Page 32 of 33 FirstFirst ... 22 27 28 29 30 31 32 33 LastLast
Results 621 to 640 of 647
  1. #621
    Join Date
    Dec 2013
    Posts
    239
    Country Flag: United States

    Default

    Quote Originally Posted by Ron Sutton View Post

    Hmmmm. I'm not sure I understand what you're saying about multiple element spoilers. Can you throw up a crude drawing?

    As far as multiple element wings, nothing is more effective & efficient. They rock.




    Essentially I'm wondering if building multiple elements into the blade type spoilers would work out in a similar fashion.
    This concept:

    On this sort of spoiler:


    It would look like you louvered the spoiler when in reality the slots would be overlapping profiled sections.



    Tech today would allow that sort of machining/3dprinting/etc


  2. #622
    Join Date
    Nov 2012
    Location
    Sacramento, CA
    Posts
    2,386
    Country Flag: United States

    Default

    Quote Originally Posted by HellPhish89 View Post
    Essentially I'm wondering if building multiple elements into the blade type spoilers would work out in a similar fashion.
    This concept:

    On this sort of spoiler:


    It would look like you louvered the spoiler when in reality the slots would be overlapping profiled sections.

    Tech today would allow that sort of machining/3dprinting/etc
    Ahhh. Gotcha. I've never been in any testing with this kind of setup, so I don't know anything "for sure."

    I "think" if you had the lower blade attached at the base to the decklid ... and the upper 2 elements were simply shorter spoilers with gaps between them ... that we would simply see reduced downforce from a solid spoiler of the same height.

    On the other hand, if you had the lower blade attached at the base to the decklid ... and the upper 2 elements were properly shaped wing elements, mounted at the optimum attack angle ... that we "could" see increased downforce from a solid spoiler of the same height. The key to it's effectiveness would be how much turbulence is generated off the base blade, going under the lowest element.

    Regardless, I am fairly confident in my opinion that it would not be as effective as a properly designed triple element wing.

    Hope that helps.



    Feel free to chime in or ask technical questions. I am here to help where I can.

    Ron Sutton

    Ron Sutton Race Technology
    Your One Stop, Turn & Go Fast, Car Building Resource Center for Autocross, Track, Road Racing & Triple Duty Pro-Touring Cars

    Check out our 400 Page Car Building Catalog HERE

    Features: Suspension, Chassis, Cages, Brakes, Rear Ends, Engines, Transmisssions, Aero & Much, Much More!

  3. #623
    Join Date
    Dec 2013
    Posts
    239
    Country Flag: United States

    Default

    Quote Originally Posted by Ron Sutton View Post
    Ahhh. Gotcha. I've never been in any testing with this kind of setup, so I don't know anything "for sure."

    I "think" if you had the lower blade attached at the base to the decklid ... and the upper 2 elements were simply shorter spoilers with gaps between them ... that we would simply see reduced downforce from a solid spoiler of the same height.

    On the other hand, if you had the lower blade attached at the base to the decklid ... and the upper 2 elements were properly shaped wing elements, mounted at the optimum attack angle ... that we "could" see increased downforce from a solid spoiler of the same height. The key to it's effectiveness would be how much turbulence is generated off the base blade, going under the lowest element.


    Regardless, I am fairly confident in my opinion that it would not be as effective as a properly designed triple element wing.


    Hope that helps.



    I've figured it would be better than a typical blade in terms of d/f and drag but not as good as a typical mutli-element wing. An in between.

    To kill turbulence, a radiused turn up into the spoiler would do quite a bit I think not to mention a different angle to the spoiler.

    Anyone have a 3D printer big enough? :-D lol

  4. #624
    Join Date
    Aug 2007
    Location
    Vancouver, BC
    Posts
    110
    Country Flag: Canada

    Default

    Thank you so much for this ridiculous amount of free knowledge, Ron! I spent the last 3 days reading thru it, and there's an immense amount of knowledge in here.

    From one of your previous posts, you mentioned that if an air dam (with no splitter) is located rear of the bumper with body panels closing out the gap above the air dam between it and the bumper, then the air dam can be angled back (top of air dam closer to windshield) several degrees from vertical. But in the same situation, if there is a splitter present, then the opposite is true.. the air dam should be angle forward several degrees (top of air dam further forward from windshield), I presume to force air down on top of the splitter to create pressure, thus directing it away from the horizontal body panel between the bumper and the top of the air dam and reducing lift on that body panel.

