Splitter design function and effects. Experience, Design knowledge?
08-18-2009, 09:33 PM
#46
Rennlist Member
Thread Starter
I could get arrested If I show you that. 
It was on the hyway, and going real fast.
If you like my splitter, you will love this contraption.
point is, it is repeatable. Ill have to dig up the pics of the 200lbs of weights sitting on the wing for max values and all the weights in between, starting at 60mph.
It was on the hyway, and going real fast.
If you like my splitter, you will love this contraption.
point is, it is repeatable. Ill have to dig up the pics of the 200lbs of weights sitting on the wing for max values and all the weights in between, starting at 60mph.
08-18-2009, 09:45 PM
#47
Drifting
Join Date: Jul 2006
Location: ..."RECALCULATING"
Posts: 3,496
Likes: 0
Received 0 Likes
on
0 Posts
I could get arrested If I show you that.
It was on the hyway, and going real fast.
If you like my splitter, you will love this contraption.
point is, it is repeatable. Ill have to dig up the pics of the 200lbs of weights sitting on the wing for max values and all the weights in between, starting at 60mph.
It was on the hyway, and going real fast.
If you like my splitter, you will love this contraption.
point is, it is repeatable. Ill have to dig up the pics of the 200lbs of weights sitting on the wing for max values and all the weights in between, starting at 60mph.
Dude...you got way too much time on your hands
08-18-2009, 09:48 PM
#48
Rennlist Member
Thread Starter
08-20-2009, 12:31 AM
#49
Rennlist Member
Thread Starter
Sunday, talked to 2 other aero-engineers on the subject. There is no way that a piece of tape on a wing 's leading edge can hurt downforce by 10%, expecially at speeds below 200knots. That is not something an F1 engineer said without qualifying it. (size of wing, position of wing, speed of car, etc). I dont know what the tape thickness was of the "helecopter tape" but it would have to be pretty thick to do any kind of mesureable lift reduction at the speeds we travel on the race track. there has been discussions regarding the effect of boundary layer for over 100 years not. Its not an exact science, even with the most exacting tools.
Not trying to argue, just want you to back the comment up with some facts.
anyway, I wont be posting unless there is more discussion on the topic.
Thanks for those that did post and offer some suggestions, and ideas, and to the rest...... welll, you know what to do.
If anyone wants me to do some pressure tests in another area of the chassis, let me know and we will see if it ends up matching the theories out there.
On to sears point to see if it all works in a couple of weeks!
Not trying to argue, just want you to back the comment up with some facts.
anyway, I wont be posting unless there is more discussion on the topic.
Thanks for those that did post and offer some suggestions, and ideas, and to the rest...... welll, you know what to do.
If anyone wants me to do some pressure tests in another area of the chassis, let me know and we will see if it ends up matching the theories out there.
On to sears point to see if it all works in a couple of weeks!
Last edited by mark kibort; 08-20-2009 at 01:07 AM.
08-20-2009, 01:46 AM
#50
Addict
Rennlist Member
Rennlist Member
Sunday, talked to 2 other aero-engineers on the subject. There is no way that a piece of tape on a wing 's leading edge can hurt downforce by 10%, expecially at speeds below 200knots. That is not something an F1 engineer said without qualifying it. (size of wing, position of wing, speed of car, etc). I dont know what the tape thickness was of the "helecopter tape" but it would have to be pretty thick to do any kind of mesureable lift reduction at the speeds we travel on the race track. there has been discussions regarding the effect of boundary layer for over 100 years not. Its not an exact science, even with the most exacting tools.
Not trying to argue, just want you to back the comment up with some facts.
anyway, I wont be posting unless there is more discussion on the topic.
Thanks for those that did post and offer some suggestions, and ideas, and to the rest...... welll, you know what to do.
If anyone wants me to do some pressure tests in another area of the chassis, let me know and we will see if it ends up matching the theories out there.
On to sears point to see if it all works in a couple of weeks!
Not trying to argue, just want you to back the comment up with some facts.
anyway, I wont be posting unless there is more discussion on the topic.
