J.M.G.

Hello to the forum,
I just came across a video*, where a 2014 E400 (EU-specs) was tested:

horsepower at the crank 366PS (more than 350PS between 4,800 and 6,200rpm!!)

torque at the crank 390ft/lb (more than 370ft/lb between 2,400 and 4,800rpm)

After a tune the car pulled 439PS and 460ft/lb at the crank!

Driftbox results, stock:
0-25mph 1.9s
0-50mph 4.2s
0-62mph 5.7s
0-80mph 8.9s (after the tune: 7.6s)
0-100mph 13.1s (11.1s)
0-125mph 21.1s (17.5s)


* Disclaimer: This is not my video!

Munich77

Not too shabby and a great addition to the line- but still no replacement for the E550 in the US. I wish they had maybe added a different V6 to replace the E350, added the E400 and kept the E550.

PeterUbers

Totally agreed with Munich

Stock true crank numbers on the ttv8 close to 450hp/500lbft

My e550 was friggen fast

J.M.G.

That is what they did in a few markets:
E320 (3.0 V6 TT, 272PS & 295lb/ft)
E400 (3.5 V6 TT, 333PS & 353lb/ft)
E550 (4.6 V8 TT, 408PS & 442lb/ft)


I do not believe those claims! I know several dyno sheets (crank horse power), that show something else: The E550 is right spot on the manufacture claims.


Manufacture claim: 408PS & 442lb/ft
Dyno graph 1: 409PS & 455lb/ft [1]
Dyno graph 2: 414PS & 466lb/ft [2]


[1] http://youtu.be/FzV7PapKsfM?t=38s
[2] See Attachment

PeterUbers

Reputable people including renntech would disagree with you, but whatever, it's your opinion

J.Raymond

The E400 3.0L V6 TT (designated M276 DELA 30) already runs a relatively high boost pressure. Reportedly 1.8 bar or 26.1 psi.

For comparison - the I6 BMW N54 and N55 both run under 10 psi from my reading.

The easy path of adding a few pounds boost pressure may not be ideal for the Mercedes (if that stock boost pressure is correct).

Not a tuner here - would be interested to hear more on this.

J.

Add: The Mercedes 3.5L V6 TT (designated M276 DELA 35) reportedly has a similar output at a reduced 0.7 bar - 10.2 psi boost.

AMGAffalterbach

The stock N54 runs at 8.8PSI hence why it has so much tuning potential, bringing it to just 15psi on stock turbos is enough to make some serious power. That is insanely high PSI stock for the E400. Though, to be honest, they don't sell enough E550s to make it worth their while to make them anymore, so I understand that. If you want a V8TT then go for an E63 which luckily they are keeping V8 and twin-turbo, perhaps shifting to the new 4.0 soon. The E400 must have some ity bity turbos.

Jeffy

The 4.6LTTV8 is not going away just yet... USA can still get it in several vehicles including E-coupe/cab and CLS. And the CLS is nicer option than E-sedan.

J.Raymond

Have a very hard time here believing the published 1.8 bar - 26.1 psi boost figure. Has to be an error.

BMW's M4 3.0L I6 (S55B30) operates at a reported 1.25 bar or 18.1 psi and achieves a significantly higher output.

J.

PS: 0.8 bar or 11.6 psi seems more likely - (1.8 bar) could be a simple typo re-reported by multiple publications.

AMGAffalterbach

That would make a LOT more sense than 26.1 PSI, that's what I thought the CLA45 AMG boost level is at.

Dema

Is E63 still offered? I guess E550 didn't get good sales, no one dealer had it for test drive in my area. So I guess MB did right decision to leave E63 for real performance lovers. 550i should be still available from BMW

sdg1871

Yes the E63 and E63 S, in both sedan and wagon form, are available in the 2015 model year. I have a 2015 E63 S sedan on order than arrives in January.

Sad that MB got rid of the E550. But unfortunately, engine sizes are shrinking at both Mercedes and BMW. The E400 will certainly be faster than the E350. But it will not be a match for the E550's power.

Yes BMW still sells the 550. It is doing very well. I see them all over the place. I still have one until I turn it in from its lease in February.

Munich77

The reason you could not find an E550 is because they were such a small percentage of E-class sales and because those that wanted one knew that 2014 was the last year. When I tried to get one in November of 2013 my dealer had no spots left for custom orders.

AMGAffalterbach

They actually only accounted for about 2% of total E-Class production worldwide

J.M.G.

I know that this rumor exists in this forum. However I have not seen a single dyno graph, that proves this!


As far as I understand these raw guess of American tuners, they measure rwhp /awhp and add a fictional percentage of drivetrain-losses. This does not work. Drivetrain-losses are dependent on friction and inertia. So for example different wheel-weights will alter the results. That is the reason why the people in Europe measure the crank horsepower. Keeping that in mind, I would like to add, that Mercedes claims a 92% efficiency factor[1] for the drivetrain of 9g-Tronic equipped cars. One easily can see, how far off these 20% drivetrain loss guess could be for current Mercedes!


