Guest iskone Posted July 30, 2003 Share Posted July 30, 2003 Does anybody know where I might be able to find how much downforce is created with say an IMSA body kit or a g-nose and wide body kit combo? Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted July 30, 2003 Share Posted July 30, 2003 None! You will probably still have lift untill you can get the car low enough that its undrivable on the street. You will need to look at getting air out of the front end after it goes in as well. None of these kits fix that problem. Douglas Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted July 30, 2003 Share Posted July 30, 2003 See how much they weigh.... Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted July 30, 2003 Share Posted July 30, 2003 Well that sux But I'm not surprised that they don't do much for downforce but I figured the g-nose would at least elimanate some lift from the front. Just to be clear I am talking about the g-nose that is from show car body parts. If you don't know it is designed to be mated with a wide body kit they also sell. I think that if you slapped the g-nose and a wide body with fender flares you could cut the lift out if you sealed up the whole engine bay. I don't know the technical name but when you slant the radiator in a box and duct that air out that would keep out alot of air. Also you use ram air for the engine. Te engine bay would still need to vent hot air wich can be done with a cowl hood. What do you think? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 30, 2003 Share Posted July 30, 2003 DELETE Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted July 31, 2003 Share Posted July 31, 2003 I like the site! It elaborates on what I've read in Chasis Engineering. I just want my 280Z to handle 1 - 1.15 g's so it shouldn't be to hard, right? Anybody know what kind of g's the IMSA style Z's can handle? Those cars look so sweet! Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted July 31, 2003 Share Posted July 31, 2003 Actually I take that back. I never got past the words "wide body kit" in your original post. Z's, especially the early ones, do experience a good bit of lift at speed from all the air getting underneath the car. The steering gets very light at 100+. In that case a good air dam will keep air out of the engine bay and help keep the front end stable. I guess that is the same as downforce. A G nose looks like it would do the same thing, but I have no experience with those. Try shooting Mike Kelly a PM. He once posted he added enough aerodynamic mods to make a Z stable at 160 MPH. Invited anyone who was interested to ask him how it was done. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted July 31, 2003 Share Posted July 31, 2003 A chin splitter added on to a commonly available airdam will give you significant downforce. It could be easiliy continued back to the front crossmember as well. BEWARE: if you do this without adding something significant in the rear as well, you'll be very tail happy at high speed. Not a good scenario. Quote Link to comment Share on other sites More sharing options...
ZROSSA Posted July 31, 2003 Share Posted July 31, 2003 Is this going to be road or track? From what I have read a spliter has to be run close to the track surface to really work. I dont think you can run a car this low and get it out of your driveway, so i would call it a track only mod. Venting the radiator and haveing a ducted air source for the engine are all going to help reduce lift but its unlikely that they will produce down force. It seems that even the best road cars have a hard time getting past 1 g on the skid pad. I think you would have to get pretty sticky tires to better it. If you are going to run it on the street the best you can hope for is to prevent as much air as you can from getting under the car. Some people run a extension on the air dam made out of convayer belt material (or similar) that can run to the ground and prevent a lot of air from getting under there but this will still eventually rip off, usually taking parts of your air dam with it. Douglas Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted August 1, 2003 Share Posted August 1, 2003 Well a splitter is probally out of the question. I will be using this car as my daily driver and some race use on weekends. As far as downforce is concerned I can use the venturi technique. If I seal up the engine bay from the front and smooth out everything on the under carriage then the car will be sucked down to the ground. Thus producing down force. I also plan to use one of those big aluminum spoilers for the rear. I am also going to look into using Shock Wave shocks, but only if I can afford them. My dream would be to convert the front suspension to dual control arms. Then change the IRS to a corvette IRS with Shock Waves. Remember the key word "DREAM" If you don't know already Shock Waves are a type of air bag. They look like regulaur coil over shocks but instead of a spring they have an air bag. I am planning on using the 280YZ kit and I will be using the fattest tallest wheels I can, maybe even those 18" x 12" ones from Ted (as soon as a bag of money falls out of the sky and lands on my head) I am still in early planning so things can change. By the way the engine I plan to use is a small block chevy 350. I intend to make from 385hp to 405hp and 400tq/lbs to 410tq/lbs depending on my cam selection. I will probably go with the 405hp/410tq because this makes less tork on the low end and that 410tq/lbs is at 4500rpm. Let me know what you think about what kind of downforce/cornering power I'll have Thanks Isk One Quote Link to comment Share on other sites More sharing options...
