Dinan 3.62 Diff question

[swamp2]

Originally Posted by Lemans_Blue_M

What's the deal here?

...

I'll continue the discussion with some more detail. But why do you write in such an incredibly hard to read and digest format? Every sentence is a paragraph, each point is made 2-3 times and there is no seeming order to your text, just a stream of consciousness. That's fine for thinking but really poor for communicating. And your on going (amusing at this point...) inability or refusal to answer a very simple and very fundamental question. Perhaps you can work on an answer before my next reply. I think it would be quite helpful for you, in all seriousness. Answer the simple question!

[dcstep]

I'm deeply involved with "modeling risk" professionally, as a mortgage banking risk manager. I literally asked a proud modeler in 2005, "What happens when you slow housing price appreciation to zero." His response was, "The model blows up." Of course, we now all know that the model did NOT blow, it simply gave an ugly but true answer.

I'm actually all for modeling, BUT it is extremely important to benchmark and correlate modeling results to real world data. Modelers tend to get caught up and defensive of their models. Once a models gets "sold", then others start giving it way more credit than it deserves. In my forty-plus years in the business, I've seen this over and over. It's part of the "Madness of Crowd" phenominum.

So, my advice is, keep modeling, but keep correlating and benchmarking to actual results. Once you start ignoring the real world and relying totally on a model, you're setting yourself up for a big failure.

Dave

[swamp2]

Originally Posted by dcstep

I'm deeply involved with "modeling risk" professionally, as a mortgage banking risk manager. I literally asked a proud modeler in 2005, "What happens when you slow housing price appreciation to zero." His response was, "The model blows up." Of course, we now all know that the model did NOT blow, it simply gave an ugly but true answer.

I'm actually all for modeling, BUT it is extremely important to benchmark and correlate modeling results to real world data. Modelers tend to get caught up and defensive of their models. Once a models gets "sold", then others start giving it way more credit than it deserves. In my forty-plus years in the business, I've seen this over and over. It's part of the "Madness of Crowd" phenominum.

So, my advice is, keep modeling, but keep correlating and benchmarking to actual results. Once you start ignoring the real world and relying totally on a model, you're setting yourself up for a big failure.

Dave

Great advice in the case of extremely large and extremely complex models that have not already been well correlated as to their suitability, range of applicability, accuracy, robustness, assumptions, inputs, etc. Changing a FD in a vehicle acceleration program is quite clearly none of these. Again here we are talking about Newtons laws (F=ma and its rotational equivalent) and integrating a first order, linear, ordinary differential equation. This is undergraduate engineering stuff.

[swamp2]

Originally Posted by Lemans_Blue_M

I have tried several times to explain why I think your numbers are off. (on the timed 0-50, 0-60, 1/4 mile acceleration results you posted)

And you continue to misinterpret the numbers and the number of significant digits. These things really should be obvious.

Originally Posted by Lemans_Blue_M

My opinion is based on the results I have actually seen over the past 3 decades of drag racing. I'm sorry if that 'evidence' contradicts what your software simulation program is telling you.

My god how many times do we have to go over this? What you get from a FD mod is both vehicle and individual result dependent. I suggest than many older cars you might have experience with at the strip are much further from an optimized FD ration for 0-60 or quarter mile. If you think that all FD mods will always do exactly the same thing (or even exhibit the same pattern) you are really foolish.

Originally Posted by Lemans_Blue_M

You have have made it perfectly clear, that you do not respect that opinion, and would rather use simulation numbers only.

For A-B comparisons on this vehicle with these FD ratios I trust simulation as much as testing since the variations are of the same size differences.

Originally Posted by Lemans_Blue_M

That's your right. Nobody is trying to say you can't. How about showing some respect for the individuals who don't bow at the alter of the almighty Car Tech software?

Quite clearly you have no experience and hence no trust in the predictive power of such software tools. When you have cut your teeth a bit you develop more trust. My advantage is I am simply trusting physics, which is never really wrong. You are trusting brash empericism, which is very often wrong.

Originally Posted by Lemans_Blue_M

I certainly hope you don't expect me to abandon my belief system...just to appease you?