    You mention this forward-leaning angle should be 1-2 degrees off of vertical.. is there a maximum angle you can recommend in general? I'd like to make an air dam for my Nova that has a forward-leaning angle that matches my front bumper (when viewed from the side), but the angle of the bumper is probably in the neighborhood of ~10 degrees leaning forward. I'm wondering if this would require a fairly significant forward extension of the splitter (4"+) to keep the air that is being redirected downwards by the air dam continuing to the sides, instead of hitting the splitter, becoming turbulent, and potentially spilling over the splitter and still flowing under the air dam. Or at this 10 degree forward angle, would a 1.2-2" long splitter even do anything?

    I'm thinking this air dam would have a fairly aggressive peak at the center, sweeping rearward as the air dam approaches the sides of the car. At the ends of the air dam, where the bumper has the bulges on the ends, I would straighten out the angle of the air dam from the aggressive peak to something more flat (perpendicular to the center plane of the car) to deflect the air outboard of the frontal area of the exposed front tires.

    How does all of this sound to you?







    My second question, is from all the reading for roof/decklid airflow, it looks like my Nova has a somewhat decent transition onto the decklid. Taking air attachment to the roof and restriction from back window trim out of the equation for this very general overview, would you say that the profile of the roof-backglass-decklid transition is pretty good considering the Nova is a trunked coupe and not a fastback? Again I'm not getting in the realm of asking for spoiler/wing advice, or how to increase downforce or reduce drag.. just curious on your initial impression of the "smoothness" of the overall shape in that area..



    Thanks again for all the learning!

    -Joe
    1972 Nova, single turbo LQ4, T56, and more --> http://www.ls1tech.com/forums/conver...1972-nova.html

  5. #625
    Join Date
    Nov 2012
    Location
    Sacramento, CA
    Posts
    2,386
    Country Flag: United States

    Default


    Hey Joe !

    Quote Originally Posted by frojoe View Post
    Thank you so much for this ridiculous amount of free knowledge, Ron! I spent the last 3 days reading thru it, and there's an immense amount of knowledge in here.

    From one of your previous posts, you mentioned that if an air dam (with no splitter) is located rear of the bumper with body panels closing out the gap above the air dam between it and the bumper, then the air dam can be angled back (top of air dam closer to windshield) several degrees from vertical. But in the same situation, if there is a splitter present, then the opposite is true.. the air dam should be angle forward several degrees (top of air dam further forward from windshield), I presume to force air down on top of the splitter to create pressure, thus directing it away from the horizontal body panel between the bumper and the top of the air dam and reducing lift on that body panel.
    You are "spot on" correct.

    You mention this forward-leaning angle should be 1-2 degrees off of vertical.. is there a maximum angle you can recommend in general?
    Not really. We just want this air pressure created by the air dam pushing down, not up.


    I'd like to make an air dam for my Nova that has a forward-leaning angle that matches my front bumper (when viewed from the side), but the angle of the bumper is probably in the neighborhood of ~10 degrees leaning forward. I'm wondering if this would require a fairly significant forward extension of the splitter (4"+) to keep the air that is being redirected downwards by the air dam continuing to the sides, instead of hitting the splitter, becoming turbulent, and potentially spilling over the splitter and still flowing under the air dam. Or at this 10 degree forward angle, would a 1.2-2" long splitter even do anything?
    I wouldn't make the air dam match the bumper angle. I would lean it forward 1-3.

    Regardless ... 1-3 or 10 ... you will will see measurable downforce with a 1.2" splitter. 2" would produce SIGNIFICANTLY more downforce (probably 60% more). 3" would produce about 40% more downforce than a 2". 4" would produce about 25% more downforce than a 3" splitter. You get the idea. A bigger splitter will create more downforce, but the gain is not linear with length.



    I'm thinking this air dam would have a fairly aggressive peak at the center, sweeping rearward as the air dam approaches the sides of the car. At the ends of the air dam, where the bumper has the bulges on the ends, I would straighten out the angle of the air dam from the aggressive peak to something more flat (perpendicular to the center plane of the car) to deflect the air outboard of the frontal area of the exposed front tires.
    Exactly what is needed.

