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3d printed intake for N/A NA miatas

Old Feb 11, 2016 | 09:02 AM
  #321  
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The youtube version is blocked in the US but I found it on daily motion:
http://www.dailymotion.com/video/x3rdsi7

That is the first time I have seen someone do bladder molding with wet layup, which is my plan. They are doing resin infusion which I am not planning on. It is interesting that they aren't using any flow media, breather material, or release material.
Old Feb 11, 2016 | 10:22 AM
  #322  
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Is drilling a 2.5 or 3 inch hole necessary to install this intake system?
Old Feb 11, 2016 | 10:23 AM
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Not for most people. Some early chassis don't have a hole in the radiator support. I haven't been able to figure out exactly which cars since it isn't something obvious like all 1990 cars.
Old Feb 11, 2016 | 10:24 AM
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Originally Posted by asmasm
Awesome results. I guess the clean sheet design was worth it. A naturally aspirated miata engine is never going to flow close to 350 CFM. An online calculator says a engine with 2000cc displacement at 8500rpm and VE of 110 would be consuming 240 cfm.

Yeah, I probably need a name for it. I was thinking just Durham Composite intake.

Also, everyone should be giving cyotani props for doing CFD for me.
I can re-run this and solve for the pressure drop at each tube that will result in a set CFM (such as 240).

Also, I'd use the BSFC method rather than that method. Solve for required Air to support a certain WHP assuming a specific BSFC. It would be good to get a stock CFM and a typical 230 whp turbo build CFM and solve for the pressure drop in both those cases.
Old Feb 11, 2016 | 10:29 AM
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Can someone with experience building highly modified miata engines can suggest a CFM for the upper bounds of naturally aspirated air consumption?
Old Feb 11, 2016 | 10:32 AM
  #326  
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Originally Posted by asmasm
Not for most people. Some early chassis don't have a hole in the radiator support. I haven't been able to figure out exactly which cars since it isn't something obvious like all 1990 cars.
My car is a 1997 chassis, hopefully no drilling is required.
Old Feb 11, 2016 | 11:17 AM
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Originally Posted by asmasm
Can someone with experience building highly modified miata engines can suggest a CFM for the upper bounds of naturally aspirated air consumption?
Someone check my math please.


Attached Thumbnails 3d printed intake for N/A NA miatas-80-miata_required_cfm_a7682f35f286a658da1fdb4b9ea007f45501bfc5.jpg  
Old Feb 11, 2016 | 11:27 AM
  #328  
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Originally Posted by my97miata
My car is a 1997 chassis, hopefully no drilling is required.
Just confirmed my 97 has the hole, want to say my 95 also had it.
Old Feb 11, 2016 | 11:34 AM
  #329  
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Here is a quick sanity check on the spreadsheet. This is a 3.5L EcoBoost I've had on the DYNO often for work over the past few months. We instrumented it with our own MAF sensor calibrated on a flow bench.

at 320 WHP it flowed 540 CFM.
AFR was 10.5.
Spreadsheet seems to check out okay.


Attached Thumbnails 3d printed intake for N/A NA miatas-80-ecoboost_69ff85b1efa8b73ea4b750cd618afb57e191d7d7.jpg   3d printed intake for N/A NA miatas-80-capture_468224724de0f0eabdf092a33e10bd0def5d4035.jpg  
Old Feb 11, 2016 | 11:37 AM
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The target user base for this has been people making 140-160whp with NB engines that are close to stock internally. Knowing it causes minimal restriction at 350 cfm it seems also seems appropriate on a cost no object build making 190whp. Also, this latest design might even fit on a k-swap car.
Old Feb 11, 2016 | 11:41 AM
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Originally Posted by asmasm
Can you plug in a 150whp vvt swap car and a 190whp e85+built everything car?
What AFR do you want that run at? I'm not sure how rich these guys run their cars. If someone who's tuned one could chime in.
Old Feb 11, 2016 | 11:43 AM
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Durham Composit Cobra CAI
Old Feb 11, 2016 | 12:11 PM
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Looks awfully familiar to one of our products.

Attached Thumbnails 3d printed intake for N/A NA miatas-80-banks_cobra_2f97adc6edbcb1cc5fe4cd3637f59de1d234e8bf.jpg  
Old Feb 11, 2016 | 12:14 PM
  #334  
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What wall thickness do those plastic intakes end up at? 2mm?
Old Feb 11, 2016 | 12:23 PM
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Originally Posted by asmasm
What wall thickness do those plastic intakes end up at? 2mm?
usually 0.15" (3.8mm).
Old Feb 11, 2016 | 12:26 PM
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I looked up the parts, they are way bigger than I was thinking. For this application, would that thickness be necessary? I think the stock crossover tube in the miata is about 2mm and is very strong.
Old Feb 11, 2016 | 12:32 PM
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Originally Posted by asmasm
I looked up the parts, they are way bigger than I was thinking. For this application, would that thickness be necessary? I think the stock crossover tube in the miata is about 2mm and is very strong.
Depends on the manufacturing process. These tubes are rotomolded (constant thickness process so we have no control of beefing up critical areas and thining out less stressed areas). Also blow molded tube are typically thinner so the material can fill the crevices of the mold easier. We could go thinner on the rotomolded tubes but the thickness and weight also adds a sense of quality in the part when you hold it. It feels more expensive than some of the thinner blow molded or plastic injected tubes.
Old Feb 12, 2016 | 11:34 PM
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Well, since I don't have a hood latch I want to install the 3d intake into that opending in hopes of achieving a total lenght of 22". I found out a 60 degree of the tb and another 45 to the intake will work perfectly. Some cutting of the hood needs to be done too. (Where the original latch was) I'll post pictures once it's done
Old Feb 13, 2016 | 06:11 PM
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Originally Posted by cyotani
Looks awfully familiar to one of our products.
Awfully familiar? Sorry but it looks nothing like it..
Old Feb 19, 2016 | 02:42 PM
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A few updates. First, the new design fits on my car. I hammered my hood about a year ago so I need to test fit it on a stock hood before having aluminum molds machined but it looks like the 2016 revision is going to work.

Second, the selection of air filters that fit in the bumper area is really poor. I really like the AEM dryflow filters for several reasons, one of them being the bell mouth they integrate into the flange. AEM doesn't make any filters that are narrow enough to fit. I contacted them about a run of custom size filters and they referred me to K&N. My solution- I found a green filter that is only slightly over sized and uses a 3.5" flange opening. I designed a simple mold to pour silicone rubber into to make a bell mouthed flange reducer with an offset hole. The upside is being able to fit a significantly larger air filter + getting that bell mouth geometry.

Attached Thumbnails 3d printed intake for N/A NA miatas-80-swiequ6_98166c13f4d4ed0eba177380ab4a34fb09caa679.png  

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