SLK55R

Hello everyone,

I just took my car to get its premod dyno so I can have my baseline.

It was a great day today! nice and sunny.

Dyno run 1:

78.43 Degs F, 29.96 in-Hg, Humidity 22%, Uncorrected 1.00
Max HP 305.46.
SAE corrected HP 299.73.

Dyno run 2:

78.26 Degs F, 29.96 in-Hg, Humidity 22%, Uncorrected 1.00
Max HP 305.47.
SAE corrected HP 299.78.


Also ... those that have had your baseline dyno's could you post what your numbers were?

sbkim

I am not an expert but your baseline seems right-on based on about 15-20% driveline loss. What were your torque numbers?

My question is how can this car, weighing over 3400 lbs, get 0-60's in 4.3sec with only 300 rwhp? Is it the tranny/gear? Or did Car and Driver have some factory freak show and we should really be seing 4.9sec as estimated by MBUSA?

SLK55R

I haven't taken mine to the track yet ... but before I do any mods I'm going for baseline 1/4mile and 0-60 times.

Some others here have taken thier SLK55's to the track and have some realworld numbers.

BTW the 7speed tranny is amazing ... I'm sure it does help with lowering the times.

zaint10

I think its due to 7 speed gear box

lennyr

Torque counts for a lot.

bloflin

A real person, either here or the other Benz forum, posted a scan of their time slip with a SLK55, a few months back. It wasn't 4.3, don't remember exactly, but I think around 4.5, definitely way under the MB spec of 4.9.

sbkim

Car and Driver must be getting more factory ringers... They tested Jeep Cherokee SRT8 at 4.5 sec 0-60 (vs factory claim of 4.9). I presume they are doing these testings in perfect, cool, dry weather.

Yellow R1

C&D launch the cars more aggressively (ie allowing minor wheelspin) than R&T & Motor Trend,etc. They routinely get quicker times than the other car mags because they are extracting the quickest times possible. They will take the fastest time after trying several launch methods. In fact, C&D state the exact launch technique used to attain the acceleration numbers at the bottom of the stat summary page for the car/truck being reviewed.

I've seen 4.2 sec 0 - 60 & 12.7 @ 111mph for the SLK55 (the quickest I have seen & I've seen 'em all). Its as quick as a C6 manual coupe while having less Hp & torque due to its 7 Spd tranny (which keeps the engine at its peak power levels for a longer period of time - it makes more efficient use of the power it produces).

-Matt

nishi

stock SLK55 was seen doing 0-60 in 4.2 ?!

Yellow R1

Yes, I forget the mag - it was last Summer? In any case, here is C&D extracting a 4.3 sprint & a 12.7 1/4 @ 111mph.

http://www.caranddriver.com/article....&page_number=1

-Matt

trompazo

How could someone post a timeslip for a 0 to 60 time? Dragstrips don't record 0 to 60 mph times. They print out 60 foot times which is completely different.

0-60 times are just useless numbers made up for people who don't actually race their car and just like to compare meaningless numbers. Theres so many variables in launching a car that a 0-60 time means nothing given how inconsistent they can be.

IMHO, anyways.

bloflin

Thanks for YOUR opinion, I'm in the process of getting a memo out to the WORLD, for everyone: Manufacturers, Car Mags, people on forums, etc. to stop wasting their time on this meaningless number.

But specific to your point:
You, of course are correct. I was trying respond to the "discussion" that the forum newbie SBKIM (by newbie I mean to this forum under that id it was his 10th post) was asking on whether the Car Mags "cheat" versus the MB spec number. This has been hashed over a lot. I was just trying to chime in that I've read where real people have got nums better than 4.9.

What I remember in some forum was an actually scan of a timeslip (because people just would not accept someone's typed data) that show the normal dragstrip times. Then in that same post, the poster also stated his 0-60 type times.

Posting at 1:00am I just ran all that together.

Regardless I can't find the scanned post.

But there are some "documented" dragtimes, like dinko's up on http://www.dragtimes.com/Mercedes-Be...slip-5170.html

Which would tend to show that the SLK55 driven by real people (not just Car Mag reviews) can do well, and that the MB spec is conservative.

Thanks.

trompazo

Good, the world should be aware that 0-60 times are pretty meaningless given a huge variance in driver skill, altitude, surface traction, temperture, etc. and should be taken with a huge grain of salt. On this forum, people seem to spout 0-60 times like they are gospel which is pretty funny.

If you want to compare numbers that do show a cars power, look at the speed at the end of the 1/4 mile as that takes traction and the launch out of the equation and is usually pretty consistent. Times only reflect traction and driver skill where speed indicates power.

