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Discussion in 'The Backstage' started by Dolebludger, Oct 13, 2017.
I was gonna say...but then it all was said,..so here's a cool pic instead.
Torque baby, yeah!
I'm not familiar with these cars, but front wheel vs rear wheel drive can have a lot to do it. Also rear suspension design is a major factor.
Horsepower sells cars, but torque wins races.
The SRT8 Challenger I had was heavy, but the 475 lb-ft of torque made it accelerate like a rocket!
I built a 2013 Subaru WRX with the help of a friend who races them. My car puts 550hp to the ground. It has been dyno'd at least a dozen times to get it right. My wife has a C 63 which is advertised to have 480hp. On the dyno it is 435 or something like that. I had a M3, claimed hp 410, actual 360. I don't think there is a production car made in Europe that is even close to what they claim. If so I have yet to come across one.
I hang with liter sport bikes off the line. My 0-60 has to be somewhere in the mid to high 2s. I also have a 67 Camaro, before that a 69 302 Boss, also had a Z06. The guys I used to meet up with take their car home when I take the Subaru out.
Horsepower isn't s particularly good measure, especially if you know what it is. I'm not a car nut but I'd look at torque first. HP at the wheels second.
Agreed. Torque is critical, but equally important is the torque curve. It's the age old dispute between big-block and small-block drag racers.
Big-blocks can produce thunderous torque at low RPMs, but run out of breath quickly. Small-blocks tend not to produce serious torque until they get past 3K+ RPM's, but you can spin a small-block to 10K. So... You can launch a small-block off the line at 5K RPM and it will keep pulling all the way to the end of the 1/4 mile.
But at the end of the day, there's no replacement for displacement.
You want to see insane 0 - 60 times in a stock car?
Look at the Tesla models. One motor per wheel and GOBS of torque from these electric motors.
The C 43 properly equipped is also very close in price to the base C 63. But there is a big difference here. The C 63 IS NOT available with AWD. The C 43 has standard AWD. Very important difference for those of us who live where it snows. And AWD is a big help in acceleration times, because one does not lose all those micro seconds when the rear wheels are spinning and the car is going nowhere. The AWD system is so good that I cannot break the rear wheels loose on my C 43 -- even on gravel. And no, Jimmy, I don't think Car & Driver accepts modded cars and tests them as stock. It is IMO the premier car mag in the US. The test article explains that their test of the 2016 C 450 with the 7 speed trans produced a time of 4.6, 0 to 60 but that the time of the 2017 C 43 was lower to 4.1 because the 9 speed trans gave the car a lower starting gearing PLUS the fact that placing the newer car in Sport+ transmission setting on the 2017 raised the idle RPM from 500 to 750. Now, I personally don't care if my car gets to 60 in 4.1 or 4.6 or something in between. But I do defend the honesty of Car & Driver magazine. This magazine also got a 0 to 60 time of 5.2 from the 252 hp Audi A 4 sedan, with the explanation that the transmission didn't launch the car until its turbo 2.0 liter engine reached 3000 RPM. And that the 325 hp Ford Fusion Sport also tested at 5.2 seconds because it had only a standard 6 speed auto trans. So yes, the transmission and gearing does make a hell of a difference.
hp and torque are fixed, measurable values and can not the least say something about a car's performance on the street/different driving situations. Engines are built differently, develop their performance in different ways. On top there are things like Turbo charged or not and so on.
Manufacturers give their cars the character they want it to have. Be it a pull bull or a quarterhorse. I had a Volvo V70 once. AFAIR 200 hp. I replaced it by a comparable 5 series Beemer with 10 hp less. But those were bavarian Beemer hp and even though less power, way better acceleration and top speed. Different horses. Gear ratio wasn't the factor though but can of course be one
Next thing today is the electronic motor management which gives uncountable new options to let the horses run
Wish I could get a total electric car, because those things are beasts at performance -- at least some of them. Good for the environment too! But here is the problem. One has to consider where the quick (?) charging stations are. Some of us live in remote parts of the US, and charging stations are further apart than the range of the cars. There is one of the big Teslas on a used car lot here in Durango CO. It will be there for a while, and I'll bet I could pick it up for cheap. Why? Goggle up a map of the charging stations near me. That car would be only a "grocery getter" for me here.
...are we talking km/h? Because when you mentioned the A4, I assumed you meant the S4, but the 2.0 litre turbo means it must be the Quattro 2.0 TFSI. That's also a lot faster than it should be. 5.2 brings it within 0.3-0.4 of the S4 (which is actually the competitor for the C43), which is also Quattro and has more than a 100 more bhp (2.0 TFSI Quattro should be ~250bhp, S4 should be ~355bhp).
These figures are miles off all of the European figures I've seen.
Put it this way: the new 2018 Audi RS3. 400bhp, Quattro AWD, Double Clutch Trans, tiny, light hatchback. There is no way the C43 beats that thing to 60mph. No way.
We are talking miles per hour. The Audi A4 2.0 turbo quatro is advertised here as doing 0-60 mph in 5.9 sec. Car & Driver's road test put the 0 -60 time at 5.2 sec. The C 43 is advertised 0 - 60 in 4.6 seconds, and this mag's road test put the time at 4.1 I haven't seen a reported test on the S4 or the RS 3
My BMW 1M puts down more Power & Torque than what BMW claims. Porsche also under claim their numbers.
As an example the 1M states 250kW when actual is 262kW. Torque is 450Nm & 500Nm on overboost. From memory Torque on overboost was way over 520Nm.
Same with acceleration times with official being 4.9 seconds to 100km/h while it is isn’t hard to achieve 4.3 seconds to 100km/h.
For our US friends 100km/h = 62.5mph.
Torque of 520Nm = 383.5ft lbs.
Power of 262kW = just over 351hp.
The 1M weighs 3,218lbs.
Gear ratios, yes. How aggressive was the "tune" (throttle response, etc.)? Was launch control used (and all of those are very different)? Traction control has a major part in it as well; some are very aggressive, some allow a little slip for better acceleration. Traction plays a role as well. Unless all these cars were tested with the same tires on the same tarmac then you're going to see some differences.
Years ago the Subaru WRX STI was tested against the Mitsubishi Evo X. The Evo was "rated" at something under 300 hp, the Subaru at 300. The Evo was faster to sixty because it only had a five speed transmission. It took one shift (first to second) to get to 60. The Subaru was a six speed and required TWO shits (first to second, second to third) to get to 60. That alone lost it the 0-60 test every time even though it was more powerful, etc.
Oh, and I'd steer WAY clear of the Audi unless you like diving a nose-heavy pig around corners (let alone reliability). I've been stung by VAG way too often to ever bother again.
Either way, you have a very nice problem here!
Also, car maker's advertised horse power and torque aren't measured at the driving wheels. These ratings are taken (I believe, correct me if I'm wrong) at the power output of the transmission. Measurements at the diving wheels will always be less, due to poser loss in the part of the drivetrain that isn't measured.
To go back to the beginning of this thread, I posted it for the reason that I have researched a good number of cars (not all of them for sure) and compared the advertised 0 - 60 times on the maker's websites to the results of car mag road tests and most of them have been SLOWER than what is shown in road tests of the mags, which have been faster. Several months ago, I test drove a number of cars, including the Audi A4 (the S4 was not yet available) and was shocked at the fast acceleration of it, in light of the claimed 252 hp and 273 lbs ft of torque. On the subject of concerns raised by algs, I rather like the car, but consulted with the folks at my local neighborhood independent repair shop (they know their stuff) and was advised against Audi due to reliability issues, so I didn't buy one. Soul Tramp is correct. Torque controls acceleration more than horse power. Horsepower, on the other hand, controls top speed more than torque. But considering torque ratings alone, I have discovered many cars accelerate faster in these road tests than the torque would indicate, and faster than manufacturer's claims -- which is odd to me.
As mentioned above, the details of the transmission also make a huge difference in acceleration. Number of gears, shift points, and whether the shifts are "hard" or "soft" all make a difference, in addition to torque and horse power. For example, the C 43 has four shift modes and a fifth one that the owner can program in. The factory settings range from "Eco" which shifts at lower RPM and launches in a higher gear than first on the nine-speed trans. to "Sport+" which lauches in first at a higher RPM, shifts at a higher RPM, and the shifts are hard as hell! I don't drive mine in that mode very much, unless I have to get out of the way of something in a big hurry. Fast, but not very comfortable.
The Audi RS3 was mentioned above. Here in the US, we get only the four door sedan version. Manufacturer's web site claims 0 - 60 in 3.9 seconds. I'll bet road tests show a much quicker time, but we'll have to wait for one to come out to see.
Manufacturers have been using different ways to give you HP and Torque numbers for ever. Is it from the crank, flywheel, transmission, final drive or wheel? All these things cause shifts in power. Here is a little write up on just the differences in BHP vs HP (brake horsepower vs horsepower.)
To summerize, HP is measured with all the accoutrements attached to the engine, to determine its maximum rate and speed. BHP, on the other hand, is more of a theoretical calculation, which is made under lab-controlled conditions, and without having anything attached to the engine.
0-60 times can also be misleading because it is affected by airtemp, ground temp, tire warmth, skill of the driver, reaction time of the driver, and also the way the transmission reacts to initial input.
In the real world all of these numbers are meaningless unless you plan on running your car WOT(wide open throttle) a lot, like a racetrack. Much like guitars, test the car you want, and buy the one you love the most.
Another aspect to consider...
Japan had (has?) a higher tax rate on cars whose HP numbers were above 276. Therefore, for a long time you'd see 276 as the HP rating even though EVERYONE knew it was way more.
I'm not sure if other countries do something similar. Did that practice create a problem? I don't know...
In the US I think there is some standard imposed by somebody on car makers for rating horsepower and torque. A few decades ago, the power ratings on then current-year models dropped somewhat -- even though they were unchanged from the previous model year. As I recall, the way power was determined changed, and that was the reason. The US has no "horsepower tax". However, if high horsepower results on fuel economy below a certain standard, there is a "gas guzzler" tax. This tax is figured on EPA mileage tests. So even if a maker rates a car at 1000 hp, one pays now such tax to buy it if fuel economy is within limits.