AMS Performance

The M3 pulley is a bare aluminum pulley pretty much. Its just slightly smaller diameter than the stock one (which is already aluminum). It is simply a basic underdriven serpentine pulley that bolts onto the main harmonic damper.

On Mercedes the pulley & harmonic damper are built into one piece so the C63 one has to incorporate all the harmonic dampening components and they also bolt on directly to the crankshaft itself and not into the harmonic damper so it needs to be significantly stronger.

Harmonic dampened pulleys are far more expensive to produce and as a result their retail cost is significantly higher.

I'm sure the cars original MSRP plays a factor as well. Typically parts always cost more for more expensive cars simply because the owners have more spare income to spend.

GHAZAN

Makes sense now, I didn't know they were different. The M3 has a higher MSRP than the C63, but that fact that this one pulley will work for the SL, E, S, etc. probably incorporates some of their MSRP too, hence $$$

Glyn M Ruck

+1 - Many would be surprised at how little torque an F1 engine produces - but then it revs!!!

giovanni821

First of all n response to Glyn's comment. You could have worked FOR MB, I don't care. You are so smart! You should know that you can NEVER have perfect real world numbers. I dont give a rats *** if my $85 dyno session is not done by you or a prestigious multi million dollar dyno. The facts are these. I dynoed the car with a reputable dyno and dyno shop and the max pull was 207.0 whp and 196.1 wtq. I never said there could be no variables possible. No one else has done a C300 dyno session and posted the info with graphs. In the original post i stated the temp and location. God forbid if I did jot do it in a controlled environment and did not state the barometric pressure and oxygen content! BLUF= I dynoed my car and posted results. If its like **** on a bull good for you, but for those who want to compare and get an idea of what the C300 can put down this is for you. Enough said?

Glyn M Ruck

You still don't get it. Others can't compare because they can't repeat what you did. Even you don't know what you did because you did not record the right things so the results are meaningless.

Do some reading.

'Nuff said & signing off from this thread.

Distalero

You're both forgetting something: that bogus claim of a 10 horse bump in output. Even if we all could pull out our weenies and measure with the same ruler, who here thinks they would even feel 10hp in a car as heavy as ours?


So called power pulleys are classic rice, on a stock daily driver motor, down on the same level as a rear wing on a front wheel drive car.

GLK4MATIC

Screw it give me a pulley and I will give you a strut tower brace. We can do tests on eachothers products and give everyone a review....LOL

micropower99

Too much crap about dyno's in this thread, that I actually started skimming the last few threads on the second page. (Not to say their not knowledgeable). But! I'm going to be taking my C300 4Matic (auto) in to a AWD dyno this Thursday/Friday and will be posting my results afterwords. All this about multimillion dollar dyno's has no relevance here as it's hard enough finding a reliable AWD dyno here locally. But honestly, it doesn't matter on the dyno what number you get, it matters what numbers change after you do mods and record on the "same" dyno afterwords.

Glyn M Ruck

No we are not forgetting the bogus claim - please read this posted earlier. And you are right - no ones butt dyno could detect 10hp even if it was there.


https://mbworld.org/forums/c-class-w...ght=AMS+pulley

Glyn M Ruck

No micro - and I'm not trying to fight with you I'm trying to help. Repeatability on the same dyno is likely crap & could mask the horsepower gain you are looking for. If you do run one in high air density - do your mods, retest on the same dyno on a lower air density day due to lower barometric pressure and higher air temperature - or heaven forbid both - you could get a reading lower than you started with. Then you are going to be pissed - not so.

So - at the very least record the barometric pressure & INLET air temperature or even better & simpler - record the air density when you do your before runs & again when you do your after runs.

Then you can pull up the SAE or DIN or JIS correction tables off the internet & correct your results for the changes in atmospheric conditions. Then you will be a lot closer to comparing apples with apples.

Otherwise you are wasting your hard earned money and might be very disappointed because you are comparing apples with pears. I'm sure you are technically astute so you will understand where I am coming from.

Glyn M Ruck

To all - this is a technically biased thread by it's very nature - If you don't want to learn & wish to place your head in the sand like a proverbial ostrich - then don't read it & move on to things of far greater importance like LED puddle lights !!!!!

Distalero

I read it.

I went on forever, but it was interesting in two regards; the first and obvious was the scope of content, and the second was how far a few folks with some background can take a discussion and not mention the basics much. That's the problem in this thread.

See, we folks without the background are only concerned with: does it work? How much does it cost? (and those of us with a pinch of background also ask ourselves: how much does a new MB 204 bottom end cost? ).

