The physics of a diesel engine - Audi R10 TDI

Discussion in 'OT Driven' started by Diesel Fumes, Mar 29, 2006.

  1. Diesel Fumes

    Diesel Fumes Guest

    Im sure you have all heard about or seen this car. What a machine!

    Anyways, im wondering how the fuck this thing works. I understand that diesels can be fast as I have a small displacement diesel motor which is way faster than an equivalent sized gasoline engine. I know diesels are very fast at accelerating once they are already moving due to the ideal torque curve, but how does it accelerate from slow speeds so fast? Why is it so quiet? WHy does the exhaust make almost no noise at all? Do you think there is a trend now for diesel race cars? Peugeot has already announced their diesel entry, who is next? Le Mans series with nothing but diesels?

    What cars will Audi be using this technology on? I have already read about an upcoming diesel Lambo which I am very excited about, but practically I will never own one. What about A8, S8 style cars or the upcoming A7? Will these cars be available with these massive torque-producing diesel engines? Watered down of course.

    If anyone has an informative link about the R10 I would like to see it.
     
  2. Chris87

    Chris87 flatoutperformance.com

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    Audi / VW already has a ton of awesome diesel engines available in many of their current cars. First with the Direct Injection's, and now with the Pump-Duese engines. The R10 engine technology will eventually trickle down into production engines.

    Here's a bunch of info that I have on the engine and the car. I've been 1/2 assed keeping track of it...

    5.5L V12 bi-turbo TDI with 650+hp, ~800ft-lbs of torque, and will be able to go 1-2 laps further per tank than with their old R8.
    [​IMG]

    [​IMG]

    "The usable power band lies between 3000 and 5000 revs per minute."

    Some more info here: http://www.fourtitude.com/news/publish/Motorsport_News/article_1851.shtml

    "For the first time ever, a diesel powered car has claimed pole position in a sportscar race. In Thursday’s qualifying session, Scotland’s Allan McNish broke the track record by over two seconds, impressively underlining the performance of the modern Audi TDI technology."
     
  3. Junkie

    Junkie re-tarded OT Supporter

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    Do you not understand what the torque curve is? It has a broader torque curve, therefore there are more RPMs it does well at and it can accelerate from more speeds well.
     
  4. Cachee0

    Cachee0 OT's Technical Recruiter, Send me your resume

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    I wonder if it sounds like shit???
     
  5. Chris87

    Chris87 flatoutperformance.com

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    ^^^

    It's literally completely quiet. Quotes from a member who was at Sebring...

    "BY FAR the coolest thing at the race was watching the new TDI P1 car... it is DEAD FUCKING QUIET. you hear the wind, tires, and gears and nothing else... its kinda creepy"

    And from someone else....
    "Those diesel Audis are just so quiet, the drivers have to watch the shift light past 3rd gear as the engine can't be heard over the wind noise."
     
  6. Diesel Fumes

    Diesel Fumes Guest

    Yes I understand what a torque curve is. It produces near max torque from ~1200 rpm all the way to its redline, whatever it may be, 5000 or something? I understand that diesels accelerate fast from a roll because the ideal torque is always available on demand, but horsepower does lack and usually doesn't come out until a higher rpm. Also, im assuming you have less revs in a diesel engine and also less gears.

    The party piece for my car is being able to accelerate fast through a road course, but when it comes to a dead stop and has to accelerate again, it is rather pathetic. But im sure this Audi is much more refined of course, but im just wondering how well it accelerates compared to other cars in the race.

    All the other cars in the race make earth shaking noise, yet the diesel makes none. I seen it on tv but im sure it does no justice. How much energy is lost to sound decibals on a gasoline race car?

    And yes, Chris, Audi and VW have many great diesel engines in their vehicles, but very few are seen here. I was rather upset to find out that VW wont be offering the TDI option in the Golf/Jetta until about 2008. I've driven 03 TDI Jetta with just a chip and 3" straight pipe and I was in heaven. I can only imagine what a Touarag V10 TDI would be like to drive
     
  7. Bugatti

    Bugatti New Member

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    They keep trying to reintroduce the diesel here in the US, but people don't get it. If the EU raises the price of diesel in Europe then we wont be seeing any of these anymore. I miss my old Audi 100 diesel it sounded like a motorboat, but ran like a train.
     
  8. Chris87

    Chris87 flatoutperformance.com

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    There isn't Mk5 TDI's in the states? :dunno: There is up here.
     
  9. Diesel Freak

    Diesel Freak ♂♂ Closet Crew OT Supporter

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    Nice article. The R10 probably has a 7 speed gearbox.
     
  10. machine81

    machine81 New Member

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    The TDIs are a dime-a-dozen in Seattle.
     
  11. Diesel Fumes

    Diesel Fumes Guest

    I live in saskatchewan :wtc:
     
  12. Chris87

    Chris87 flatoutperformance.com

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    :rofl: :Owned:




    ....Oh wait. So do I. :o

    Who the hell are you and what city do you live in? :o VW does have at least 1 tdi model in most of their cars. They were out in the mk5's nearly the same time as the new 2.5L's. I've probably seen more tdi's then any other new mk5 so far.
     
  13. YoSmoovKid

    YoSmoovKid New Member

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    :wavey: 2004 Passat TDi :wiggle:
     
  14. Cachee0

    Cachee0 OT's Technical Recruiter, Send me your resume

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    :ugh: see that would piss me off.:o
     
  15. Diesel Fumes

    Diesel Fumes Guest

    I was told by a dealer that the only MKV diesel is the Jetta for 06, but its gone for 07 and so are (all?) TDI models for 07. Something to do with the new low sulfar diesel or something?

    What kind of fuel does it use? Pump diesel or some high cetane with additives?
     
  16. Chris87

    Chris87 flatoutperformance.com

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    ^^^ That's weird. I havent' really been following up on the whole issue with low-sulfur diesel and everything, so I really have no idea what the deal is.
     
  17. Eurbauk

    Eurbauk New Member

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    I'm in Sask, too.


    The new mk5 TDI Jetta is borrringg..
     
  18. MrBucket

    MrBucket OT Supporter

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    no, they went down a speed from the r8 to a 5 speed, the reason was so they could make the gears wider and able to handle the extra power
     
  19. deusexaethera

    deusexaethera OT Supporter

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    It's quite simple. Diesel fuel has a higher spontaneous-combustion temperature, so the engine can compress it more before igniting it. (ignore the way that diesels ignite their fuel for the time being.) Because it can compress its fuel more, the engine can convert a higher percentage of the fuel's energy into force instead of heat compared to a gasoline engine. That's what makes it more efficient.

    Diesel also contains more potential energy than gasoline, so the more powerful combustion combined with the higher compression gives the engine more torque.

    The reason diesels can't rev as high as gasoline engines is because the higher compression puts more stress on the crankshaft. But since diesels make more torque, you can just slap faster gears on the drivetrain to convert that higher torque into higher speed at the wheels. That gives diesels similar performance to gasoline engines. Most people don't expect that, because in America most diesel engines are inside heavy trucks that are designed to haul loads instead of ass.
     
  20. spitfyre

    spitfyre OT Supporter

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    amazing technology
     
  21. JAFAR

    JAFAR FPS whore OT Supporter

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    :bowdown:
     

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