hood vents

[lunarhighway]

in the spirit of trying to turn bad luck into an opportunity i was thinking about the following:

my hood got damaged in an accident i had last week although it's not too bad compared to the fender and the bumper. the right side is slightly deformed and the front right corner is rather bent with a lot of paint chipped off.

it could be straigtened with a little care but a "new" second hand hood shouldn't cost to much either and in order to restore to car to it's former glory it would need to be completely repainted either way.

however it might not be to hard to get my hands on a kadett GSI hood.

the GSI was a high performance versions of my car wich basically had the same body with a bigger engine. there was a spoiler on the back a different bumper/airdam and small sideskirts. but it also had air extraction vents in the hood. the best part is all these where not just for show but it was claimed they actually lowered the Cd from 0.32 to 0.30!
while the vents alone would only be responsible for a small fraction of this
they're resessed so it's unlikely they'll cause additional drag either and they're designed to improve airflow wich might enable a bigger grillblock.

the advantage also is that this would be a factory designed windtunnel tested setup. no mather how theoreticly sound some aeromods are, it's still a bit of a gamble. i couldn't really go wrong with this one. and i think technical inspection wouldn't make to much trouble as it's a stock part. in fact you'd barely notice when painted.

what do you think? could this have a positive effect on FE? would there be any measurable gains (combined with a bigger grillblock). or should i save myself the trouble and have everything repaired and painted in one go?
and would there be a downside to these things?

[oneinchsidehop]

Originally Posted by lunarhighway

in the spirit of trying to turn bad luck into an opportunity i was thinking about the following:

my hood got damaged in an accident i had last week although it's not too bad compared to the fender and the bumper. the right side is slightly deformed and the front right corner is rather bent with a lot of paint chipped off.

it could be straigtened with a little care but a "new" second hand hood shouldn't cost to much either and in order to restore to car to it's former glory it would need to be completely repainted either way.

however it might not be to hard to get my hands on a kadett GSI hood.

the GSI was a high performance versions of my car wich basically had the same body with a bigger engine. there was a spoiler on the back a different bumper/airdam and small sideskirts. but it also had air extraction vents in the hood. the best part is all these where not just for show but it was claimed they actually lowered the Cd from 0.32 to 0.30!
while the vents alone would only be responsible for a small fraction of this
they're resessed so it's unlikely they'll cause additional drag either and they're designed to improve airflow wich might enable a bigger grillblock.

the advantage also is that this would be a factory designed windtunnel tested setup. no mather how theoreticly sound some aeromods are, it's still a bit of a gamble. i couldn't really go wrong with this one. and i think technical inspection wouldn't make to much trouble as it's a stock part. in fact you'd barely notice when painted.

what do you think? could this have a positive effect on FE? would there be any measurable gains (combined with a bigger grillblock). or should i save myself the trouble and have everything repaired and painted in one go?
and would there be a downside to these things?

If you have blocked your grill and there is no air entering through it you would have a low pressure area under the hood. Adding vents would suck air in rather than vent it out. This is only a pracitcal problem if the car is low enough to the ground or you have an air dam that create (at least small) ground effects. I'm guessing it'd make no difference at all... but it might look cool.

The bigger grill block might help though.