Thanks for those that did post and offer some suggestions, and ideas, and to the rest...... welll, you know what to do.
If anyone wants me to do some pressure tests in another area of the chassis, let me know and we will see if it ends up matching the theories out there.
On to sears point to see if it all works in a couple of weeks!
I don't find what Sunday Driver wrote about his discussion with 2 F1 aero engineers to be out of the ordinary. They were probably commenting to what they know and that's F1 cars at the maximum levels. On a sports car the level of aero drag would most likely be less because of the lower speeds acheived and naturally the overall difference in shapes.
But without question, the leading edge of ANY WING whether it be a plane or race car should never be covered if your going to acheive the highest level of efficiency at any level. These F1 aerodynamisists are obsessive compulsive when it comes to the most minute detail and probably only 2nd to NASA engineers when it comes to this stuff.
Look closely at the leading edge of a front or rear wing on an F1 car and more times than not you'll find they don't even paint it in the livery of the rest of the car. Know why? They found that when they painted the leading edge and the paint became chipped up during the course of a race from flying pebbles, debris, etc, that it actually reduced aero efficiency. Just from chipped painted edges!!
F1 teams use helicoptor tape mostly on flush verticle surfaces to create a smoothing effect on panel gaps or to cover flush, countersink screw heads. As I said, OCD...
08-20-2009, 09:13 AM
#51
Rennlist Member
Thread Starter
point is, there is not a 10% of downforce lost with tape used on our wings at the speed we travel on course. by the way, the engineers I was speaking to worked at NASA and were involved in early space shuttle design.
The claim has many holes in it and needs to be qualified. to blast out that tape can cause 10% loss in lift, with no other changes is a little irresponsible. sure, wing efficiency is paramount in extreme applications, but in our cars with so many other dominant factors, it would not be as great of a factor. The drag and lift factors are fairly well understood. you can test out these ideas pretty easily. again, we are talking about use of the wings in speeds generally, below 150mph. There are plenty of simulators out there for wings. you can put a .5mm lip (or whatever the tape thickness is) and see how it effects lift and drag factors. Now, 1/8 gurney flaps in the rear have much more effectiveness for other reasons. (it ineffect, changes the angle of attack, without some of the drag costs)
The claim has many holes in it and needs to be qualified. to blast out that tape can cause 10% loss in lift, with no other changes is a little irresponsible. sure, wing efficiency is paramount in extreme applications, but in our cars with so many other dominant factors, it would not be as great of a factor. The drag and lift factors are fairly well understood. you can test out these ideas pretty easily. again, we are talking about use of the wings in speeds generally, below 150mph. There are plenty of simulators out there for wings. you can put a .5mm lip (or whatever the tape thickness is) and see how it effects lift and drag factors. Now, 1/8 gurney flaps in the rear have much more effectiveness for other reasons. (it ineffect, changes the angle of attack, without some of the drag costs)
Kibort,
I don't find what Sunday Driver wrote about his discussion with 2 F1 aero engineers to be out of the ordinary. They were probably commenting to what they know and that's F1 cars at the maximum levels. On a sports car the level of aero drag would most likely be less because of the lower speeds acheived and naturally the overall difference in shapes.
But without question, the leading edge of ANY WING whether it be a plane or race car should never be covered if your going to acheive the highest level of efficiency at any level. These F1 aerodynamisists are obsessive compulsive when it comes to the most minute detail and probably only 2nd to NASA engineers when it comes to this stuff.
Look closely at the leading edge of a front or rear wing on an F1 car and more times than not you'll find they don't even paint it in the livery of the rest of the car. Know why? They found that when they painted the leading edge and the paint became chipped up during the course of a race from flying pebbles, debris, etc, that it actually reduced aero efficiency. Just from chipped painted edges!!
F1 teams use helicoptor tape mostly on flush verticle surfaces to create a smoothing effect on panel gaps or to cover flush, countersink screw heads. As I said, OCD...
I don't find what Sunday Driver wrote about his discussion with 2 F1 aero engineers to be out of the ordinary. They were probably commenting to what they know and that's F1 cars at the maximum levels. On a sports car the level of aero drag would most likely be less because of the lower speeds acheived and naturally the overall difference in shapes.
