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On paper the new Alfa Romeo Giulia Quadrifoglio sounds exceptional with a reasonable MSRP of $73,595. In exchange buyers will get a twin-turbocharged 2.9-liter V6 powered luxury vehicle with an output of 505 hp and 443 lb-ft of torque.

AutoAvanti managed to get their hands on one and dyno tested a rear wheel drive Giulia Quadrifoglio. Uploaded onto their Youtube channel as part 5 of their “Owning an Alfa Romeo Giulia Quadrifoglio” series, enthusiasts will be able to see just how much of that power is transferred to the wheels.

Drivetrain power loss is expected when it comes to dyno tests as the output is measured at the wheel and not at the crank which is what the auto industry published. The Giulia Quadrifoglio was no different as it took a 113 hp hit and only put down 392 rear-wheel horsepower. Torque output also showed numbers lower than those listed by Alfa Romeo at 389 lb-ft.

That may sound surprising as the power loss is on the high side of average, but the Mustang AWD Dynamometer they used may have affected the final result. Its rates are lower than that of the DynoJet or Dyno Dynamics. Some commenters asked about using a two-wheel dyno instead of an all-wheel one, but AutoAvanti says that the Giulia will go into limp mode if that happens.

You can watch the full test below and let us know what you think.

 

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Well - its as fast as the C63s (500 hp) in testing so I tend to believe Alfa's numbers.
I have had many cars dynoed over the years, my experience is 20%-23% power loss to the rear wheels from a front engine car is normal. its called physics.....
 

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E=mc^2

I have had many cars dynoed over the years, my experience is 20%-23% power loss to the rear wheels from a front engine car is normal. its called physics.....
Sooooo

what happened with BMW's M3/M4?

Also the 1M?

(look up some dynos, then compare to the rated numbers)

"On K&N’s dyno, the M3 put down 379 horsepower at 6600 rpm and 378 lb.-ft. of torque at 4300 rpm. BMW rates the engine at 425 hp at 5500 rpm and 406 lb.-ft. of torque at 1850 rpm. Using 13 percent as a rough estimate for drivetrain loss, the figures are spot on. The peaks are different, but what’s more important is the shape of the curve. This chart effectively represents what happens when you stomp the gas in fourth gear at 2300 rpm. Look how quickly the torque builds and look how consistent its delivery remains. Horsepower doesn’t begin to fall off until before 7000 rpm, and not by much. As a result, the S55’s power delivery feels broad, no matter where you pick up the throttle." - Motortrend

Here's another one

"EAS strapped an M3 to its dyno and recorded an absurd 424 horsepower and 426 lb-ft of torque—at the wheels. BMW claims that the M3 produces 425 horsepower and 406 lb-ft at the crank. Accounting for the typical 15 percent driveline losses from friction, etc., this means the 2015 M3 is really putting down something in the neighborhood of 480 horsepower and 480 lb-ft of torque at the crank. Assuming the M3 used for this dyno pull is real, that’s awesome news for future owners of the M3 and its two-door sibling, the M4." - blog from Car and Driver - with video..

Argue that its over rated thats fine and then alfa is under rated right? then why does the giulia out perform the m3? if its making roughly the same power?

too may variables..


and then explain

how the 0-60 times make sense vs all the competitors in its class........

physics right? i mean lets take into account, limp mode if not properly set up, altitude, weather, the dyno itself, then compare....... if it was identical situations, then so be it...
 

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One dope on the M3 Forum is now arguing that the Alfa only makes like 30hp more than the Quadrifoglio thanks to this lousy dyno test. Totally inaccurate. Really wish this dyno, of all dyno results, was never posted. Now we have to listen to idiots claim the Alfa is over-rated while the M3 is "under-rated". Ugh!!
 

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I have posted it sometime before, you can do so many things wrong on a dyno.
It makes a difference if the car sits on top of the roll or inbetween two rolls (like in this video). It even makes a difference if or how hard you strap the car onto the dyno.
If you strap it harder of course there will be more friction and therefore less hp at the wheels. However the crank horsepower is not lost in the drivetrain but because of the friction between the tires and the dyno.

Of course you want to know, how many horses you are putting down at the wheels, however a dyno run is never complete whithout measuring the "breaking-power" at the end of the dyno run to get a feeling on how much friction there is between the crank and the dyno (you cannot tell whether it is the drivetrain or the dynosetup)
As the Giulia is using the same ZF 8-speed like most of its competitors (not the M3 oder C63) the loss should be somewhere in the same range. The torque vectoring diff should generate a little higher loss
 

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Speed Sensors and Air Flow....without either satisfied the car will pull power. Plain and simple.

One benefit of this lower reading, in the real world, is the perception of a weaker car....which will catch a few folks off guard :)
 
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Its alright, she has Mafioso backing her up!
Honestly, she looks like she's under serious duress while filming that statement!
 
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maybe someone can riddle me this...when it comes to Dyno numbers....
I believe we all concede that "physics, temp, atmospheric conditions etc" all play into getting a Dyno reading from a Chassis Dyno...whatever brand...

what about a good old Bench Dyno??...back in the engine building days you would throw the block up and run the numbers...these would be what I would call Pure numbers....THEN deduct whatever percentage range to get your RWHP....no?? is that acceptable??
Do manufacturers do that when they create a new engine for a line???
Thanks
M
 

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maybe someone can riddle me this...when it comes to Dyno numbers....
I believe we all concede that "physics, temp, atmospheric conditions etc" all play into getting a Dyno reading from a Chassis Dyno...whatever brand...
All those factors do effect the results, however the dyno software is normally used to correct the numbers to standard conditions.

what about a good old Bench Dyno??...back in the engine building days you would throw the block up and run the numbers...these would be what I would call Pure numbers....THEN deduct whatever percentage range to get your RWHP....no?? is that acceptable??
It's not really an option. First you would have to pull the engine out of the car. Then you would have to fabricate a bell hosing adapter to connect it to the dyno since you can't purchase one. Then you would have to connect it to enough stuff so that the engine's ECU thinks it's still in the car, and this would take a massive effort.

Once it's all done, there will still be debates because engine dynos and testing conditions vary just as the wheel dynos do.


Do manufacturers do that when they create a new engine for a line???
Thanks
M
Yes, they do, and it's in an environmentally controlled room.

Greg
 

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All those factors do effect the results, however the dyno software is normally used to correct the numbers to standard conditions.



It's not really an option. First you would have to pull the engine out of the car. Then you would have to fabricate a bell hosing adapter to connect it to the dyno since you can't purchase one. Then you would have to connect it to enough stuff so that the engine's ECU thinks it's still in the car, and this would take a massive effort.

Once it's all done, there will still be debates because engine dynos and testing conditions vary just as the wheel dynos do.




Yes, they do, and it's in an environmentally controlled room.

Greg
thanks for the clarification/insight...so ASSUMING..and I hate to do that...the QV block was indeed done in that fashion..the 505hp rating is a true number...I don't see why they would under OR over rate the numbers.....if you OVER rate them you will surely get caught in the fib....and UNDER rating nets you nothing...I would think that you would want to scream how much HP you make especially today...that we live in the land of the 707Hp Hellcat>:)

My butt dyno tells me the QV is **** close to 500hp all day....and it just continues to pull even in the upper rev range when most other Turbos start to lose steam....
 

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I am certainly not saying that the QV is over or under rated. However there have been cases of engines being under rated to help control insurance rates. I doubt that's the case here. I don't think it's over rated either, in all likelihood it has every one of those 505 horsepower, and if it doesn't then it's beating these other cars through magic.

Greg
 

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^^ Correction factors applied.
It's not exactly a correction factor, but the simulation of the transmission losses, which by the way are surprisingly low(7,4%*) which show the efficiency of Giulia thanks to its transmission and carbon fibre shaft, if not you would have the wheel horse power.

obviously ;)

However, it also gives wheelpower in the video :
475 Hp @ 6600
570 Nm @ 3400
of course but manufacturers measure the power output at the engine's flywheel(BHP) and not at the wheels(WHP).


*usually transmission losses are around 15% for RWD, and 20-25% for AWD.
 
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