You started your argument in this thread focused on dyno readings, and on the basis that known variables are significant, and will do what their title says, vary, on any given day. Therefore, sayeth your argument, one may or may not be able to argue that the mythical 10hp will be there to measure, on a car modified with a lighter pulley, and, horrors, this is also true of the baseline hp on a stock and completely untouched motor. So, here's what I got out all of this...

1. Whatever a power pulley actually gives in increased output on a good day, it may or may not be there on a different day, so consider that increased output chiseled in cream cheese, assuming it was there to begin with.

2. On that good day, you will not be able to actually FEEL a 10hp increase on our cars. Too heavy (actually I walked into the discussion knowing this).

3. And the unasked question, and consequently unaddressed answer, is WHERE in the power band, does this huge 10hp show up, on that good day?

This would bring us back to the discussion about dyno results and their non transferability.

Now, I know that for folks with a professional background it's all sort of swirling around in your heads, so much so that it's almost painful to actually focus on the basic issues, but question number 3 emphasizes the real world results of any increase in output: is it useable when I go to the supermarket, or try to impress the GF, or my buddies down there in SoCal?

WHERE in the power band does this 10hp show up, and more importantly, where does that "X" amount of torque show up. Torque: gotta love it. It's less of a theoretical measurement that HP is, and what any non background type of guy wants to take to the bank.

giovanni821

How can you say my results are meaningless? It's an example! If someone shot a target at 300m does that mean I cannot because the weather and altitudes are different? You don't get my intent. But I will stop here because it seems we are definately not on the same sheet of music.

Glyn M Ruck

I hear you. You also need to consider Tims point regarding gearing. Some of the worlds greatest performance vehicles produce very little torque - All screaming high RPM horsepower. A Formula 1 engine is typical of this. It produces very little torque which is why it does not brake crankshafts or run harmonically dampened pulleys. High torque American style engines break crankshafts if harmonics & resonance are not kept in check.

My straight answer on these pulleys is that they are a load of crap.

Glyn M Ruck

Good!

giovanni821

I agree with you. I didn't mean to be an *** before but your previous comment on my result really pissed me off. But yes, discussions like these are worthwhile in my opinion.

bobterry99

Because M-B knows better. And that's what really amazes me about how anyone buys these products, as several safeguards have to fail. One's intuition ought to tell you that these pulleys are a bad product; if it doesn't, then you can apply basic physics to prove to yourself they make less than 1 horsepower under the most favorable circumstances; and if you don't understand any physics, well finally you have your common sense to save you. If a lighter pulley were beneficial, why wouldn't Mercedes' in-house tuner AMG use one?

By the way, here is a video of an AMS pulley self-destructing just as timf and others speculated it might because it is under-engineered: http://www.benzworld.org/forums/w202...ml#post3400323.

Glyn M Ruck

Did not want to mention that - pleased you did.

Excuse likely goes something like this.

"Vehicle suffered electrical failure - errant pulley severed the wiring harness!"

timdf

In a past life I saw many a F1 V10 engine being engine dyno tested - some times to destruction

Idle speed was about 5500rpm and they could accelerate to just over 19000 rpm in something like 300mS - the rate of change of RPM was phenominal. In fact posted on youtube is a video of an engine singing 'god save the queen'. Worth a listen....

http://www.youtube.com/watch?v=MGEqlNU30Tg

As part of routine development the engines would be tested with no parasitic ancilliaries like water pump, alternator and related belts and pulleys,

This was in an attempt to measure raw HP accurately.

Interestingly when the ancilliaries were reconnected via belts & pulleys we could detect no significant difference in power output.

Moral of the story - if we couldn't measure any significant difference on a race engine changing rpm that fast with / without pulleys etc, there's not a 'rats ***' chance of detecting significant difference on a road engine with a standard size light weight 'performance pulley' going from 750 rpm to 6000 rpm in a matter of seconds.

Thus I agree with Glyn's rather blunt assessment mentioned below "a load of crap".

But hey - if it makes you feel good and have the money to waste -why not ?

Glyn M Ruck

Excuse the blunt response but I was being pushed by Distalero to stick to basics & answer the question for those less technically inclined. I answered it to the best of my ability.

Distalero

And I, for one, appreciated it.

If you go down the thread titles on this forum you get a sense of where many live: deep in the heart of light modification (nothing wrong with that) with no particular rationale, and a primary focus on cost.

We ALL, those with technical background and experience, and the stylers, would run right to a thread with the title of "Power Pulleys: A Load of Crap". It gets down to it.