Answers on a postcard..............

1) Why are the outer two bonnet vents blanked off on the underside?

2) If you remove the blanking panels will it make any perfomance increase (cooler air into intake?)

3) Is it possible you would get uneven engine temperature ("cool spots" under said vents, hotter elsewhere)?

Thanks

 

1) Something to do with the road car needing to look like the rally car - someone else might be able to give a more technical explanation ! They serve no purpose whatsoever - in fact the new Impreza doesn't have them at all.
2)Nope - several people have done this & noticed no improvement (prepare to be corrected) Obviously there is a sound increase but bear in mind some of the cars electrics are located under one of the vents so be careful of water getting in there !
3) Dunno.

Brew.

[This message has been edited by BrewandBake (edited 12 October 2000).]

 

1) To stop water getting in.

2) No.

3) It is more likely the water allowed in will affect some of the gubbins that the blanking plate is their to keep dry.

Have you tried a search on this forum using bonnet vents as a key word?

 

1) Because the rally car can't have holes in the bodywork that aren't present in the road-going version (homologation).

2) Upside:
Should let hot air leaving the front radiator to escape out of the engine bay more easily. Will allow hot air to escape from the engine bay when the car is idling. Should also reduce the amount of hot air around the intercooler and turbo assembly.

Downside:
Will expose the battery (left side) and possibly the air-flow meter (right side) to rain, which is why the blanking plates have proper rain channels & a drainage hole.

3) Some hot air will no longer be flowing through the engine bay, but seeing as the bulk of the airflow is through the front radiator, wheel arches and out through the bonnet & under the car, I'd say it's unlikely to cause any major problems.

IMHO of course.

 

My side bonnet vents have a gap between the blanking plates and the bonnet.
Thought they all did.
This allows some hot air to escape, while preventing rain getting onto the engine parts.
Probably easy to do on all models. Just add spacers in.

 

Lets not forget the Impreza was a homologation special.Secondly if you have seen a WRC up class although you dont seem to have many of them competing in England, the vents on either side are just big holes in the bonnet,I would think you could almost put your hand through to the engine they are so big.
Regards
Kevo

 

Before I got my scoops I always used to remove the blanking plates on track days, you could see the heat pouring out so they must have helped. I've never had electrical problems with water ingress with either the blanking plates removed, or with my scoops!

 

Ho hum... well removing the blanking plates has worked for me... you know it's helping when you see the heat haze rising from the vents when you're stuck in traffic on a hot day...

Oh and my alarm will sound if someone were able to cut the battery connection through the vent, so let's not go there again.

Moray

 

They must be for air release. I have a Sport and on cold days when the bonnet is damp there are 2 totally dry squares in the exact position where the turbo vents are.