    How does all of this sound to you?







    ABOVE ... 4" is a pretty good ground clearance number. You should be able to get in most driveways & handle most speedbumps without knocking it off. 3.5" starts to get beat up pretty rough & less than that is brutal on the street. Of course 4.5" or 5" would be better for the street but would lose a ton of downforce effectiveness.

    With 4" of ground clearance ... if you run a high travel front suspension strategy on track ... say 3"-3.5" ... you'll practically close off airflow under the front end (during cornering). This will create MUCHO front grip & allow you significantly higher cornering speeds.



    My second question, is from all the reading for roof/decklid airflow, it looks like my Nova has a somewhat decent transition onto the decklid.
    It's OK to Good-ish. it's not 80's G-body bad. But it's not C7 Corvette/ 2016 Shelby Mustang good either.

    Taking air attachment to the roof and restriction from back window trim out of the equation for this very general overview, would you say that the profile of the roof-backglass-decklid transition is pretty good considering the Nova is a trunked coupe and not a fastback? Again I'm not getting in the realm of asking for spoiler/wing advice, or how to increase downforce or reduce drag.. just curious on your initial impression of the "smoothness" of the overall shape in that area..
    From 100 foot away the roof to back glass transition looks great. Up close, we see the shape edge on the trailing edge of the roof ... which causes airflow to break away. And the window trim combined with the rear glass set down in means there is no airflow attachment at the top of the back glass. The airflow "probably" reattaches somewhere near area where the bottom of the glass meets the deck lid. Frankly, that is pretty good. So we probably have 30" or so of attached airflow on the decklid. If you use a blade style spoiler or effective wing design, you CAN create good downforce with this car.




    Thanks again for all the learning!

    -Joe

    Glad to help Joe. I LOVE the 68-72 Novas. Best wishes with your project.





    Last edited by Ron Sutton; 02-02-2017 at 12:45 PM.
    Feel free to chime in or ask technical questions. I am here to help where I can.

    Ron Sutton

    Ron Sutton Race Technology
    Your One Stop, Turn & Go Fast, Car Building Resource Center for Autocross, Track, Road Racing & Triple Duty Pro-Touring Cars

    Check out our 400 Page Car Building Catalog HERE

    Features: Suspension, Chassis, Cages, Brakes, Rear Ends, Engines, Transmisssions, Aero & Much, Much More!

  6. #626
    Join Date
    Aug 2007
    Location
    Vancouver, BC
    Posts
    110
    Country Flag: Canada

    Default

    Awesome, thanks for that feedback, Ron!

    All were very good points.. regarding the 4" ground clearance, my subframe is currently 4.5" off the ground, and my current exhaust (have plans to remake larger, with fabricated oval tubing) is 3.5" off the ground and scrapes on some speedbumps still! My coilovers are currently medium-stiff, nicely compliant on the road but certainly not slammed-import-faux-racer stiff.. however with the angle of my UCA's after doing the Guldstrand mod, I get next to no dive purely from the braking torque on the control arms, which means the little diving I do get feels like it's almost entirely from weight transfer due to the braking deceleration. I can't say for certain, since I've never measured it, but I don't believe my front bumper area would be diving more than 1-2" under hard cornering. This will definitely be an area I'd like to test.. maybe ziptie an unused stick of chalk to temporary bracket bolted under the bumper, and lower the chalk until I see a wear mark.

    Also great point about the top of the rear glass. It is recessed about 0.5-0.75" and I guess even that amount of recess on what would otherwise be a decently-low rear glass angle is enough recess that the air "drops off the cliff" of the top window trim, and flows rearwards quite a bit before it happily finds glass/trim/decklid to re-attach to. I'm very open to putting a little blade spoiler on the rear edge of the decklid, however I've seen a few instances of people that have grafted a 1st gen Camaro decklid curved spoiler and it just doesn't quite look right on the back.


    Another interesting thing I came across, is a leading edge spoiler in front of the hood vents on an old Ford GT. I'm not sure if this exact design would be the best way to go about it, and assuming sacrificing drag for downforce/cooling.. if the deflector were a bit of a steeper angle, would this be a good way of going about building a slight amount more pressure on the nose of the hood (to help compensate for lost area of downforce where vents are) as well as create a low pressure zone behind the deflector to help "suck" hot air out of the radiator/hood ducting?