Michael Posted August 10, 2003 Share Posted August 10, 2003 The causes of the Z’s aerodynamics problems (lift, high drag) are multiple and in my considered opinion, can not be entirely “fixed” unless you are willing to undertake extensive sheet metal modifications. In the front, the the g-nose does help somewhat, but its curvature was designed more for aesthetics than function. Your idea of smoothing underbody flow is conceptually a good one, but keep in mind that proper design of venturi-type ducts requires consideration of pressure recovery, crossflow inside the duct, entrance and exit conditions, transient effects, .... It can be done, but you need to think of the entire vehicle configuration – and that’s best done with a clean-sheet-of-paper design. I recommend following the original BRE-type approach: urethane air dam in the front, small upswept spoiler in the rear. Each sells for around $100 (for example, at Motorsport). Those two pieces are the 70% solution for street-driving purposes. For all-out racing, the modifications will be driven more by class rules than by optimal performance. For getting better steering feel in “exciting” street driving, seriously consider those two parts. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted August 10, 2003 Share Posted August 10, 2003 You don't think that one of those aluminum spoilers will do the trick for downforce in the rear? In my book it says the farther back and higher you can mount a spooiler the better. Where do you learn about venturi's The G-Nose aith an air dam should really help out the down force. I alot was starting to read about side air dams, but havn't learned much yet. CAn you recomend any books? Thanks Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 10, 2003 Share Posted August 10, 2003 You want your car to hit 1 to 1.15 G's at what, 100 mph? Why not concentrate on the suspension? A well thought out Z suspension will get you 1 to 1.15 G's on a skidpad at around 40mph with sticky DOT race tires or slicks. I've no clue as to what the airbag suspension would do to your benefit. Seems like you'll just have to drag along a compressor and a bunch of wiring to make it work. If you want 18" wheels, a 350, upper and lower control arms, more aerodynamic body, and Vette rear suspension, why not buy a used Vette and some wheels? You'll probably have more money in a Z to get it that way then if you just bought the Vette to start. If you put wings on, you better match them front to back, or you'll end up with a car that pushes or oversteers really badly. You also better attach that gigantic wing in the back to something solid, otherwise you'll ruin the sheetmetal its attached to and have to buy a new hatch, especially if its not just for looks and actually produces downforce. A cowl hood is for putting air INTO the engine compartment. That's why they are "cowl induction" hoods. Body kits for Z's are usually just for looks, sometimes they are for racing so that you can get bigger tires under the fenders, but not specifically for downforce (at least none that I've seen). I don't think the G nose is a good idea for downforce. Look at it from the side. The bottom of the radiator opening starts a little below stock hoodline, and slopes down to the core support. This would act like a huge wedge driving air under the car, from what I can see. Jon Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted August 10, 2003 Share Posted August 10, 2003 Yeah, at 100mph. I will be building the supension to do just that. I say Corvette just because that is the kind of rear I want, really I just meant a five link with coilovers. The air bags are just an idea so I can raise and lower the car. The airbags are on the bottom of my list. Why not just buy a corvette? Because I think they are ugly and I don't want one. Also I want to do somthing of my own. I will be building the frame myself(maybe not by myself but you get the idea) A cowl hood is for induction yeah, but if the engine bay is sealed up then the hot air in it would go out the cowl. You could be right about the g-nose even with the air dam there can be a better design for down force. I need to do some more reading. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 10, 2003 Share Posted August 10, 2003 There is a lot of pressure at the cowl, because of the slope of the windshield. Its like putting a hole right at the base of a spoiler. I don't think you'll be able to exhaust air through the cowl at all. Have you looked at Terry Oxendale's car? He's BlueOvalZ in here. It might give you some ideas. His car is unbelievable! I think he's got pics in the album area. Good luck with your project. Jon Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted August 10, 2003 Share Posted August 10, 2003 Yeah I've seen that car!! It is real nice. Maybe i'll just vent teh hood with hood vents. Thanks isk Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 10, 2003 Share Posted August 10, 2003 I just "got it". You want to completely seal the entire engine compartment. So at some point the pressure through the radiator would be greater than the pressure from the cowl, so the air would vent. I'm with you now. What about at speed, say above 30 mph where the air would be significantly slowed through the radiator. Might cause some cooling problems. Something to think about. I've seen some cool things fabricated: MG midget with Corolla GTS drivetrain, 280Z rear suspension converted to double wishbone, Mini with turbo Subaru AWD, etc. I for one will be curious to see what you come up with. Also, I understand you not wanting the Vette (I'm not a big fan either), I just threw that out there because it seems like you'll be building a Vette style chassis and suspension. Jon Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 10, 2003 Share Posted August 10, 2003 An idea for the front suspension...still a prototype. http://www.hybridz.org/phpBB2/viewtopic.php?p=180081#180081 Quote Link to comment Share on other sites More sharing options...
ozzinc Posted August 11, 2003 Share Posted August 11, 2003 8) if anyone needs any technical info on how to measure And calculate the the differents between A regular motorsport spoiler And A gnose spoiler, please go to http://www.eng-tips.com this is the very best site because this site has real aerodynamic engineers & specialists who can explain the basic principals And tips on how to measure downforce. Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 11, 2003 Share Posted August 11, 2003 BTW, we have our own resident Aerodynamics expert. Michael has a PhD in Aerospace Engineering and did his PhD dissertation in the aerodynamics field. Quote Link to comment Share on other sites More sharing options...
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