FD airflow
 

Interesting article.

http://autospeed.drive.com.au/cms/A_1080/article.html

Another one...
 

the first is an excellent aero article.

thanks for the link.

as someone who is proud to deliberately run the stock 93 nose w the R1 splitter and no rear spoiler i am delighted w the low drag numbers on my car and the job mazda did to get there.

perhaps mazda concluded on later models that they needed more air into the engine package (given the meltdown-prone OEM turbo package) but the aero guys at mazda that worked so hard at giving the car a small low drag frontal area must have been greatly disappointed.

perhaps the new nose came from the gold chain marketing crowd. whatever. it and 99% of the aftermarket abominations give an originally slick aero car the drag of a hummer.

i can tell you that w my setup i can run thru turn one at Brainerd at 170+ mph and the car is steady as if it were cruising at 70.

howard coleman

Terrific -thanks!

I would like to see wool tuft tests on different body kits. I think for the most part alot of them would fail hard. Anyone know what kind of rims that rx7 has? Been looking for some like those.

Nice info

That leads me to wonder what "aero" kits there are for the FD. Which ones have spent time in the wind tunnel.

And why the heck is that aussie making 400hp out of a t04 and a stock intercooler!?

because he is running 21 pounds of boost!

From looking at the C-West website, one of their kits was developed in the wind tunnel.

RE: the second article

a stock intercooler eh?

There are only a handful of bodykits that are wind tunnel tested.

C-West
AutoExe
Mazdaspeed

does anyone know what CWest kits have been tested, and what the results were? I'm pretty set on the N1 bumper, but am now in the air, pending the answer to this question.

thanks, good info

ryan

considering wind tunnel expense i would be highly skeptical of any claimed tunnel time.

Aero Resistance is a combination of frontal area times drag coefficient.

do you see any "aero" (joke) kits on the market w less frontal area than the stock 93-93 FD?

hey, if they look good to you bolt them on but don't rationalise them on an engineering basis.

howard coleman

the test was versus the 99 front end which is much much dragier than the 93-95.

btw, i don't dispute you'll get lots more downforce w most of the kits. downforce costs lots of drag however and i would rather not make that tradeoff.

i do stand corrected as to C-west. thnx for the link.

howard coleman

This can't be overstated and I couldn't of said it better myself.

The test was vs pre 99 spec. Look at the picture carefully - you'll see that the turn signal indicators are not 99 spec ones.

There is also an R1 lip.

Too cool! I've always liked my base model's lines, and this just reinforces how GREAT that design was. Er, IS....lol!
A .29 coefficient of drag is phenomenal.

Thanks for the article!

In the second article the guy is running a 21lb through a stock intercooler and expects to turn 10s.

LOL talk about doing it the hard way.

Cool articles. I read all five installments.

I need to find/fabricate a spoiler for the top of my Mercedes wagon . . .

:-) neil

https://us1.webpublications.com.au/s...1/1110_9lo.jpg

whats with those red tail lights? is the 92 s6 different? the whole rear bumper seems to be different on that car.

Yes, rear bumpers have a wider area to put the license plate on than the USDM FD's

I believe those are rear "fog" lights

Great articles! Thanks Chris!

The '99 front is "dragier", but it's also "coolier" too, and I believe that was one of Mazda's stated reasons for the design. The openings (particularly the oil coolers) are MUCH bigger to aid in cooling. You'd make the 93/95 even slipperier by closing up the openings (the way they tape off the rad. grill on winston cup cars or use smaller brake ducts in F1), but not without cost.

The thing is too, "more drag" in a different front-end design, or even "more downforce" doesn't mean efficiency relative to slipperierness. You might be getting 5% more downforce for 20% more drag. A bad trade-off. At least with the '99 or the C-West, they've run it through a tunnel and (at least w/ Mazda R&D) probably didn't allow such a tradeoff to happen... they'd have refined it to better match the gain/loss.

nice info, learned something today, thanks

a good read

That rear bumper came on cars designated to Europe.

Great info. Thanks for posting.

Anyone who doubts the Gen 3s rear end tendency to "lift" at high speed only needs to view the video of Racing Beat's first attempt at the land speed record back in the early 90s with their White FD. It definitely lifts from the rear (at 230 mph), and Big Jim was fortunate to walk away from the incident. Their later "Back in Black" FD sported a Porsche-like duck tail on the back which cured the lift problem all the way to 242 mph. :)

I would love to see the differences between pre and post 99 Spec design. Has anyone published these numbers or done tests to compare them? I would like to see what the trade off really is.

Although you should keep in mind that aerodynamic effects on the flats are much different than a raceway - the entrained sand dust actually makes the air more viscous and dense in nature than clean air.

So the forces on the cars at bonneville don't align perfectly with normal aero designs.

Dave

I doubt the 93/95 numbers were done with a liscense plate, so it probably won't look good, since you can't remove it from the OE '99 bumper.

I don't beleive '99+, C-West or any other model would give as much downfoce as Knightsports V. My second favorite is Damd with the adjustable aluminum center flap.

Nice article. Also, not really related but the 87-88 sport package equipped FCs also posted a drag coefficient of .29 , so the FD isnt all that special ;)

That is a great article. I've seen a few of Autospeed's other wool tuft articles, but those cars (Subarus and Skylines) had pretty poor aero, with tons of separation at the rear windows.



Drag coefficient is only part of the equation, my friends. Frontal Area is just as important.


Total drag = Coefficient of Drag * Frontal Area * 0.5 * Air density * (Velocity)^2
(see http://www.grc.nasa.gov/WWW/K-12/airplane/drageq.html for more info)

A Cd of 0.29 isn't uncommon for modern cars (which have been designed with the help of computer aero simulation tools), but most of them have a much greater Frontal Area than the 3rd Gen. I'm not sure about the FCs: they're a bit taller, but not quite as wide.

-s-

Yep, that's why one of the major car magazines (C&D?) has turned to publishing the Coefficient of drag * Frontal Area instead of just the drag coefficient.

Dave