    1972 Nova, single turbo LQ4, T56, and more --> http://www.ls1tech.com/forums/conver...1972-nova.html

  7. #627
    Join Date
    Feb 2017
    Posts
    2

    Default

    Isn't the primary reason for tertiary elements on a multi stage wing to maintain laminar flow at higher angles of attack? Does not the wing tends to stall at a point just past maximum lift (or down-force). Which leads me back to the spoiler and the stacked element idea. A few years back we were running a sports racer in SOLO. We were limited in area on the wings by rule. We discovered we could run a lip spoiler to take advantage of the large clear deck, and use the spill air of the spoiler on our bottom side of the wing to maintain laminar flow on the bottom of the wing at higher angle of attack than we could with just our two wing elements. Tuft testing showed this and test times supported better performance. Although this probably would not work on a production car with the turbulence off of the greenhouse. Wing height was critical took lots of trial and error to find the sweet spot. Unfortunately we ran out of money lol as is usually the case with race cars.

  8. #628
    Join Date
    Feb 2017
    Posts
    2

    Default

    I do have a question for Ron.

    Our current car is an open top car (think Miata but its not, thank god) At SOLO Speeds would you be better off running a steeper wicker? The rules limit us to 10 inches from the factory deck lid, in any direction so long as it does not extend past the end of the rear bumper. The deck lid with a full tonneau cover is effectively quite long, but the turbulence from the windshield negates a bunch of that. The question is, as a baseline for starting our testing, do we extend the length of the deck as much as possible with a steeper but shorter spoiler? Or run a lower angle on the spoiler but taller? What do you think would be the optimum spoiler angle to start with given speeds in the 40-70 MPH range

  9. #629
    Join Date
    Nov 2012
    Location
    Sacramento, CA
    Posts
    2,386
    Country Flag: United States

    Default

    Hey guys! Slammed with projects right now. I'll be back on here in a couple weeks.
    Feel free to chime in or ask technical questions. I am here to help where I can.

    Ron Sutton

    Ron Sutton Race Technology
    Your One Stop, Turn & Go Fast, Car Building Resource Center for Autocross, Track, Road Racing & Triple Duty Pro-Touring Cars

    Check out our 400 Page Car Building Catalog HERE

    Features: Suspension, Chassis, Cages, Brakes, Rear Ends, Engines, Transmisssions, Aero & Much, Much More!

  10. #630
    Join Date
    Jun 2006
    Location
    Orange County, NY
    Posts
    281

    Default

    Ron,
    So far great and informative reading and as such creates some questions. As I continue to read through all the pages I may or may not find answers to two questions in particular hope you would not mind addressing them for me. In regards to my car, an 86 Monte Carlo SS, I added a splitter to the front end last year that mounts between the main nose and the lower valance. The splitter sits about 5" above the ground and the lower valance projects about 2" below the splitter. Does having the projection beneath the splitter counter any positive attributes of the splitter. Also, the splitter is a one peice unit that also serves as a belly pan as sorts sealing the entire open area under the nose from the front of airdam to the engine cross member. My other question pertains to Vortex Generators. would they be a help in cleaning the VERY dirty air that happens as air flow transitions from the roof past the notchback and across the decklid? Thanks for any insights, since I have not been on the site in a couple of years due to a lengthy illness I'm off to continue reading.

    1986 Monte SS, 427 sbc, Victor E manifold, FAST TB, FAST XFI, T56 6spd, Moser M9 rear 3:70, SC&C G5, Spohn lowers, Pole Position Uppers, Alston Coil Overs, Pirelli all around

  11. #631
    Join Date
    Mar 2007
    Location
    Florida
    Posts
    2,361
    Country Flag: United States

    Default

    This thread seems to have died but I'm back, and still alive! So I'm dragging the thread back up! Heart attack almost stopped me but an operation to install a couple stents, some recovery time, and I'm back at it. I've been working on the LAB-14 UNDER TRAY DESIGNwhich will hopefully work out well and versions of the concept can be used by others with PT cars. I think it might also lend itself well to being used as an active system by incorporating linear actuators, computers etc. to raise/lower and change rake, rear diffuser angle, etc.

