S30Z Bushido Posted March 2, 2003 Share Posted March 2, 2003 Quote Link to comment Share on other sites More sharing options...
S30Z Bushido Posted March 2, 2003 Author Share Posted March 2, 2003 I made that pic above in Photoshop, it's the rear of a Skyline R34 GTR with a Titanium Nismo Muffler , i only wish it was real... comments? Quote Link to comment Share on other sites More sharing options...
v8dats Posted March 2, 2003 Share Posted March 2, 2003 pretty cool i like the idea of a rear difuser! nice muffler! Quote Link to comment Share on other sites More sharing options...
Guest Zachb55 Posted March 2, 2003 Share Posted March 2, 2003 hmm, that would be sweet if you could really make somethin like that and mold it into the body to make it look real nice... im sure it would help with our downforce, i mean Lift problem , maybe you should whip up a real one and take some pics and run a few tests?? please? lol, well i guess photoshop will have to do for now... Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 2, 2003 Share Posted March 2, 2003 aww im hoping my HKS muffler will look that good on the Z when all said and done...................which will be never!!!!!!!!!!!!!!!! i hate life mike Quote Link to comment Share on other sites More sharing options...
BRAD D Posted March 3, 2003 Share Posted March 3, 2003 I saw this photo on the album first, you tricked me. Looks cool. I did not think the stock gas tank would allow that muffler to come out at that angle. Quote Link to comment Share on other sites More sharing options...
Guest thinkmonkey Posted March 3, 2003 Share Posted March 3, 2003 I'm planning on fabricating a rear diffuser for my Z, one that I can unbolt. I'm going to run dual exhaust with a center mounted fuel cell and the diffuser will be between the mufflers running back to diff area. English wheel (or just have it straight/bent. the main thing to remember is to have the airflow expand towards the back) the main diffuser element out of sheet metal and add 3 vertical slats to channel airflow. I'm concerned about highspeed lift mainly because of the cars tendency to oversteer at extralegal speeds. A rice wing is the quick and dirty solution but it is ugly and I couldn't live with holes to bolt it on. If you sand down the rough metal edges and paint it flat black it would really set off the rearend of the car to look like a euro touring car. I'd recomend shaving the bumper also. Another effective downforce aid is to disrupt airflow on the roof before the hatch. Hatchbacks smooth body lines create a lot more lift that 3 box style cars, and upsetting the rear overbody airflow with tubing or supra style wings (previous generation) can help curb lift. -David Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 3, 2003 Share Posted March 3, 2003 i would love to have a rear diffuser like that. I wouldnt know where to look to get one made.. plus i think carbon fiber would be alot of money. also about the no rear bumper.... im liking that idea of no rear bumper but just a Front Euro bumpr.. do you guys think it would look good or no? mike Quote Link to comment Share on other sites More sharing options...
DavyZ Posted March 3, 2003 Share Posted March 3, 2003 Wikked looking diffuser. Someday I'll learn photoshop too I think that if you could make one for the car. it might actually help things---plus, it looks really cool under there. I do like the rice pipe too Davy Quote Link to comment Share on other sites More sharing options...
S30Z Bushido Posted March 3, 2003 Author Share Posted March 3, 2003 heres one i did for the front. Quote Link to comment Share on other sites More sharing options...
peej410 Posted March 3, 2003 Share Posted March 3, 2003 s30 your Z is beautiful and youve got some photoshop skills where are you from?, eventually once my Z is mobile i will be doing carbon fiber/ carbon kevlar work, maybe we could get together and make some sick parts! - pete Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted March 4, 2003 Share Posted March 4, 2003 Hey is that rear diffuser like a wing?... kinda hard to see...a wing like a deck spoiler i mean. like those universal aluminum wings you see on all kinds of rice. hmmmm you got me thinking again of the rear bellypan exhaust problems......hmmm more ideas... think of a flat wing parallel to the ground supported in 2-4 spots under the car... maybe adjustable...hmmm Kinda also reminds me of the nose wings on the lambo countach... not all had it... it was right down at the front of the hood...on the bumper i think... sorry for wildly writing this all down....just want to keep this idea going.. I'm going to link this thread to the one in the high tech forum... I would think I could fab something like that for a test...run some supports down from where my stock 280 bumper shock absorbers mounted to the car..... Quote Link to comment Share on other sites More sharing options...
S30Z Bushido Posted March 4, 2003 Author Share Posted March 4, 2003 the rear diffuser i photoshopped on my car above is basically a wing.. i'm sure you all know how a wing works, air flows under the car and over top of the wing which makes downforce and therefore keeps the rear of the car down. i'm going to attempt of fabricate something that looks and functions similar to the picture above when i start on my bodywork. Quote Link to comment Share on other sites More sharing options...
Mudge Posted March 4, 2003 Share Posted March 4, 2003 I like the idea of doing SOMETHING on the underside and rear of the car, but blocking too much of the rear is not a good thing, since that would trap air. Plus if one were to go with the whole undertray idea, you want some kind of rake from front to back, where the rear is higher than the front, somewhere between 4-11º (7-9 seems most common?). Quote Link to comment Share on other sites More sharing options...
