I wanted to report how impressed I am with my dealer. He and his contacts at MB seem just as determined about figuring out what is going on as I do.


We are working on this with MB and I will update the board with our findings.

 

Not if MB only limits the torque output in lower gears where the multiplier is the greatest. So it may make less hp in lower gears but when you hit the higher gears the multiplier is lower and the gear box can finally handle the lesser load and the full power is produced.

The 7-speed gear box has a greater gear spread than the 5-speed and has a numerically higher lower gears, thus higher multiplier and higher load. Remember this 7-speed gear box cannot handle the torque of the supercharged 55 motor and that's why the 55 are stuck with the 5-speed.
Even the bulletproof 5-speed has its limits and hence the electronically limited torque output of the 65's turbocharged engines.

If in the unfortunate event that the engine only makes full power in 7th gear, the worse case scenario, then MB is kinda home free from the Law's stand point as it does make full power, but it's not in a usable range, bad PR for sure but I don't think it's sue-able.

For those who swear by the dynojet instead of a proper engine dyno, what gear did the pull run in? 4th? Is is possible to do the pull in like 5th, 6th or 7th? This may not be practical as there is a speed limiter at 155 so again just about the only reliable way to prove how much power the engine is making is to take it out and put it on a engine dyno.

 

Broken-in or not, the gearbox more than likely cannot handle the full load. Plus for the time the gearbox is broken so is the engine and most engine is suppose to make a little more power after broken in.

Below is pure speculation on my part:

I think the max load the 7-speed gearbox can handle is just over 400lb-ft, so the 550 engine is unrestricted and gains the gear and speed advantage of the transmission. The 63 at 465lb-ft is just a little too much for the 7-speed and the 500+ln-ft from the 55 Kompressor is too much to even consider. MB probable did some testing with the 63 mated to the 5-speed and found out without the extra torque of the 55 and without the gear ratio advantage of the 7-speed it is slower than the 55 it's suppose to replace.
MB probably found out that by limiting the torque output of the 63 engine in the lower gears, it can be mated to the 7-speed, while the power output is down, it gains the gearing advantage and thus more or less puts down the same performance as the 55.

MB probably just want to get by the first year with this compromise and figure out how to beef up the 7-speed for future applications.

Another theory why MB is doing this is that AMG did too good a job in making the motor, producing a little too much than MB spec-ed for the 7-speed. AMG more than likely had the V10 in the M5 as bogey, they did match the hp output but producing way more torque than the V10 in the process and thus put MB in a jam. I am sure the 7-speed will have no problem what so ever handling the BMW V10 as I think it makes even less torque than the 550 engine.

 

Not to argue, but I would think that a multi-billion dollar international company like MB would be pretty "horsepower" conscious as well no?

My point is... that dyno's may are great for judging mods. You do a pull, make your changes, and then run a second pull. Bingo... But you're saying that this particular dynojet is accurate based on comparing it to itself. Consistancy is great... but if you use a ruler that is 13" and says 12", you're going to get a consistant error. You need a accurate benchmark first as well as the conditions under which MB does its testing.

These machines are NOT regulated. They're NOT validated. Does anyone really believe that if you ran the same car on 10 dynos throughout the USA with the same gas, at the same temperature, that you'd get the same results across the board? I certainl;y don't. I'd be shocked if you got 25% being the same.

~ Ian

 

Why are you guys in SO MUCH DENIAL?!?!?! We already have consistency in numbers in the ONLY two known dyno tested E63's on two different dynojets in different parts of the country. The ET's are consistent with the low HP readings. WHAT MORE DO YOU NEED?!?!?! Are you so busy MB flag waiving that youve grown some rose colored contacts on your eyeballs?

 

Actually the gearbox is under the highest load under higher gears at speed. This is why manual gearboxes with slipping clutches first start to display symtoms of clutch slippage in 5th and 6th gears at speed on the freeway. So if they are limiting torque to save the tranny, it seems that this "torque limitation" is about as real as a granny goose fairy tale told by a Teddy Ruxpin doll. Your theory is bupkus.