    There are several obstacles making it difficult to add a truly functional splitter/under tray/rear diffuser to our old cars that can be easily removed or used on the street. I think I've come up with a concept I'll share the basics here. For more details follow this link. https://www.linkedin.com/pulse/heigh...ick-john-paige

    FEATURES
    Height adjustable. Lower it for competition and raise for normal use, tune for particular track, raise up and drive home or onto trailer after event.
    Rake adjustable. Using the individual height adjusters rake can be set independent of chassis rake.
    Fully suspended. Suspending the system allows relatively easy installation and panels can rise if they hit the ground reducing potential damage.
    Quick release. Whole assembly can be installed/removed by a single person without jacking up car.
    Optimal height. Being height adjustable raise/lower to tune for down force needed to enable lowest lap time for different tracks and conditions.
    Heat escape. With the tray assembly suspended it allows more air circulation reducing potential engine, trans, rear end issues.



    Last edited by NOT A TA; 08-11-2017 at 10:48 AM.

  12. #632
    Join Date
    Mar 2007
    Location
    Florida
    Posts
    2,361
    Country Flag: United States

    Default

    Couple more pics of the Lab-14 Under Tray Design to give a better idea of how it is set up since I had it out in the drive to work on it. Need a few more pieces of box tubing and 4 more support rods. I'm on a budget so I buy a few pieces a few at a time so I can keep progressing since there's a lot of labor involved to keep me busy. Also, I buy drops at a local industrial metal fab shop so I have to wait for are considered "scraps" to them I can buy that are suitable for my projects. The white 4 X 8 sheets are corrugated plastic of 2 different thicknesses. With side pipe exhaust I don't have some of the heat concerns under the car from firewall back those with traditional exhaust have. Under the engine, side pipe headers, and side pipes I'm only using aluminum.






  13. #633
    Join Date
    May 2012
    Location
    Hungary
    Posts
    226
    Country Flag: Hungary

    Default

    I am in the same shoe with a 72 Nova so it was really good to read something "specialized" for the 3rd gen Nova.
    I have never really pay attention about aerodynamic but as we approach to the end of the body work I just started to think a few months ago.
    My goal would be just to compete with today's sport cars in performance. Power, handling, etc. nothing really crazy stuff, I do not have Auto X or road racing in mind but to have a good old muscle car in Europe that can keep steps with these BMWs, Audis and japanese cars here.
    Power is ok as I had LS already under my hood before we took apart the car for restoration.
    I assume handling will be ok as well as I got c6 corvette based full frame under the car.
    So I will be able to go pretty fast but I do not want to fly off of the road.
    I think here is the area for the aerodynamic to jump in.
    I would need more downforce I guess.
    I started to read this thread and I got some really good idea that we can use but I need just a little encouragement and advices to step forward.
    Here are the things I have in mind to actualize.

    1. Air dam + splitter similar to above.
    2. 1st gen Camaro hood vent from Trackspec ( however I am not really sure if it would work properly as it would be only a cut out on the hood without ducting anything)
    3. spoiler at the rear ( I saw earlier here that a 4-5" tall spoiler at 40 degree angle would work fine at this level of build)
    4. flush mount windshields front and rear (hopefully those will hit the market soon)
    5. modified bumpers that will follow the body lines and curves perfectly . 3rd gen Nova has horrible big heavy dumb bumpers from factory...

    What we can do with the grill assy? Is it necessary to have a specially designed sealed grille assy that would be sealed to the radiator? It is my goal to have a new front look anyway.
    Any other idea that can come into play?

    I appreciate all help. Thank you.

  14. #634
    Join Date
    Nov 2012
    Location
    Sacramento, CA
    Posts
    2,386
    Country Flag: United States

    Default

    Quote Originally Posted by medbali76 View Post
    I am in the same shoe with a 72 Nova so it was really good to read something "specialized" for the 3rd gen Nova.
    I have never really pay attention about aerodynamic but as we approach to the end of the body work I just started to think a few months ago.
    My goal would be just to compete with today's sport cars in performance. Power, handling, etc. nothing really crazy stuff, I do not have Auto X or road racing in mind but to have a good old muscle car in Europe that can keep steps with these BMWs, Audis and japanese cars here.
    Power is ok as I had LS already under my hood before we took apart the car for restoration.
    I assume handling will be ok as well as I got c6 corvette based full frame under the car.
    So I will be able to go pretty fast but I do not want to fly off of the road.
    I think here is the area for the aerodynamic to jump in.
    I would need more downforce I guess.
    I started to read this thread and I got some really good idea that we can use but I need just a little encouragement and advices to step forward.
    Here are the things I have in mind to actualize.