S30Z Bushido Posted March 4, 2003 Author Share Posted March 4, 2003 s30 your Z is beautiful and youve got some photoshop skills where are you from?, eventually once my Z is mobile i will be doing carbon fiber/ carbon kevlar work, maybe we could get together and make some sick parts! - pete Thanks for the compliments man! I'm from Pompano Beach Florida, near Ft. Lauderdale. I'd love to learn how to fabricate carbon fiber/kevlar parts, and would be more than willing to help out with it, i have a few ideas for cf parts for an S30. 8) Quote Link to comment Share on other sites More sharing options...
Guest thinkmonkey Posted March 4, 2003 Share Posted March 4, 2003 Actually the diffuser doesn't work exactly like a wing, but it works on a similar principle. Wings have a curved surface on the top and a flat surface on the bottom. Air must travel faster on the curved/longer surface and in accordance with Bernoulli's Principle air that travels faster over a surface creates a low pressure zone. Atmospheric pressure below the wing, low pressure above creates lift. Turn it upside down and you have a spoiler. The diffuser acts on the principle of a ground effect first used by Lotus in F1 racing. Air is flowing beneath the car at a semi-fixed rate. Hopefully you have an air dam or splitter in the front to lessen the amount of air to create a low pressure zone, but still some air flows under the car. When it reaches the back of the car and when it first goes underneath the diffuser it is at a certain air pressure. As the diffuser angles up, the closer it gets to the bumper the volume contained gets larger, but the amount of air in that volume does not. More volume but same air equals low pressure. Again, atmospheric on top, low on the bottom equals downforce. You can run into problems with the diffuser trapping air but if you do build one you should consider fabricating a partially flat undertray that goes up to the engine bay. This will smooth out the airflow and eliminate pockets of turbulence. You have to be concerned about high pressure air entering the diffuser, and that is why there are vertical slats. Also side skirts help keep out air from around the rockers. If you look at the new Ferrari Enzo it has a partial front airdam that lets air in only at the center. The air is then channeled under the car. The channel's width increases towards the back of the car creating massive amounts of downforce. That same air is then again used in the rear diffuser. No wings needed, very nice undertray. The only problem we can run into if you cover the engine bay area is the hassle and cleanliness problems, and cooling problems. Vents in the hood, fenders, or into the cowl would be needed and may require electrical fan assist. If you were to vent the air into the fenders you would need fender vents to avoid the lift there. Bet you didn't think all those wings, spoilers, diffusers, air dams, skirts, and vents actually did anything did ya! If you really want some high speed cruising, passive ground effects are simple and satisfying. Beware of downforce though, it can really fudge with your handling or suspension travel at high speeds. The 360 modena ran into this problem and came up with a solution were the lower the car was, the less downforce it made, reaching equilibrium at around 170mph. Tricky those Italians. The easiest way really is to just jack up the rear and slam the front. Make the car one big wing. Doesn't work well beyond the 1320 though for very long. -David Quote Link to comment Share on other sites More sharing options...
stony Posted March 4, 2003 Share Posted March 4, 2003 i need to get photoshop ;> Quote Link to comment Share on other sites More sharing options...
Guest Zachb55 Posted March 4, 2003 Share Posted March 4, 2003 hey that front pic is exactly like what i would like to do, of course id love a diffuser in the back too, but maybe that can be carbon project #2 i just got my front valance in like a week ago, but i would love to do some fiber work to make a nice little lip on the front of it to give it more downforce and maybe even better the aerodynamics of my Z. The Diffuser is a great idea, and actually something that all Z's should probly have to get rid of that lift. They can be extremely effective in creating downforce, but the technology goes into great detail, and that detail must be followed. Also, remember what it looks like when one of those Le-Mans cars pulls a back flip? well that happens alot because of a bumpy road which screws up the angle of the diffuser, leading to catastrophic loss of downforce and potentially very bad things. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 4, 2003 Share Posted March 4, 2003 Diffusers that work are not simple things. When you start relying on aero for chassis grip the suspension has to be designed to control any changes in rake. In particular this means anti-dive needs to be built into the front and rear suspensions. The worst thing that can happen is for the car to nose forward under hard braking. This spills air out of the rear diffuser and you lose rear downforce (grip) when you need it the most. The side strakes of the rear diffuser must be parallel and as close to the ground as possible and the up angle of the top plate should be 7 degrees. Anything more then that and the airflow starts separating and you create turbulence (drag). The diffuser should also be as long as possible. Education: http://www.mulsannescorner.com/ Quote Link to comment Share on other sites More sharing options...
Guest thinkmonkey Posted March 4, 2003 Share Posted March 4, 2003 The reason the Mercedes did the backflip at Le Mans was because Mercedes lowered their downforce levels so much, in the pursuit of a higher topspeed, that when they crested that hill... -David Quote Link to comment Share on other sites More sharing options...
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