After seeing pictures of the GK's undercarriage from Jimmy's thread here: https://www.fitfreak.net/forums/3rd-...aka-fitty.html





It got me thinking about the possibility of retrofitting it to other Fits.

The part number is 74641-T5R-A00
74641-T5R-A00 | Honda COVER, FR. FLOOR (LOWER) - Bernardi Parts

#20 in diagram


Don't have the funds to spend $265.93 plus oversized shipping on it so the search to eBay and Craigslist I go for someone parting out a GK.

This combined with the CRZ front underpanel
https://www.fitfreak.net/forums/2nd-...ed-my-fit.html
should improve airflow and increase MPG nicely.

Thoughts?

 

Would be worth a shot, not sure if you would honestly see any noticeable improvement in MPG though

 

Cool, go for it!

 

Underbody Panels and MPG Test

 

I saw that page. Very interesting, got me thinking of making underpanels and rear wheel well covers. I got the wheel covers figured out just don't want to spend the time and have it look totally stupid. Not sure on the panels though. Still looking into materials, engine bay ventilation and what to do about exhaust heat.

 

Start by managing the air before it becomes a problem, with a grille block and air dam. Quick, cheap and easy to make, and easy to keep from looking stupid:



Once you've cleaned up the overall shape and minimized the airflow underneath the car, you can worry about smoothing out what's left- including engine bay ventilation. I haven't had to modify mine yet to allow more airflow, but I'll probably have to pretty soon. As you can see, the stock airdam could use a little extending before underbody panels would be able to do their best.

 

I get the feeling the op is looking for the best of both worlds, speed/mpg. I was kinda thinking that myself. I have read about less drag on the bottom helping with cross breeze, aerodynamics and mpg. I began to mod wanting to get a sportier ride and noticed increase in mpg with a few mods. In my head if i can reduce drag while still keeping airflow to the intake/engine i get a bit of both. I also live where roads suck and snow can be deep but hard frozen & the under pannel would provide protection. If i was going strictly eco i would be out covering the grill right now.

 

The way you get less drag on the bottom is by reducing the amount of air that gets under there. Pop the hood and look at the big grille and how all if that air is channeled under the car. Smoothing out the flow can only help so much if you're using your front end as the intake to a big compressor. The biggest benefit is from reducing the amount of air in the first place.

A cleaner shape is higher performance whichever way your priorities lie. Is less drag a bad thing because it will also save gas?

 

so let the top grill feed the intake and radiator and block the bottom grill?
I can't go lower with the dam though, i already scrape a bit from time to time.

 

and no, I would never consider less drag or saving gas a bad thing....ever.

 

I had a speed run yesterday. Crappy traffic in the beginning, then highway for about 35 miles. I kept it over 65 except for the tolls, mainly keeping it between 70-75. Not much hypermiling gets done under those conditions, but I got 40 and change for the trip.

Aero mods are even more effective at higher speeds.