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Old 03-08-2019, 06:59 PM   #11 (permalink)
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Quote:
Originally Posted by Assassintime14 View Post
The use case for me is pretty much for a daily driver and for taking to auto crossing In the following months hopefully.
If you're actually competitive (i.e. not just doing fun runs), you'll want to be careful of class rules. Don't want to inadvertently bump up to Prepared or something by accident.

One thought if you add an airdam and are autocrossing: body lean will eat up the outside edges if it's low enough, and brake dive the center, so you'll probably want stiffer springs and dampers.

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Old 03-09-2019, 08:23 AM   #12 (permalink)
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Quote:
Thanks for responding. Your words say daily driver, but your attachment says time attack.
I'm thinking of making something of an in between, i agree that splitter is awfully aggressive for a car like mine. I'm thinking of just making it a round half the size of that one.


Quote:
The Kammback you have in mind, can you please provide a link and or image of the Geo metro hatch?
It won't let me post a link until i hit 5 posts , but its the one "making a permanent parital kammback" from MetroMPG

Quote:
If you're actually competitive (i.e. not just doing fun runs), you'll want to be careful of class rules. Don't want to inadvertently bump up to Prepared or something by accident
.

I'm not sure of class rules as since i have't auto crossed before, i can look into it possibly.

Quote:
One thought if you add an airdam and are autocrossing: body lean will eat up the outside edges if it's low enough, and brake dive the center, so you'll probably want stiffer springs and dampers.
I'm currently on my way to do this. After my birthday on the 14th i should be picking up a set of BC Racing coil-overs. That will include a drop in ride height from 1-3in. So I'm thinking that the airdam should go down from the bumper an inch or 2, the car is getting dropped atleast one inch, probably 2in. The mirage's ground clearance is 6.3in stock, leaving me in the end with 2.3 in of scrape clearance

And once again, thank for all of your guys' help so far
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Old 03-09-2019, 12:32 PM   #13 (permalink)
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splitter

Quote:
Originally Posted by Assassintime14 View Post
The use case for me is pretty much for a daily driver and for taking to auto crossing In the following months hopefully.

According to Mitsu's press release "These aero enhancements help the 2017 Mirage achieve a very low coefficient of drag at only 0.27 (Cd)."

The projects I've liked are are the partial kammback on that geo metro hatch, and some of the air dams you guys have created.

The Capstone is to prove that me, and my team can follow the engineering design process. I'm fine with using tried and true designs since it will be a bit easier.

For a front splitter, I'm becoming a fan of this one from

Attachment 25608

Attachment 25609

Making some fans to act as a rear diffuser would be probably easy to model and produce.
I'd recommend against the splitter.They're only for downforce,and that's not an issue at posted legal speeds.They work against fuel economy.
Ferrari spent an easy $100,000 developing tuned suction fans,ducting,and ejector nozzles for the rear of one of their models.
Without hundreds of iterations in either a full-scale wind tunnel, or industry-grade CFD,I don't know how you could possibly arrive at a working solution.
A 2.8-degree,or 4-degree diffuser,depending on where you begin the up-sweep would be a 'proven',no guesswork solution.
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Old 03-09-2019, 01:59 PM   #14 (permalink)
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Hey Assassintime14 -

I removed your duplicate post - not sure why it went in the moderation queue. Have other posts you've made been moderated?

Quote:
Originally Posted by Vman455 View Post
There's an aerodynamicist for one of the OEMs who posts occasionally on Jalopnik and TTAC
Do you know what the username is? I'm a regular reader of both and have missed his posts.

Quote:
If you don't have grill shutters (I don't remember if the Mirage does or not), block as much of the grill as you can without affecting coolant temperatures.
It does not. However Mitsu tuned the functional size based on transmission -- manual cars have a smaller opening than CVT-equipped cars.

I played around a bit with a 2014 Mirage. Very similar to the 2017, aerodynamically, with the exception of a revised angle to the drag-reducing hatchback spoiler, and the 2017 lost the hard chine on the corners of the rear bumper cover, which were there to promote clean flow separation on the 2014-15 cars.







Thread: 2014 Mirage aeromods A-B test: grille block, mini-Kammback, air dam, mirrors, 1 wiper
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Old 03-09-2019, 03:45 PM   #15 (permalink)
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Quote:
I'm thinking of making something of an in between, i agree that splitter is awfully aggressive for a car like mine. I'm thinking of just making it a round half the size of that one.
https://duckduckgo.com/?q=infinity+wing+splitter

Quote:
The mirage's ground clearance is 6.3in stock, leaving me in the end with 2.3 in of scrape clearance
My Superbeetle looked really good with the adjustable struts and 50-series tires, but I had to lift it to 3.5" to clear 90% of speed bumps. If you have a tow hook or something that makes one side lower than the other, approach at an angle at enough speed the car rolls side-to-side at just the right time.

