DavyZ Posted December 2, 2007 Share Posted December 2, 2007 No Carl, It hasn't... I hope to have it back up in the near future. Haven't had a lot of extra time lately. Mike Mike, if you get the chance to upload it to the forum, please make it a sticky in this forum. I think it deserves to be that way. I'm sure they cut the crap out of it (figuratively ) and I'd love to read EVERYTHING you wrote. We have the space for the whole shebang here Davy Quote Link to comment Share on other sites More sharing options...
Michael Posted December 3, 2007 Share Posted December 3, 2007 Katz’s book is a good start, and his reference list is an excellent one-stop-shop intro to more specialized material. That said, his book has some drawbacks from the viewpoint of explaining the theory and from practical tips on what does and does not work. As a second reference I recommend: "Aerodynamics of Road Vehicles" by Wolf-Heinrich Hucho, Editor. It is published by SAE International. Knowing that blocking off the radiator grill area had such an effect in the first wind tunnel campaign, we can infer that front-end mods are a useful area for concentration; replace the stock hood with something more “swoopy†and with a smaller fishmouth, improve the airdam and seal the area underneath the car between the airdam’s lip and the steering crossmember. I believe that this will yield max bang for the buck. Smoothing the underbody, recessing the exhaust, adding diffusers etc. is hypothetically cool and is great for bench racing, but is impractical because there are too many variables and too much fabrication is required to get it “rightâ€. My own wish-list would be to explore front-end modifications that take advantage of the space freed up by V8 installations, lowered radiators, etc. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 3, 2007 Share Posted December 3, 2007 Lord I wished I lived there. I would give anything to validate the work on my car (a design based solely on aviation and automotive reference material). Quote Link to comment Share on other sites More sharing options...
Z-TARD Posted December 3, 2007 Share Posted December 3, 2007 Lord I wished I lived there. I would give anything to validate the work on my car (a design based solely on aviation and automotive reference material). Screams and beats chest while wearing beer hat: "ROAD TRIP! ROAD TRIP! ROAD TRIP!!!!!!" Quote Link to comment Share on other sites More sharing options...
OlderThanMe Posted December 3, 2007 Share Posted December 3, 2007 I have always had a feeling that a G-nose with a vertical wall going straight down from the front edge of the bumper would be a lot better than the standard G-nose that directs air to the underside of the nose. Just a thought... OTM Quote Link to comment Share on other sites More sharing options...
mark Posted December 3, 2007 Share Posted December 3, 2007 Lord I wished I lived there. I would give anything to validate the work on my car (a design based solely on aviation and automotive reference material). It would be worth the drive Terry. The first test was a blast. Quote Link to comment Share on other sites More sharing options...
jt1 Posted December 3, 2007 Share Posted December 3, 2007 I'd like to see Terry's car in the test. I suspect the radiator venting will go a long way towards achieving negative underhood pressure. jt Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 3, 2007 Share Posted December 3, 2007 That's were I wonder though. My understanding is that a radiator at high speed is seen as almost a solid object. The longer, lower nose with a flat front is what intrigues me. At high speed I've seen the hood push down on top of the spinning water pump pulley. Quote Link to comment Share on other sites More sharing options...
Challenger Posted December 4, 2007 Share Posted December 4, 2007 Any possibility of a baseline for a stock 2+2? Is there a possibility of doing a completely stock 2+2? Just a quick base line to see the difference? Im sure there is somone with a 2+2 that would help. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted December 5, 2007 Share Posted December 5, 2007 This may or may not be feasable, and is just a thought that I wanted to share. Was watching "Futurecar" last night and they were discussing how easily designers can check/test their designs in virtual windtunnels before any models are put together. This got me to thinkning, w/ our VAST membership base, do was have ANY folks working for any car companies or know anyone w/ access to these programs? Here's my thought. Say we generate another couple of grand for more testing. Could we apply that to having some virtual models of the S30 and all the popular and even custom body "add ons" that folks on the site have? Then have those tested w/ the virtual results gained? Is this a dumb idea, am I just being a bit over zealous w/ what's out there? I have no idea of the hours it takes to model something or run these programs, again, was just a thought... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 5, 2007 Share Posted December 5, 2007 CFD (computational fluid dynamics) is what you're talking about. That would be a nice idea, but someone would have to program in the shape of the Z to get the ball rolling, and then also change the shape to test other configurations. My understanding is that the CFD is only as good as the shape used, and it can get pretty complicated with the underside of the car. It will be interesting to see what people like Michael think of the accuracy of one type of testing relative to the other. Certainly our cheapo wind tunnel test isn't as good as it could be with a rolling road, etc. I have no personal experience with CFD, but it seems like it would be a very good idea if it's not super labor intensive to do. Quote Link to comment Share on other sites More sharing options...
MrFancypants Posted December 5, 2007 Share Posted December 5, 2007 Any of the guys that punched holes in their engine bays with side fender vents available to drive out to the aero test site? It would be interesting to see how well they work, especially in conjunction with sealing the bottom of the engine bay. Im sure we all agree from the results of the last test that they MUST help, but Im more curious to see how much. - Greg - Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted December 5, 2007 Share Posted December 5, 2007 ^ Agree with fender venting tests big time. Alternatively I would like to see some different hood vent styles if possible. In any case, my brother has Light Wave or somethinging similar that has CFD built into it. The issue is not so much getting the program but more drawing the correct shape of a 240z. That would be very time consuming. Since the data indicates that very minute changes result in big differences in numbers. Accuracy would have to be quite high. It would be much easier though to try different wing designs, angles, and vortex generators independant of the car or with just a basic profile. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted December 5, 2007 Share Posted December 5, 2007 Even if the acuracy was lacking, it would be a constant error throughout all the studies, and the study should still show reletive effect comparing different set-ups. Quote Link to comment Share on other sites More sharing options...
Tombarace14 Posted December 6, 2007 Share Posted December 6, 2007 We semi tested the fender vents in the first test, with Roddys car. We taped them up to simulate them not being there, as well. Quote Link to comment Share on other sites More sharing options...
Carl Beck Posted December 6, 2007 Share Posted December 6, 2007 This may or may not be feasable, and is just a thought that I wanted to share. Was watching "Futurecar" last night and they were discussing how easily designers can check/test their designs in virtual windtunnels before any models are put together. This got me to thinkning, w/ our VAST membership base, do was have ANY folks working for any car companies or know anyone w/ access to these programs? Hi Bill: When it come to design, design simulation, analysis and verification the designers mentioned on "Futurecar" hold a huge advantage over us... They are paid to create the design in digital form from the beginning.... by the time they have a concept that has been moved forward to the development stages of design, they most likely have thousands of man-hours invested in that digital data base containing the 3D geometry of their creation. Yes, at that point they can simulate, analyze and then iterate the design in an extremely efficient manor. Taking an existing form from the physical world, and recreating it in digital form: ie. reverse engineering it if you will - can take hundreds of hours, using tens of thousands of dollars worth of software and computer hardware. That or it takes more advanced, large scale scanning technology like large laser scanners - or fixed point digital photo sessions. All relatively easy IF YOU HAVE THE EQUIPMENT... and knowledge of how to best use it. Contracting the work out can easily cost tens of thousands of dollars, because of the overhead costs of having that capital equipment... An alternative comes to my mind. The Franklin Mint already has a very detailed, three dimensional model of a pure stock S30. They used fixed point digital images to feed their software, to build that model. It is so fine that you can actually read the VIN tag on their model. 1) Get with Sport Z Magazine and approach the Franklin Mint - to see if they are willing to "donate" the use of that model for this group's simulation. In exchange for the publicity it could generate. 2) Use a smaller, and far less expensive 3D laser scanner - and scan a Franklin Mint Model. Then use the scan to feed the simulation and analysis programs. Past either of these alternatives - you still have to have someone with access to the software and hardware necessary to feed the 3D model into and then run the CFD programs. I think in the end, everyone involved in making all the above happen, would agree that they would rather have just paid the $3K of $5K themselves for the wind tunnel FWIW, Carl B. Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted December 6, 2007 Share Posted December 6, 2007 Carl, thanks for the insight. I totaly understand the amount of hours and work it takes to get that "digital image" we would need, let alone running that model through a CFD enviroment. I was really posing the question more as "Can anyone out there help do this type of work, with their connections or know how. The ideas below are exactly the types of things that I was looking for. Creative and potentially really accurate ideas! 1) Get with Sport Z Magazine and approach the Franklin Mint - to see if they are willing to "donate" the use of that model for this group's simulation. In exchange for the publicity it could generate. 2) Use a smaller, and far less expensive 3D laser scanner - and scan a Franklin Mint Model. Then use the scan to feed the simulation and analysis programs.Carl B. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted December 6, 2007 Share Posted December 6, 2007 I will see my brother over christmas break. He has the software to do this kind of stuff. If he lends me a copy or shows me a student version and how to use it, I can probably run some basic wings and such (not really 240z specific, but it might help out to find out what works and what doesn't). No promises. Quote Link to comment Share on other sites More sharing options...
Carl Beck Posted December 8, 2007 Share Posted December 8, 2007 Anyone want to buy themselves a present? For $2500.00 you can scan your Franklin Mint Model into a 3D data base... Next Engine: https://www.nextengine.com/indexSecure.htm FWIW, Carl B. Quote Link to comment Share on other sites More sharing options...
Tony D Posted December 10, 2007 Share Posted December 10, 2007 Having disassembled several 280Z's this past month (particularly the front ends) I would be curious as to the effect the larger bumpers, turn signal relocation, and little winglets behind the bumper all have on the flow on the front of the car 280Z versus 240Z. From the data Nissan used, they referenced 'the prior model' in the S130 literature, but their diagrams show a 240Z. I have gotten curious as to the aero difference between an all stock 240 with the skinny bumper, versus the 77/78 models with the big bumpers and all the other radiator opening blocking items (bumper, turn signals, turn signal mounting brackets, etc). Being that last word I got was 'the rules will be rewritten in this off season' I'm having a bad feeling that our Bonneville effort will not be reproduced with a G-Nose on the car, but with full 77/78 280Z factory dress. And I'm not loving the thought of sourcing new bumper rubbers...saved two sets, but the $$$ on E-Bay people get for them is making it cheaper to run a G-Nose! Quote Link to comment Share on other sites More sharing options...
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