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    Originally posted by Motheye99 View Post
    I'm sure it's very minor on E30's but isn't a rear lip also designed to keep a car stable at high speed, not in the way of down force. But increasing the drag on the car in a predictable way. I'm not very knowledgeable on car areo but we use devices very similar on rockets to increase "base drag".

    Sent from my SM-G950U using Tapatalk
    it *decreases* drag - it doesn't increase it.

    Fun fact: facelift E30s were actually wind tunnel tested. :rofl:
    Build thread

    Bimmerlabs

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      I know Alpina did a lot of Aero testing on the early E30's with both their front and rear spoilers. The Alpina front spoiler definitely does make a difference at highway speeds, but I have't tried my B6 on the track yet - will do it the next open track day I think just for S & G.
      1991 325i MT2 Touring (JDM bro)
      2016 Ford Flex
      2011 Audi A3 - wife's other German car

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        Originally posted by nando View Post
        it *decreases* drag - it doesn't increase it.

        Fun fact: facelift E30s were actually wind tunnel tested. :rofl:
        Yeah, by detaching the turbulent air from the rear of the car somewhat better.
        That may, in fact, stabilize the car, if the turbulent air is generating lift or
        buffeting on the rear end.
        Or it may not, depending.

        It would be fun to see the wind tunnel test results-

        I've seen pix of 2002s in wind tunnels, but that doesn't mean BMW did any DEVELOPMENT in them, just stuck the cars in and said,
        "hmmm, very interesting. Bratwurst or Knockwurst for lunch today, Hans?"

        t
        now, sometimes I just mess with people. It's more entertaining that way. george graves

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          on wikipedia a wingless mk4 supra is .33
          and with the big ass factory turbo wing .34
          so the e30 sport rubber strip probably is just to make it look sporty.
          Last edited by LowR3V'in; 03-09-2019, 05:17 PM.

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            Originally posted by haaken675 View Post
            So I am finally getting to the point in my build where I can actually think about aero. I plan on doing a front splitter, rear diffuser as I no longer have a spare tire well, and a gt wing. Does anyone know if it makes a big enough difference in wing height? I was looking at an APR GT-250 or an APR GTC-300, but it looks like total height is somewhere around 13 inches. Roofline is somewhere around 17-18 inches. This height is achieved with their standard 11 inch pedestals. Apparently that being said, they offer a 14 inch pedestal that I could custom order that would likely bring the total height to around 16.5 inches.

            Would that work better, especially if I went with the 2d shape of the GT-250 wing?

            Still interested in knowing the answer to this^^^
            1988 BMW 325i Zinoberrot
            1984 BMW 533i Alpinweiss
            1986 BMW 528e Delphin Metallic
            1998 BMW 528i Touring

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              According to Johnny 9 lives racing, the higher the better since you will be getting out of the air stream and into open air. Seeing that Time Trials and the like have rules against the wings being wider than the car, or higher than the roof, I would tend to think he is correct (not to mention his resume lol).

              He says a lot in this thread (and is a professional aero expert for many pro teams)...

              https://forum.champcar.org/topic/188...ero-questions/
              john@m20guru.com
              Links:
              Transaction feedback: Here, here and here. Thanks :D

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                Originally posted by ForcedFirebird View Post
                According to Johnny 9 lives racing, the higher the better since you will be getting out of the air stream and into open air. Seeing that Time Trials and the like have rules against the wings being wider than the car, or higher than the roof, I would tend to think he is correct (not to mention his resume lol).

                He says a lot in this thread (and is a professional aero expert for many pro teams)...

                https://forum.champcar.org/topic/188...ero-questions/
                Thanks for posting that link. Read through a few pages while sitting at the trade show booth twiddling my thumbs...

                Also checked out Nine Lives Racing's website and it looks like they are working on an e30 kit: https://9livesracing.com/products/e30-big-wang-kit

                Comment


                  Looking for advice on splitter materials and construction. I made v1 out of mostly 1/8" ABS, angle aluminum and 304SS - the aluminum and SS used for brackets and support. I liked the ABS because it's flexible and is already black, but now I see it's just a bit too flexible to be a sturdy aero component. Currently looking for alternatives. I've seen alumalite suggested and used. I also found a local source for dibond (similar to alumalite but with a solid poly core). And I'm also considering sheet aluminum. What materials have others used successfully? My untested thoughts are a toss up between all three. Biggest question for either alumalite or dibond is 1/8" vs 1/4" thick. If I went aluminum seems 1/8 is plenty strong. Only concern against aluminum is that if I smash it on something it will bend and be a pain to flatten vs dibond/alumalite which seem to a be a bit more durable in that regard. As far as construction design goes I initially mounted the splitter to the bottom of the valence by way of an ABS skirt which clipped into the IS brackets in the valence, and screwed into the splitter through angle aluminum. While it looks good, it's not durable nor very structural and is prone to popping out of position with minor scraping/rubbing against the road/driveway (which is kinda what I intended - but too much). I'm trying to engineer some planned failure mode into this whole thing so that if I smash the splitter on something like a cone or off-track adventure I don't also smash the valence along with it. So in other words I want to mount both splitter and front lip separate from each other. Splitter mounted to the frame rails with brackets + support struts and some (easily broken) plastic clips to the lip. Then the lip mounted to the valence with sturdy brackets. I hope that this will allow the splitter to be sturdy enough to provide actual aero benefit without damaging more than just the splitter in an "incident". Thoughts?
                  Last edited by Sh3rpak!ng; 11-12-2019, 03:30 PM.
                  '89 325i OBD2 S52 BUILD THREAD
                  Shadetree30

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                    Alumilite and plywood seem to be the preferred materials for the E36 guys.