Ground strikes at freeway speeds happen at bridge aprons.

Quote:
I'm doing a capstone project for my CADD engineering class.
Quote:
Originally Posted by aerohead
Without hundreds of iterations in either a full-scale wind tunnel, or industry-grade CFD,I don't know how you could possibly arrive at a working solution.
If your looking forward into an advancing state of the art for CFD, follow OpenVDB.

This is currently implemented in Maya and Blender and other applications. Watch for CFD animations that use it. I used to use a knowledgebase to edit file directory structures, so I'm familiar with sparsely populated, shallow inverted B-trees so I understand the advance it makes. Using the application toolchain is apparently above my pay grade. Good luck.
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Old 03-10-2019, 01:43 PM   #16 (permalink)
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Quote:
Originally Posted by freebeard View Post
I was trying to find an example someone posted of a conveyor belt airdam with a central notch. No success so far but I did run across these examples I hadn't seen before:

https://ecomodder.com/forum/showthre...per-29400.html

Spats, skirts and a truncated boat tail vs standard Ecomodder mods.
Nice project example, I don't remember that one, thank you for posting it.

I call that chin spoiler a "rural" solution as it would not survive parallel parking on urban streets.

It should be able to survive college and grocery store parking lots because the car is so short and does not take the full length of a parking space.

The upper rear wheel partial covering (skirt) might do a tad better if the leading edge were tucked into the opening, but one has to admire the simple installation as shown.

EDIT:

As far as gaps in a chin spoiler go, this was done on the 1964-1973 Porsche 911, not sure why though.

FS: S Fiberglass Front Bumper for Early 911
http://forums.pelicanparts.com/porsc...rly-911-a.html




EDIT-2: I found this......................

Storm tested: Adaptive Aerodynamics
https://newsroom.porsche.com/fallbac...ted-10734.html
Quote:
Based on this experience, Porsche equipped the 911 S with the first front spoiler in 1971. It accelerated the air flow underneath the vehicle, diverted some of the air around the sides and therefore reduced aerodynamic lift of the vehicle’s front section. The advantages were improved directional stability and easier controllability. The Carrera RS 2.7, designed for motor sports in 1972, brought a milestone in aerodynamic development to the market: Not only was it equipped with a low-slung front spoiler, but also with a distinctive spoiler over the bonnet - the legendary “ducktail”. Both add-on components improved airflow around the 911 and reduced aerodynamic lift and drag. The result: The Carrera RS 2.7 was particularly fast and efficient, while also offering excellent road-handling characteristics at high speeds. One year later, the prototype of the first 911 Turbo further intensified on-going aerodynamic development of the 911 chassis with a large, fixed rear spoiler.
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Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html

Last edited by kach22i; 03-10-2019 at 02:05 PM..
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Old 03-11-2019, 01:20 AM   #17 (permalink)
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That's my Odyssey with the dam/splitter. It's still got 7" of ground clearance, I only ever worry about high parking curbs. Driveways and speed bumps are not an issue.
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Old 03-11-2019, 04:41 PM   #18 (permalink)
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Quote:
Originally Posted by MetroMPG View Post
Do you know what the username is? I'm a regular reader of both and have missed his posts.
<rockbottom>. I would find some of his posts, except I don't know how to search the comments.
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Old 03-12-2019, 01:36 PM   #19 (permalink)
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Being in Ohio, I recommend a lot of the warm up mods I've done on my Mirage. I absolutely love how fast it warms up. I'll definitely have to remove some grill blocking once it starts warming up, but until then its been absolutely wonderful. Here is a link to my garage page with links to my mods.

https://ecomodder.com/forum/emgarage...ehicleid=10160
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Old 03-13-2019, 04:49 PM   #20 (permalink)
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I forgot to mention that along with wanting to have the car get better mpg, doesn't mean I wouldn't like it to handle quite a bit better as well, thus the splitter. This car I have some decent issues with handling, and since it will be for taking to autocross I'd like to use this project as a way to get both, I designed something similar to the Miata earlier. The main things that are different are that it fits my car's width, a little past, 4in or so. Also for the air dam, should it be mounted at the edge of the bumper, or a little back from it? I will try to post pictures of my model tomorrow. This project is for MPG but also handling and a little style of course.

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