust fumes that spew out sulphur clouds, etc? Then again, tristan might not be a student of technological history...

Sure petrol engines have had more development, but mostly because as a basic concept they are better suited for life in the 20th Century. I don't blindly believe them to be better, and when diesel, or any other source, becomes better then I will want that instead. But petrol is so hugely better at driving cars than diesel on racetracks that I cannot come to any other conclusion. 4WD might be a bit quicker in some cars on some tracks, but they are so boring to drive and race that I can't understand why anyone would want to. I suspect you aren't a 'student of technological history' either, otherwise you wouldn't say stuff like this...

Quote from Jamexing :

But when alternatives are allowed to develop as well as that particular narrow category of vehicles, any reasonable and logical person is forced to reevaluate things. There's more than one way to achieve a given requirement.

There is more than one way, yes. And I do/will re-evaluate things, but there is no contest yet between diesel and petrol for performance cars...

Quote from Jamexing :

Wind power is good for the environment? What made you think I'll say such a thing? Fact is, they could cause all sorts of trouble, from spoiling the scenery to disrupting wind patterns in undesirable ways. Conservation of energy is always applicable as far as physics can knows, so power form the wind is NOT free

Correct

Quote from Jamexing :

Solar power? Hmmm, Unreliable, inefficient (best cells typically used are just over 10% efficient!) and HIDEOUSLY expensive. Solution? Not until solar cell efficency goes WAY up. Could take quite a while...

Correct

Quote from Jamexing :

Geothermal, a great idea if you live in say, Iceland? Your not going to cause much extra change. It's just the use of heat that the earth already spews out itself. Reliable too, since the earths core won't cool down any soon...

Correct

Note, all of these could have 400 years of discussion on them, so other readers mustn't draw conclusions from such short sentences.

Quote from Jamexing :

All this based on engineering/scientific literature, personal experience of working with them and field expereince from field experiments and real life users.

Oh, I see. Not only do you personally design and install wind farms and geothermal plants, but you also designed the best diesel engine, work on F1 cars, created the universe...

I love that Americans don't understand irony - James certainly doesn't. Read my posts again with an irony alert, and you'll see James fall for it EVERY time...

Quote from Jamexing :

Anyway, gotta go for now. Work, work, work...

Of course. Don't we all.

Please, jamesxing and tristancliffe, could you have your discussion where it belongs? In private? Or would you guys be missing the audience?

No way, continue it here.
:munching_
:bitehard3

BMW won the Nurburgring 24hr in 1998 with a diesel engine.

Just sayin'...

Quote from Linsen :

Please, jamesxing and tristancliffe, could you have your discussion where it belongs? In private? Or would you guys be missing the audience?

nah, I like it here

Jamexing will never be able to form a convincing arguement without matching tristancliffe's mastery of the multiquote addition this forum was gifted last year.

tristancliffe will never be able to win because he is always on the defensive, similarly Jamexing can not win if he continues to make offensives without checking his facts.

Either Jamexing needs to locate a substantial library with a few hundred books on the physics of motorsport, tyre development, new engine technology, and the proper use of English and the formulation of a water tight arguement.

Or, tristancliffe needs to do more than prove he knows more than Jamexing about the subject matter at hand, and genuinly educate him that we already know about everything he's "revealing" to us, the concequence of which being, he shall stop imbedding simplifications into "n00bs".

My own personal opinion, is that it does not matter even slightly within the Live for Speed context which is better, because real racing, and all it's plus points, stem from every competitor having a vehicle that is as similar to all the others as possible. This premotes tight, competative racing, where technique rather than fuel dictates the order of the cars accross the finish line. Except that I am not "revealing" anything to anyone, because we all already know this.

In conclusion, just because you are using standardised point, counterpoint, conclusion based arguements, does not mean you know what you are talking about. As demonstrated ever so clearly by this very post.

This thread is supposed to be about diesels, so let's have a look at some diesels. Unless there's something ineteresting about diesels to say, I'll rather have this thread permanantly closed.

http://www.worldcarfans.com/ne ... /audi-q7-v12-tdi-revealed

Not bad by both diesel and petrol standards. 80+bhp per liter isn't exactly underpowered. With 500bhp and 1000Nm from just 1750rpm to 3000rpm, flexibilty would never be an issue. That kind of peak power it achieves would be impossible if the torque band was absolutely terrible.

Let me remind everyone here that this is an SUV that goes to 100km/h in under 6 seconds. Not slow by any standard. All while meeting Euro V regualtions, sipping 11.9L/100km and generating relatively little noise.

Thi one's even more interesting:

http://automen.blogspot.com/search/label/engines

100hp/L is good even by turbocharged turbo standards. With this kind of power/ torque curve:

http://bp3.blogger.com/_CVOr0T ... h/BMW_diesel_engine_3.jpg

I don't see why modern turbodiesel powerbands are any worse than their turbo petrol counterparts. These days, many turbodiesels have powerbands that make them useful from maximum torque to redline or almost redline.

Note: Don't even look at toyota diesels. They do a great job of reinforcing old diesel stereotypes of great torque but TINY powerbands and complete inability to rev usefully to redline. NO toyota diesel I've driven so far is of any use beyond 3500rpm. Their latest turbodiesel prado carries on this horrible tradtion too:

http://www.caradvice.com.au/11 ... sel-gx-gxl-vx-and-grande/

http://prado.toyota.com.au/toy ... n/0,4668,1712_582,00.html

If you drive toyotas only, you'll be stuck in this "diesels can't rev properly to redline" paradigm forever.

WTH, they make HORRIBLE petrol engines too. Tiny and useless powerbands seem to be a toyota trademark (max torque at 6800rpm and 191ps, anyone?). They've installed a 6 speed manual/5 speed auto for their latest turbodiesel prado, but that won't compensate for a fundamnetally bad power curve.

BTW, I've recently seen a Lexus petrol powered car that has EIGHT gears! Speaking of pure sillyness. With cars like that, it's more vanity (aka me got bigger more than you muhahahaha) than genuine performance/economy. If I remember correctly, only the first 6 gears are actually of any real use. The top 3 are only useful if you drive at constant speed over absolutely flat terrain and No headwind or some taliwind.

Just an interesting car/engined to look at. May Dr Rudolf Diesel finally rest in peace. The irony of all this was that he invented CI (compression ignition) to empower farmers against the oil companies, allowing them to use their own products to generate mechanical power. It's amazing how history has this tendency to come around...

The poor guy was robbed and left for dead in his final days, his corpse found a few days after his supposed death.

Wonder what would turbodiesels be like given another 5 years of development.

If only we have a V-12 6L 600hp, 1100Nm dieselturbo in LFS in a mid-engined 4wd rally monster. Max power at 4800rpm, 5000rpm redline. Maxiumum torque at 2500rpm, with an optimum powerband from 2500rpm to redline. Maximum mass with driver and full load of 1200kg, 45/55 F/R mass distribution, 4 wheel independant double wishbone suspension with 300mm of maximum travel. Progressive springs and frequency selective bypass (position sensitive) dampers. Spinning all 4 wheels at 100km/h on tarmac (with wet tires).

This thread was about the inclusion of diesel cars in LFS, right? Let's keep on topic and bring some positive life to this thread. No point bickering when we could all discuss some interesing automotive stuff for a change.

100bhp/L can be acheived easily, and reliably from a Petrol N/A, as in the case of the Civic Type-R, which has a bullet proof engine.
But if you want to compare it versus a sporty production road-going Petrol Turbo, then look at the Evo 8 F***ingQuick400. 200bhp/litre with warranty, and neither of these vehicles are exactly Exotic.

My own Polo is 170bhp/Litre and the only weaklink unfortunately is the gearbox. The engine itself takes it like a man.

Quote from EeekiE :

My own Polo is 170bhp/Litre and the only weaklink unfortunately is the gearbox. The engine itself takes it like a man.

I always thought the "G-Lader" would cause most of the problems in the G40. Is your one reliable?