    1. Air dam + splitter similar to above.
    2. 1st gen Camaro hood vent from Trackspec ( however I am not really sure if it would work properly as it would be only a cut out on the hood without ducting anything)
    3. spoiler at the rear ( I saw earlier here that a 4-5" tall spoiler at 40 degree angle would work fine at this level of build)
    4. flush mount windshields front and rear (hopefully those will hit the market soon)
    5. modified bumpers that will follow the body lines and curves perfectly . 3rd gen Nova has horrible big heavy dumb bumpers from factory...

    What we can do with the grill assy? Is it necessary to have a specially designed sealed grille assy that would be sealed to the radiator? It is my goal to have a new front look anyway.
    Any other idea that can come into play?

    I appreciate all help. Thank you.
    The airflow into the grill is always a challenging area. Getting airflow in is easy. Blocking airflow out is easy. The tough part is deciding how much to let in & block off.

    The more airflow you can make go over or around the front end (not in the grill) the more front downforce the car will have. But obviously if we block off too much, the engine overheats.

    For Pro-Touring Cars I am a fan of blocking off any airflow that is not specifically for the radiator & brake ducts. Some bumpers & Lower valances have slots. If they're not needed, block them off in a smooth way.

    As far as the grille goes, I like to make black aluminum sheets (cut to fit) in multiple sizes (or restriction amounts) that go behind the grille to partially close off airflow. Then you can play around with how much to close off without permanently affecting the car's appearance.


    Feel free to chime in or ask technical questions. I am here to help where I can.

    Ron Sutton

    Ron Sutton Race Technology
    Your One Stop, Turn & Go Fast, Car Building Resource Center for Autocross, Track, Road Racing & Triple Duty Pro-Touring Cars

    Check out our 400 Page Car Building Catalog HERE

    Features: Suspension, Chassis, Cages, Brakes, Rear Ends, Engines, Transmisssions, Aero & Much, Much More!

  15. #635
    Join Date
    Nov 2012
    Location
    Sacramento, CA
    Posts
    2,386
    Country Flag: United States

    Default

    Quote Originally Posted by NOT A TA View Post
    Couple more pics of the Lab-14 Under Tray Design to give a better idea of how it is set up since I had it out in the drive to work on it. Need a few more pieces of box tubing and 4 more support rods. I'm on a budget so I buy a few pieces a few at a time so I can keep progressing since there's a lot of labor involved to keep me busy. Also, I buy drops at a local industrial metal fab shop so I have to wait for are considered "scraps" to them I can buy that are suitable for my projects. The white 4 X 8 sheets are corrugated plastic of 2 different thicknesses. With side pipe exhaust I don't have some of the heat concerns under the car from firewall back those with traditional exhaust have. Under the engine, side pipe headers, and side pipes I'm only using aluminum.

    Looking good John!

    Are you planning to add strakes to the diffuser?

    Feel free to chime in or ask technical questions. I am here to help where I can.

    Ron Sutton

    Ron Sutton Race Technology
    Your One Stop, Turn & Go Fast, Car Building Resource Center for Autocross, Track, Road Racing & Triple Duty Pro-Touring Cars

    Check out our 400 Page Car Building Catalog HERE

    Features: Suspension, Chassis, Cages, Brakes, Rear Ends, Engines, Transmisssions, Aero & Much, Much More!

  16. #636
    Join Date
    Sep 2012
    Location
    San Diego
    Posts
    255
    Country Flag: United States

    Default

    Quote Originally Posted by Ron Sutton View Post

    Looking good John!

    Are you planning to add strakes to the diffuser?

    What are strakes?
    71 maverick.
    71 comet in build process.
    i work at Current Auto Performance www.currentautoperformance.com. i also build the differentials for San Diego Gear and Axle.

  17. #637
    Join Date
    Nov 2012
    Location
    Sacramento, CA
    Posts
    2,386
    Country Flag: United States

    Default

    Quote Originally Posted by bryant View Post
    What are strakes?

