AWD Dyno
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From: Vancouver, BC
2008 Mercedes C300 4Matic
Hey, yeah thats where I was planning to go. I was there yesterday talking to them about it.
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The truth is that it could be worse than nothing. Getting dyno repeatability below 10% can be a battle. What if your mod only gives an 8% or smaller improvement? The inlet air temperature as an example increases by 4 degrees from before to after testing & you show zero or negative improvement. Then you are confused. You have wasted your time & money.
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In a light tone - I'm staggered at the general lack of technical competence on the 204 forum. I'm sometimes dread to admit I own one.
but the tradgedy lies in the fact that someone might believe the nonesense & garbage that will come out of an amateur American type street side dyno. I have plenty of experience of them too and their output is rubbish.
Edit: There are going to be those on the forum that prefer to listen to Fred Flintstone - I respect that. I'll back Einstein every time thanks.
but the tradgedy lies in the fact that someone might believe the nonesense & garbage that will come out of an amateur American type street side dyno. I have plenty of experience of them too and their output is rubbish.
Edit: There are going to be those on the forum that prefer to listen to Fred Flintstone - I respect that. I'll back Einstein every time thanks.
You're right, silly Americans shouldn't try to use their inferior science. Then again, you're closer to a gibbon than an Einstein.
Last edited by Peabody; Dec 5, 2009 at 02:27 PM.
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late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
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W204
They are amazing people, all of them are great.
And I saw your picture on whdnl's facebook
I was the one he told him how to blackout his car and paint his grill.
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[(460+70)/(460+74)]^.5 = .995 (ignoring the trivial .18 ME effect).
A 4 degree temp rise, F or C, does not cancel an independent 8% power gain.
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Last edited by kevink2; Dec 5, 2009 at 09:29 PM.
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With the shift issue, ony peak hp output will be usefull. How consistent were the 3 runs in peak hp? It appears an SAE correction factor was used ... see if you can find the value.
Also, I got 3 runs for $90.
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Thread Starter
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Yeah Wes spoke of you a bit, his car def looks much better blacked out. Plus he blacked out just enough and didn't overdo it. I like it!
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I'll try to find out what SAE correction factor was used. The peak HP was 180 on all 3 runs. well on the first was 179, second 180 and third 181 I believe.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
It sounds like you assumed no SAE CF was applied. Ok, then assume power produced is related to ambient temperature by that equation in J1349 used by all engine mfg's. It's Correction Factor is a function of the sq-rt of the absolute ambient temp ratio. So for a 70F vs a 74F test day (and related higher intake air temp), the correction factor for the power produced is:
[(460+70)/(460+74)]^.5 = .995 (ignoring the trivial .18 ME effect).
A 4 degree temp rise, F or C, does not cancel an independent 8% power gain.
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[(460+70)/(460+74)]^.5 = .995 (ignoring the trivial .18 ME effect).
A 4 degree temp rise, F or C, does not cancel an independent 8% power gain.
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As people don't want to believe me they should search the net. There is some surprisingly good data on why dyno results are not repeatable & can be problematic in absolute terms. Cosworth also have some good data. Some of the best material is by those testing motorcycles. With bikes you have an easier situation generally because you can connect the GB output sprocket shaft direct to an eddy current brake or whatever. You don't have brake pads touching rotors & other things to throw you off track.
I'm going to clear out of micropower's thread now. We have some of the few dynos here at SASTECH that operate in a truly altitude compensated environment. You can wind the effective air pressure up & down in the dyno rooms - control IAT etc. Getting meaningful, repeatable results is still a nightmare irrespective of dyno resolution.
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There is some argument whether IAT's are for instant IAT value, or general average value for a period of the day, since most have very slow response. But IAT is not a strong variable, as I showed.
My main point is there are "unintended consequences" when a forum guru like you makes a specific example like that. Your followers walk away thinking a 4 deg temp rise can wipe out an independent 8% power gain, and then overestimate the effect of intake temperature.
-----------------
I do consider you a true oil guru. I hope you will add links at the end of your ultimate-oil thread, to your many valuable oil explanations in various threads.
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Last edited by kevink2; Dec 6, 2009 at 04:23 PM.
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W204
Yeah definitely. I talked to Alex but also met Curtis through his gf. Hopefully will get the ECU tune done in a couple weeks time and then either right before New Years or right after I will get another dyno done. Yeah Wes spoke of you a bit, his car def looks much better blacked out. Plus he blacked out just enough and didn't overdo it. I like it!
Yeah Wes spoke of you a bit, his car def looks much better blacked out. Plus he blacked out just enough and didn't overdo it. I like it!Well go with Advance, they are amazing people and they have the best service I have ever found.
