The building of AMS TA X! BACK ON TRACK!
Jun 17, 2009, 06:38 PM
#496
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On the top center page 19 :
a single element wing on a "sedan-based racecar" showed best vehicle downforce when at about 0.7 of its chord above the rear deck, again with downforce reducing at higher or lower positions.
The pics I show are Le mans GT2 class cars, the 2009 regulation rule for the wing is at roof height, but as you can see, many team are not mounting them at roof height, if you think roof height can achieved more clean air for downforce why arent they doing it ?
a single element wing on a "sedan-based racecar" showed best vehicle downforce when at about 0.7 of its chord above the rear deck, again with downforce reducing at higher or lower positions.
The pics I show are Le mans GT2 class cars, the 2009 regulation rule for the wing is at roof height, but as you can see, many team are not mounting them at roof height, if you think roof height can achieved more clean air for downforce why arent they doing it ?
Jun 17, 2009, 08:11 PM
#498
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Because they know what works for them.
Theres big variances in the chord length metric across even those cars pictured. As noted in the rest of the article past the first section, this metric is dependent on each vehicle body shape and specific application. I'm sure they'll figure it out in due time without having to refer to breif magazine articles.
Food for thought: if the rear wing is used primarily as a trim device with a small contribution to the overall downforce, would it make sense to put it at a position where the balance can be affected significantly with a low downforce/low drag wing?
Theres big variances in the chord length metric across even those cars pictured. As noted in the rest of the article past the first section, this metric is dependent on each vehicle body shape and specific application. I'm sure they'll figure it out in due time without having to refer to breif magazine articles.
Food for thought: if the rear wing is used primarily as a trim device with a small contribution to the overall downforce, would it make sense to put it at a position where the balance can be affected significantly with a low downforce/low drag wing?
I wish you guys the best with TA X!!! 
Jun 17, 2009, 09:46 PM
#500
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That depends on the track and the amount of HP Martin lets me (or Mark) run, crank up the boost to offset the drag. How many corners are above ~70mph?
How many corners above ~70mph lead onto straights?
How many high speed brake zones are there?
etc. etc.
A shame we are not going to any real fast tracks this year, the aero thing is almost a moot point at most of the small tight tracks we are running
Again... Unlimited = Fun
Jun 17, 2009, 09:56 PM
#501
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Such a loaded question That depends on the track and the amount of HP Martin lets me (or Mark) run, crank up the boost to offset the drag.
How many corners are above ~70mph?
How many corners above ~70mph lead onto straights?
How many high speed brake zones are there?
etc. etc.
A shame we are not going to any real fast tracks this year, the aero thing is almost a moot point at most of the small tight tracks we are running
Again... Unlimited = Fun
That depends on the track and the amount of HP Martin lets me (or Mark) run, crank up the boost to offset the drag. How many corners are above ~70mph?
How many corners above ~70mph lead onto straights?
How many high speed brake zones are there?
etc. etc.
A shame we are not going to any real fast tracks this year, the aero thing is almost a moot point at most of the small tight tracks we are running
Again... Unlimited = Fun
Interesting!
Sam
Last edited by Sales@IveyTune; Jun 17, 2009 at 10:03 PM.
You guys never disappoint
now all you need is to add me to the team
Jun 18, 2009, 08:09 AM
#503
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Such a loaded question That depends on the track and the amount of HP Martin lets me (or Mark) run, crank up the boost to offset the drag.
How many corners are above ~70mph?
How many corners above ~70mph lead onto straights?
How many high speed brake zones are there?
etc. etc.
A shame we are not going to any real fast tracks this year, the aero thing is almost a moot point at most of the small tight tracks we are running
Again... Unlimited = Fun
That depends on the track and the amount of HP Martin lets me (or Mark) run, crank up the boost to offset the drag. How many corners are above ~70mph?
How many corners above ~70mph lead onto straights?
How many high speed brake zones are there?
etc. etc.
A shame we are not going to any real fast tracks this year, the aero thing is almost a moot point at most of the small tight tracks we are running
Again... Unlimited = Fun
AutoClub Speedway is pretty darn fast. GST was hitting 170mph on the banking. Spring mountain has at least one corner I can think of where the AMS car should be well over 100mph, accelerating, while going through a right hand turn.
Jun 18, 2009, 08:34 AM
#504
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CFD is awesome for those who can afford it, we might be grabbing a seat at work pretty soon. But until then I'll happily play with strain gauges and string pots. Empirical data is pretty useful stuff, often times it takes lots of tweaks just to get a computer model to recreate test results - and without the test results you'd never tune your model.
