54 replies to this topic

[davecarama]

I found a pretty cool thread on Britishspeed about a splitter fabrication for the Lotus 211.
Here: http://www.britishsp...-Splitter/page5

It looks pretty cool to me, and since I will be driving in ITA, I think it is something I think I could do to my Miata. I am sure some of you have made a splitter for your Miata (90-97)?
What materials are being used? (looks like metal is not aloud (or is it). I have seen ABS plastic, carbon fiber, and now ply wood)
How are you all mounting these to your bumpers?

I assume a wood piece would be pretty thin, would it be worth the weight to install one of these? Would it throw off the balance of the car or make it that much more planted.

8. Body/Structure

a. Fenders and wheel openings shall remain unmodified. It is permitted to roll under or flatten any interior lip on the wheel opening for tire clearance. Cars with plastic/composite fenders may remove any interior wheel opening lip, but the resulting material edge shall be no thinner than the basic fender material thickness. Non-metallic inner fender liners may be removed.

b. A front spoiler/air dam is permitted. It shall not protrude beyond the overall outline of the body when viewed from above perpendicular to the ground, or aft of the forward most part of the front fender opening. This body outline does not include bumpers or bumper mounts. The spoiler/air dam shall be mounted to the body, and may extend no higher than four (4) inches above the horizontal centerline of the front wheel hubs. It shall not cover the normal grille opening(s) at the front of the car. Openings are permitted for the purposes of ducting air to the brakes, cooler, and radiator. Dealer installed or limited production front/rear spoilers/air dams/wings are prohibited. The spoiler shall have no support or reinforcement extending aft of the forward most part of the front fender wheel opening.

NOTE: Integrated bumper assemblies are defined as those designs where an external non-metallic bumper cover completely encloses the primary energy-absorbing bumper and where this cover could be installed in its normal position with the underlying bumper removed. On cars with integrated bumpers, the front spoiler or airdam may be attached to the bumper cover.

Where an air dam/spoiler is used, two total openings may be cut in the front valance to allow the passage of up to a three (3) inch diameter duct leading to each front brake/rotor assembly.

Where no air dam/spoiler is used, two total openings of a maximum size five (5) inches by seven (7) inches maybe cut in the front valance so that brake ducts can be added with a three (3) inch diameter hose leading to each front brake/rotor assembly.

[red986s]

I've thought about it (splitter) but came to the conclusion that it wouldn't help my car. I get excellent grip up front. It's the light rear that could use some downforce. Not sure but wouldn't a front splitter alone unbalance the car?

[davecarama]

Not sure! I know that the front lip spoiler made the car feel more stable in highway conditions (was "floaty" without it). I also know some of the front runners in ITA in the WDC region are using them.

I guess the only way to know for sure how it will work for me is to build one and try it.

I have a hunch that an understeering car may become neutral or oversteer... But what do I know

[davecarama]

I am also not talking a huge splitter, it can't go past the front nose of the car, so it looks like it would only be about 3"

[pitbull113]

dave, this has been discussed at improvedtouring.com. i think you'll find more IT info there.

[davecarama]

dave, this has been discussed at improvedtouring.com. i think you'll find more IT info there.

Any search tips? I am not coming up with anything.

[red986s]

I guess the only way to know for sure how it will work for me is to build one and try it.

True! Go for it!

[pitbull113]

front spoiler or spoiler gave the most returns. i recommend signing up and starting a thread there as well.there is a wealth of knowledge there and the IT guys are always willing to help. andy bettencourt posts here sometimes and if he see's this thread he'll probably respond he has some of the fastest ITA miata's out there and has always been willing to help. i know you're considering building your own spoiler but check out ISC's website, mike has a nice front spoiler for the NA miata that's recieved some good reviews.good luck

[davecarama]

Here is the ISC link:
http://www.iscracing...fiberglass.html

Dunno if I am into having anything fiberglass on my car right now... I had an Elise and that stuff breaks!

It sounds like he used Aluminum under his "flat" version. Couldn't I extend that metal piece out a little to make my splitter? Aluminum would be lighter and just as strong if not stronger.

