Ditch the Splash Guards?

[RH77]

First question -- I recall a thread at some point in time, that credited the front flaps for redirecting airflow around the rear wheel. Is there something to this?

The rear ones, I assume, are parachutes...

The car is rarely clean anymore, and I don't drive in gravel but maybe once or twice a year -- so the intended purpose is no longer an issue.

RH77

[Otto]

Rather than ditching the splash guards, why not re-shape them to act as fairings and splash guards all in one?

[RH77]

Originally Posted by Otto

Rather than ditching the splash guards, why not re-shape them to act as fairings and splash guards all in one?

Aero is my weak area, so bear with me here

The 2 left images are of the front flap, and the 3 is a shot of the rear. What do you recommend as far a fairing?

Last question -- if you look at the bottom of the bumper, theres a false indentation that looks like it's hollow. It appears to be molded into the bumper. If this was opened-up, would air exit more efficiently (I guess the license plate would need angled as well.

RH77

(I had the camera out for another project, so...)

[Daox]

To answer the bumper question, as of now (no bellypan), filling in the indentation would do nothing for you.

[Otto]

You could use those flaps as partial templates for one end of an elongated teardrop-shape fairing. It could be carved from styrofoam, as is used in house insulation and sold at Home Depot, etc.. Or, you could ditch the mudflaps and just use the attach points for fairings.

Look at the rear wheel fairings on a Prius, as a guide.

As for the rear bumper cover, does it act like a parachute and scoop up air that is trying to escape from under the car? See various posts and pictures of Coroplast undertrays.

[Otto]

Originally Posted by Daox

To answer the bumper question, as of now (no bellypan), filling in the indentation would do nothing for you.

Seems to me, the main priority should be the nose and wheels. By the time the airflow gets to the rear, it's so buggered that improvements would be marginal.

[RH77]

Good info...

Cutting out or filling that rear portion would be a permanent cut into the bumper, so good to know.

I'll take a look at the Prius for inspiration.

Aero effects really hit a harsh reality lately with strong winds. I may get bolder with trying new aero treatments (currently not a whole lot going on in that department).

RH77

[Otto]

Originally Posted by RH77

Good info...

Cutting out or filling that rear portion would be a permanent cut into the bumper, so good to know.

I'll take a look at the Prius for inspiration.

Aero effects really hit a harsh reality lately with strong winds. I may get bolder with trying new aero treatments (currently not a whole lot going on in that department).

RH77

Various posts here, such as those by Fabrio, offer good insight. Also, a visit to a Honda or Toyota dealer to see their latest stuff should help.

[RH77]

Originally Posted by Otto

Various posts here, such as those by Fabrio, offer good insight. Also, a visit to a Honda or Toyota dealer to see their latest stuff should help.

Funny you should mention! I was just out in the garage looking over (and under) the TSX, so I started investigating something...

Prius Cd: 0.26
TSX Cd: 0.27

The pics at the bottom show the treatments that are (somewhat) easily visible (sorry for the poor quality -- lighting and space is minimal -- raining outside).

The rear diffuser, rear spat, front spat, and ~1" chin spoiler (Not shown: partial undertray, flared fairings, and miscellaneous underbody pans).

On Teggy, I may start with an small undertray and carefully placed spats. Up front, I really need to figure out a grille block.

Are spats difficult to measure and place? I have plenty of black, scrap plastic to make them...

RH77

[RH77]

So last night I started tinkering with the aero challenges on this car...

I pulled the splash guards and saved them for future use.

Issue: The rear guards were part of the wheel well. Now I have a big hole in the rear 1/3 of the well.

Could this be beneficial to relieve pressure in this area, or could the air get stuck under the rear of the car and create additional drag?

RH77