But without question, the leading edge of ANY WING whether it be a plane or race car should never be covered if your going to acheive the highest level of efficiency at any level. These F1 aerodynamisists are obsessive compulsive when it comes to the most minute detail and probably only 2nd to NASA engineers when it comes to this stuff.
Look closely at the leading edge of a front or rear wing on an F1 car and more times than not you'll find they don't even paint it in the livery of the rest of the car. Know why? They found that when they painted the leading edge and the paint became chipped up during the course of a race from flying pebbles, debris, etc, that it actually reduced aero efficiency. Just from chipped painted edges!!
F1 teams use helicoptor tape mostly on flush verticle surfaces to create a smoothing effect on panel gaps or to cover flush, countersink screw heads. As I said, OCD...
08-20-2009, 01:48 PM
#52
Pro
Join Date: Nov 2004
Posts: 689
Likes: 0
Received 0 Likes
on
0 Posts
Have you read the string of articles in Race Car Engineering about aero on touring/gt cars, there is quite a good amount of information there.
Also, i'm not sure I read it anywhere in the thread, but are you going to put any diffusers in front of the front wheels built into the splitter?
I started to test this on a bmw I had, but never got to finish the testing. But first track tests went well.
I think if you have a way to have some of the airflow extracted and reduce the pressure in the wheel well area (vents, etc) you can do quite well with creating a low pressure are in that small space in front of the diffuser to the leading edge of the splitter (which should be made rounded up, just like a wing).
To make a really the most effective splitter and have it be worth your time you will need to have a molded composite piece made, that has some thickness to it.
Also, i'm not sure I read it anywhere in the thread, but are you going to put any diffusers in front of the front wheels built into the splitter?
I started to test this on a bmw I had, but never got to finish the testing. But first track tests went well.
I think if you have a way to have some of the airflow extracted and reduce the pressure in the wheel well area (vents, etc) you can do quite well with creating a low pressure are in that small space in front of the diffuser to the leading edge of the splitter (which should be made rounded up, just like a wing).
To make a really the most effective splitter and have it be worth your time you will need to have a molded composite piece made, that has some thickness to it.
08-20-2009, 03:40 PM
#53
Addict
Rennlist Member
Rennlist Member
Kibort,
I don't find what Sunday Driver wrote about his discussion with 2 F1 aero engineers to be out of the ordinary. They were probably commenting to what they know and that's F1 cars at the maximum levels. On a sports car the level of aero drag would most likely be less because of the lower speeds acheived and naturally the overall difference in shapes.
But without question, the leading edge of ANY WING whether it be a plane or race car should never be covered if your going to acheive the highest level of efficiency at any level. These F1 aerodynamisists are obsessive compulsive when it comes to the most minute detail and probably only 2nd to NASA engineers when it comes to this stuff.
Look closely at the leading edge of a front or rear wing on an F1 car and more times than not you'll find they don't even paint it in the livery of the rest of the car. Know why? They found that when they painted the leading edge and the paint became chipped up during the course of a race from flying pebbles, debris, etc, that it actually reduced aero efficiency. Just from chipped painted edges!!
F1 teams use helicoptor tape mostly on flush verticle surfaces to create a smoothing effect on panel gaps or to cover flush, countersink screw heads. As I said, OCD...
I don't find what Sunday Driver wrote about his discussion with 2 F1 aero engineers to be out of the ordinary. They were probably commenting to what they know and that's F1 cars at the maximum levels. On a sports car the level of aero drag would most likely be less because of the lower speeds acheived and naturally the overall difference in shapes.
But without question, the leading edge of ANY WING whether it be a plane or race car should never be covered if your going to acheive the highest level of efficiency at any level. These F1 aerodynamisists are obsessive compulsive when it comes to the most minute detail and probably only 2nd to NASA engineers when it comes to this stuff.
Look closely at the leading edge of a front or rear wing on an F1 car and more times than not you'll find they don't even paint it in the livery of the rest of the car. Know why? They found that when they painted the leading edge and the paint became chipped up during the course of a race from flying pebbles, debris, etc, that it actually reduced aero efficiency. Just from chipped painted edges!!
