Me and my Aero

[joeereid]

Remember that song that was drilled into our brains back in the 70's! It's been swirling 'round my brain all weekend.
Well the project has begun. Inspired the fantastic job that jmills with the splitter he managed to adapt to his MSM without hacking it up, I've decided to give it a go as well. MrHyde has done his own interesting approach as well, but that's on his "over the top" NA so it doesn't
really apply. The particular challenge that I am facing is that even though my car is only used for tracking, I don't trailer the car so it needs to remain semi-streetable to get to and from the tracks, which range from 40 to 250 miles away.
  I have two approaches that I will be sorting out this week. One is to make the front/center section of the splitter removable so it does not get torn off in the driveway outside the shop on my way to the track. The second is to make the unit so that it can be installed/removed from the car  in the pits in @10 minutes or less with @ 8 fasteners of some sort and then stowed for transport on the trunk lid, but I don't think that  may be practical, not that the other idea is practical, but we'll see how it goes once I get a little further into it.
The splitter plane will most likely be either 2 or 3 pieces of Baltic Birch, epoxied together cross grain, net 3/8"~1/2" thick and then the splitter will be cut out at a 45 deg. angle to the grain, which will make it super stiff flatness-wise.
 I was able to use my old TDR "splitter", (that I removed from my car after after witnessing MrHyde returning to the track from Subway with his sitting in the passenger seat), as a starting point. I was able to measure various point just by using the old mounting hole as reference points. I started with a basic tracing of the TDR (I eliminated the center "notch out" portion) and then moved it forward +1, +2  and +3 inches and traced the outline(s). The standard TDR protrudes @ 1 7/8" fro the nose of the car so I chose the +1 outline as a starting point. I added @3" to each side of the outline, moved forward @12" parallel to the centerline, so there's enough width to Spat/Canard the front wheels, and used a Fairgate Curve ruler to establish a new compound radius. The rough template is @35" deep(fore+aft) which nets @ 3'' protrusion at the front and will extend aft to the end of the stock under tray without blocking the "scoops" right before the oil pan. Width is @66'' at the front of the wheel well. I forgot to pull a dimension for the width of the tongue that extends toward the oil pan so I cut it at 32'' and will figure that out once I slip it under the car. It was up on a lift getting  a new diff so I pulled just about every dimension that will probably never be needed and, of course, forgot a couple of the simple ones.
I've got a few pics of todays progress but they're "phone' pics so I'll need to get one of my better cameras set up at the shop for a bit better resolution.
The APR wing should be here in about a week. I'm going to look at stiffening the sides of my spare trunk lid where it mounts to prevent buckling and R+D some sort of solid (hard rubber) blocking for the rain gutter to transfer the load to the body/chassis better.
....So...here we go! The photos are in the gallery if they don't make it to the page.

[BreezyRacer]

Love the song reference! And I will be awaiting postings on your project too.

[millsj]

Interesting thought about making the front center portion removable.  I never thought about that approach.  That would probably be a lot easier than having to remove the entire splitter.  Installation and removal of the splitter is not a 10 minute process for me.  I can probably get it off in 10 minutes, but it takes longer to install.  It's also MUCH easier when the car is on jack stands with the tires removed.  The removal of the tires aids in installation of the arches that cover the portion of the tires that stick out beyond the fender.  

Just thinking out loud if you wanted the front portion removable....you could probably cut the splitter in half so that the front could be removed.  You could install two or three sections of tubing or pipe on the installed side and then have the next smaller size installed on the removable part.  When you go to install the front piece, you could slide the smaller tubing into the larger one and then have some sort of fasterner on the bottom of the splitter prevent it from separating.  I think the front air dam might be one of the complications of this approach.  

I think I read somewhere that someone made a splitter with a piano hinge in the middle so it would fold in half.  I haven't thought through this approach, but thought I would throw it out there.

I found that it wasn't too hard to make the splitter stiff front to back.  I did find it was hard to make the sides stiff since it is hard to find a mounting place near the sides of the car.  I mounted square tubing to help stiffen it up.  My only mounting points are at the washers just inside of the middle of the tubing (aluminum rod passing through the frame rain to the splitter), the turn buckles, and the PVC spacers near the rear of the splitter.  There really isn't anything toward the sides.  My dive planes and wheel covers also help support the sides.



