54 replies to this topic

[davecarama]

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.

Nice. That is the stuff I think I want. The ABS stuff is a bit spendy, the Plywood is a bit... Constructiony...

Sounds like I need to do a lot of testing if I put that much aero on the front. Me thinks the car will drive like the Lotus did... tail happy.

[davecarama]

This guy makes his own stuff:



Rob is a former RX7 guy (3rd gen):
http://robrobinette.com/

and he did a lot of testing... I'll see if I can get him to help me set my car up.

[red986s]

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

Alumalite is another sign board like others that have been mentioned. You can get it at any sign supply company. Comes in a bunch of different colors. This one is a plastic honeycomb sandwiched between Aluminum sheets. Cuts easily and is fairly tough.

http://www.laminator...ducts/alumalite

[Andy Bettencourt]

The cars are definiately faster with a spoiler/splitter. IMHO, the key is to get some air around those front tires. The car is not great aero-wise and in ITA, you are not running in large draft-packs. I have data to prove it.

When I went to a splitter, I went up in the front spring rate to compensate it it was perfect. Tweaking with rear bar settings and shocks will dial you back in.

[davecarama]

The cars are definiately faster with a spoiler/splitter. IMHO, the key is to get some air around those front tires. The car is not great aero-wise and in ITA, you are not running in large draft-packs. I have data to prove it.

When I went to a splitter, I went up in the front spring rate to compensate it it was perfect. Tweaking with rear bar settings and shocks will dial you back in.

Very cool! Yeah, what I am seeing in my research is that if I add a splitter, I will need to stiffen my spring rates, possibly re-valve my (now old and worn out) shocks, and set up the the car completely different. But then I am talking about completely re-learning the car, as it will behave VERY different!

This weekend, I am going with "same Old Car". My first race!

Dave

[Glenn]

Tyler, any updates on the STL car using a splitter along with the rear wing? Also which rear wing are you using. I purchased my STL car this weekend and cant wait to finish the build.

[Tyler Raatz]

Tyler, any updates on the STL car using a splitter along with the rear wing? Also which rear wing are you using. I purchased my STL car this weekend and cant wait to finish the build.

I built my own splitter with an integrated undertray back to the wheel centerline. The wing is the class spec SCCA APR GTC200. Using the same bar rates and front spring rates as my ITA car. Went up 30% on rear spring over the ITA car, with the front bar in the middle position and the rear bar on full stiff, the car is a little pushy at all speeds with the wing at 0deg. Knowing how loose the ITA car was with softer rear springs and a splitter only (no full undertray, no wing), it is quite evident how well the APR wing works! I am planning a larger splitter and better air management around the front tires before trying to go up on rear springs. I dont want to upset the balance too much knowing there is an additional 50whp sitting on the stand ready to drop in the car when needed.
I highly recommend the APR wing, it is a little spendy, but is a well known part that works, it was the spec wing for world challenge.

[trey]

I built my own splitter with an integrated undertray back to the wheel centerline. The wing is the class spec SCCA APR GTC200. Using the same bar rates and front spring rates as my ITA car. Went up 30% on rear spring over the ITA car, with the front bar in the middle position and the rear bar on full stiff, the car is a little pushy at all speeds with the wing at 0deg. Knowing how loose the ITA car was with softer rear springs and a splitter only (no full undertray, no wing), it is quite evident how well the APR wing works! I am planning a larger splitter and better air management around the front tires before trying to go up on rear springs. I dont want to upset the balance too much knowing there is an additional 50whp sitting on the stand ready to drop in the car when needed.
I highly recommend the APR wing, it is a little spendy, but is a well known part that works, it was the spec wing for world challenge.

Tyler , Any thoughts on how much lap times dropped via F & R Aero on the ITA motor ?

I'm considering converting my ITA car to STL Spec

So far in SW Division , we have had zero STL entries , but all the SM's stopped running ITA and are running STU ... I'm guessing that will change in 2012

[Tyler Raatz]

Tyler , Any thoughts on how much lap times dropped via F & R Aero on the ITA motor ?

