I have a pic under heavy braking going down a hill. I will see how high it is. My splitter sticks out from the bumper about 3". I don't know what spring rates I have. The coil overs are a cheap set of street b.c coil overs (gold) with whatever spring rates they come with. I payed $600 for them 2nd hand.

lol @ using a craftsman deep socket as a measurement unit.

-Ryan

Car one is the far superior design. The easiest way to think of aero for me is to imagine the particular part your building being placed in running water ie like a creek. Now your job is to channel that water so it has the least resistance. I know that sounds silly but others have to have their brain wired like mine :) lol

Superior for what? The second design will likely create more downforce as it looks to have a greater surface area for the splitter. If that is your goal.

Well car 1's design is similar to Crusher. Too bad that car is really slow and never wins any races.

Rear main fail:
https://www.miataturbo.net/attachmen...ine=1350319223

Car one with the apocalypseTM front end has a more effect means of evacuating the air above the splitter, has less drag, and creates less turbulent air for heat exchangers and brake ducting. Both designs have been tested here in Texas up to 150ish mph. Design one on the same car with no other changes has to run a lot smaller splitter to keep the balance the same. The goal is really to create negative lift on the front end which translates to more downforce, the stock miata bumper is a great design on the top 4" ;)

Here is version 1 that we built in the winter of 2010 for JohnZ's car (spoolin2bars)
http://www.speedhunters.com/2011/03/...w_track_miata/

JohnR, ZXTEX car one, took it forward and used a better material and covered the front tires better with out canards. I have several improvments in my head but need a fresh junk bumper and some free time. Spoolin also needs more rear aero before we improve on the front design. Look how small the splitters are on both the straight down designs, they are more effective period.

I agree with you mostly. I think it would be interesting to quantify the differences via CFD.

Look at spoolin2bars birch splitter we made in the post below, it was like a 6" splitter. No other changes but added the apocalypse front end and the splitter had to be trimmed down to 2" to keep the balance the same. I believe ZXTEX had the same experience as us on splitter length once you go to the flat front end.

https://www.miataturbo.net/race-prep...r-52759/page4/

I also believe spoolin picked up some mph on several straight's here on local tracks.

I'd like to see what a large front splitter with a flat front air dam would do. Judging from your experience and others you've referenced it would unnecessarily shift the aero balance forward.

There is some interesting stuff in that thread. Like the structural adhesive tape idea.

I'll be running a front air dam and splitter but I'll be going topless. What is the best way to balance out the effects of the front splitter to get rear downforce ? The car will be PT/IT/TT

Depends what your goals are. Personally I think air dams and/or splitters should be used to correct aerodynamic balance after adjusting or changing a rear wing (assuming a diffuser that works is already on the vehicle). The correcting of aerodynamic balance will also add downforce. Also, a decrease in drag can usually be gained by the addition of either a splitter or air dam.

I have simulated both of these types of setups in cfd. If interested, check it out.

https://dl.dropbox.com/u/105015076/a...ata_122612.pdf

Thanks for the response. I definitely need the front down force. I am running with NO hartop and I need a little help figuring the location of the rear wing to help balance out the front. With no top your model is not effective.I don't need to be spinning,chasing my tail due to lack of rear down force. Miatas need all the downforce they can get.

With no top, the air over the car is a swirling chaotic mess. It's a huge oversimplification, but your wing needs to be as high in the air as possible to have a chance at getting some clear air to cut. Fastback>hardtop>open top for aero.

From what I've heard, on the spoiler cars make more rear downforce running a tonneau cover compared to just a straight open top.

I've been told the hardtop is worth 5 mph at 120 ??? dunno but I need the head space and the roll cage will not fit under the hardtop. I can go 6" ( maybe 8" ) above the front windshield height. I'm just looking for any help you guys might have to offer. Thanks

Thought this deserved a spot in this thread

I really like how he did those front fenders. Is there any more info on them in particular?

What materials are people using for flat underbody's?

Im about to put a front end on an NA the same as the blue car with the big Hoosier sticker, and I have a diffuser to put on the back, I was considering just riveting aluminium angle to the pinch welds and screwing an alumalite panel to it with perhaps a few alluminium angle's running across it for stiffness, and of course the whole exhaust will need to be wrapped.

Is there a foolproof option that wont melt? 1/4 birch seems heavy for an entire undertray.

Dann