Remember that you really don't want anything mounted to the bumper for incidents like your avatar.  

You may have already found this thread, but there are a number of pictures of my wing and splitter starting on this page.
http://www.mazda-speed.com/forum2/index.php/topic,25098.75.html

If you are swapping trunk lids, you will have to do something about the wiring.  I cut the factory wires (I hate doing this) and installed a (4) plug trailer light connector.  I installed the other end of the same connector on both my OEM and spare trunk lid.  It works great and I can also unplug the connector when I am working in the trunk area without killing my battery because of the tag light. Details are in the link above.

I be eagerly awaiting to see how you ultimately find a solution.    Meanwhile, I will continue to toil on the radiator ducting.  

I have tons of pictures of you want to know how I did anything specific.

[HELLIONMX5]

elk.jpeg in!

[joeereid]

Good news! I won't need a splitter! I just won a FREE EZ Lip that should take care of all my aero needs. All kidding aside...I filled out their online survey and actually won! Basically I squawked about the lack of any durometer specs and lack of a engineered profile drawing of their upgraded garage door bottom seal. We'll see what it looks like when it gets here. Who knows' I may actually be able to incorporate it into my design...of course I'll need to know it's PROFILE SPECS first.
 The trunk lid will be a one time swap. Wing goes on then the stock MSM lid goes on the shelf. I never "street" this car. The new lid came missing the license lights so I'll address that and I will be mounting an AfterBurner Rain/Brake light that I've had on the "mods" bench waiting for me to devise a mounting solution that didn't involve me drilling into my Black Mica lid. So the new lid solves that dilemma.
I'm impressed by your aluminum rod dropped thru the frame rail support idea and will probably be adopting that as a starting point.
 Once I slid the template under the car the "removable front" idea became a bit more difficult than I had envisioned it, (but that's what the cardboard is for, right?) as it clearly makes mounting the garden edging a real challenge. I have been toying with the "Receiver" type mount since you and Hyde started your splitters so it's still on the table.
  I think I'll make a rough cutout and hang it in place with zip-ties and see how high/low I can go and still get it out of the shop. The parking lot is like a "proving ground" for this project as it contains myriad road conditions, dips, wallows slopes, curbs etc.
  Support rods; FiveStar Bodies, hollow alum hex tube and rod end kit. I can swap the bolts for clevis pins for removal.

[millsj]

I thought about some sort of receiver type mount, but my concern was that it wouldn't be "break away" in the event of an off.  I have seen a couple attached this way and the mount looked too secure in my eyes.  I am sure it could be designed differently, but I haven't thought about how to do it. 

The rear attachment point is where the rear of the plastic under tray attaches.  With my design, these attachment points aren't really supporting much weight and really act more to hold everything in place.  If you look at your car, the undertray bolts screw into small tabs.  I was originally using metal bolts, but later switched to nylon bolts.  The problem with the metal bolts was that if you hit the front of the splitter against something solid, the metal tabs would bend.  I found this out when loading the car onto the car trailer.  I have homemade ramp extension with wooden "steps".  If I hit the splitter on one of the steps, it would push the splitter rearward just slightly, but bend the metal tabs.  The nylon bolts allow more movement.  I haven't had any issue and have been using them for the last year and a half or so.  The aluminum support rods and the turn buckles allow for a little movement with no issues. 

When I say movement, I don't mean that I can grab the splitter and wiggle it around.  It takes a good bit of force move it, but a car moving a .5 mph and jamming the splitter against an immovable object is enough to do it. 

['95MSM]

Hyde and I have discussed splitter mounting more than a few times. I would try to build a splitter so that the front can be raised. Whether this would require hinges or just a flexible mounting system is to be determined. You could suspend the front of the splitter with cables, and line the contact points between the splitter and any speed bumps, driveways, etc with Jabroc, delrin strips or some other similarly durable material that can scrape along the pavement without too much damage. Or make a support like Joe has, but design it to be able to collapse.

My race car may or may not have a similar system with support rods that set the angle of attack, but have a sliding portion so the front of the splitter can be raised. This violates the letter of the rules about movable aerodynamic devices, but the reality is that if I keep the car on track, the only time the splitter is raised is when I load the car into the trailer. If anyone ever complained, I could cut a spacer to the correct length and make the setup rigid for the track. The spacers would be removable in a few seconds, restoring the flex capability that is so useful when I load the car.

[joeereid]

After staring at the cardboard mock-up for a few days I still haven't had any epiphanies as to what exactly I'm going to do. Making it fold up at the front or making it easy to raise/lower is not so much a problem, it's how to make the airdam transition between the MSM bodywork and the splitter adapt to the position(s) of the splitter. I have it mocked up at@ 3.5" off the ground right now. Gonna calculate the flat tire angle and enter that into the equation as well.
 On another note, my APR wing showed up today so I can start looking at the trunk mounting situation.

[joeereid]

The splitter design is still rolling around in my brain. Got some good ideas from seeing a custom one piece GT3 nose that is based on the "receiver" technology at the track the other day. I discussed my project with the builder and we hashed out a few ideas that I will need to prove in cardboard before I proceed in earnest. I'm waiting on some telescoping aluminum tubing and some 2-part foam samples and I need to brush up on my Fiberglassing skills. The last time I work with it was 1974,so...
 While doing some research I stumbled across the fact that the inside of my rear bumper is basically a parachute so I thought I'd try and address that and hopefully eliminate some of the drag it may be causing. I took an old foam couch cushion and cut it up into "plugs" with an electric steak knife, and then sprayed them with Rubberized Undercoater. I made plugs for every void except the ones directly above the stock tiedowns, as that is where the trunk rain gutter drains. I made a paper template and was able to form them so that they are wedge-locked into place by the aluminum bumper, yet can be easily removed.

[HELLIONMX5]

There was a post on cr  from mt  that the best for rear bumper was
1. Diffuser
2. No bumper
3. Stock rear bumper
.4. Cut out

Some test were done, but I can't remember where the thread went.

The parachute effect you speak about is true up to a point. The test showed that it created a pocket of AiR there and didn't cause the parachute effect anymore because it stayed trapped in that area.

[joeereid]

There was a post on cr  from mt  that the best for rear bumper was
1. Diffuser
2. No bumper
3. Stock rear bumper
.4. Cut out

Some test were done, but I can't remember where the thread went.

The parachute effect you speak about is true up to a point. The test showed that it created a pocket of AiR there and didn't cause the parachute effect anymore because it stayed trapped in that area.

Good to know. I figured it couldn't hurt to plug it up. Shooting for #3 with #1 on the list

[HELLIONMX5]

you're welcome buddy. Good luck!

[joeereid]

Couch cushion segments installed. We'll see if the do anything. Back to the splitter..Looking into something along the lines of the GV Urethane front lip to merge between my splitter "plank" and the lower portion of the OEM bumper. Most of that stuff is for stock NB front ends but thinking about trimming it to fit.  Ebay has some cheap options for mockup purposes that I may experiment with. REV9 shows a NUE Front under diffuser that's specifically for the Mazdaspeed front end. Is this something new or has this been around for a while and/or has anybody seen one?

[millsj]

I still think the Home Depot hard plastic garden edging is a good option for the front air dam.  It's cheap, easy to form with a heat gun and easy to cut/trim.  I'm not sure the GV lip would get the splitter as low as you would want.  If you are driving to the track, you probably want it a little higher than my splitter (set at 3" off the ground), but even at 4", you will need a pretty sizable drop below the bumper. 

[joeereid]

I still think the Home Depot hard plastic garden edging is a good option for the front air dam.  It's cheap, easy to form with a heat gun and easy to cut/trim.  I'm not sure the GV lip would get the splitter as low as you would want.  If you are driving to the track, you probably want it a little higher than my splitter (set at 3" off the ground), but even at 4", you will need a pretty sizable drop below the bumper. 

Agreed. Been toying with some HD edging. Problem is the vertical "fence" required to attach the edging to the splitter is complicating the "removable/receiver" type design I am contemplating. Trying to come up with some sort of air dam that would remain on the car while the splitter planes are removed. True, probably not enough vertical drop, but if it matched the lower contour of the bumper I could morph something to it that would reach the splitter. Just another idea I'm tossing at the wall to see if it sticks. More and more it looks like I'll messing with some 2-part foam and making my own piece if I go the "receiver" route.