(car engine roaring) – The Dodge Viper is like baseball or driving on the right side of the road, is the most American thing ever.
So when Dodge shut downproduction on the Viper back in 2017, it hurt man.
And I hope I'm wrong when I say this, but it will be the lastAmerican made supercar with a beaten under the hood, and that hurts even more.
But, instead of living in the past, today, I'm gonna pay homage, we'regonna look at America's most track capableproduction car ever built, the Dodge Viper ACR.
So first, we're gonnatalk about that acclaimed pushrod v10 engine.
And then we're gonna diveinto some of the incredible engineering that went intothe aerodynamics of the snake, (mumbles) which helpedit set 13 track records all over the world, all whilebeing a quarter of the cost of a European supercarbrethren, let's go America.
(upbeat music) The Viper has always hadthe reputation as a car that is trying to kill you.
The first one in 1992had an eight liter V10, with no automatic transmission, no AC, no exterior door handles, no windows, no airbags, no analyze brakes.
So that gives you a senseof what Dodge was going for with the Viper.
They built a wild horsethat was buff, and mean.
And if you could get on and stay on, you could have the time of your life.
But watch out 'causethis is gonna buck you up and it's not a matter ofif, it's a matter of when, cue clip of a dude driving oneof these things off a cliff.
(car engine roaring) (woman screaming) Now the fifth gen Viper ACR is also definitely stilltrying to kill you.
It's still that same wild (beep–) horse, but now it's even tougherand it's even meaner with that new v10 under the hood.
But, this time, Dodge hasalso kindly provided you with a nice little saddle, toraj a new little buff pony, and that saddle is the aeroand with their powers combined, it is an insane beast that you can gallop, your happy little tush aroundthe tracks all over the world.
So let's talk about the horse.
Why, and how is this thing so crazy? Now this is the fifth gen Viperand it has things like ABS, an electronic stability control because it's federally mandated, but you can turn thosegadgets off and experience what it's like to control 645 horsepower out of an aluminumnaturally aspirated V10.
So what makes this engine so special? Well, first, it's what'scalled a pushrod engine.
And there are two main types of engines in mass produced vehicles today, you got your overhead cam motors, and you got your pushrod motors, also called overhead valve engines.
Now the Viper uses themore simplistic of the two and that's the pushrod.
And I say it's simplisticbecause overhead cam engines are typically more mechanically complex and are more complicated to operate, and from a production standpoint, they arrived on the scene much later on in the history of American made cars.
So let's explain the differencebetween the two engines starting with the overhead cam design.
Now, we've talked about this a bunch, but in an internal combustion engine, you need a way to get air in, and a way to get exhaust gases out.
And a few weeks ago, wetalked about the four cycles in a four stroke engine usingthe sweet acronym SS BB, suck squeeze, bang blow.
Now the piston draws airand fuel into the cylinder through the intake valves, squeezes it, a spark plug lights that air fuel mixture and explosion happens bang, boom, and the piston blows the exhaustgas out the exhaust valves, the process starts all over again.
Now the timing of windowsintake and exhaust valves open and close to let air in, andexhaust gas out might seem like it's magic, but in actuality, it's reallyjust very cleverly engineered, mechanical components at work, and that magical metalpiece whose job it is to control all thattiming is, the camshaft.
Now in overhead camengines, you have a camshaft that sits over the combustionchamber in the cylinder head, with the valves sitting below it, and the camshaft has these avocado shaped, people compared they say pear shaped but I'm gonna say avocadoshape because I'm cool.
Now the camshaft havethese avocado shaped lobes on them called cams, and the camshaft is beingdriven by the crank shaft by either a belt, or chain and that's called the timingbelt, or the timing chain.
So when the camshaft rotates, those avocado shaped lobes push down on the valve stems, which caused them to open and that lets freshair in and exhaust out.
So what about pushrods engines? ♪ Whuu! ♪ (upbeat music) well, the difference between a pushrod and a overhead cam motor, is in the location of the camshaft.
A pushrod engine has thecamshaft located inside the block rather than in the head.