F1 teams use helicoptor tape mostly on flush verticle surfaces to create a smoothing effect on panel gaps or to cover flush, countersink screw heads. As I said, OCD...
The American Airlines fleet is not "silver" per se... it's just not painted in order to save fuel from the 100's of lbs. of paint that is avoided. Seriously, though, while paint would have a much smaller influence in road cars, I'm surprised that no one has mentioned the tradeoffs re: the weight effects from adding extra aerodynamic surfaces. Certainly there must be diminishing returns on this dimension?Assuming that paint's contribution to weight in road cars is indeed insignificant, what about color? My stock chin spoiler is black, but I've been experimenting with white for about a week, (installed in the pics below) and it has definitely improved my commute time to work.
So... I started thinking about track day livery, and am planning to test red as my next color (on the floor, ready for install). I think the red is going to perform even better than the white. My theory is that it's not actually the hue, but rather, the saturation level that makes the difference. So if the red works out well, the next test would need to be with a brighter red.
08-20-2009, 04:47 PM
#54
Drifting
08-20-2009, 05:49 PM
#56
Instructor
Join Date: Feb 2008
Location: Ft Worth TX
Posts: 207
Likes: 0
Received 0 Likes
on
0 Posts
So... I started thinking about track day livery, and am planning to test red as my next color (on the floor, ready for install). I think the red is going to perform even better than the white. My theory is that it's not actually the hue, but rather, the saturation level that makes the difference. So if the red works out well, the next test would need to be with a brighter red.
Seriously though, I like the contrast with black rather than all white. Either way the car looks great!
08-21-2009, 01:49 AM
#57
Rennlist Member
Thread Starter
Yes, I have been following some of the racing rags in the aero area.
I dont reallly understand what you are talking about, as far as "defuser" in front of the wheel. there is a high pressure zone in the wheel well, and there are two things that Ive seen done. vent the fender at the low pressure area on the top of the fender, AND vent the rear of the fender, just in front of the door. I havent done the hole cuts until I measure a significant amount of pressure build up there.
explain a "defuser " in the front of the car. as far as I know, that means taking an area of low pressure and venting it out to higher pressure, as is done in the rear of most race cars now.
Now as far as a splitter up front, it is just that. Not a wing, it separates two flow and pressure zones. you dont need thick, but it helps for stability, strength and its ability to be integrated into the undertray.
I dont reallly understand what you are talking about, as far as "defuser" in front of the wheel. there is a high pressure zone in the wheel well, and there are two things that Ive seen done. vent the fender at the low pressure area on the top of the fender, AND vent the rear of the fender, just in front of the door. I havent done the hole cuts until I measure a significant amount of pressure build up there.
explain a "defuser " in the front of the car. as far as I know, that means taking an area of low pressure and venting it out to higher pressure, as is done in the rear of most race cars now.
Now as far as a splitter up front, it is just that. Not a wing, it separates two flow and pressure zones. you dont need thick, but it helps for stability, strength and its ability to be integrated into the undertray.
Have you read the string of articles in Race Car Engineering about aero on touring/gt cars, there is quite a good amount of information there.
Also, i'm not sure I read it anywhere in the thread, but are you going to put any diffusers in front of the front wheels built into the splitter?
I started to test this on a bmw I had, but never got to finish the testing. But first track tests went well.
I think if you have a way to have some of the airflow extracted and reduce the pressure in the wheel well area (vents, etc) you can do quite well with creating a low pressure are in that small space in front of the diffuser to the leading edge of the splitter (which should be made rounded up, just like a wing).
To make a really the most effective splitter and have it be worth your time you will need to have a molded composite piece made, that has some thickness to it.
Also, i'm not sure I read it anywhere in the thread, but are you going to put any diffusers in front of the front wheels built into the splitter?
I started to test this on a bmw I had, but never got to finish the testing. But first track tests went well.