                    RISING EDGE

                    Let's drive fast and have fun.

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                      Originally posted by Digitalwave View Post
                      Alumilite and plywood seem to be the preferred materials for the E36 guys.
                      I also used a version of "Alumalite" called Alupoly from a local plastics shop for my front splitter. I ended up using a 3mm (approximately 1/8") thick version, but they also offer a slightly thicker version as well. I sent in a CAD template that I made and they CNC cut it in a day.

                      The mounting is not the most ideal setup for fully functional aero as I just bolted to my IS lip every 6-8 inches, but it does feel very sturdy up to speed on the highway. I would also need to block the front gap on the lip for additional functional down force. This version overhangs about 3", but I also have a 5" version that I will eventually try when I decide to make the switch to a rear wing.

                      E30 Front Splitter




                      1991 LS1 Swapped 318is
                      Instagram:
                      https://instagram.com/saltybeast/
                      LS Build Thread:
                      https://www.r3vlimited.com/board/for...s-e30-ls1-swap

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                        Originally posted by Digitalwave View Post
                        Alumilite and plywood seem to be the preferred materials for the E36 guys.
                        I picked up a 1/4" piece of ABS this past weekend that I will test out. It's several magnitudes more rigid than the 1/8" and should provide nice impact resistance. None of the local sign shops with dibond or alumalite are open on the weekends or weekdays past 5pm which makes it near impossible for me to pickup.
                        Originally posted by ian e30 318is View Post

                        I also used a version of "Alumalite" called Alupoly from a local plastics shop for my front splitter. I ended up using a 3mm (approximately 1/8") thick version, but they also offer a slightly thicker version as well. I sent in a CAD template that I made and they CNC cut it in a day.

                        The mounting is not the most ideal setup for fully functional aero as I just bolted to my IS lip every 6-8 inches, but it does feel very sturdy up to speed on the highway. I would also need to block the front gap on the lip for additional functional down force. This version overhangs about 3", but I also have a 5" version that I will eventually try when I decide to make the switch to a rear wing.

                        E30 Front Splitter
                        That's a nice piece. I just fixed my computer and am looking for a "light" CAD program to do simple drawings for parts like this. Any suggestions?
                        '89 325i OBD2 S52 BUILD THREAD
                        Shadetree30

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                          Originally posted by Sh3rpak!ng View Post
                          I picked up a 1/4" piece of ABS this past weekend that I will test out. It's several magnitudes more rigid than the 1/8" and should provide nice impact resistance. None of the local sign shops with dibond or alumalite are open on the weekends or weekdays past 5pm which makes it near impossible for me to pickup.

                          That's a nice piece. I just fixed my computer and am looking for a "light" CAD program to do simple drawings for parts like this. Any suggestions?
                          You might be able to get Auto desk inventor for students, it last 3 years. Just fill the form out and say your in community college.
                          91' 318is 90' 325is

                          Originally posted by Sonny
                          Buy the E30s, they ain't gonna last long
                          E30 can make you, E30 can break you
                          "He who controls the Nova's, controls the Boomers"

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                            Originally posted by Sh3rpak!ng View Post
                            I picked up a 1/4" piece of ABS this past weekend that I will test out. It's several magnitudes more rigid than the 1/8" and should provide nice impact resistance. None of the local sign shops with dibond or alumalite are open on the weekends or weekdays past 5pm which makes it near impossible for me to pickup.

                            That's a nice piece. I just fixed my computer and am looking for a "light" CAD program to do simple drawings for parts like this. Any suggestions?
                            Onshape is free and what I use. The only stipulation if you don't want to pay is that all your work is public and can be accessed/copied by others. I messaged you on IG (Saltybeast) and my offer still stands to share the models with you if you'd like.

                            1991 LS1 Swapped 318is
                            Instagram:
                            https://instagram.com/saltybeast/
                            LS Build Thread:
                            https://www.r3vlimited.com/board/for...s-e30-ls1-swap

                            Comment


                              Originally posted by Sh3rpak!ng View Post
                              Thoughts?
                              Quick thought, what reasons are there to have that splitter so short and not go back further towards the front axle? The oil-pan is pretty low right, but you can cut around that. The reason I ask is because we've seen yuge gains on CFD data from extending the bottom of the splitter back as far as possible, on multiple chassis.


                              We've(9LR) been testing several materials on our NA/NB miata aero packages. 1/2" polymer coated birch, 10mm alumalight, and tegris have seen the best results. We've settled on 1/2" birch coated with...... "rocket nozzle" polymer It requires less mounting points than alumalite and just a tad heavier. Not too far off weight after we did some stress-testing on the birch and removed the material...





                              Also, very relevant to this post and forum. E30 wáng kits are actually ready: https://9livesracing.com/products/e30-big-wang-kit
                              Last edited by flier129; 11-22-2019, 02:17 PM.
                              Marcus @ Nine Lives Racing

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                                is that coating proprietary? I really like your stuff
                                91' 318is 90' 325is

                                Originally posted by Sonny
                                Buy the E30s, they ain't gonna last long
                                E30 can make you, E30 can break you
                                "He who controls the Nova's, controls the Boomers"

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