Brian17Si
Senior Member
- First Name
- Brian
- Joined
- Jul 23, 2017
- Threads
- 8
- Messages
- 253
- Reaction score
- 279
- Location
- Hartford CT
- Vehicle(s)
- 2017 Honda Civic Si
- Vehicle Showcase
- 1
- Thread starter
- #16
Cosmetic improvement, reduce drag, increase downforce.What are you attempting to gain by doing this modification?
Thanks Invader and he's 100% correct with his posts. All the super cars and race cars have openings in rear bumpers and diffusers to reduce drag and increase downforce. Air gets trapped in that area of the bumper causing drag to the vehicle's airflow and aerodynamics.No. Front vents are better left shut for reduced drag. That's why we see active front shutters on some models which close at higher speeds to improve fuel efficiency.
Venting out the rear bumper cover helps by reducing drag, which is why it's of common practice in drag racing... Weight savings are of course negligible.
It already looks better because the rear vents are no longer fake. It does also look lighter. It will look great once it's finished and opened up behind.
Thanks for your reply. Like Invader said it will improve in a positive way small or larger. Something moving with a wall on it's rear end will trap and restrict air flow. Think if you ran with a parachute open behind you it would definitely add resistance and make it more difficult to accelerate. If you were to cut holes in the parachute you would be able to accelerate and move more freely and quickly.Do you have actual test data to support that? Opening up those spaces would save weight and material. If it would improve fuel efficiency or performance even by the tiniest imaginable amount, don't you think Honda would have done that from the factory? I can't think of anything better for a manufacturer than saving weight, material, and money while gaining performance and fuel efficiency at the same time!
In a worst-case scenario, allowing air to flow through areas not intended could actually create additional drag and decrease efficiency and performance. It may also alter the airflow characteristics in such a way that causes exhaust fumes to be drawn into the vehicle. We'd need a wind tunnel and several hundred thousand dollars worth of test equipment and fluid modeling software to validate these wild guesses.
I feel Honda was really itching to make these vents real but for whatever reason decided to go the more conservative route. Who knows but I got the hint because they started it! One thing I'm sure about is I don't like big fake vents.
Here are a few good links related to this topic...
Porsche forum - https://rennlist.com/forums/964-forum/820881-rear-bumper-venting-2.html
Hey, this is real no Photoshop and here are some images of the work in progress. I'm going to be cutting the bumper and struggling if I'm going to cut the entire section or just the slanted thinner section in middle and spray additional section flat black behind vents.Its Monday, so I'm a little slow. But are the pics above of the actual conversion or are they just photoshoped images?
PS, I think it looks good. Might have to do some black paint mitigation behind the vents but thats no big deal.
Sponsored
Last edited by a moderator: