What's the best way to add downforce to a stockbody FD? Or is there any kits that offer close-to-stock looks?

I'm looking to generate more downforce front, back and sides.

Pics of kits/wings/wingmirrors/anything appreciated

 

rear diffuser?... 99 spec front lip, front diffuser.....

 

check the pics thread for pics . . .

i agree with post #2

 

I think you'd have to fab up a completely flat floor under the body that flow into a rear diffuser.



Also the 99 spec front bumper with 99 lip, and the 99 rear wing have been proven to be more aerodynamic than the original 93+ bumpers

 

yeah, y'know...
get some like... stuff,..
and like, maybe a hammer or something...
n',.. y'know...
fab that **** right up in your garage.

lol...

 

I would think that a setup such as the Enzo... would be risky on an FD. Enzo is a mid engine platform (i believe) and as such, the exhaust is very short. An FD with a full tray would have to figure out how to get the excess heat from the exhaust out of there efficiently. Aww screw it.... Just go side exhaust and flatten that (under)bitch out.

 

There's a lot of legitimate looking cars that use rear diffusers. Are they only effective if the entire bottom of the car is flat?

Also looking to generate more downforce than stock

Maybe steal the viper ACR fins?

 

As far as I'm aware, the MazdaSpeed Rear diffuser and front undertray with the 99 spec front end have a proved effect on downforce. I'm running the above combo on mine, and on the occasions where I've temporarily removed the underbody gubbins, the car certainly feels a lot less stable at higher speed without them

 

that ferrari crap is worthless on an FD, front-engine RWD vehicles use the drive train tunnel to evacuate the air forced through the radiator and engine bay. rear diffuser works just fine and adds over9000 cool points.

 

the 99 spec helps downforce. http://www.rx7.net.nz/newrx7.htm

they actually list the downforce/lift about halfway down, it does not give a speed though.

you also will notice please that the bigger the angle of the wing, the more downforce it has on the rear, but the more lift it gets on the front!

 

Also keep in mind that for the most part, downforce does not come free. The more downforce you generate, the more drag you create.

 

well, the main function of a full underbody splitter setup is to maximize the air flow velocity hence decreasing the pressure under the car. As a result of lower pressure under the car, you will be getting more downforce.

Back to OP's topic, if you want to keep your stock body look and increase some downforce, the best you can do is change the front bumper and get a good front splitter and add a small wing, such as the 99 spec or Mazdaspeed (aka Racing Beat Type II). If you want to stick with stock front bumper setup, just add a Mazdaspeed front lip or the 99 spec lip. For the side, you can add some skirts. The main purpose of adding side skirts is not hoping the pieces will generate much extra downforce directly, they are there to minimize the gap between the car and the ground to limit the amount of high air from flowing into the underbody. For the rear, a diffuser would be a good addition as well since it again increases the air flow.

BTW, you can also add some canards on the front bumper if you are aiming at tracks with more corners than long straight. Canards tend to generate lots of vortices on the side of the car hence giving you more drag so a bad choice for high speed tracks.

Hope this helps!

 

I'd like to start by saying I am in no way an aerodynamicist, but there have been many FR cars that have utilized a flat or semi-flat underbody to decrease lift and turbulence under the car's body. The FR cars typically need to vent heat either through the hood or through the underbody panels to keep things cool, and sometimes the will leave the area open that the exhaust travels down, but it is definitely a feasible idea. However it will take a well designed panel set to increase downforce. Most do this with a slight rake in the car's body front to back (as well as a raised area in the rear diffuser similar to the old school re-amemiya diffuser) to help create a low pressure area towards the rear of the car, sucking it to the ground. Here is a picture of the Ferrari 550, an FR V12 platform, where you can see the vented area under the engine and the open tunnel for the exhaust:

 

That looks like it could work for an FD... well, the design style. A small lip just in front of the opening below the engine would help the engine bay evacuate hot air if my memory serves me correctly.

 

Doesn't the stock R1 wing help on down force?

 

...............

 

^ no just looks if anything

 

http://www.youtube.com/watch?v=u6_MUycoPPs

hope that helps

 

Yes, the stock R1 wing and lip combined provde quite a bit of downforce. It's been tested and proven in wind tunnels and on roads.

I've always wanted to do a full underbody diffuser on the FD...I'm just waiting for someone who knows more than I do to create one

 

Actually they don't. The lip may help marginally but the wing only create more drag but does nothing to produce downforce, its purely aesthetic.

 

I've driven my R1 and a good friend's touring (no lip or wing) back to back on long stretches of Texas highway, and his car felt VERY light over about 140mph, so much so that I backed out of it. My stock body R1 felt rock solid at 170mph.

 

Most of the front engine / rear drive STREET cars I've seen can't make use of a flat underbody where the exhaust and mechanicals are covered up. Not a problem on a race car where you can get around the challenges of heat management through clever building/engineering.

For street driving, I have never needed more downforce. Can't say I ever needed it on track either on my mildly prepared street car.

 

Sorry, I mistook CoD for Downforce when I made that post, but I would trust Goodfella's word on this over anyone elses short of howard colman's, but I'm pretty sure coleman agrees with Rich on this one.

 

R1 wing mounts too low to be in the effective region so it cant get enough air flow pressure. It might give you slightly more downforce but not significant enough to really help. Since its fairly thin so the drag it creates is also small due to the same reason, the wing is not in a clean air flow zone.

 

Kevin, it would me sweet if you worked up an underbody aero for your GTC kit...

Hm??!!