 

Thats great to hear you have a good dealer.Sometimes I think they dont exist.Im really curious to see the outcome of this,seeing how I was 1 week away from buying the 63 myself.

 

Sorry to burst your bubble but lets take out your calculator and do some simple maths:

To refresh your memory, in simplest term gears in the gear box rotating against each other, the diameter or tooth count difference between each pair of rotating gear is the gear ratios between the 2 of them. Ratios with a number higher than 1 means a smaller gear is turning a larger gear, also called underdrive and is useful for gaining mechanical advantage as it multiplies the torque input by the same gear ratio. So e.g. for a pair of gears with a 2:1 ratio means the smaller gear rotates 2 times for every rotation of the big gear, with a input of 10lb-ft of torque to the smaller gear the larger gear will produced 20lb-ft of torque while rotating half as fast.

Still with me? Here we go

I do not have the spec for the drivetrain in the e63 handy but I have gotten the info for a s550 and for this simple calculations it will suffice.


Gear Ratio Overall Ratio
1st 4.38 11.61
2nd 2.86 7.58
3rd 1.92 5.09
4th 1.37 3.63
5th 1 2.65
6th 0.82 2.17
7th 0.73 1.93

Final drive ratio is 2.65 as taken from the specs for a S550

For the 63 engine the motor makes it's peak torque 465lb-ft at 5200rpm, let's do the calculations at peak torque: (remember the engine represent the smaller gear here) so:

Gear Ratio Torque at Gearbox Torque at rearend
1st 4.38 2036.7lb-ft 5398.65lb-ft
2nd 2.86 1329.9lb-ft 3524.7lb-ft
3rd 1.92 892.8lb-ft 2366.85lb-ft
4th 1.37 637.05lb-ft 1687.95lb-ft
5th 1.00 465lb-ft 1232.25lb-ft
6th 0.82 381.3lb-ft 1009.05lb-ft
7th 0.73 339.45lb-ft 897.45lb-ft

The torque at rearend are split 50-50 between each rear wheels in normal conditions.

See how the the numbers are bigger in the lower gears? That's the multiplier working.

If you are lost already, I will put it in simplier terms:

When you floor it from first gear, more than likely you will smoke the tires, but if you floor it from 5th gear, you WILL NOT smoke the tires period. That's because the multiplied torque in first gear can over come the traction provided by the tires easily but it is not enough to do that in 5th.

When you go to the drag strip, there are times when you see someone breaking rearends, driveshafts, halfshafts at launch but you won't see that at the finish line. Why? look at the numbers, in first gear there are over 2ton-ft of torque acting on the components, that's a lot of power for the drivetrain to handle.

When you launch a car from standstill, the g-force pushing you into your seat lessens with each gear change, get my point?

Why do gearbox makers put the beefiest gears in the lower gears? BECAUSE THEY TAKES THE HIGHEST LOAD!!!!

In your example for slipping clutch, more than likely you cannot detect the slippage in the lower gears because your acceleration in the lowers gears is too great for you to notice the slippage. In top gear the acceleration is slow enough for you to notice the difference between engine rpm and speed rising.

I could have gone all technical on you but I don't think you can handle that.

Yours Truely

Whoopsy

 

OMG I'm sorry. Two DYNO's. Here I thought it was only one. They should test drugs that way... TWO DOCTORS and TWO patients, and then just go with whatever results they get. That's all you need... right?

What I would need is SAE Certified test with conditions that are the same as what MB used. That would mean ALL variables would be the same (i.e. fuel, temperature, altitude, etc.). I'd also want to see it done on not one car, not two, but ten or twenty. That's what you're going to need to prove MB wrong anyway cowboy.

Sorry if I'm a little more scientific than the Viper guys. I just don't take things for face value, and if forced to guess or lean one way, it would be on the side of the entity who has considerably more on the line.

~ Ian

 

Manufacturers have historically underrated their engines and in several high profile cases, they overrated their engines. Most recently, Yamaha offered buy backs on their latest sportbike because it didn't rev as high as they claimed.

I've said several times, on this board, that 2 cars aren't a representative sample but independant testing is needed to figure out the problem. A chassis dyno has proved effective in the past to get manufacturers to admit to a problem or intentionally overrating output.

We should get together a group from this board, everyone hit area dealerships for a test drive and take them to a local dyno

 

 

............I agree. I never understood why some think that one would have to pluck out the engine from the car in order to prove that it is underpowered.


Ted

 

I cannot believe how much misinformation about transmissions and torque transfer is present in this thread.

 

Ok you must be right then. Even though the dyno runs were done in 4th and 5th gears, according to your theory they MBZ only is allowing 507hp on 6th and 7th gears. When most people utilize those gears to save gas, MBZ ONLY allows the complete hp of the car to be exploited in gears used above 100mph. So when youre out crusing on the freeway at 80mph, you hit the gas your car downshifts, oops your still F$cked because the whoopsy rose-colored, MB flag waiving theory says MB wont allow the car to create max torque/power. Problem is, then there is a speed limiter on the car so, I guess the E63 just NEVER makes full power......EVER. But its ok because whoopsy wants to be a MB Cheerleader.

 

the two dyno runs, coupled with poor showings at the track are indicative a possible problem.
This thread is about asking others to dyno their cars and report their findings and come to a logical conclusion.

It has to start somewhere...condescending ***

 

That's a really gay response and addresses none of the points he makes which can only mean you are bereft of any meaningful insights into this matter

 

btw it the 7 speed in the new 63 cars is different than my SLK55 with the 7 speed and there are different versions.

I believe one of the differences is the clutch packs inside.

 

Lots of ideas/theories in this thread, but lets get back to the basics.

After two dyno's (and HP loss corrections) the 63 engine is not producing the advertised 507-510hp.

It should be noted, as many know, that AMG tests its engines to redline speeds before they are crated and shipped from Affalterbach. The engine MUST produce 507hp or more. Any less and it is back to the shop.

Now "getbitten" is concerned and rightly so. I also do not believe 50hp will magically appear after a few thousand miles; no engine requires thousands of miles to give you the kick in the pants it promised. When was the last time any of you bought cars that promised full potential but only after a few thousand miles?

These dyno numbers are disappointing as I still vouch for this new V8. It has done wonders with a 3.45 final drive (ref: ML63).

Speaking from a legal point of view, in the UK, the consumer has remedies under the Sale of Goods Act; criminal proceedings can be taken against MB under the Trade Descriptions Act and not to mention the "common law" actions for misrepresentation in contract.*DO NOT TAKE THIS AS LEGAL ADVICE.*

I am 100% behind "getbitten" to fully investigate this matter. As a consumer you are fully entitled to get what you paid for. We buy the E63 because of its engine. Period.




PS, the 7G can handle 516lbs/ft but the V8K is still too "strong". There is no way a torque limiter is applied to the 63.

 

The most well written, accurate and fair observation of this problem thus far.
Thank you.

 

No problem bud, you kinda need the support!

 

After reading this thread something dawned on me. What if the engine does make 507Hp at the crank, but the ECU limits the output to protect the transmission.
This could be a sticky situation since all MB claims is that the engine makes 507hp, which is does. They have not made a rwhp claim, so if they limit the car via the ECU or trasnmission, they have not technically commited false advertising.

Though that begs the question why make a 507hp car is your don't have a transmission that can handle it. (or why pair up a tranny and a engine that don't "match")?

PT

 

Someone needs to ask AMG "Where did you hide the 400hp to 500hp button."

 

+1. i'm behind you too. give us the 507hp you blatantly stated.

 

that would be the stupidest thing mb could do, if mb actually did that. that puts them a the grey area for false advertising. they're practically deceiving their customers...

 

Maybe this has been done already but why not arrange a stock E55 vs E63 race from a roll from say 30 mph to 130 or 140 of 150. The result will be very telling.