And in a V engine like in the Viper, it's right between the V, right between the two rows of cylinders.
Now it's still connected to the crankshaft either by a chain or by gears, but it operates the valvesin a much different way.
So as the camshaft rotates, the lobes push on rods, the rods push the rockers, and the rockers push on the valves.
So if both engines do the same thing, they cause valves to openand they just go about it in a different way, while aoverhead cam engines considered technologically better.
Well first, is in theplacement of the valves.
Now in an overhead cam engine, because you have individual camshafts, operating the intake and exhaust valves, you can position those valvesat their optimal angle, which in turn helps theengine breathe better and therefore you can make more power.
And with a pushrod engine, your intake exhaust valves have to be inline simply dueto the nature of the layout of a pushrod engine.
Now because you onlyhave a single camshaft, you can't get funky withwhere you position your intake and exhaust valve.
Secondly, overhead camengines can rev higher.
Because the motion transferredfrom the cams to the valves is more direct with fewer moving parts, there's less reciprocatingmass to deal with.
Remember, with a pushrod engine, that motion from the cam, has to travel all the wayup the length of the rod to get to the valves.
So those extra parts, thatextra mass, is therefore harder to move and it's harderto move them faster.
I mean, watch this, when Istand next to this light switch, I can flick it on and off really fast.
My finger is in directcontact with the switch.
Now if I take a step back, and I try to turn that switch on and off with a broom handle, it is much harder to dothe same task quickly, even if I'm really good at it, like I'm the best damnbroomstick light switch flicker in the entire free world, I will still never be able to match the speed if my fingerwas directly on the switch.
So just so we're clear, thebroomstick is like a pushrod and overhead cam engine is my finger.
I don't know if I wasclear enough, I hope I was, I don't want to leave anybody out.
So the last advantage Iwanna talk about is that, with overhead cam engines, youcan alter the timing and lift through clever ways such as VTech or NVTC.
Now, we talked about variable valve timing and our 300ZX episodeshould go back and watch it.
But VVT is a way in which you can advance, or retard the timing of the valves using a specially designed camshaft.
And that is a great feature, because it allows the car to be more fuel efficient, you can produce more power, you can have better throttle response.
There's a bunch of goodreasons why you would want to have that.
And then a pushrod engine, you don't have the luxury of using multiple cams toalter your engine's performance on the fly, well, unlessyou have a Dodge Viper, as it turns out theengineers over at Dodge got all VVT jealous, and cameup with their own clever way of using variable valvetiming in a pushrod engine.
And I'm gonna get to that in a second, but first I wanna talkabout the advantages of pushrod engines in general.
I mean, there has to be areason Dodge still uses them and not only Dodge, what aboutChevy with their LS engines, one of the best engines ever made.
(car engine roaring) So first and foremost is thesize of a pushrod engine, they are smaller than overhead cam engine.
A single camshaft placedin the center of your V, means you have smaller cylinder heads, and smaller heads, mean asmaller overall engine package and that is great on two fronts.
For one, when you don'thave big cam sitting on top of your engine, you havemore space to work with when designing your engine placement.
Take the 300ZX for example, that car is (beep–) to work on and that's because it's got four (mumbles) and it's a big motor packedin a tiny, tiny space, people hate working on that car, you can place the enginelower in the chassis, which then lowers the center of gravity.
Having a lower center ofgravity, is obviously great when it comes to stability and handling.
There's a reason F1 carsare low to the ground, and you want as much massto be as low in the car as you can.
And not only that, but the engine itself has a lower center of gravity, with the camshaft being in the block rather than on top of the heads.
Secondly pushrod engineshave tons of low end torque and the reason they have thattorque in the low rev range, is because they usetwo valves per cylinder and more valves mightseem like a better option, but let me explain.
At low RPM, the air enteringthe cylinder is more restricted and then that air speedsup because of that, that sped up air is more turbulent and causes better fuel air mixing.
Higher air velocity plusa better fuel air mixture creates a better boom andthat means more torque.
And the ACR, it has a lot of torque the most in any naturallyaspirated gas engine, in any production car ever built.