I think if you have a way to have some of the airflow extracted and reduce the pressure in the wheel well area (vents, etc) you can do quite well with creating a low pressure are in that small space in front of the diffuser to the leading edge of the splitter (which should be made rounded up, just like a wing).
To make a really the most effective splitter and have it be worth your time you will need to have a molded composite piece made, that has some thickness to it.
08-21-2009, 01:54 AM
#58
Rennlist Member
Thread Starter
I like the red!
Hey, we are taking about 100mph cars not .85 mach airliners.
Ill bet ANY amount of anything that tape has no bearing on lift or drag on the leading edge of our wings at the speed we travel. there might be a drag factor on a F1 car going 230knots. at speeds down in the 100mph range, it is not physically possible for that much lift to be lost with no other changes but tape on the leading edge. (unless the "tape" was wood strips )
Hey, we are taking about 100mph cars not .85 mach airliners.
Ill bet ANY amount of anything that tape has no bearing on lift or drag on the leading edge of our wings at the speed we travel. there might be a drag factor on a F1 car going 230knots. at speeds down in the 100mph range, it is not physically possible for that much lift to be lost with no other changes but tape on the leading edge. (unless the "tape" was wood strips
) Not to mention the added weight of the paint The American Airlines fleet is not "silver" per se... it's just not painted in order to save fuel from the 100's of lbs. of paint that is avoided. Seriously, though, while paint would have a much smaller influence in road cars, I'm surprised that no one has mentioned the tradeoffs re: the weight effects from adding extra aerodynamic surfaces. Certainly there must be diminishing returns on this dimension?
Assuming that paint's contribution to weight in road cars is indeed insignificant, what about color? My stock chin spoiler is black, but I've been experimenting with white for about a week, (installed in the pics below) and it has definitely improved my commute time to work.
So... I started thinking about track day livery, and am planning to test red as my next color (on the floor, ready for install). I think the red is going to perform even better than the white. My theory is that it's not actually the hue, but rather, the saturation level that makes the difference. So if the red works out well, the next test would need to be with a brighter red.
The American Airlines fleet is not "silver" per se... it's just not painted in order to save fuel from the 100's of lbs. of paint that is avoided. Seriously, though, while paint would have a much smaller influence in road cars, I'm surprised that no one has mentioned the tradeoffs re: the weight effects from adding extra aerodynamic surfaces. Certainly there must be diminishing returns on this dimension?Assuming that paint's contribution to weight in road cars is indeed insignificant, what about color? My stock chin spoiler is black, but I've been experimenting with white for about a week, (installed in the pics below) and it has definitely improved my commute time to work.
So... I started thinking about track day livery, and am planning to test red as my next color (on the floor, ready for install). I think the red is going to perform even better than the white. My theory is that it's not actually the hue, but rather, the saturation level that makes the difference. So if the red works out well, the next test would need to be with a brighter red.
08-21-2009, 03:05 AM
#59
Burning Brakes
Join Date: Oct 2004
Location: Kelowna, BC, Canada
Posts: 1,031
Likes: 0
Received 0 Likes
on
0 Posts
FYI, the front air dam of the car USUALLY slows the air down enough to allow it to flow underneath the car with only the use of a splitter, but there are cars that have employed front diffusers, such as the Toyota GT-1 that competed in the 1999 24 Hrs of Le Mans.
Front diffusers, while rare, do exist.
Front diffusers, while rare, do exist.
08-21-2009, 03:30 AM
#60
FYI, the front air dam of the car USUALLY slows the air down enough to allow it to flow underneath the car with only the use of a splitter, but there are cars that have employed front diffusers, such as the Toyota GT-1 that competed in the 1999 24 Hrs of Le Mans.
Front diffusers, while rare, do exist.
Front diffusers, while rare, do exist.
Here are some detailed pictures of the front diffuser of the Audi R8
http://www.mulsannescorner.com/audir8-01-3.html
New acura p1 car diffuser
http://www.mulsannescorner.com/AcuraARX-01-5.html
As well as every other prototype car on the grid for the past 10 yrs...
And here's a picture of the old viper GTSR front splitter/diffuser - circa 1997 or so.