    Hi Bryant,

    Good question.
    "Strakes" ... no idea or care where the term originated ... are the vertical panels or vanes utilized in well designed diffusers. See the photos here:

    Name:  APR-Honda-S2000-Rear-Diffuser-1.jpg
Views: 141
Size:  28.9 KB

    Name:  diffuser_single_diffuser.jpg
Views: 141
Size:  119.2 KB

    Name:  DiffuserP03_4T.jpg
Views: 152
Size:  42.9 KB

    Name:  xdifusser-2.gif.pagespeed.ic.nBRz40SkrL.jpg
Views: 147
Size:  9.6 KB

    They serve two key purposes and are, in my experience, the most valuable part of the diffuser assembly.
    1.
    They straighten the airflow before it exits the car ... helping to reduce turbulence & aid blending/merging of airflow coming over & around the car. This improves the evacuation of airflow from under the car, increasing the downforce ... and as a bonus reduces drag.
    2. They act as rudders or spill plates to create side force. In professional racing, we're looking to increase side force as much as we are down force. The 4+ strakes ... hopefully of good size ... do a similar job that spill plates do on wings ... in both directing the airflow & creating sideforce.

    P.S. Sideforce is directional & changes with the direction the car is turning. Our goal is to create sideforce on the outside rear area of the car. If we're turning right, the sideforce created by rear diffuser strakes (and rear wing spill plates) is actually pushing on the left side (outside) of the car, at the rear. Many racers think this is increasing our rear tire grip ... because it acts & feels like it. But in reality sideforce it is increasing how much g-force loads the rear of the car can handle before the rear loses traction & the car gets loose.

    If you watch NASCAR much, I'm sure you've heard Larry McReynolds mention how one car got on the outside of another car ... taking its air away. He's referring to airflow onto the outside rear quarter panel being blocked ... on the inside car ... taking away the side force & making that car loose.




    Feel free to chime in or ask technical questions. I am here to help where I can.

    Ron Sutton

    Ron Sutton Race Technology
    Your One Stop, Turn & Go Fast, Car Building Resource Center for Autocross, Track, Road Racing & Triple Duty Pro-Touring Cars

    Check out our 400 Page Car Building Catalog HERE

    Features: Suspension, Chassis, Cages, Brakes, Rear Ends, Engines, Transmisssions, Aero & Much, Much More!

  18. #638
    Join Date
    Mar 2007
    Location
    Florida
    Posts
    2,361
    Country Flag: United States

    Default

    Quote Originally Posted by Ron Sutton View Post

    Looking good John!

    Are you planning to add strakes to the diffuser?

    Yes, diffuser will have strakes and the fences on the sides shaped to keep out tire squirt as much as possible. Center section of the diffuser will be open to the area between the car floor pan and the under tray assembly. It's a unique approach to a splitter/under tray/diffuser combination no one has tried to my knowledge. I decided to try and make the obstacles work for me rather than trying to fight them. On an all out race car that is purpose built to "win" it might not be an optimal design however for what many of us are hoping to achieve it might be a good compromise. Was working on the diffuser when Irma started knocking on the front door.

    Where most people solidly bolt trays to the underside of the car and try to seal off everything I've taken a different approach and am allowing air to flow between the floor and under tray. This makes it easier for folks with PT type cars to get the benefits of reduced lift/increased downforce without the hassles of figuring out what to do about exhaust heat, transmission heat, rear end heat, and some of the heat from engine cooling. Everything ahead of the front wheels is sealed so only air coming through the core support area above the splitter has to pass through the radiator except the brake duct flow which goes into the wheel wells. I may have to change the design after testing if the diffuser section becomes a parachute for air flowing through above the under tray. As mentioned, no one has tried it so we'll see. Worst that can happen is that I change opening sizes or need to seal between the sides of car and under tray along with possibly increasing mechanical cooling for trans and rear end.

  19. #639
    Join Date
    Mar 2007
    Location
    Florida
    Posts
    2,361
    Country Flag: United States

    Default

    Under tray section is mostly complete other than some work I want to do on the area behind the front wheels where the side pipe headers come out. Been working on a cardboard mock up version of the rear diffuser.






  20. #640
    Join Date
    Mar 2007
    Location
    Florida
    Posts
    2,361
    Country Flag: United States

Page 32 of 33 FirstFirst ... 22 27 28 29 30 31 32 33 LastLast


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •