Modify front bumper and cars body aerodynamics 1999 corolla

[Gasoline Fumes]

Originally Posted by freebeard

If you go for an air dam follow cowmeat's (IIRC) example:


A central jet down the underbody is beneficial (apparently) and is less likely to high-center on wallowed-out gravel roads.

edit, a full width splitter no deeper than the front bumper with upturned winglets for create air curtains might be worth considering. Something like the Honda example with the tire deflectors inverted.

That's my old Civic! Nothing was properly tested, but MPG kept going up. I have no idea if it was the mods or my driving! I had multiple mounting holes for the license plate. As pictured was good in most conditions at moderate speeds. I had to open it up a lot more at highway speeds. It was fully closed in the winter.
https://ecomodder.com/forum/showthre...gon-37759.html

Throttle stop testing can be used to test changes in drag.
https://ecomodder.com/forum/showthre...rag-38322.html

[freebeard]

Misattribution at #2 corrected. I found that in an old thread and squirreled it away in an album.

Were those deflectors made from conveyor belting?

[Gasoline Fumes]

Originally Posted by freebeard

Were those deflectors made from conveyor belting?

Yeah, specifically baler belting from Tractor Supply. Easy to work with. I should try something similar on the Insight. Honda put little deflectors on the Insight, but bigger might be better!

[y2kbug]

Got material for underneath the corolla. Currently waiting for more car parts then i can put the engine back together. I am getting the cooling system working properly before i start blocking the radiator off. The fans were running when the engine was cold.

[y2kbug]

not much progress has been made on the front bumper. Been thinking about it alot lately and hope to start on it soon if i can get some free time

[freebeard]

Just curious, did you do any A-B-A testing with that sheet of Coroplast in place? It seems like an interesting melding of an half-tonneau and spoiler.

I'd predict massive negative lift. The entrained bubble of air would press down behind the axle and pull up within the wheelbase.

[y2kbug]

no i did not do any testing of it in the back of the truck. I was just happy it didn't excape on my drive home. I plan on buying a new tonneau cover for my truck. my old fiberglass one is way to heavy. i hate putting it on and off the truck.

I started putting coroplast on the bottom of my corolla but im not impressed so far. It makes it hard when i need to repair stuff. most of it is laying in the garage right now. may just make a big air dam instead.

[freebeard]

Thanks for posting the pic anyway. I need to find someone who can run a CFD analysis. My computer is only really suitable for web browsing. Maybe my son, he just got a new 'Thermaltake LCGS View 9870T-270 Gaming Desktop'. Something like that could run OpenFOAM.

His Silverado has a trifold tonneau:

automoblog.com
5 Best Hard Folding Tonneau Covers (2025 Ultimate Guide)
Mar 26, 2025Folding tonneau covers: The most common types are hard tri-fold tonneau covers, which feature three folding sections. Some tri-fold hard tonneau covers, like the Tonno Pro on this list, can be installed and removed within a few minutes without any tools.

[y2kbug]

Originally Posted by freebeard

Thanks for posting the pic anyway. I need to find someone who can run a CFD analysis. My computer is only really suitable for web browsing. Maybe my son, he just got a new 'Thermaltake LCGS View 9870T-270 Gaming Desktop'. Something like that could run OpenFOAM.

His Silverado has a trifold tonneau:

OpenFOAM sounds like a fun program i have no idea how to use. I'll probably get a folding tonneau cover for the truck eventually. My dad has one on his little toyota truck.


I took the bumper off to repair many cracks and tears. Now that i did that people are going start asking me how i crashed my car. ha ha. No i did not crash my car i just took the bumper off to repair it!
as you can see the car had been in some previous wreckes and had a rough life If it wasn't for my dad and me this car would have been taken to the scrap yard 7 years ago. I don't think it is worth it to buy another bumper as the rest of the car's appearance looks just as bad.



I took an old soldering iron and sorta melted the plastic back together. I know its not the best way but im working with what i already got around the house.


Then i glued it on the inside with left over glue i had from another project.



I'll let it sit for a few days for the glue to harden...

[freebeard]

Break it again and use the drifter stitch:


https://youtu.be/RqVuQMB1_2s