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View Poll Results: Where do you shift your 996 3.6L street engine'd racer
shift at redline to maximize HP and acceleration on any straight
13
36.11%
shift at 300rpm below redline to save then engine and its "noise" anyway.
11
30.56%
I dont know, but want to learn how to maximize acceleration on any straight on the track.
1
2.78%
I dont know and dont care. Ill just do whatever VR says I should do.
11
30.56%
Multiple Choice Poll. Voters: 36. You may not vote on this poll

996 3.6L street engine race car owners. Where do you shift?

 
Old 02-09-2011, 07:19 PM
  #46  
Greg Smith
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Originally Posted by Veloce Raptor View Post
And yet, in the real world, what was true in your car is also true in the 996.
The real world is irrelavent in this situation because those involved real cars, the spreadsheet posted earlier were hypothetical numbers of a different car and my post is based purely off those numbers. Based on the info from the spread sheet, shifting at 7250rpm for all gears would be the quickest, for that car. Your post #42, which was in regard to that spread sheet, is wrong. For a 996(or whatever we're comparing at this point) I don't know the answer, but if someone sends me the info I'm asking for I'd be willing to find out.
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Old 02-09-2011, 07:20 PM
  #47  
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Originally Posted by Greg Smith View Post
Kibort, please learn how to use the multi-quote feature!
Sorry, here you go! >>>>

Originally Posted by utkinpol View Post
as just an outside observer i can see what kibort is trying to say but i do not see what are you trying to say here. is there an alternative shifting chart to see?
just curious.
really, my question too!

Originally Posted by Greg Smith View Post
Baby steps Dave, baby steps.

PS-Someone email me a dyno file!
Let me know, ill send you one

Originally Posted by Veloce Raptor View Post
So wait....this chart seems to show that--GASP!--you don't really need to upshift at redline with this motor. But...but...but...how could that be? 42,000 defensive words of protest in 2 separate threads seem to indicate it is impossible! Zut alors!!!

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Ummmm, are we looking at the same chart Dave??

all you mention, and this post and you still dont get it?? I give up......
maybe not.



Originally Posted by Greg Smith View Post
Actually that chart shows that you're best off always shifting at 7250rpm(assuming that's the rev limiter).
exactly. I dont think Dave reads charts too well. certainly hasnt for years, why start now.

Originally Posted by Veloce Raptor View Post
Not in gears 4 or 5, which is (not coincidentally) some of the gears in question in Brinkley's video.
yes, in gear 4-5 transition. what chart or values are you looking at???

as a note, look at the drama that happens in the 2-3rd shift too. 100ft-lbs and thats before the final drive!!! you still stand by your "Data" and "experience".
I wouldnt lump the other guys into your corral, just yet.



Originally Posted by Greg Smith View Post
No it's not, you make more transmission output torque at 7250 RPM in 4th gear than you do at 6060rpm in 5th gear. You also make more transmission output torque at 7250rpm in 5th gear than you do at 5970rpm in 6th gear.

Using my old car as an example, with a 7000rpm redline. From 1st to 2nd and 2nd to 3rd my optimal shift was 7000rpm, for 3rd to 4th it was 6800rpm, for 4th to 5th it was 6500rpm. So yes it's true for some cars, but it depends on the torque/power curve and gearing.
yes, exactly right.
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Old 02-09-2011, 07:20 PM
  #48  
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Originally Posted by Greg Smith View Post
The real world is irrelavent
This tells us all we need to know about both these threads.









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Old 02-09-2011, 07:24 PM
  #49  
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Originally Posted by Veloce Raptor View Post
This tells us all we need to know about both these threads.
Taking my quotes out of context Dave, bravo. Way to change the subject.
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Old 02-09-2011, 07:24 PM
  #50  
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in any car with a peaky hp curve, or even a flat top, its going to be true. your "real world" data is cluttered up a bit with other factors. If you have the data, show us a run to run comparison down a straight, with the g's listed at 7000rpm vs 7200rpm vs the post shift rpm. Because you failed to even see the difference on a very clear spreadsheet, something tells me you would have a hard time reading more complex information on the data aqu. output. Just a guess. in fact, you can try and find a dyno run that simulates your theory, but unfortunately, it would have probably had to be a 928.

anyway, as Greg posted, from 4th to 5th, the difference is from 204 vs the post shift torque of 180. 24ftlbs BEFORE even a rear end multiplier. so, more like near 100ftlbs difference! But, your data shows to the contrary. Hmmm, I wonder why. seriously. Or, i would like to really know the true comparison you did or what you are looking at, in order for others to not make this same mistake!

Originally Posted by Veloce Raptor View Post
And yet, in the real world, what was true in your car is also true in the 996.









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Old 02-09-2011, 07:26 PM
  #51  
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VR,

Have you looked at this article?:

http://www.allpar.com/eek/hp-vs-torque.html

It covers much of this. Here is another paragraph:

Not all cars should be shifted at the redline for maximum performance. But it's true for many cars. You can determine optimal shift points by graphing horsepower vs. velocity or transmission torque vs. RPM. Engine torque alone will not determine shift points.

That is what Greg is talking about and he is willing to do the math to show what the optimal shift points actually are.

Scott
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Old 02-09-2011, 07:30 PM
  #52  
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Originally Posted by Veloce Raptor View Post
This tells us all we need to know about both these threads.
even when he fails a task, he cant admit defeat. denial!

Originally Posted by Greg Smith View Post
Taking my quotes out of context Dave, bravo. Way to change the subject.
That's his style.
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Old 02-09-2011, 07:39 PM
  #53  
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Originally Posted by Greg Smith View Post
The real world is irrelavent in this situation because those involved real cars, the spreadsheet posted earlier were hypothetical numbers of a different car and my post is based purely off those numbers. Based on the info from the spread sheet, shifting at 7250rpm for all gears would be the quickest, for that car. Your post #42, which was in regard to that spread sheet, is wrong. For a 996(or whatever we're comparing at this point) I don't know the answer, but if someone sends me the info I'm asking for I'd be willing to find out.

https://rennlist.com/forums/996-foru...light=996+dyno
This is the chart I used Greg. It was easier to get the dyno numbers off it than the one in this thread. Feel free to check my work.

Here are the gear ratios: http://www.californiamotorsports.net...oxster%20S.htm
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Old 02-09-2011, 07:39 PM
  #54  
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Originally Posted by Greg Smith View Post
Taking my quotes out of context Dave, bravo. Way to change the subject.
There is no change of subject. All of these academic theoretical exercises don't change what PedroNole, Viking, myself, mglobe, and may others have figured out in the real world. Look carefully at 0:36 and 1:21 in this video, for example. I cannot IMAGINE why Darren does not shift at redline in these places. Hmmm.....clearly he has not been "educated" by the slowpoke of 50,000 words here. He's ONLY doing a 2:05 here.





As many of us said in the other thread, sometimes it makes sense & is faster to shift short of redline, and this is often true with a street based 996 motor. Which neither you nor Mark have seat time in.

Ay ay ay....








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Old 02-09-2011, 07:51 PM
  #55  
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Originally Posted by winders View Post
VR,

Have you looked at this article?:

http://www.allpar.com/eek/hp-vs-torque.html

It covers much of this. Here is another paragraph:

Not all cars should be shifted at the redline for maximum performance. But it's true for many cars. You can determine optimal shift points by graphing horsepower vs. velocity or transmission torque vs. RPM. Engine torque alone will not determine shift points.

That is what Greg is talking about and he is willing to do the math to show what the optimal shift points actually are.

Scott
Scott, check the video I posted. I am pretty sure an RSR is a pretty peaky motor compared with a street 996 motor, yet Darren is upshifting short of redline in at least two places. Q.E.D.








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Old 02-09-2011, 08:03 PM
  #56  
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But the real question is does Darren shift at or before redline between turns 16 and 17?
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Old 02-09-2011, 08:39 PM
  #57  
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Originally Posted by GTgears View Post
But the real question is does Darren shift at or before redline between turns 16 and 17?
LMAO! Amazing how quiet the peanut gallery suddenly got here, eh?









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Old 02-09-2011, 08:39 PM
  #58  
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Originally Posted by Veloce Raptor View Post
Scott, check the video I posted. I am pretty sure an RSR is a pretty peaky motor compared with a street 996 motor, yet Darren is upshifting short of redline in at least two places. Q.E.D.
VR,

Sure. I raced motorcycles (even more peaky motors) which are more sensitive than cars to traction changes in corners. With the higher horsepower bikes there were places on most tracks where I would up shift before red line so I would not upset the bike in the corner.

Would Mr. Law be shifting before red line if he were on the Mulsanne Straight? I don't think he would.

Unlike one other, I am not arguing absolutes here. I know there are good reasons to not shift at red line. But, if we narrow the scenario to accelerating down a straight, I think we can say that in that case, shifting early would not allow one to get down that straight faster.

Scott
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Old 02-09-2011, 08:42 PM
  #59  
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Originally Posted by winders View Post
But, if we narrow the scenario to accelerating down a straight, I think we can say that in that case, shifting early would not allow one to get down that straight faster.

Scott
But that WASN'T the scenario.









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Old 02-09-2011, 09:11 PM
  #60  
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Originally Posted by Veloce Raptor View Post
But that WASN'T the scenario.
To be honest, with all the crap that has gone on, I don't recall the original scenario. But, as I said, I am not arguing absolutes here. I know there are good reasons to not shift at red line in certain situations.....

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