Btw: The Audi S6 / S7 has been tested around 450-460hp (crank) and although it has roughly the same weight as the CLS / E 550, it destroys the Benz from 62-125mph...which is another indicator, that the M278 is well below that figure!


[1] http://blog.mercedes-benz-passion.co...onic-getriebe/

Arrie

Would you explain in more detail " That is the reason why the people in Europe measure the crank horsepower".


I used to work in a factory making heavy earth moving equipment and I know how we measured the crank shaft power (I assume your reference to "crank" is the same) from an engine. How do you think the "Europeans do it"?


The other thing: The inertia or like you call for example the "wheel weights" has absolutely no practical effect to the power curve when measured from the car. Inertia only effects during acceleration and if you want to measure how fast the engine can speed up it has to do with it but during normal power curve measurement it is negligent as the power curve is done slowly so that the true power from the engine can be seen.


Calculating gear box loss for the power is quite accurate. Depending on how well each gear mesh is designed it will waste 1% - 2% of the power. I don't know how many gear meshes there are from the engine to the wheels in our cars but using 1.5% loss for each gear mesh brings you pretty close to what really happens, i.e. 5 gear mesh means 7.5% loss of power for the "friction" in the gears. This is the simple reason (with the added weight) why gas mileage on a 4-wheel drive car is worse than on the same car with RWD.


I don't know how much power is lost in the torque converter. It varies by the model and speed it is used at. With the max speed it should lock up and loss is zero.

J.M.G.

Thank you for your question. I already tried to explain this in another thread, but I will give it another shot here.


In most parts of the world, dyno runs are different from those carried out in the US:


1. Acceleration in a fixed gear to measure wheel horse power (same like in the US)
2. after reaching the rev limiter pressing the clutch. During the rollout, the dyno measures, how much resistance the drivetrain has.


So one gets two results:
wheel horse power
power dissipation


To make the results even more accurate, most dyno manufactures (including dynojet, MAHA, Sunflow, Bosch) do have an algorithm, that corrects the power dissipation for known "problems", like the HALDEX 4wd system and so on.


The dyno than adds those results and displays a crank horse power value, which is very, very close (usually +/- 5hp) to the value one can measure, when the engine is strapped on an engine dyno. This has been done several times during law suits against car manufactures here in Germany, where the buyer claimed that the car lacks power while the seller denied that. Some courts tended to refuse dyno sheets in the past. So the buyers had an expert to pull the engine off the car and give it a run on an engine dyno...with the above mentioned results. Meanwhile all known manufactures accept dyno sheets over here...



Just think about it again. What is a car doing on the dyno? It accelerates from (i.e.) 2,000-6,500 rpm. So all rotating devices, such as wheels, brake rotors, drive shafts, torque tube and so on alter there angular rate.


If you want to see this effect, just ask your dyno operator to alter the eddy current brake of the dyno during two runs and take a look at the wheel horse power. The faster the dyno spools up, the lower the rwhp will be (and the higher the power dissipation will be, so the sum of rwhp and power dissipation is always constant).

ss3964spd

Wheels, tires, and rotors act exactly like a flywheel on the back of the engine. The heavier they are the more energy it takes to accelerate them. The same applies when it comes time to stop them.

Arrie

Yes, correct. The inertia of the transmission parts plays a role in how fast the car can accelerate but the dyno test is not made to measure the acceleration. It is made to test how much power the car engine generates. This power is simply the rotational speed multiplied by the torque and when this is done correctly it is done slow enough so that the acceleration of the inertia of the parts does not play a role in it.

Arrie

As I said in the earlier post a correctly done dyno test gives a curve for the engine showing the torque the engine generates at given rpm. Or it can also be shown as torque with rpm of the dyno drum.


The test shoul be done so that with the maximum gas pedal the dyno controls the torque and allows the engine to rev up slowly. This results the torque - rpm graph, which shows the maximum torque the engine generates with the different engine speeds. If this test is done too fast the acceleration of all of the inertia will eat up some torque so you get worse result than what the engine can do, i.e. the measured torque is less because some of the engine torque is wasted for the acceleration.

J.M.G.

In my opinion inertia is an important factor as soon as one alters the angular rate of any rotating device. Therefore I totally disagree with you, especially when keeping that most dyno runs do not take that long while the engine spools up from 2,000-6,500 rpm.

Arrie

And the faster the acceleration the more error in the result.
I don't know what you disagree with me because I also think the inertia is important factor in this but if the test is done slow enough it does not skew the values too much.
It also is that people mostly are interested of the max power when the torque levels out and the test is terminated. That is when acceleration stops and effect of inertia goes to zero.

petee1997

Not quite true. In Canada the E400 W212 replaced the E350 and we still have the W212 E550.

AMGAffalterbach

I wish they had done that here! What the hell! Probably CAFE laws...

Munich77

Precisely the reasons if you ask me.....Personally I think performance wise the E400 is a better competitor to the 535 and A6 3.0T which would mean there is rooom for a 240-260 hp entry level model to compete with the 528i and the A6 2.0T (no I am not counting the E250 diesel).