What really matters is that AMS is out getting it done and trying some stuff on their own, and sharing the process with everyone here. That's cool.
Some stuff I used to get the airflow angle over the back of the car. To me it seems like a wing set at zero relative to the ground will see an angle of attack of about 10 degrees.
Last edited by jid2; Jun 18, 2009 at 08:36 AM.
Jun 18, 2009, 09:22 AM
#505
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Voltex spent time adjusting the wing height in a wind tunnel for the EVO, and they came up with roughly roof height mounting.
CFD is awesome for those who can afford it, we might be grabbing a seat at work pretty soon. But until then I'll happily play with strain gauges and string pots. Empirical data is pretty useful stuff, often times it takes lots of tweaks just to get a computer model to recreate test results - and without the test results you'd never tune your model.
What really matters is that AMS is out getting it done and trying some stuff on their own, and sharing the process with everyone here. That's cool.
Some stuff I used to get the airflow angle over the back of the car. To me it seems like a wing set at zero relative to the ground will see an angle of attack of about 10 degrees.
CFD is awesome for those who can afford it, we might be grabbing a seat at work pretty soon. But until then I'll happily play with strain gauges and string pots. Empirical data is pretty useful stuff, often times it takes lots of tweaks just to get a computer model to recreate test results - and without the test results you'd never tune your model.
What really matters is that AMS is out getting it done and trying some stuff on their own, and sharing the process with everyone here. That's cool.
Some stuff I used to get the airflow angle over the back of the car. To me it seems like a wing set at zero relative to the ground will see an angle of attack of about 10 degrees.
There was a part where they were correcting the wing angle
http://www.youtube.com/watch?v=kqjKxDFEK98
Jun 18, 2009, 02:30 PM
#506
I think it was in this thread that it was asked but the best lap time on this track by a production based car is a 1:25.693 by a GT3 durring a SCCA National event.
For reference our TA1 car in top form would of been capable of a low 1:28 in top form with the Street tires we had to run.
TA-X could be a real contender for this record but we will see.
Eric
For reference our TA1 car in top form would of been capable of a low 1:28 in top form with the Street tires we had to run.
TA-X could be a real contender for this record but we will see.
Eric
Jun 18, 2009, 03:36 PM
#507
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i think the TA-X is going to be a record setter hands down, but i also think there are more and more serious TA teams and cars sprouting up and also more privateers trying to get serious, the TA-X so far as i can see is the most advanced ive seen that hasnt removed some part of the unibody and replaced it with a tube frame section, since slicks will be allowed this year in unlimited i am very curious to see the records that all of the teams break...set...then break again
no matter how you cut it the TA-X is the baddest, most mean purpose built evo X stateside and im going to do everything in my power to see this beast at an event this season
no matter how you cut it the TA-X is the baddest, most mean purpose built evo X stateside and im going to do everything in my power to see this beast at an event this season
Sep 7, 2009, 03:21 PM
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Someone pointed me to this thread talking to me about that elise but I thought I could put some additional information to explain some things. I have a huge respect for Joseph Katz by the way, love his books. Some of them I have read 3 times or more, but be careful to put the data of that article in context. I think what they were experiencing and tried to make it clear was a deck to wing interaction on the Elise. If you look at an elise rear deck and know the history of the cars aero a little bit. The original elise rear deck design was revised. The body that was done by the designer (for looks only) was found out to produce undesirably high positive lift numbers in pre production. They brought in an aerodynamicist and the rear deck took its new current shape. The deck itself on the elise is a fairly aggressive upward sweep, completely different than the square block that an EVO has. What I'm getting at here is that the closer they got the deck the interactions strengthen each others effect like a double deck wing.
You can't just go and apply that to *any* car you have to do the same sorts of testing on your own body, CFD, tunnel, on road, etc. However even the article acknowledges that more often than not the rule of thumb is as high and as far back as possible. This definitely holds true in American/European GT classes, and SuperGT (Americans still call it JGTC for some reason).
A lot of the wings for sale in Japan are different than what you typically see in the states and frequently used in other GT series. They trickle down from SuperGT which are heavily power limited 500 and 300hp classes, that wing looks like the sort of typical "Fuji special". It's such a common contemporary design because Fuji is close enough to tokyo that everyone goes there and features a very very long straight. But totally different rules apply to totally different wing shapes, the typical twisted span for example in the C6R shown above totally different set of rules.
