Do holes in your rear bumper really make you faster?


_JT

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Well, I have a bad bumper on my car, a new one waiting to be fitted. I live about 15km's away from the German autobahn. It's 00:05 in the night here at sunday evening. In other words, silent as ****. I got a GPS to measure top speed and a G-Tech Pro RR to measure acceleration.

Anyone wanna have a guess at what I'm gonna do right now? :D

See you in little over an hour, with results :D
 
Well im board out of my head @ work looking forward to your results!:nice::nice:
 
Leaving now with a battery drill in my trunk :D
 
good stuff, aerodynamically correctly placed holes work wonders, mainly noticeable at high speeds
 
Alright. Took WAY longer than I expected. The junctions at which I had to turn directions were 30km's (20 miles) apart. So you can just about calculate how long it will take to do 3 runs. After that, my tank became a bit empty :( So I had to fill her up. And of course there was no gas station near the autobahn where I drove.

Went back, to the parking spot from which I launched every run. Got my drill :D And....it friggin' didn't work! I think there's a beam, directly behind the bumper, or my drill is not strong enough, but it kept turning (though slower than in the beginning) while it didn't got that far into the plastic. So this will be continued for sure! Tommorow or tuesday!
 
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There is no beem behind your bumper mate!:secret:
Sounds like you took a dead drill out! lol

Look forward to reading your progress!:nice:
 
There is no beem behind your bumper mate!:secret:
Sounds like you took a dead drill out! lol

Look forward to reading your progress!:nice:
I charged the battery for more than 12 straight hours the day before yesterday so that means the drill is too weak :p Then I have to find a place where I can plug in my big drill :D
 
how about you just remover the rear bumper and re - test, its only held on by a few clips and a couple screws,
 
how about you just remover the rear bumper and re - test, its only held on by a few clips and a couple screws,
For starters, I don't know if that is allowed in Germany, driving without bumpers. Second, There is an aedynamical difference between bumper with holes or no bumper. The question is, will holes in your rear bumper make a _noticable_ difference in acceleration and top speed? Who knows without bumper will make a difference, but with bumper with holes, would make an insignificant difference (like 1km/h) and could be considered error margin. But thanks for your input :)
 
For starters, I don't know if that is allowed in Germany, driving without bumpers. Second, There is an aedynamical difference between bumper with holes or no bumper. The question is, will holes in your rear bumper make a _noticable_ difference in acceleration and top speed? Who knows without bumper will make a difference, but with bumper with holes, would make an insignificant difference (like 1km/h) and could be considered error margin. But thanks for your input :)

cool, look forward to seeing your results :nice:
 
For starters, I don't know if that is allowed in Germany, driving without bumpers. Second, There is an aedynamical difference between bumper with holes or no bumper. The question is, will holes in your rear bumper make a _noticable_ difference in acceleration and top speed? Who knows without bumper will make a difference, but with bumper with holes, would make an insignificant difference (like 1km/h) and could be considered error margin. But thanks for your input :)

i think it wont make any differrnce in accleration at any speed...a lot of guys here in our city put holes in their rear bumper some doesnt even know why they put holes in it...some during drag race(illegal) front and rear bumpers are removed..dont know why they do this but it REALLY doesnt make any changes...:))
 
i think it wont make any differrnce in accleration at any speed...a lot of guys here in our city put holes in their rear bumper some doesnt even know why they put holes in it...some during drag race(illegal) front and rear bumpers are removed..dont know why they do this but it REALLY doesnt make any changes...:))
Got numbers to back it up? Cause I will soon have... :)
 
its not just about accelaration, lot of factors such as pressures, resistance etc come into play, hopefully someone who works in aerodynamics can chime in
 
Be interesting to do the same comparison with a rear diffuser fitted aswell..

Look forward to seeing the results!
 
By rights it should make a good difference because the back bamper is more or less one big air sock.
 
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