Quote from z3r0c00l :

My own personal opinion

I laughed at that

Sorry for OT

Quote from EeekiE :

100bhp/L can be acheived easily, and reliably from a Petrol N/A, as in the case of the Civic Type-R, which has a bullet proof engine.
But if you want to compare it versus a sporty production road-going Petrol Turbo, then look at the Evo 8 F***ingQuick400. 200bhp/litre with warranty, and neither of these vehicles are exactly Exotic.

My own Polo is 170bhp/Litre and the only weaklink unfortunately is the gearbox. The engine itself takes it like a man.

I'm all too familiar with Mitsubishi Lancer Evoltuions compared to most here, and I do agree they are amazing pertrol engines, but people are really missing my point here. FYI, the FQ360 is a much better car overall, with excellent power but none of the severe turbo lag issues coupled with a much WIDER powerband. In layman terms, it's faster when the path gets tight and twisty. 4G63s are hardcore rally engines with the benefits of a development life that's lasted about 2 decades.

Just look back 5 years and all this was unachieveable. BTW, when was the last time you find a turbocharged petrol Mazda MX-5 with 100hp/L?

I'm familiar with those 2.0L engines from Honda with amaing specific power. Looks great on paper, but when you take a good look at their torque bands, they are horrible. Absolutely gutless at low revs, requring copious clutch slip or at least 3000rpm (and a lead foot) if there is any positive gradient.

http://autos.msn.com/research/ ... p;model=RSX&trimid=-1

Hmm.....

Max power at 7800rpm, max torque at 7000rpm? If you rev like a nutter 99% of the time that's great.

The classic example is the toyota engine I mentioned earlier: max torque at 6800rpm, max power at 7800rpm. Stalling and knocking are its middle names.

BTW, this makes for an interesting read:

http://www.grandpapencil.com/projects/concepts/diesel.htm

The more one delves into history, the more motives one finds for why NOT to develop diesel as far as it could have. Has a lot to do with bottom lines, etc but the important thing is that anything that has any potential to cut profits shall be suppressed or eliminated with extreme prejudice.

Back on topic, please. So, if anyone wants a diesel car in LFS, please bring forth some interesting vehicles/engines for discussion. We wasted enough time and server space on matters not directly related to the essence of the issue in question.

Quote from Jamexing :

BTW, when was the last time you find a turbocharged petrol Mazda MX-5 with 100hp/L?

1991 was such a year, when BBR made a 152hp 1.6 MX-5 via the Mazda network (i.e. officially approved and warrantied). But they also did a 200hp version with a few tweaks albeit without manufacturer approval. Various people have already got the 1.6 engine to over 300hp in turbo form, which I guess works out at about 200hp/litre.

Bored of your discussion on diesels as you have completely missed the point, and the history of diesel, and how you think there have been conspiracies to halt it's development are wrong and tiresome... The fact that you haven't managed to provide evidence of a performance diesel that would be better on a race track in equal conditions to a petrol engine just proves my/our point. Skew the rules and anything could win...

Quote from herki :

I always thought the "G-Lader" would cause most of the problems in the G40. Is your one reliable?


I laughed at that

Sorry for OT

Yes it was, that's why I swapped it for an Eaton M45 charger


Jamexing, I was only quoting BHP/Litre figures because you were; and you were saying they were comparable to good Petrol engines, when they aren't.

The two I mentioned are just passenger cars. There are Porsches with BHP/Litre figures way higher than that of the Civic, with very broad powerbands. There are also F/I cars knocking about with more than 200bhp/Litre that don't have as much lag as the FQ400.
My own Polo pulls like a train through the entire rev-range, and it's a measly 170bhp/Litre. Still, even that makes 80bhp/Litre look puny.

Of course, you can double the power of the OEM miata engines. After say, slapping on a big turbocharger (intercooled of course), forged psitons, billet/forged steel/titanium conrods, ...... And hopefully the OEM gearbox doesn't blow up after 500kms of hard use..... Reinforcing the block (if possible) would be a great idea too. I've seen rotaries and even V8s in miatas, but that's another story.

As for the latest 996 turbo, variable geometry turbo does wonders for any engine. And I've seen a fair share of 750hp 996 turboes too. Twin turbocharging and practically rebuilt/redesigned engines. All very impressive. But then, such powerbands were achieved with... drum roll... turbo technology.

BTW, if that polo is going to be discussed, please provide full details (size, peak power/ torque and rpms, redline, powerbands, etc). To compare power per liter with say a 2.0L turbo with something like say a W-16 is plain silly. That silly W-16 from the veyron needed QUAD turbos to generate the required powerband. See what happens when some old corporate fart comes up with arbitrary goals?

If maximum specific power is all that matters here, just get a rotary. 350hp form 1.3L(approx.260hp/L)! Along with a quart of oil every 5000kms, temperamental apex seals, fuel consumption that make SUVs look like econoboxes, ......

As for racing, for better parity between petrol and diesel, use the dakar rally as an example. 2.5L turbo vs. 4.0L petrol. Both finished really well. In fact, it's an achievement just to finish. BTW, the diesel touregs were actually FASTER than the petrol Pajeros over single stages.

Honestly, no one really knows how to setup absolutely fair rules for diesels and petrols, so drop the rule excues. Both engines have their merits and problems, and only time and experience will teach us how to regulate them in a fair manner. As technology is allowed to progress naturally, both engines will only get more equal in terms of performance for a given capacity, induction pressure, etc.

I still rememeber how the mazda rotaries were effectively banned after their winning race. They simply used the rules to cripple it beyond any hope. Wonder what would have happened if they allowed it to develop properly by tweaking the rules over time to allow gradually increased parity among different engines instead of effectively killing it after a single win. I'm perfectly happy with improving parity, but to cripple any new engine to non-competitiveness goes a long way to explaining why all alternatives to petrol engines for performance use were effectively suppressed for a long time. It's like condenming children to slavery before they even had a chance to learn some useful skill/science.

The real question is, do we REALLY want to eliminate all possible rivals to 4 cycle petrol engines for race use, or do we want to allow more engines to develop so all will benefit while justifying motorsports beyond the sheer waste of resources of a gluttonous few?

Please, get back on topic.

It is on topic.

A rotary engine is pretty much as far opposite from Diesel as you can get. Probably why they strangled it out of the rule books for use in competition versus regular 4-stroke like you say.

Where did anyone mention the Veyron? Are you trying to compare my Polo to a Veyron?

The Polo is a baby 1272cc Supercharged 8v engine. It has not been dynoed, but spark advance has been tailed off on the map to stop the suspension turrets pulling away from the bulkhead (needs welding) and to stop it from shredding the teeth on the crownwheel.
So basically, it's a petrol F/I car, with no lag, no flat spots, running at the limits of the current chassis state. Remember, we're discussing engine tech here, not transmission or chassis.

The Veyron didn't NEED Quad turbos.

There are N/A Porsches with over 100bhp/litre with large powerbands.

As for the 750bhp Porsche you mentioned:

Quote :

But then, such powerbands were achieved with... drum roll... turbo technology.

How do you think TDI's work? Show me a N/A Diesel Race/Sporty engine.

And there's more to broad powerbands than just "turbo technology". There are many things common to all N/A engines that need to be tuned and adjusted to best use the boost and reduce lag. This is engine tuning, not cheating.

Enginetuning is all about getting fresh air into the combustion camber and getting all the burned air out again as fast as possible

True. It didn't absolutely NEED quad turbos to get 1001ps. But that's not my real point. My point is after exhasutive testing they discovered that a quad small turbo system was required for a nice and flat torque curve they set out to achieve. It could theoretically do it with one BIG turbo, but packaging and other issues make that a silly option. They tried twin turboes, only to end up with undersirable torque crurves.

Stangle everything that's NOT 4-cycle petrol piston engines? Great idea if you're obsessed with removing all possible alternatives. Also makes racing a technically boring experience. Slowing it down OR removing some other advantage is OK if it evens the odds a bit. To absolutely KILL IT just reaks. At this rate, no alternatie to petrol piston engines will ever show up, no matter how much undeveloped potential there is. Or would we all rather play straight into toyotas marketting hype and make do with the prius?

Ah, WTH, most rather watch a bunch of monkeys on flintstone spec vehicles trying to get each other killed...

Next thing we know the greenies will be even MORE empowered and would finally ge their wish: sliminate all motorsports. Why are people so obsessed with playing into their trap?

Another point is that getting large engines such as 7.3L V8s to rev like Honda's high rpm engines isn't as easy as getting a 2L 4-pot to rev its guts out. The shear difference in rotational inertia makes this comparison impossible.

As for the NA porsches, they've grown proggressively larger in capacity and rpm. Explains both increases in peak power and torque. Sure, their powerbands are quite good, though they're no rally engines. They had the benefit of variable cam timing and lift that's been upgraded and refined over time too. Not to mention decades of tuning and technological experience.

And when did I say turbo tuning is cheating? Of course, it all goes down to getting air and fuel burned as efficiently and effectively as possible. So are the 2 any different in this sense? No. Of course I'm aware of all the mechanical monkey motion they employ with valve timing, lift, etc. And of course, the less the restriction on the airflow paths, the better.

Why turbos? To force more air into the same space, that's why! If airflow rate is thought of as current in an electric circuit, resistance as the engine's inherent airflow restrictions and voltage as the pressure differences, turboes simply get more "current" in via ramping up the voltage. It's a simple but VERY effective method to achieve great power. Well, 4G63s have been reliably generating beautiful power and torque curves WAY before any NA tricks like valve monkey motion, etc were employed. I'm just saying that turbos allow the generation of excellent powerbands relatively more easily, with nothing more than a quick spooling turbo(s) and excellent boost control.

BTW, that polo sounds very non-stock. More like an overtuned monster. Never heard of stock vehicles needing detuning to portect drivelines. I wonder if you removed the cats too. Lag? Of course not. The blower's DIRECTLY connected to the driveshaft! How can there be any lag? Silly comparison vs. turbos. And I'll be more concerned about its durability if I were ou, unless you've gone all the way with internals too. Nothing insideous, just genuine concern for the poor thing. Just that in my experience, I've seen too many such projects end in disaster. Thank god you're smart enough to at least try preserve the car by retarding ignition. I'll be happy if you don't and if I happen to be your clutch supplier too.

In case you're wondering why there are no performance NA diesels, the reason is quite simple, really. They are already seriously overbuilt, and the extra turbo inducted air is great for everything form boosting power to keeping internals clean, pure synergy. it's simply the simplest way to boost airflow ASAP. Also, no one's ever tried to apply NA only tuning to diesels, so honestly, no one really has an answer to that. All we can be sure of is with today's fuel injection tech, it'll be be MUCH better than the old days.

Just in case you're all wondering, exhaust tuning works great on diesels too. The increase in power and torque from a change of 1.5inch diameter to 2.25 inch exhaust diamtere liberated as much as 10-15% out of both parameters.

So, do you all REALLY believe that the current boosts in turbodiesel power is all because of increasing turbo boost? Thats where its all wrong. TDI, common-rail, idrect injection, all work on the principle of injecting finely atomized fuel at high pressures. Fuel atomization is the key to efficient burn and getting better energy efficiency and less overall pollution.

....

Judas Preist, for the love of God......

... :rolleyes:

I know a lot of friendly pillows full of a lot less fluff!

lol, this is just so funny ... Jamexing is good at sticking his fingers in his ears and going "la la la la I can't hear you!"

I don't think he's managed to read and understand any post in opposition to his own so far. Good try though, Eeekie

Quote from Jamexing :

As for the NA porsches, they've grown proggressively larger in capacity and rpm. Explains both increases in peak power and torque. Sure, their powerbands are quite good, though they're no rally engines. They had the benefit of variable cam timing and lift that's been upgraded and refined over time too. Not to mention decades of tuning and technological experience.

Mate you're arguing with your own inner monolouge by the looks of it.

What are you trying to say with the above, and the Veyron examples? That to prove Petrols are no better than Diesels, they shouldn't tune them as much? Or not try so hard? The fact Petrols are better is because they get tuned?

The best way to get alot of power from an N/A engine after everything has been optimised is to increase the RPM it does, thus increasing the amount of work it does in the same amount of time. This practice doesn't work as well with N/A Diesels, which is why the only Diesel engines worth talking about are TDI. The only logical reason you'd want to make a sporty N/A Diesel engine instead of a sporty N/A Diesel engine, is if you wanted to make a sporty N/A Diesel engine. As it just doesn't make sense. Which then brings us F/I Diesel vs F/I petrol.

All you're doing is telling me why Diesels aren't quite as good as Petrols, while arguing the case of Diesels; it doesn't make sense.

Quote from Jamexing :

BTW, that polo sounds very non-stock. More like an overtuned monster. Never heard of stock vehicles needing detuning to portect drivelines. I wonder if you removed the cats too. Lag? Of course not. The blower's DIRECTLY connected to the driveshaft! How can there be any lag? Silly comparison vs. turbos. And I'll be more concerned about its durability if I were ou, unless you've gone all the way with internals too. Nothing insideous, just genuine concern for the poor thing. Just that in my experience, I've seen too many such projects end in disaster. Thank god you're smart enough to at least try preserve the car by retarding ignition. I'll be happy if you don't and if I happen to be your clutch supplier too.

I never said it was stock. Please bear in mind the Polo is the grannies version of the VW Golf, it is in no way a sports car.

The reason I mentioned supercharging was because you said a Petrol engine can never have a broad torque curve like a Diesel because of turbo lag (unless you actually tune them properly and use multiple turbos??! but ignore this point for now as it complicates things).
My point was, turbocharging isn't the only option to get a broad powerband on a F/I Petrol engine.

Superchargers aren't bolted to the driveshaft.

Again, I wasn't comparing them versus Turbos. I was comparing them versus Diesels with regards torque band. Stop creating your own arguments.

So long as correct A/F ratio is maintained the internals will be fine. The tuning shop that performed the work has yet to blow up a bottom end from excessive power, and they have engines far more strained than mine.

I have no problems with my clutch. It's a cerametallic paddle clutch, or is that cheating because I found a tuning solution to a tuning problem?

So just once again for completeness:

The whole point of bringing Supercharging into the thread, was to show you that a Petrol engine can have a wide usefull powerband, without having to have a massive Turbo that will lag. (Even though you can have multiple turbos and not the same problem with lag... if you tune your car correctly....?!??? :tilt

Add just to round it up, I have no problems with there being a Diesel car put into LFS. But for on the limit seat of your pants racing, I acknowledge that a PROPERLY TUNED Petrol engine that's well suited to it's chassis, along with a decent gearbox always wins.

Not that it's worth saying anything in this thread, but you one can have a wide useful powerband in a petrol / turbo engine even without lagless supercharging. Almost any modern turbo engine is a good example. 250lb ft from 2000 to 4500RPM is pretty decent, with a power peak at 5800.

Quote from Ball Bearing Turbo :

Not that it's worth saying anything in this thread, but you one can have a wide useful powerband in a petrol / turbo engine even without lagless supercharging. Almost any modern turbo engine is a good example. 250lb ft from 2000 to 4500RPM is pretty decent, with a power peak at 5800.

Good point. I still remember the 70s when any kind of decent turbo response and powerband was nothing but a dream. With advancements such as reduced bearing friction, reduced inertia via superstrong and lightweight materials such as titanium, twin scroll turbos, variable geometry vanes, EBC, etc, so much has changed. My message has always been about letting all potentially good technologies develop properly so we can really know how good/bad they are, not just suppress all alternatives to petrol 4 cycles.

Supercharging is a great way to get more power if you want to maintain the characteristic of an engine that already has a broad powerband and don't really need to seriously work on thge top end. This is true for all positive displacement superchargers, but centrifugal types work the same way as turbos too, so that's a different story. But end of the day, if you want as big a peak high rpm power number as possible, a BIG turbo is still the answer. of course you could do a supercharger/turbo dual system, but that just gets horribly complicated. What really limits supercharges is the same reason for their instant response: their direct belt connection to the crankshaft. This adds quite a bit of parasitic drag and there's a limit to how much rpm the belts could take before the get in trouble. More complicated mechanical monkey motion does mean more mechanical parts to worry about. You could control boost pressure with pressure release valves as well like turbos, though you'll still need horribly complicated gearing/clutcihng mechanisms if you really want to control the supercharger speeds properly. With turbos, just vent the right amount of pressure and overspeeding problems are cured. Simple yet very effective, with better mechanical reliability simply because of its simplicity.

BTW, the latest mini cooper s has just changed from supercharging to turbocharging to get better fuel economy while getting more power.

An interesting thing about the 2 fuel types is the parameters that define them. In terms of safety, diesel always win hands down due to lowered likelihood to spontanoulsy ignite in atmospheric conditions. Their quality is defined as cetane (of course there's stuff like unwanted algea, particulate matter, sulphur, etc but lets not dwell on those details for now ), basically how quickly it ignites in high compression conditions of diesel engines. If it wasn't for the current surge in diesel passenger car use, the fuel type would have been really neglected. Did we have diesel fuel like the 55 cetane BP Diesel Ultimate on the mass market we have these days just 15 years ago? Guess not.

The point is, the real reason why iesel engines still can't rev effectively to as high an rpm yet as petrols has a LOT to do with fuel quality. The real limit is the ability for diesel fuel to ignite ASAP and burn as quickly as possible. With increasing cetane, the diesel can't rev argument really starts to go down the drain. Again, it only goes to show my point that diesels aren't inferior to petrols imply because of their fundamental design. Another case of severely unfair disparities in development. 100 cetane diesel... POWERRR!!!!

With petrol, it's about octane. Basically the inability to spontanously ignite. Basically you want the fuel to survive as high a compression ratio as possible before donating on its own. So in this way, the desirable properties are very much opposite. With the ban on leaded perol, a simple shotcut to ridiculously high ocatne (100+MON!) was eliminated, but then they went on to develop new ways to achieve higher octane. All the modern high performance petrol wonders would simply be impossible if the octane of current petrol wasn't so high. Ever tried running the RB26T with 89 MON fuel? A CRIPPLING experience, eh?

Just some interesting things to think about.

Guy's here's an interesting read:

http://72.14.253.104/search?q= ... t=clnk&cd=1&gl=au

Just download the pdf file to read it properly.

Note that distilled and oxidized methyl esters have a cetane number practically identical to BP Diesel Ultimate...

Also note that Rapeseed Ethyl ester had been measured to as high as as 64.9 cetane on one test paper too. None of them are worse than petrodiesel if cetane is of the essence.

Of course there's a large variance simply because the production of biodiesel is still a relatively underdeveloped, thanks to neglect forced upon by you know whom. the current production methods for biodiesel still favour small scale producers such as farmers. Malaysia has a severe overproduction of palm oil, which coincodentally is great for making quality biodiesel with significantly better cetane than any petrodiesel. Power to developing nations is definitely no good for plans of world domination...

Wonder what happens if the normal diesel cetane reaches 60 (basically when you can't get anything worse than that from the pumps) AND diesel engines get optimized for such high cetane fuel...

Lots of untapped potential. Maybe the poor Dr. was right all along?

There's no need for them to produce and sell Diesel at the pumps of that quality. Just as there are petrol fuels that far exceed anything you can buy at the pump.

Supercharging vs Turbocharging is a different thread alltogether and it all boils down to personal taste. For road use, I much prefer drivability over chasing numbers.

I think some people need to learn to love something, but not keep trying to prove how superior it is. My car for instance, handles like a pig on ice, goes like shit off a shovel, and stops like Lisa Riley falling down some stairs but I blummin' love it, and wouldn't want to swap it for say a 205 GTI which I acknowledge would be a faster car.