Nope. But I can still try to convince you of some basics you keep missing. ANSWER THE QUESTION I HAVE POSED THREE TIMES NOW, VERY DIRECTLY.

Originally Posted by Lemans_Blue_M

I have met a great deal of Engineers over the course of life, and I have the utmost respect for many of them. They can calculate anything you can possibly imagine...on paper. I have also seen these engineers out on the track. (after running endless simulations on 'generic' software programs). One size does NOT fit all.

When some of their calculations don't TRANSLATE well to the real world performance on the track, there is a moment where they appear to look like a deer caught in the headlights. I have seen this look many times.

I am not arguing my drag racing nor track driving abilities. That has absolutely positively nothing to do with this debate. I'm also not talking about detailed calculations for esoteric and very fine parameters. Diversion is this (transparent) technique of yours and it is not relevant.

Originally Posted by Lemans_Blue_M

Regardless of how many degrees you have, or how much book knowledge you posses...that has to be backed up with some basic common sense.

You are the one ignoring common sense. Well not really you just keep ignoring the physics, time in each gear vs. torque multiplication. I don't really blame you too much the easy answer of the common man is add a higher FD diff and the gains are a no brainer.

Originally Posted by Lemans_Blue_M

I don't doubt the fact that these software simulations can point you in the right direction, but I think it's very foolish to put all your eggs in that basket. Your risk is actually greater by choosing that path, than actually choosing your mod upgrades from a trusted individual(s) who have vast experience making those hardware changes. (again, real world track experience is worth it's weight in gold)

Again, please answer, very simply and directly. WHERE IS THE EVIDENCE FOR THESE RATIOS IN THE M3? It just is not the case that if you always do what you always did you will always get what you always got.

Originally Posted by Lemans_Blue_M

Seeking the knowledge of a trained professional (who has literally seen it all), is significantly more valuable to me than a set of artificially derived numbers on a software simulation. Sorry to see that you think so little of using this methodology.

Your ongoing insistence that CarTest (by the way not my software) is "artificially derived" is patently false drivel with absolutely no justification. Word have precise meanings and your diction here is terrible.

Originally Posted by Lemans_Blue_M

I'm sure all the racing organizations I speak with, don't factor in all the experience they have gained over the years at all. It's all about what the computer simulation tells them to do. I'm sure that's exactly how it works, when they need to upgrade their hardware componants...

Simulation does not work for everything all the time, I never claimed it did and very well know it does not. Here we can agree.

Originally Posted by Lemans_Blue_M

I tend to put more stock in the tried and true method of upgrading parts, which is based on real world experience and knowledge.

And this is part of the reason so many parts actually don't deliver or deliver a small fraction of what the claim they will. This is a prime case. As others have pointed out much of the effect of a FD mod will be a perception of improved performance without much of a significant (if any) delivery. Again this is due to less time in each gear and torque multiplication comparing gear by gear or results without shifts.

Originally Posted by Lemans_Blue_M

The software 'simulations' are indeed a useful tool. And I am not discounting that point at all. There is certainly no doubt that it can help you in some aspects. But I do not believe for one minute, that it should be the determining factor in choosing one path over another. If you make even the slightest error in your input values, the results can (and will) look very different. That can change your entire perspective on which path to take.

Agree. Whew.... finally.

Originally Posted by Lemans_Blue_M

You never qualified your numbers until I dared to challenge the results. Do you realize that?

You never bothered to apply a reasonable and fairly obvious interpretation to the numbers until our debate began. You have also clearly not seen the prior validation work I have done for the M3 and other vehicles right here on the forum. I've done work on many more I have not posted about either.

Originally Posted by Lemans_Blue_M

All the simulation numbers in this thread are 'guesstimates'. Regardless of how many mathematical formulas were used, that's what they are...

The numbers are derived using theories and assumptions. They are not infallible, and your refusal to admit that is telling.

Wrong, wrong, wrong. Simulation is not a guesstimate. You simply could not be more wrong about that. I completely agree with the second point though, however I have not refused to admit that point.

Originally Posted by Lemans_Blue_M

... the results of some random software simulation?

Incorrect classification. Do some homework before making such an accusation.

Originally Posted by Lemans_Blue_M

If those are my two choices, guess which path I'm going to take.

I have no doubts. Guess how often you will not get what you think you will.

Originally Posted by Lemans_Blue_M

I see now, that's it's truly impossible for you to see things from that real world perspective. (after trying in vain to get that across to you several times)

I deeply appreciate the value of both testing and simulation but I also am acutely aware of the complexities (impossibility) of "perfect" apple to apples testing.

Originally Posted by Lemans_Blue_M

You wrap yourself up in a bunch of arbitrary numbers, and you resist any attempt to discuss things in a rational real world manner.

Pot, kettle, black. "Arbitrary" is again an entirely false, meritless and idiotic claim. You are the one who patently refuses to believe anything, even the most basic acceleration simulations based on your misunderstanding of the outputs (significant digits) and relevant physics. Hence YOU have become irrational.

Originally Posted by Lemans_Blue_M

The hubris that you project to the members of this board is breathtaking. In that respect, you are unrivaled. You are right, and everyone else is always wrong. That's the image you project from what I have seen in a number of threads.

I pride myself on being correct much much more often than not. That is also my reputation. However, when I am not I always graciously admit it, apologize as needed, thank those that deserve it and move right along. No drama, no problems.

Originally Posted by Lemans_Blue_M

Not only that, but you seem to go out of your way to type most most condescending posts I have ever seen on an internet message board. (if someone challenges your opinion)

You confuse healthy debate with condescension. But your condescension toward simulation is amply evident. So, once again, pot, kettle, black.

Originally Posted by Lemans_Blue_M

I go out of my way to help the members of this board on a variety of automotive related topics. I post the information they need to make an informed decision on a specific mod. My history clearly indicates that intent.

Your willingness to be helpful is not in question. However, your advice is simply not 100 reliable not always factually correct. When it is not you will get called out on it. I am not the first to do so. Also my questioning and correction to vendor BS and other false claims or unsubstantiated claims is a way in which I have provided great assistance to this forum. My post count, a very miniscule amount of which are socializing or "empty content" posts is indicitive of my dedication to this board. We can compare those metrics as you like.

Originally Posted by Lemans_Blue_M

But unfortunately, your aptitude in debating any issue, with anyone on this board (sans the condescending tone)...is an unmitigated disaster.

You do this every time someone disagrees with your opinion.

There can be no debate without at least the tacit acceptance...

Aptitude is clearly the wrong word here. I honestly think I need to buy a dictionary for you. You can try www.dictionary.com as well. Debate is a term you seem totally uncomfortable with. Your criticisms, specifically on this topic are completely hollow and rest on nothing other than misunderstandings, inappropriate comparisons and inapplicable past results. You have nothing else to stand on and refuse to actually debate and answer my questions. You also keep referring to data but have NONE. Your deep criticism of simulation remains unfounded and seemingly entirely based on lack of experience, lack of understanding and distrust based on emotion. However, if you want to get down to the facts I will repeat myself. I am correct and win debates here much more often than not. Again, when I lose or am wrong there is always clear and simple action on my behalf.

Really, this is all getting old. This is personal and emotional, not any valuable debate. Answer the questions, provide some shred of some data (actual numbers, this car or others) that can be the source of some well defined disagreement. Drop the dismissal of things you don't understand. Until you are willing to do these things there is not much real debate here. Real debate about simulation and its accuracy as well as my ability to obtain accurate results from it are also all perfectly fine topics to discuss and actually debate but I am sick of this meta-debate crap.

I will suggest a challenge. I will be able to adequately predict the overall correct behavior of a FD modification in the M3 or any other car of your choice if multiple consistent test runs can be provided. I'll provide any metric available from CarTest, but will focus on common magazine specs. There will always be some results that will be clearly correct, those adequately correct, perhaps those inconclusive and maybe even some incorrect. We can leave it to the board to judge the overall adequacy and accuracy of the results. Put up or shut up, really.

[eeeboy]

I want to see a stock dct race a dct with 3.62,,,PLEASE!!!!!!someone