• Mar 16, 2010
2010 Dodge Viper ACR-X on the dyno - Click above to watch the video after the jump

There's something about glowing hot metal that gets our hearts racing here at Autoblog. Whether it's disc brakes on a racing prototype during an endurance night race or an exhaust manifold at redline during dyno testing, there's something about metal resisting the forces of incredible heat that appeals to the gearhead in us. That's why we took particular interest in this video of the new 2010 Viper ACR-X that shows Dodge's engineers going through final testing of its 8.4-liter V10.

Because it's built for the track and not the street, the ACR-X gets a few tweaks compared to the stock Viper V10. Gone are the catalytic converters and in go forged pistons, a modified calibration and long tube headers good for 640 horsepower and 605 lb-ft torque. Those headers not only look fantastic when the engine is off, they glow bright orange when the V10 is strapped to the engine dyno and revved to redline for sustained periods. You can see both the Viper ACR-X in action and the dyno tests in the video after the jump.



[Source: Dodge via YouTube]



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    • 1 Second Ago
  • 39 Comments
      • 4 Years Ago
      Cook some hot dogs on that sucker!
      • 4 Years Ago
      Post a link to the picture then (PLEASE:)!!!
      • 4 Years Ago
      When you push for more she gets mader and mader .
      love it.........
      • 4 Years Ago
      The Germans could probably send over a 3 liter diesel to kick it's ass!
        • 4 Years Ago
        If only they had one capable of doing that...
      • 4 Years Ago
      That is insteresting...

      But I see that glow as being untapped energy.

      TURBOS. This thing needs TURBOS. Turn some of that heat into more kinetic energy!

      I am not the biggest fan of hybrids... but why don't some hybrids re-cycle waste heat as electricity? A turbo impeller mated to a gear reduction, and an electric generator, if you don't want to use an intake air compressor, to cycle heat into pressure, and send it back through the engine again.
        • 4 Years Ago
        @BoxerFanatic :

        It's funny you should mention that... I remember reading a while ago (on AB Green, maybe) that one of the German car companies was looking for a way to use waste decay heat. Given the high energy density of gasoline, and the relatively low efficiency of an ICE, the wasted energy is tremendous (about 25kw/h per gallon). Unfortunately, recapturing thermal energy usually requires mechanisms that aren't packaging-friendly to vehicles that are already weight and space constrained.

        Imagine a boiler/turbine setup to recapture the 25kw/h of heat energy.... then imagine it bolted on to your car somewhere :)
        • 4 Years Ago
        Boxer: TURBOes are powered by the movement of air through the exhaust system. Not heat or a mechanical source. Mate a compressor to a reduction gear, and you have a Supercharger. Turbo = Air driven, SuperCharger = Gear driven. Heat is the common enemy of both turbo & super chargers.

        A cooler charge into the combustion chamber is denser and creates more power. This is why turbo & super charged cars have intercoolers.
        • 4 Years Ago
        Dr. Greenthumb...

        It is a common mis-understanding that a turbo runs solely on flow.

        Flow does have some effect, but heat and pressure do, as well.

        The impeller housing is tapered around it's spiral chamber, and the differential diameter change creates a pressure change, the pressure change helps spin the impeller faster.

        The exhaust flow doesn't account for 40,000 RPM turbo rotational speeds. Certainly not on a diesel engine that operates slower than a gasoline engine, anyway, but operates on much higher pressures.

        And according to the ideal gas law, heat is related related to pressure and volume, and heat increases in a specific volume raises pressure. changing the volume increases or decreases the pressure, as well.

        If pressure weren't a factor, a wastegate wouldn't work nearly as effectively, as it doesn't impede flow, but creates alternate flow, and relieves pressure.

        Like a turbine engine... a turbo-charger is driven by flow, and also by pressure and heat increasing flow rates within the impeller housing.
      • 4 Years Ago
      @BoxerFanatic :

      It's funny you should mention that... I remember reading a while ago (on AB Green, maybe) that one of the German car companies was looking for a way to use waste decay heat. Given the high energy density of gasoline, and the relatively low efficiency of an ICE, the wasted energy is tremendous (about 25kw/h per gallon). Unfortunately, recapturing thermal energy usually requires mechanisms that aren't packaging-friendly to vehicles that are already weight and space constrained.

      Imagine a boiler/turbine setup to recapture the 25kw/h of heat energy.... then imagine it bolted on to your car somewhere :)
      • 4 Years Ago
      What???? no airbag? with all that power, I just gotta smash it all up!
        • 4 Years Ago
        in soviet racing, YOU are the airbag
      • 4 Years Ago
      Those are headers, not an exhaust manifold.

      You all really don't know much about cars, do you?
        • 4 Years Ago
        @Syllepse

        you're seriously not getting it are you? how the he'll are you getting that he's correcting the whole article out of just one sentence?

        he's neither correct or incorrect in correcting AB. as said before, it can be called either depending on profession.
        • 4 Years Ago
        destroypop01, aren't you embarrassed that you had to say what you said?
        • 4 Years Ago
        @Syllepse

        really? you're kidding right? THE ARTICLE STILL SAID "EXHAUST MANIFOLD". he was correcting AB even though it didn't need to be corrected since they can be called either. but that isn't the fact.

        you and many other morons jumped on his balls because you didn't read the article and see that they called it an "exhaust manifold".

        you just feel the need to argue because you don't want to admit you were wrong and to say you're sorry.
        • 4 Years Ago
        Way to put your foot in your mouth chief!!! hahahaha It's better to say less sometimes isn't it?
        • 4 Years Ago
        This is infuriating. Can you really not grasp the difference? You made the same mistake the original poster did, and it shows your lack of reading comprehension. I'm not arguing because I can't read, or chose not to read. In fact, I only watched the video after seeing this post the second time.

        > "you and many other morons jumped on his balls because you didn't read the article and see that they called it an "exhaust manifold""

        Let's pretend this is the SAT.

        Read the first paragraph:

        "There's something about glowing hot metal that gets our hearts racing here at Autoblog. Whether it's disc brakes on a racing prototype during an endurance night race or an exhaust manifold at redline during dyno testing, there's something about metal resisting the forces of incredible heat that appeals to the gearhead in us. That's why we took particular interest in this video of the new 2010 Viper ACR-X that shows Dodge's engineers going through final testing of its 8.4-liter V10."

        The following segment is called a "True or False Test". The numbered statements are to be read and evaluated. If you think the statement is true, you write "true". If you think the statement is false, you write "false". Ready?

        1. "Exhaust manifold" is mentioned.
        2. "Exhaust manifold at redline during dyno testing" is mentioned.
        3. The referenced video is said to include footage of an "exhaust manifold".

        Number 1 is true. Number 2 is true. Number 3 is false.

        Let's continue, shall we?

        "Because it's built for the track and not the street, the ACR-X gets a few tweaks compared to the stock Viper V10. Gone are the catalytic converters and in go forged pistons, a modified calibration and long tube headers good for 640 horsepower and 605 lb-ft torque. Those headers not only look fantastic when the engine is off, they glow bright orange when the V10 is strapped to the engine dyno and revved to redline for sustained periods. You can see both the Viper ACR-X in action and the dyno tests in the video after the jump."

        We'll do this the same way. True or False?

        1. Exhaust manifolds are mentioned.
        2. Headers are mentioned.
        3. Headers are referenced in the video.
        4. Exhaust manifolds are referenced in the video.

        Number 1 is false, number 2 is true, number 3 is true, and number 4 is false. Do you want to know something cool? You can't reference something you don't mention. That the answer to number 1 is false implies that the answer to number 4 cannot be anything other than false.
        • 4 Years Ago
        You really don't know much about reading, do you?
        • 4 Years Ago
        @everybody who said it didn't say exhaust manifold in the article

        read the 2nd sentence.

        these are the type of idiots who flip through magazines and books just to look at pictures. only difference, they went straight to the video.

        here's a tiny lesson...

        read an article before jumping someones balls and correcting them on something that didn't need to be corrected.
        • 4 Years Ago
        Yeah, you must think motors and engines are different too!

        Wait... nevermind.
        • 4 Years Ago
        @Elmo

        How ironic. I very much suggest you take your own advice and READ CAREFULLY. The relevant part of the second sentence of the article is "Whether it's disc brakes ... or an exhaust manifold at redline during dyno testing, ... ".

        "Exhaust manifold" is mentioned. It is not, however, declared to be the subject of the video, which is what the first poster was complaining about. It seems that you missed exactly the same thing he did. Keep reading: "Those headers not only look fantastic when the engine is off, they glow bright orange when the V10 is strapped to the engine dyno and revved to redline for sustained periods." This is in the second paragraph, if you're having trouble finding it.

        The video is clearly described as showing the bright glow of the *headers*. This is what Andre pointed out.

        Nice try, and thanks for playing, but keep your comments to yourself if all you're going to do is insult someone without fully analyzing the situation.
      DMC194
      • 4 Years Ago
      AMERICAN RACING HEADERS ,WAY TO GO
      • 4 Years Ago
      destroypop01, exhaust manifold is actually the proper term for "headers." Maybe it is you that doesn't know much about cars.
      • 4 Years Ago
      One word: AMAZING!!!Seriously though, the 600 hp ACR was (and is) already amazing enough as it is, but the 640 ACR-x kicks plenty of rear ends :) I would like to know it's top speed though... The ACR tops out at about 180mph unlike the regular Viper Srt-10's 199mph because of increased downforce and drag.
        • 4 Years Ago
        @Saheed:

        The ACR tops out at 180mph, but only in certain situations. For example, the wing can be trimmed out quite a bit (it's adjustable), to the point where it isn't contributing much downforce or drag. The biggest factor is gearing... most ACRs aren't set up with top-end gearing. It's rare to get to a track where you are going to go over 160, so you would gear it for the purpose.

        Road cars will have the top gear set for fuel economy... not for what it can pull. For example, my Z06 could, in theory, go 270 in 6th - assuming I had the engine and tires for it. On the track, though, 6th is useless in the car (as is 5th most of the time).
      • 4 Years Ago
      meh.
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