Ultimate hp test 100-300kph
11-15-2006, 09:22 AM
#91
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Jean,
The reference to 'lateral' g's in my post above was incorrect as noticed - you're good at this. It should have been the g's on your graph which are longitudinal. That'll teach me for posting so early in the morning..
Cheers, Rich
The reference to 'lateral' g's in my post above was incorrect as noticed - you're good at this. It should have been the g's on your graph which are longitudinal. That'll teach me for posting so early in the morning..
Cheers, Rich
11-15-2006, 09:44 AM
#92
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Originally Posted by 935racer
Kiko, Interesting point about the bullet. Luckily, I am no expert on guns but this can perhaps be explained by the fact that the expanding gases are still exerting a force on the bullet AFTER it leaves the barrel. This is easily explained by the viscosity of air and the massivly expanding gases from the barrel. The surrounding air simply cannot letthe hot gases expand quick enough dueto the airs viscosity and thus there is still a net force exerted on the bullet.
I really dont know but things dont accelerate unless they are subject to a net force.
Richard.
I really dont know but things dont accelerate unless they are subject to a net force.
Richard.
11-15-2006, 11:32 AM
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Originally Posted by Jean
First let me say that I agree with all that is begin said by Richard and others, after installing my sequential gearbox, it has taken me a lot of time and analysis to get to this point just because I studied the motion dynamics formulas and they did not make sense compared to what I was seeing.
Hi Rich, these are long Gs, lateral Gs are used to determine grip usually. Acceleration is m/s square, so it is how much distance the car gains in a second, per second. Maybe this is why you see that. The sampling is too quick (several times per second) , it needs to be smoothened to get more valid data.
Colin, I never get in neutral, I have a sequential gearbox, always in gear. All the charts that I have back when I was using the normal gearbox are showing negative Gs, most of my charts with sequential gearbox show it too, however with the right shifts, I get curves that keep the Gs positive, like the one posted above. I guess I will have to post a video.
I am open to share my raw data to be checked, I am more critical of my runs and my tuner than anyone else
I test my data on excel with mathematical formulas for slope, Gs, speed, distance everytime I do a run, I have also tested throroughly on the track, comparing different lines, G forces long and lateral, braking points, etc. The device is very well secured, otherwise the slightest move will throw a strange long G on the chart. You would be surprised to see how many runs looking perfectly good had in fact some small issues.
Colin, TB's data is done with the AX22, as are all the runs that I have. I don't know what else to post so that it is believed before assuming the tool is not accurate. Maybe TB can do some runs with the Driftbox and the AX22 inside the car and show us how they compare. If all the dataloggers including Motec (which will also show speed picking up briefly after shifting, while Gs are dropping) are wrong, then we are maybe not there yet technologically or the physics theory of rotational mass has a few more angles to it that we don't know of ourselves.
The key here are 2 things, first, I have a sequential gearbox, I am always in gear, the second thing is that while shifting, the car is seeing Gs dropping, but in the meantime the car is still gaining speed through momentum. I know the formulas involved I have researched this at length and the ones I posted above on an earlier post explain what this is due to.
In any case, this has been a good discussion, my intention is just to share my observations about shift points, gearboxes aerodynamics etc. which I find to be an interesting subject, so with the data posted, everyone should go with their own outcomes, in the meantime, looking forward to see more runs
Hi Rich, these are long Gs, lateral Gs are used to determine grip usually. Acceleration is m/s square, so it is how much distance the car gains in a second, per second. Maybe this is why you see that. The sampling is too quick (several times per second) , it needs to be smoothened to get more valid data.
Colin, I never get in neutral, I have a sequential gearbox, always in gear. All the charts that I have back when I was using the normal gearbox are showing negative Gs, most of my charts with sequential gearbox show it too, however with the right shifts, I get curves that keep the Gs positive, like the one posted above. I guess I will have to post a video.