I'm considering converting my ITA car to STL Spec

So far in SW Division , we have had zero STL entries , but all the SM's stopped running ITA and are running STU ... I'm guessing that will change in 2012

I built a new car for STL, so never ran it with an ITA motor. The motor that has been in the car all season is a bone stock 80k 99 with a header, intake, dual feed fuel rail and fuel pressure regulator, stock 97 ECU. This engine made a whopping 133.9/118.5 on Rossini's dynojet. It has been more than enough so far since there is zero competition in the sediv right now, a great reliable starter motor while developing the real STL engine/engine management system. With this setup, it is a 1-2 seconds faster than my ITA car on tight tracks/handeling tracks (CMP, Roebling), it is way slow at high HP tracks (road Atlanta), the aero slows the car a ton on long straights. I think it could be significantly faster if I was using the aero grip 100%, i'm just not there yet. The new motor should overcome the topend aero loss.

[Glenn]

Tyler, Im starting my STL Miata with a 1.6. If I can keep the weight down the 300# will be a huge advantage....I hope. I hope to run some in the SE next year CMP, VIR and Savannah, but mostly here in DC area. Bobby T will probably drive it some down south. Thanks for the info on the aero!

[trey]

With this setup, it is a 1-2 seconds faster than my ITA car on tight tracks/handeling tracks (CMP, Roebling), it is way slow at high HP tracks (road Atlanta), the aero slows the car a ton on long straights. I think it could be significantly faster if I was using the aero grip 100%, i'm just not there yet. The new motor should overcome the topend aero loss.

Thanks for the confirmation

My main tracks are TWS & MSRH ... I doubt the aero would do me much good until I build a motor.

[davecarama]

I am glad this thread came back to life, because I am thinking about it again...

Trackdog (TDR) makes one that I think looks interesting but it is actually the shape of the R-package spoiler and does not cover the section under the car up to the leading edge of the wheel well (better picture of the underneath in the installation PDF):




I spoke with Gary from TDR in an e-mail and he told me that:
"You could buy some ABS plastic from a plastic company hopefully near by and make you a second section. The air splitters are 3/16” thick, but I would suggest getting a sheet of 1/8” to make your addition."

I think I am going to get this one. It is $99 and at a minimum I can use it as a template to make a more aggressive one should I need it later on.
I did get the R-Package trunk lid spoiler recently, Dunno if it actually does anything, but I figure I'll try it out for now since that is all thats legal in ITA.

Dave

[Glenn]

I am glad this thread came back to life, because I am thinking about it again...

Trackdog (TDR) makes one that I think looks interesting but it is actually the shape of the R-package spoiler and does not cover the section under the car up to the leading edge of the wheel well (better picture of the underneath in the installation PDF):




I spoke with Gary from TDR in an e-mail and he told me that:
"You could buy some ABS plastic from a plastic company hopefully near by and make you a second section. The air splitters are 3/16” thick, but I would suggest getting a sheet of 1/8” to make your addition."

I think I am going to get this one. It is $99 and at a minimum I can use it as a template to make a more aggressive one should I need it later on.
I did get the R-Package trunk lid spoiler recently, Dunno if it actually does anything, but I figure I'll try it out for now since that is all thats legal in ITA.

Dave

Dave does Bret have a pattern that you/we could use to fab one? I would be nterested in working with you to develope a working splitter. My needs are for STL so mine would go all the way to the CL of the wheels. Come by the Meathead camp next race and we can meet and chat.

[davecarama]

Dave does Bret have a pattern that you/we could use to fab one? I would be nterested in working with you to develope a working splitter. My needs are for STL so mine would go all the way to the CL of the wheels. Come by the Meathead camp next race and we can meet and chat.

I know Bret has the carbon fiber ones they fabricated for Brian Price. His are NICE NICE NICE, but expensive from what I hear (in the $500 range). I'm not sure he would let me copy his pattern... I guess I could ask, but I bet he will look at me like I am crazy since I think he wants to sell these things. But he might let me, ya never know.

I sent a note to a plastics shop out here in MD for a source for ABS plastic sheets. I'd want to pick them up since the sheets would be rather large making shipping on the expensive side.

Unfortunately, I just heard last night from a friend that Brian used ABS plastic for his earlier versions of his splitter and shattered them pretty quickly, and that is why he moved on to Carbon Fiber... which from what I hear, he still damaged from time to time, but was able to fix it up with some glass repair skills.