And with regards to someone posting 1/4 time slips and then saying what his 0-60 times are, how would he know what his 0-60 times are? No dragstrips record 0-60 times. And the devices that most people have like a G-tech pro are too rudamnetary to be relied upon. Unless someone has $4000 timing equipment that they own, no one will know ther 0-60 mph times

Ynot

I used my stopwatch, you telling me I can't get an accurate 0-60 time with it? You are crazy..
















j/k.

dinko

As far as I remember I was the first to achieve a 12.7

bloflin

You seem smart, so it must be my communication skills, 'cause you can't be that dense.

The 0-60 time was NOT from the strip run.

Let me go slowly.

Newcomers asking legitimate questions vis-a-vi MB specs vs Car Mags (though these questions have been hashed over and over ever since SLK55 came out).

Wants to know if Car Mags are FOS.

I respond, trying to show some evidence that real people are getting some good performance results (i.e. better than the MB specs would have you believe).

Instead of just giving some completely anecdotal evidence, I tried to communicate some more empirical evidence.

In one post on either this or the BenzWorld forum, last year someone posted an actually picture (scan) of a time slip.

Please NOTE the time slip did NOT have a 0 to 60mph measurement.

In the continuing discussion in that post, the person was asked his "street" time 0 to 60mph. I don't remember the exact response, but was around or just under 4.5sec.

In summary, though still somewhat anecdotal, I was trying to establish a logical connection between someone who:

- has an SLK55
- has driven the SLK55 in performance runs
- has documented evidence of his performance
- has ancillary (but undocumented) 0 to 60mph performance that is much better than MB spec

With the goal of trying to answer the poster's question.

Got it?

P.S. No where in all of this was I trying to claim anyone had NASA calibrated laser equipment or whatever.

dsb

I hit 60mph well before i count to "five aligators or five mississippi's"

trompazo

You don't have to go slowly, I understand what you are saying. At least I understand how you are modifying your original statement about someone posting a timeslip about a 0-60 time.

Now you're saying it was an estimated figure based on a timeslip from a quarter mile time.

And I will say, with great confidence, that estimating a 0-60 time based on a quarter mile time is about as accurate as counting "one mississipi, two mississipi. etc." as it's still too dependent on the launch and traction.

My point is that who cares about 0-60 times. Is there any form of racing that records this time? Do people in the real world race from 0 to 60 and then slam on the brakes when their speedo (also inaccurate) hits 60mph?

I would say no. I would also say that most SLK owners don't even race their car anyways, so who cares about what the 0-60 time is? Its all about a hypothetical discussion on hugely varient times on a car that is hardly ever raced anyways.

I'm not going to argue this point anymore, because my point is that argueing about 0-60 times is, by defacto, a silly concept.

Dyno times are also hugely inaccurate and of little use as you can adjust dyno reading to say almost anything you want.

The only thing worth discussing about a cars performance is the speed at the end of the quater mile as it is something that is reproduceable and easy to measure, and is a good indicator of power.

Remonster

Usually Mercedes likes to give out very conservative claims for the performance of their vehicles, either that or they have a very bad test driver/bad conditions LOL! but I have noticed that "real world' 0-60 times and those in magazines are much lower (usually by 3 tenths or more) than those on the MBUSA site. I personally see this as a sign that Mercedes is not only whole heartedly honest about their performance claims, but also that they have no intention of lying or inflating their power/performance figures, so IMO thats a big kudos to them in general.

CalifSLK

Haven't done it in a while but while in high school, we would mark off a quarter mile on a back county road and count the seconds between the two markers. Unforntunately I was doing it with my parents' '66 Ford Custom 500 with a stock 352 cid V8.

bloflin

Trompazo -

We get it. We really, really, really, really get it. You've declared a fatwa on 0-60mph "benchmarking". More power to you, it will be a long slog. You will have to have an army of volunteers to catch every post on the internet and post your proclamation.

But for the rest of us in the "ignorant" world, the question was asked about 0-60 times. I tried to respond, as that is what we do on these forums when a question is asked.

trompazo

Blofin,

Thats my point, poeple on this forums are too concerned about 0-60 times. O-60 times are only quoted by people who like to quote numbers of what they think there car could be capable of doing for bragging rights only, but are irrelevent to those who are actually going to use the car to it's potential (which in reality is a small proportion of MB owners).

trompazo

However, that being said, I think the car is excellent for what it proclaims to be.

I've only had it a few weeks, and it is a fun car to drive around town. it's not really fast (to my standards) but it has more than enough power for daily driving purposes on public roads and it's a good compromise between performance, luxury, and style.

It's not a race car, but for it's intended purpose, it does it well. Thats why I don't see the big need to argue 0-60 times. It's one of the slowest cars I own, but it is my first choice as a daily driver.

SLK55R

Yeah but you have to remember that most of us don't have the cars in your garage ...

trompazo

Good pioint. The car is actually pretty fast. The problem with power is that it is addictive. Once you have lots, it hard to be happy with less.

The same could be said for money, sex, or anything else that increases the dopamine release in the nucleus accumbens of our brainstem.