Regarding cars in GT series sometimes using lower mounted wings. Not everyone is at the same place in their aero development process, not everyone has the same aero targets or the same body shape. There are lots and lots of reasons why a car can have a certain wing height, not all of them are because a lower wing height is better. There are a lot of teams who are running near stock Porsche race cars that come with aero packages designed to fit many different classes. The teams that win almost invariably have tested and modified the aero packages from how the cars came.
And finally, regarding the Voltex wind tunnel. Well I commend voltex on their neat wind tunnel and being one of the first companies (maybe the first) to build a wind tunnel just to test street car parts in, however their wind tunnel, to be perfectly honest its completely wide open after the blower onto the nose, there is some data that I would give a high level of value to from their wind tunnel and honestly I wouldnt trust damn near any rear wing data from a tunnel like that. The primary limitations are the velocity and direction of air flowing at the rear of the car, #1 and #2 the overall maximum wind speed of their tunnel is way low compared to 'real' tunnels. The envelope around the rear of a car is **completely** different at 60kph than 200kph. Without talking to them directly I wont know if/how they are compensating for that but that wind tunnels max speed is definitely not where I would be optimizing the wing AOA for, even for a very tight circuit like Tsukuba.
You can't just go and apply that to *any* car you have to do the same sorts of testing on your own body, CFD, tunnel, on road, etc. However even the article acknowledges that more often than not the rule of thumb is as high and as far back as possible. This definitely holds true in American/European GT classes, and SuperGT (Americans still call it JGTC for some reason).
A lot of the wings for sale in Japan are different than what you typically see in the states and frequently used in other GT series. They trickle down from SuperGT which are heavily power limited 500 and 300hp classes, that wing looks like the sort of typical "Fuji special". It's such a common contemporary design because Fuji is close enough to tokyo that everyone goes there and features a very very long straight. But totally different rules apply to totally different wing shapes, the typical twisted span for example in the C6R shown above totally different set of rules.
Regarding cars in GT series sometimes using lower mounted wings. Not everyone is at the same place in their aero development process, not everyone has the same aero targets or the same body shape. There are lots and lots of reasons why a car can have a certain wing height, not all of them are because a lower wing height is better. There are a lot of teams who are running near stock Porsche race cars that come with aero packages designed to fit many different classes. The teams that win almost invariably have tested and modified the aero packages from how the cars came.
And finally, regarding the Voltex wind tunnel. Well I commend voltex on their neat wind tunnel and being one of the first companies (maybe the first) to build a wind tunnel just to test street car parts in, however their wind tunnel, to be perfectly honest its completely wide open after the blower onto the nose, there is some data that I would give a high level of value to from their wind tunnel and honestly I wouldnt trust damn near any rear wing data from a tunnel like that. The primary limitations are the velocity and direction of air flowing at the rear of the car, #1 and #2 the overall maximum wind speed of their tunnel is way low compared to 'real' tunnels. The envelope around the rear of a car is **completely** different at 60kph than 200kph. Without talking to them directly I wont know if/how they are compensating for that but that wind tunnels max speed is definitely not where I would be optimizing the wing AOA for, even for a very tight circuit like Tsukuba.
Voltex spent time adjusting the wing height in a wind tunnel for the EVO, and they came up with roughly roof height mounting.
CFD is awesome for those who can afford it, we might be grabbing a seat at work pretty soon. But until then I'll happily play with strain gauges and string pots. Empirical data is pretty useful stuff, often times it takes lots of tweaks just to get a computer model to recreate test results - and without the test results you'd never tune your model.
What really matters is that AMS is out getting it done and trying some stuff on their own, and sharing the process with everyone here. That's cool.
Some stuff I used to get the airflow angle over the back of the car. To me it seems like a wing set at zero relative to the ground will see an angle of attack of about 10 degrees.
CFD is awesome for those who can afford it, we might be grabbing a seat at work pretty soon. But until then I'll happily play with strain gauges and string pots. Empirical data is pretty useful stuff, often times it takes lots of tweaks just to get a computer model to recreate test results - and without the test results you'd never tune your model.
What really matters is that AMS is out getting it done and trying some stuff on their own, and sharing the process with everyone here. That's cool.
Some stuff I used to get the airflow angle over the back of the car. To me it seems like a wing set at zero relative to the ground will see an angle of attack of about 10 degrees.
Last edited by gixxer_drew; Sep 7, 2009 at 05:03 PM.