I told wes to get his eisenmann exhaust before the ecu tune
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That MAY well have been your intention, but you came off as complete douchebag that doesn't think a dyno can measure anything accurately accurate unless it costs a billion dollars and is operated by you and your friends, that Americans are too stupid to measure an elementary force or calculate variables, and that putting a car on a dyno before and after a mod is a ridiculous idea and a waste of time.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
With a mustang dyno, the pull can be longer to help line out some of the variables.
There is some argument whether IAT's are are for instant IAT value, or general average value for the day, since most have slow response. But it is not a strong variable,a s I showed.
My main point is there are "unintended consequences" when a forum "guru" like you makes an example like that, as you did. Your followers walk away thinking a 4 deg temp rise can wipe out an independent 8% power gain.
-----------------
I do consider you a true oil guru. I hope you will add links at the end of your ultimate-oil thread, to your many valuable oil explanations.
There is some argument whether IAT's are are for instant IAT value, or general average value for the day, since most have slow response. But it is not a strong variable,a s I showed.
My main point is there are "unintended consequences" when a forum "guru" like you makes an example like that, as you did. Your followers walk away thinking a 4 deg temp rise can wipe out an independent 8% power gain.
-----------------
I do consider you a true oil guru. I hope you will add links at the end of your ultimate-oil thread, to your many valuable oil explanations.
I'm sure that you would agree that variation in IAT effects different engines differently with respect to output - it is not as simple as a JIS or SAE formula - even they do not correlate. On some set ups differences can be quite dramatic.
Suffice to say it is my experience that major engine builders involved in serious racing do not depend on dyno absolute power readings to predict the performance of an engine on a real world race track.
I do not retreat from my stance and I'm sure I have more time spent running dyno tests than most on this forum with all it's foibles. Certainly more hours than those that criticise or choose to call me a douchebag.
I do apologise for my sometimes blunt expression. I'm South African & that is our way.
Should you be interested in some even more blunt commentary from myself and timdf you might like to read these threads & those attached to them. Unfortunately poor micropower was involved in one of them which I had forgotten. Now I see why he thinks I troll for dyno threads. I don't.
https://mbworld.org/forums/c-class-w...ey-system.html
Here people are called "Idiots, Knuckleheads, Retards & worse!!
I also host a discussion on the AMS pulley - see link in thread
https://mbworld.org/forums/c-class-w...****+on+a+bull
Last edited by Glyn M Ruck; Dec 6, 2009 at 06:02 PM.
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There is nothing wrong with seeing where your car stands from point A to B.
I've have had done many dyno runs on my EJ205 motor at sea level, identical temperature and humidity within a span of many months. All done because I was tuning my car and I've seen relative, consistent gains. Does this mean none of it is real? Nope. If I had multimillion dollar facility to "measure" my cars, I wouldn't have bought a C Class anyway.
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Because he would be better off measuring a standing quarter mile or whatever distance of choice. Read the other threads - I'm not suggesting buggering around with a multi million dollar Dyno setup.
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Here's my problem with that.. not only do you have the same variables in the dyno lab affecting the outcome of this result (air density, temperature) but you introduce several human variables into the equation that make the results significantly less predictable.
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From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
BTW - If I was talking about complex driving (rather than just flooring the car) such as driving the European urban cycle. Then I would let a computer drive the car on a very well sorted & calibrated dyno.
Last edited by Glyn M Ruck; Dec 7, 2009 at 03:04 AM.
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There's several variables added besides wind resistance that will make clocking a quarter mile less predictable than a dyno. Tire heating, traction, lateral movement for course correction, reaction time, et al. So yeah, that's my four dollar haircut opinion, but at least it's better than yours.
Last edited by Peabody; Dec 7, 2009 at 03:34 AM.
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How many times have you actually done it??? And how many times have you tried to stabalise a dyno. Sounds good in theory but in practice it's another story. If I had to choose between the opinions of Cosworth & you. Cosworth wins hands down. I also trust my own experience. Been down this road many times.
Your modesty is staggering.
Your modesty is staggering.
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You can be "blunt" for being from a racist ****hole like South Africa, but it's pretty hypocritical to criticize me not not being modest enough. I'm not arguing that there are variables to consider in working with a dyno, just consider that your experience may have skewed your perspective outside what is considered normal and acceptable practice. A dynometer isn't made from voodoo magik, it uses newtonian physics from the 17th Century. It needs calibration like ANY engineering device, to include things as simple as a weight. You may also need to measure and compensate for variables to achieve a truly accurate result. Unfortunately, there's no way to calibrate a quarter mile run or compensate for most of the variables.
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Your argument is the equivalent of me arguing about the variables of contact resistance, electrical capacitance of air by mineral composition, and the effect of battery temperature on electron flow makes using a multimeter an inaccurate way determining the current flow of a 9 volt battery so you can achieve more predictable and practical results by using the "stick it to the tip of your tongue" test.
Last edited by Peabody; Dec 7, 2009 at 04:33 AM.