It's at 600 foot pounds of torque.
Just think about that for a second.
Think about all the carsthat have been manufactured in the history of cars.
The fifth gen Viper ACR standsat the top of that podium in that category, that is wild.
So while the Viper has loads of torque, what about horsepower? How does that archaicnaturally aspirated pushrod v10 get you 645 horsepower in the ACR? Well, we gotta bring ourfavorite donut equation into the mix, we got more air, plus more fuel equals more power, and we can usually tackle themore air part of the equation by adding turbos, oradding a supercharger, but for Dodge and true Viper fashion, they did it the good old fashioned way.
They made it bigger, theykept it naturally aspirated, and they use displacement as their ally.
No turbos, no superchargers and when you're not using force induction, you need as much displacement as possible.
And the Viper does that byusing 8.
4 liters of displacement across 10 cylinders.
So I'm a visual person.
So to help explain how muchthat is, I have a bottle here, and it has exactly 840 milliliters in it.
The contents of this bottle will fill up only one cylinder in the Viper.
So imagine this times 10 (mumbles) 10 of those, that is alot of air getting pulled into the combustion chamber.
You might be asking, hey, how this is dude have afriggin graduated bottle because that's the last placeI worked in a lab, I stole it.
(laughing) Don't say don't put that in.
(upbeat music) I teased earlier that theViper has its own version of variable valve timing.
But how can a pushrod enginevary the timing of its valves, when it only has One camshaftand what performance benefit does that even get you, well, like all good engineering devices, the Vipers camshaft is quite ingenious.
Have you ever seen one ofthese types of drawings? (upbeat music) Well that's kind of whatDodge did with their camshaft, it's insane, it useswhat's called a DuoCam, now this Duo single cam system consists of a solid intake camshaft, within a hollow exhaust camshaft and the solid shaft hasholes for cylindrical pins five of them to be exactand when activated, they align with slots inthe hollow outer shaft.
The two camshafts, then become one and the exhaust timing is altered.
So why would you want this? Well the camshaft inthe Viper is considered a performance camshaft, normally this type of camshaft would be illegal in a production car.
Now performance camshaft isthere for one sole purpose and that is to increase performance.
(mumbles) But it also increases emissions 'cause you're basicallyjust sitting there, always churning at full bore.
That's why when you hear some muscle cars, they have that low sound, (mumbles) That is a performance cam andit is also almost definitely always not meeting emission standards.
So when you're trying tobuild a high horsepower, high torque engine thatis also street legal, you have to strike abalance between performance and emissions regulations.
So to combat that problem, the Dodge engineers use their new DuoCamcamshaft to reduce the amount of exhaust gas dilution at lower RPMs, making the Viper a more Eco friendly car, and the Viper was the firstproduction pushrod engine with VVT on the exhaustvalves, pretty nifty.
So that was the firstpart of the equation.
The Wild (beep–) beaten horseyou got bitwixe your thighs, but how do you keep a carwith such an insane engine on the road? Well, in the past withthe Viper, you didn't, the car was in a constantstate of trying to kill you.
It's what made it so charming.
Ted Bundy was a charmer.
And don't get me wrong, this ACR Viper stillhas the genetic makeup to put you six foot under.
But at least the engineersover at Dodge give you a bunch of aero so that when you start going fast, the less angry the Viper is at you.
Now the second half that makesthe Viper ACR the best car to ever come out of the USA, is its ability to stick to the ground.
We're talking about downforce.
(engine car roaring) Better understand downforce, I'll start by explaining lift.
Now with a plane youhave a wing like this, and as it goes along, youhave air that pushes up on it and it causes it to lift.
Now if we flip that wings upside down, the reverse happens and nowinstead of the air pushing up, it pushes down, andthat is called downforce or negative lift.
And in the car world we use a spoiler or rear wing to do that, andin the case of the Viper ACR, they use a very big spoiler, a1776 millimeter wide spoiler.
Yep, you heard it right, 1776 the same year the USA was founded because of course, this is the best car toever be built in America.
I'm trying to tell you guysthis, I'm preaching it.
I'm preaching the gospel, youwill be my flock of sheep.
I'm the Dodge Jesus (laughing).
And that's the size of thestandard wing on the ACR.
If you get the extreme aero package, it widens it by another 100millimeters to 1886 millimeters.
That's six foot two inches.
I'm six foot four inches, that's only two inches shorter than me, just laying there on the wings, it's getting air blasted down, wild man, even the material thewing uses is special.
And while most wings havesome sort of structure core to support it, the ACS wing is hollow and it uses only fourlayers of carbon fiber, but it's still amazingly strong.
And there's even structuralsupport built into the trunk to help support all thatdownforce created by this wing.
A full grown (beep–) man could stand on the end of this wingand it wouldn't break.
That is a really strongspoiler and trust me, that's the kind of school you want when you do a really dumb stuff like this.
(car engine roaring) That dude for sure lost his teeth, like he doesn't have teeth right now, like homeboy is COVID up withno teeth, just gum and food.
Homey, what are you doing? Don't ever do that (beep–)is so stupid (laughing).
That spoiler creates a ton of downforce, and I actually read afunny story about this.
A guy who was towing hisViper behind his truck in an open trailer, was getting two miles pergallon horse fuel economy because of how much force theViper spoiler was pushing down on the rear end of the trailer, slowing his truck down ashe was towed along the road.
That is pretty cool, I mean sucks for him, but pretty interesting.
So if you have all thatadded force pushing down on the back of the car, why doesn't the Viper just do a wheelie? (mumbles) Well, there's a bunch of goodies up front that helped create downforceon the front end of the Viper.
First, there's a frontsplitter that sticks out about five inches past thebumper in the front of the car, and it also goes a couple feet in towards the center of the car.
And like the rear end diffuser, there are these vertical strikesand those vertical strikes, they keep the air confined in that area, it traps the air in, so youdon't lose any downforce when you're turning.
It's the same reason whythe wing has vertical ends on the two sides.
It's like a book-end itkeeps the air right in place.
Adding even more downforceare these little winglets on the front bumper, andthey have two purposes like the rear wing, theyhelp produce downforce and actually if you look close, they also have vertical edges on the side to keep the air in place.
And the second functionthey have is a thin air to help cool the brakes.
So moving to the fendersthe ACR has louvers.
And the purpose of louvers isto vent high pressure building from under the car.
So what does all theseaero bits equate to? Well, it equates to the mostdownforce in any production car ever built, 800 kilograms, 1700 pounds when it's going to topspeed of 177 miles per.
And the more downforce you make, the better your car grips the track.
And the better your car grip track, the faster you can take corners, and the fast you take corners, the more track records you set.
(car engine roaring) Now all that downforcecomes with a trade off and that trade off is drag, and now drag is just air resistance.
It's the force acting oppositeto the relative motion of whatever moving on object you have.
So with the aero package, it takes the bass Viper with a coefficient of drag a 0.
37, and it bumps it up to 0.
That increase in drag, effectively decreasesits top speed as well, so you lose 29 milesper hour on the top end.
And what the ACR lost in topspeed it more than made up for it in the corners.
And when it was released, it went on a run ofdestroying track records across the globe.
Dodge took the old school beast of a car with some engineering turnedit into an amazing machine.
It sucks it's not around anymore, man.
It breaks my friggin heart.
It's one of my favorite cars of all time, and for the money there's nota more capable car out there.
Hopefully one day they'll make another one and it'll try to kill you just as hard.
Thank you guys so muchfor watching this episode of Bumper 2 Bumper.
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Follow us on Instagram@Donutmedia, follow @Jeremiahburton if you got a Viper ACR, you got any Viper, hit me up show me somepictures of a man's.
One of my favorite cars of all time, I had two posters in myroom as a kid I had a Viper, second gen Viper blue with white stripes, and I had a purple Lamborghini Diablo.
I'm gonna have both of themone day you just watch.
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Stay safe out there, bye for now.
(car engin roaring).