I'll have to come up with something. I'll test it out with and without in the same weekend.

I'll keep looking and post more...

I prefer to NOT have to put links to other forums (and I am sure the mods to do). If I find some good stuff, I will though. I'll try to add as much I can here. This place needs good content!

Dave

[davecarama]

Back to plywood. I was told by the Lotus guys that they used a 9mm plywood (which is about 1/4"). I think you can get a 4'x8' board for between $9 and $19. That might make 2 splitters!!

The board mentioned above would weigh about 19#, so the spoiler would be closer to 10# once cut.

I think the major concern is that it would delaminate if you didn't use the right stuff... OK, back to researching...

[pitbull113]

my concern with having a strong splitter is if i get into something instead of the splitter breaking i start crushing fenders and nose pieces.

[Keith Novak]

Don't make it too weak. I saw one made out of plywood that over 60mph started going WHACK WHACK WHACK WHACK WHACK WHACK WHACK!!! on the ground until it flew apart. Funny to watch but dangerous, especially to drive behind. There are different grades of plywood too, and the $9 a sheet stuff isn't something I'd suggest.

[trey]

Here's a good thread from miata.net

http://forum.miata.n...ad.php?t=402663

If STL gets going , we'll be able to balance the aero ... Check out what 949 racing has going on with their SuperMiata Series aero

[Tyler Raatz]

I ran the 1st half of last season with a splitter and fought handling woes the entire time. In fast sweepers the car was wicked loose, adjust out the high speed loose and the car would not turn at low speeds when the splitter was not making downforce. I removed the splitter and was able to balance the car in 2 sessions of a test day and never looked back.

STL will be a different story, I am going back to a splitter and undertray to balance the downforce from the rear wing. I do not expect the same results with the STL car as we had in the ITA car.

Regaurding materials, Plywood is for construction!
Try polymetal. 4-5mm thick, polymer laminated between 2 thin aluminum sheets. Its cheap and easy to work with, lighter and stiffer when properly mounted.

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[red986s]

Back to plywood. I was told by the Lotus guys that they used a 9mm plywood (which is about 1/4"). I think you can get a 4'x8' board for between $9 and $19. That might make 2 splitters!!

The board mentioned above would weigh about 19#, so the spoiler would be closer to 10# once cut.

Dave that's what I used when I was still playing with C Sports Racers. Super cheap, super easy to produce.





This one actually caused the car to porpoise really bad. I ended up cutting it down to 1.5" off the fiberglass. Like others have mentioned, one good smack against a gator and it's gone. I also experimented with Alumalite type materials. I recommend those over wood.

[davecarama]

Regaurding materials, Plywood is for construction!
Try polymetal. 4-5mm thick, polymer laminated between 2 thin aluminum sheets. Its cheap and easy to work with, lighter and stiffer when properly mounted.

Where can one get Polymetal and how much does it cost?

[davecarama]

This one actually caused the car to porpoise really bad. I ended up cutting it down to 1.5" off the fiberglass. I also experimented with Alumalite type material.

Is alumalite like Lexan? I thought that would be too fragile...

[pitbull113]

Here's a good thread from miata.net

http://forum.miata.n...ad.php?t=402663

If STL gets going , we'll be able to balance the aero ... Check out what 949 racing has going on with their SuperMiata Series aero

this is the thread i was thinking of earlier.no wonder i couldn't find it on it dot com it was on miata dot net doh!!

[Tyler Raatz]

Where can one get Polymetal and how much does it cost?

Available from any sign equipment shop, google "polymetal" and you should get a few hits. I think I pay about $50/sheet.
I can make 3 ITA splitters (undertray stops at wheel opening) or 2 STL splitters (undertray stops at wheel centerline)
per sheet.

[davecarama]

Here's a good thread from miata.net

http://forum.miata.n...ad.php?t=402663

If STL gets going , we'll be able to balance the aero ... Check out what 949 racing has going on with their SuperMiata Series aero

Yup, the RP performance car is why I was considering the spoiler. He beats all track records when he drives that car... which is for sale I hear...