I am open to share my raw data to be checked, I am more critical of my runs and my tuner than anyone else
I test my data on excel with mathematical formulas for slope, Gs, speed, distance everytime I do a run, I have also tested throroughly on the track, comparing different lines, G forces long and lateral, braking points, etc. The device is very well secured, otherwise the slightest move will throw a strange long G on the chart. You would be surprised to see how many runs looking perfectly good had in fact some small issues.Colin, TB's data is done with the AX22, as are all the runs that I have. I don't know what else to post so that it is believed before assuming the tool is not accurate. Maybe TB can do some runs with the Driftbox and the AX22 inside the car and show us how they compare. If all the dataloggers including Motec (which will also show speed picking up briefly after shifting, while Gs are dropping) are wrong, then we are maybe not there yet technologically or the physics theory of rotational mass has a few more angles to it that we don't know of ourselves.
The key here are 2 things, first, I have a sequential gearbox, I am always in gear, the second thing is that while shifting, the car is seeing Gs dropping, but in the meantime the car is still gaining speed through momentum. I know the formulas involved I have researched this at length and the ones I posted above on an earlier post explain what this is due to.
In any case, this has been a good discussion, my intention is just to share my observations about shift points, gearboxes aerodynamics etc. which I find to be an interesting subject, so with the data posted, everyone should go with their own outcomes, in the meantime, looking forward to see more runs
) free time....plus at the end of the day there is always errors of some kind, so are you quicker or slower than toby's RS car as per your numerous calculations and graphs.... 
11-15-2006, 12:36 PM
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Jean, with all due respect I would strongly advise to join me and do what one customarily does with Trolls -don't feed the juvenile ego, ignore them
11-15-2006, 01:01 PM
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Keep it above board guys (As you know I am the "poster child of this thinking...)
Jean, TB, and Leon, your cars are amazing and TB although it may be true that your car
was not performing correctly...on that day side by side, it would appear that Leon beat you.
We would all love to see a rematch!!
MK
Jean, TB, and Leon, your cars are amazing and TB although it may be true that your car
was not performing correctly...on that day side by side, it would appear that Leon beat you.
We would all love to see a rematch!!
MK
11-15-2006, 03:25 PM
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Originally Posted by Jean
The sampling is too quick (several times per second) , it needs to be smoothened to get more valid data.
Originally Posted by Jean
Colin, I never get in neutral, I have a sequential gearbox, always in gear. All the charts that I have back when I was using the normal gearbox are showing negative Gs, most of my charts with sequential gearbox show it too, however with the right shifts, I get curves that keep the Gs positive, like the one posted above. I guess I will have to post a video.
Originally Posted by Jean
I am open to share my raw data to be checked...
Originally Posted by Jean
I don't know what else to post so that it is believed before assuming the tool is not accurate.
Keep up the good work.
11-15-2006, 03:49 PM
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Originally Posted by leonsamonas
all this data analysis must take up a lot of your time jean, you must have alot (too much ) free time....plus at the end of the day there is always errors of some kind, so are you quicker or slower than toby's RS car as per your numerous calculations and graphs....
) free time....plus at the end of the day there is always errors of some kind, so are you quicker or slower than toby's RS car as per your numerous calculations and graphs....
11-15-2006, 04:50 PM
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Originally Posted by Kiko
Thats one SILLY post to say the least. Instead of appreciating the time another respected fellow rennlister takes collecting data, posting it and discuss it to the benefit and knowledge of all you just pass on to personal remarks. You clearly have an hidden agenda and this post makes you look like a troll unless you come out and say whats REALLY bothering you...
every one has their OWN opinion...now you know mine
11-15-2006, 04:53 PM
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Originally Posted by TB993tt
Jean, with all due respect I would strongly advise to join me and do what one customarily does with Trolls -don't feed the juvenile ego, ignore them
11-15-2006, 06:19 PM
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I've just looked at my data-logged run that went to over 200mph and on every gearchange the longitudal acceleration not only dropped to zero in the gearchanges, but went to as much as negative 0.1g in the higher gears(presumably from air resistance), whereas it only dropped slightly below zero in the 1-2 change. This is what would be expected.
If you are getting positive g through gear-changes then I would (hesitantly) suggest that perhaps you are getting incorrect readings for acceleration.
Guy
If you are getting positive g through gear-changes then I would (hesitantly) suggest that perhaps you are getting incorrect readings for acceleration.
Guy
11-15-2006, 06:23 PM
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Hello
this has nothing to do with 100-300 but if one wnats to know how fast you can shift today here the max in a car that has the latest technology in shifting in Gt cars The 997 cup car (the new 997 Gt3 RSR race will be a little better)
we divide ****ing in 4 parts.
a: time when you pull the lever (the lower gear is not in any more)
b: time to put the new gear in
c: time to start accelarating with the gear in.
d: time to take the engine starting accelarating and reach its max Long G (the gear is already in)
a to c is the real shifting
a to d is the time it takes for the shifting. Most people ignore d and thinks shifting is only the time that takes to change the gear.
997 cup car with full Pro Driver in Silverstone Porsche Supercup race in 2006
a: 0.04 sec
b: 0.02 sec
c: 0.02 sec
d: 0.02 sec
I mesure at 50 times per sec.
Display accurancy is 0.02 sec. (so if it takes 0.015 or 0.003 sec I say it is just 0.02 sec
The speed at 183 km/h drops during the gear change at 0.4 km/h during 0.04 sec
already in part b: the car is gaining speed. this is the limit of the dataloging unit. it should gain after/during part c:
I can datalog faster at least 20 times faster but there is no reason for this. I use the datalog Time for other more important things.
Konstantin
BTW: downshifting is where you gain time during a race
this has nothing to do with 100-300 but if one wnats to know how fast you can shift today here the max in a car that has the latest technology in shifting in Gt cars The 997 cup car (the new 997 Gt3 RSR race will be a little better)
we divide ****ing in 4 parts.
a: time when you pull the lever (the lower gear is not in any more)
b: time to put the new gear in
c: time to start accelarating with the gear in.
d: time to take the engine starting accelarating and reach its max Long G (the gear is already in)
a to c is the real shifting
a to d is the time it takes for the shifting. Most people ignore d and thinks shifting is only the time that takes to change the gear.
997 cup car with full Pro Driver in Silverstone Porsche Supercup race in 2006
a: 0.04 sec
b: 0.02 sec
c: 0.02 sec
d: 0.02 sec
I mesure at 50 times per sec.
Display accurancy is 0.02 sec. (so if it takes 0.015 or 0.003 sec I say it is just 0.02 sec
The speed at 183 km/h drops during the gear change at 0.4 km/h during 0.04 sec
already in part b: the car is gaining speed. this is the limit of the dataloging unit. it should gain after/during part c:
I can datalog faster at least 20 times faster but there is no reason for this. I use the datalog Time for other more important things.
Konstantin
BTW: downshifting is where you gain time during a race
11-15-2006, 11:53 PM
#104
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What makes Rennlist a great place is the diversity of people that one can find, from clueless and arrogant trolls to people like Konstantin and Richard who are willing to share true life experiences with others without a hidden agenda or a potential sale ringing in their ears..
Guy, I am talking about a sequential gearbox. All my stock gearbox readings show the same trends as yours, it is a different story altogether though.
Konstantin (thanks BTW) has given a pretty good idea of what goes on with a sequential box. The car looses speed of only 0.4kph at 183kph for a duration of 0.04s, and then starts picking up (see my data posted earlier for similarities).
Colin, thanks for your POV. I have traced back TB's AX22 runs and wheel thrust curves all the way to the engine dyno readings using his exact car specs of gearing, tires, aerodynamics etc.. and they were almost spot on, results were shared with him.
Guy, I am talking about a sequential gearbox. All my stock gearbox readings show the same trends as yours, it is a different story altogether though.
Konstantin (thanks BTW) has given a pretty good idea of what goes on with a sequential box. The car looses speed of only 0.4kph at 183kph for a duration of 0.04s, and then starts picking up (see my data posted earlier for similarities).
Colin, thanks for your POV. I have traced back TB's AX22 runs and wheel thrust curves all the way to the engine dyno readings using his exact car specs of gearing, tires, aerodynamics etc.. and they were almost spot on, results were shared with him.
Last edited by Jean; 11-16-2006 at 06:02 AM.
11-16-2006, 02:33 AM
#105
Jean,
Anybody who knows anything realizes that your's is the car to beat...
When I get back from Honolulu, I'm going to ask Knighton what I'll need to knock you off your throne...
Anybody who knows anything realizes that your's is the car to beat...
When I get back from Honolulu, I'm going to ask Knighton what I'll need to knock you off your throne...