cjsafski

iTrader: (2)

Started working on my splitter and airdam today. The design is similar to the one I helped Sonny build on his msm except this one is completly suspended by cables. I found that if I ran a cable from far back all the way to the front of the bumper, (3rd pic) it pretty much eliminates any rotation of the splitter. It is pretty stable, supports my weight and quick to remove. Also I left a gap between the bottom of the airdam and the splitter which is filled by the garden edging. Still need to clean up the cut but the benifit is this allows it to flex upward a decent amount.









I still need to finalize the design of the splitter. Part of that depends on if I can get all this stuff to play nice.

ThePass

iTrader: (3)

Dat last pic.

Dunning Kruger Affect

That's pretty amazing.

jpreston

iTrader: (4)

Where did you find that plastic garden edging? That's exactly what I want, but I've tried every garden/home improvement store around here and can't find it. If you still have the packaging and a brand/part number that I could google/Amazon search, that would be awesome.

emilio700

iTrader: (3)

Chris's EP dam and splitter are pretty much standard issue around here. Each guy on the team that has a car, and John building mine, have all contributed to it's evolution. Garden edging from Home Depot Motorsports, as are the cables, buckles, hardware, birch ply. If making a splitter, 15/32's to withstand downforce. If it's just an undertray we use the stuff closer to 3/8". Above about 130mph, even the undertray generates significant downforce when it's countersunk behind the air dam so you can't use the super thin plywood without it getting sucked down and scraping.

cjsafski

iTrader: (2)

For the garden edging look in the garden section at home depot. The stuff you want is not kept with the main grouping of lawn edging for some stupid reason. It is usually hidden somewhere near the bricks. There are two different versions I have seen there. One is like what I have and the other has bits connecting the base that you need to cut before you can bend it.

Supe

Yes, it's often referred to as paver edging. I haven't found it at Lowes, but have at HD.

M.Adamovits

THANK YOU FOR THIS. Seached thru pages and pages of garden edge and found nothing that would work.

So many options once you know what it's called.

Supe

No problem. I feel your pain, it wasn't until I came across it accidentally while looking at pavers that I knew what to look for! The only thing that sucked was that the one with the "links" you have to clip off is pretty robust - a PITA to bend, needs to be trimmed for fairly tight radiuses, and is way heavier than it needs to be.

mr_hyde

iTrader: (4)

This stuff is about to allude me for the third winter in a row. I have seen it in stock over the summer but I haven't been in car building mode at the time so I have skipped it. During winter tear-down and development, I go looking for it and flame out. Oh well. It should be back on the shelves by the beginning of march which will be plenty of time to make the early events up here and MRLS.

jpreston

iTrader: (4)

I tried my home depot and lowes and struck out too. I'm tempted to try and find time to run by a home depot while I'm in cali for the 25hr... if I find it in stock for cheap, I'm shipping some home to myself lol. Now that I know it's called "paver edging", it looks like it's pretty readily available online though.

Dimex E-Z Connect 16 ft. Multipurpose No Dig Lawn Edging and Landscape Border Project Kit in Black-1504BK-16C at The Home Depot

cjsafski

iTrader: (2)

Been working on trying to get my simulation to work right. So far I got the program to calculate the coefficient of drag to be .34 (actual .38). However, Autodesk Falcon is not consistent in its results. Either it gives a reasonable value near .34 or something ridiculous with successive trials. As such I have very little confidence in any results. I guess that is what I get for using freeware. The computer in my laboratory has Comsol on it which can do the calculation. Just need to find a time when it is not being used for micromagnetic simulations.

Leafy

iTrader: (1)

If that graphic is showing your actual trial resolution you're multiple orders of magnitude too coarse. I found, even just doing the wing in 3d, if it took less than an hour to simulate it would give weird results, that was in cosmos. I would think the whole car ought to take a couple hours unless you're running on some serious hardware.

cjsafski

iTrader: (2)

The resolution is much higher than those vectors when you plot with different methods. Usually the scans take a few hours to get a decent value or I just leave it going overnight.

circuitmstr74

iTrader: (1)

does anyone have more detailed pictures on how they mounted their APR Gt-250?
getting mine as a christmas present lol

circuitmstr74

iTrader: (1)

maybe not so soon, as I was just informed that these are no longer available from 949. Looks like I would need to order a custom wind from apr, or explore another option. Any ideas on an optimal yet practical 2d wing for a low hp PT/TT car?

Lincoln Logs

iTrader: (1)

I think the general consensus for practical(affordable) 2D wing is still the COT from eBay.

emilio700

iTrader: (3)

Affordable, but not an ideal foil profile. The COT wing profile is optimized for speeds a Miata won't achieve unless it's dropped from the stratosphere. I understand the Ciro Design foil is basically the same as the GT250. I might be wrong there.

jpreston

iTrader: (4)

Brooks Motorsports has some nice looking wings and seem pretty open to custom stuff. Last time I saw one of their wings was a few years ago before the company changed hands, and it was a little rough around the edges but overall pretty nice. The only real complaint I had was a very rough leading edge from the mold parting line, and they've supposedly changed the molds to eliminate that. I don't know anything about the foil profiles they're using, though.

Lincoln Logs

iTrader: (1)

I don't disagree on the optimization, any reason you're stopping production on the GT-250s?

I saw a Brooks wing on a friend's car recently and the leading edge was fairly rough as well.