Once I have an appropriate pattern, hell, I can use wood, aluminum, or anything.

I'd like to try something for the Labor Day weekend, but I doubt I'll have the loot or time to fidgit before then.

[red986s]

I did get the R-Package trunk lid spoiler recently, Dunno if it actually does anything, but I figure I'll try it out for now since that is all thats legal in ITA.

Dave

Huh? The R-package truck spoiler is legal in ITA?

[davecarama]

Huh? The R-package truck spoiler is legal in ITA?

That is what I have been told. I'll look it up now, but what would make it not legal? It is an OEM part.

Dave

[red986s]

That is what I have been told. I'll look it up now, but what would make it not legal? It is an OEM part.

Dave

Yeah, I'd research that. I think if your car came from the factory with an R-package you'd be okay. I was told that all R-packages were dealer installed. Like you I was "told" that. Not sure what's fact and what's fiction.

GCR 9.1.3.D.8.b. "Dealer installed or limited production front/rear spoilers/air dams/wings are prohibited."

Hope I'm wrong on that. Hopefully someone who has looked into this subject will chime in.

[davecarama]

I asked some people that I know have the trunk spoiler on their car how it is legal (because when I looked, I would have thought it is not)

The rule says: "Dealer installed or limited production front/rear spoilers/air dams/wings are prohibited." Pretty cut and dry right? That is what I thought too...

The R package cars were package options available from the manufacturer. An R package car was delivered with the Bilstein suspension, front and rear spoilers (and even a finishing panel at the bottom of the rear bumper). And even though they had limited numbers, it was not limited by the manufacturer, it was simply not a popular option package, so not many people purchased it.

So one could convert their car to an R package car and be legal by the GCR since it is an option level, not a single part add on... or that is how it was described to me.

I welcome any thoughts on that though (especially since I have not added mine yet)

1995 R Package
The R package was a $1500 option package and not a special model

Equipment: Sport Suspension (Bilstein shocks, heavy-duty rear springs, heavier sway bars), rear spoiler, front air dam, rear skirt, alloy wheels, Torsen limited slip differential The R package was not available with power steering, automatic transmission or Popular Equipment and Leather option packages
Optional: air conditioning, hardtop (dealer installed only)
Production: 465
Base MSRP: $19,000 plus $440 freight, plus options
Brochures: The R Package was described in the 1995 sales brochure
http://www.miata.net...dster 1995.html

1990 brochure: http://www.miata.net...1990/index.html

[davecarama]

They certainly didn't install bilstein shocks, torsen diff, and all the other stuff, remove PS, AC, etc... just to make a base car with no options an R package car to roll off the lot.

My understanding is that the manufacturer made them to order, and delivered the cars with the equipment (similar to the club sport 99+ cars that were available from Mazda Motorsports with Soft top delete and only a hard top, and no interior finishings). Now, if the parts were installed at the dealer on delivery, it is usually so they wouldn't get damaged in shipping (lots of companies do that) and I don't consider that a dealer installed part. That is more dealer prep on receipt than dealer install.

The harder sell for me is the NON-OEM trunk spoilers that you are seeing on cars now. The OEM part was discontinued in something like '99. That makes the OEM part more of a "holy grail" find. Other after market manufacturers are making a SIMILAR part, but usually they are larger and more functional than the puny OEM part. The GCR says you can use superseded parts... but what if the part is discontinued and the factory doesn't specify a replacement? I think it is only fair that people should be able to source like parts.

Hope that makes sense. Maybe SCCA will clarify that rule in future fast-tracks... maybe they will allow de-powered steering racks too... One can only dream

[davecarama]

Interesting...


There were no R-Package 1.6 cars. The rear trunk spoilers on 1.6 cars were a dealer installed accessory. So I guess that means any 1.6 built ITA car can't have the spoiler?

All years of the 1.8 cars (94-97) all had an R-Package Option level and there were 1841 total R-Package cars built and delivered. The front & rear spoilers were part of that option package. Those spoilers were also available as a dealer installed accessory.

http://www.miata.net...production.html

I guess that settles it?