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Please help me get this clutch working properly!!

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Old 07-12-2009, 02:10 PM
  #196  
Tom. M
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LOL

Last edited by Tom. M; 12-14-2012 at 05:12 PM.
Old 07-12-2009, 02:16 PM
  #197  
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Old 07-12-2009, 04:58 PM
  #198  
mark kibort
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Glen,
Here again I am posting the results of you own spread sheet, which I do like by the way. As expected, there is an even greater diff from 0-25 or 0-40mph that can be take off for road racing. (.25 to .6 seconds) Your condecention has reached new levels. Im trying to explain the effects of gearing and acceleration and you, ironically, find isolated instances where you are right. Overall, this is misleading and wrong. You find an infinite set of speed ranges and Ill show no gains at all for any rear end gear set up, becuase gears dont make HP! The simulator is a great way to prove this. Im just wondering why are numbers are not matching up.

By the way, where did you get 2 seconds??? plus why didnt the values I have with your spreadsheet match what I got. I changed nothing but the 3.09 where the 2.75 was and then did it for the S4 2.2.

3 seconds for the 2.2 vs the 2.75, and 3.09's 2.39/2.7second advantage. (roughly .3 to .6 second diff) . Now, take that off for road racing comparisons below.
speeds for the 2.2:1 S4 gear box, vs *( 3.09 / 2.75 on glens car)

0-100mph 11.46sec for the 2.2 ( 11.13 / 11.53 for the 3.09/2.75)
0-118mph 16.49sec for the 2.2 ( 16.19/15.86)
0-130mph 20.49sec for the 2.2 ( 20.33/20.86)
0-140mph 25.00sec for the 2.2 (24.76/25.69)

so, remove the launch tmes to 25 or 40mph ( .25 to .6 seconds depending on the other gear box or 25mph or 40mph starting speeds) and look what you got! (the 3.09 is .45 seconds faster 0-25, and .61 seconds faster 0-40mph) The 2.2 is better than all of the gear at all the above speeds, except the 2.75 at 118mph. (probably due to a gear shift... yes, just confirmed, you have the 2.2 shifting at 106mph with your car and tire size)

It is clear to see above that if you take off the start launch time diffs of .3 to .6 seconds (2.75/3.09 respectively) you can see that the 2.2 is more optimum for these speed ranges. Kind of a departuure from what you are claiming to be an advange in racing by just going up in gear box final drive ratio. It proves my point of speed ranges and ratio mixes being optimized for one another and one is not nessesarily better for all speed ranges. Again, I didnt cherry pick the speeds, I used ones that I frequent at the track. As a racer, this is the stuff you NEED to look at to optimize you set up.

There you have it glen. depending on the speed range you frequent, all sorts of gear boxes will allow for best acceleration. Again, it depends!
Originally Posted by GlenL
The simple fact is that my understanding is beyond yours but you're determined to not be taught. And your little jabs irritate me.

But I'll try one anyways...

I modeled my Euro using both a 2.2 and a 3.09 rear end. (This would be with the BenchRace.xls I wrote that you jerkily implied was "not professional" without the barest understanding of how it works or that I am a professional.) Running from 5 to 140 mph the 3.09 car takes 25.26 seconds while the 2.2 car takes 27.33 seconds. Just over 2 seconds faster for the shorter gears.

Now I could, being a professional, create an analysis for all 10000+ increments between 1 and 140 mph. (2 to 140, 7 to 25, all of them) and show which rear end provided the best acceleration at each increment, which had the most "won" increments, what the total advantage was, etc. But you'd just deny the value of the data and instead continue to cherry pick and ignore.

I really just threw this topic in as a follow-on to other people's frustration on your intransigence in technical discussions. Here's some friendly advice: learn to write from the perspective of your intended audience and also proofread. The lecture in your head is from and to someone who already believes your position and consequently won't convince or educate a non-believer.

How about some race reports?
SOUNDS LIKE WE NEED A NEW THREAD

Last edited by mark kibort; 07-12-2009 at 10:21 PM.



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