Notices

Bonnet Vents.

Thread Tools
 
Search this Thread
 
Old 02 September 2005, 01:41 PM
  #1  
john w
Scooby Regular
Thread Starter
 
john w's Avatar
 
Join Date: Aug 2005
Posts: 40
Likes: 0
Received 0 Likes on 0 Posts
Default Bonnet Vents.

Can anyone tell me why the bonnet vents on my Classic have blanking plates on the underside ? Is there any advantages/disadvantages if i removed these plates ?
Old 02 September 2005, 02:10 PM
  #2  
morpheous
Scooby Regular
iTrader: (9)
 
morpheous's Avatar
 
Join Date: Jul 2004
Location: In the middle somewhere and No i'm not a Brummie
Posts: 1,715
Likes: 0
Received 0 Likes on 0 Posts
Default

Water mainly
Originally Posted by john w
Can anyone tell me why the bonnet vents on my Classic have blanking plates on the underside ? Is there any advantages/disadvantages if i removed these plates ?
Old 02 September 2005, 02:32 PM
  #3  
john w
Scooby Regular
Thread Starter
 
john w's Avatar
 
Join Date: Aug 2005
Posts: 40
Likes: 0
Received 0 Likes on 0 Posts
Default Bonnet Vents

Water getting into engine bay i know would be bit of a problem but removing these blanking plates would it improve air flow through the engine bay etc ?





Originally Posted by morpheous
Water mainly
Old 02 September 2005, 10:26 PM
  #4  
remfanuk
Scooby Regular
 
remfanuk's Avatar
 
Join Date: Jun 2005
Location: Lincoln
Posts: 119
Likes: 0
Received 0 Likes on 0 Posts
Default

so just what purpose do the vents actually serve if they are blanked off? i had thought of opening mine, thinking that letting heat out or cool air in would be a good move...anyone able to answer that one?
Old 02 September 2005, 10:30 PM
  #5  
s70rjw
Scooby Senior
iTrader: (2)
 
s70rjw's Avatar
 
Join Date: Sep 2004
Posts: 5,013
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by remfanuk
so just what purpose do the vents actually serve if they are blanked off? i had thought of opening mine, thinking that letting heat out or cool air in would be a good move...anyone able to answer that one?
They do let out heat. You can see the heat haze around them when the engines hot
Old 02 September 2005, 10:44 PM
  #6  
Fizz
Scooby Regular
iTrader: (1)
 
Fizz's Avatar
 
Join Date: Jul 2000
Location: Stourbridge
Posts: 1,813
Likes: 0
Received 3 Likes on 2 Posts
Default

a better comprimise as I did on mine is to remove them wind a nut onto the thread, remove the foam from the plates and then put them back on. This creates a nice gap around the edge letting more heat out and some air in at speed and no water in when parked
Old 02 September 2005, 11:16 PM
  #7  
tath
Scooby Regular
 
tath's Avatar
 
Join Date: Feb 2005
Location: Llandudno
Posts: 1,448
Likes: 0
Received 0 Likes on 0 Posts
Default

The men who know on here claim that the engine bay is desiged to flow air through the grills at the front which combines with the main vent flow to draw the air over the gearbox and out the back. removing the covers apparently disrupts the flow and actually increases under bonnet temps.

That said, I've removed my driver's side one and boxed off my induction kit.
Old 03 September 2005, 12:14 AM
  #8  
JTaylor
Scooby Regular
 
JTaylor's Avatar
 
Join Date: Jun 2005
Location: Home
Posts: 14,758
Likes: 0
Received 0 Likes on 0 Posts
Default

Additionally.

Water ingress around the the MAF area is not good. Also removing the blanking plate from the drivers side vent will cause a chimney effect and will actually draw hot air to the airbox area.

They are essentially cosmetic.
Old 03 September 2005, 12:15 AM
  #9  
JTaylor
Scooby Regular
 
JTaylor's Avatar
 
Join Date: Jun 2005
Location: Home
Posts: 14,758
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Fizz
a better comprimise as I did on mine is to remove them wind a nut onto the thread, remove the foam from the plates and then put them back on. This creates a nice gap around the edge letting more heat out and some air in at speed and no water in when parked
Agreed
Old 03 September 2005, 12:21 AM
  #10  
tath
Scooby Regular
 
tath's Avatar
 
Join Date: Feb 2005
Location: Llandudno
Posts: 1,448
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by JTaylor
Additionally.

Water ingress around the the MAF area is not good. Also removing the blanking plate from the drivers side vent will cause a chimney effect and will actually draw hot air to the airbox area.

They are essentially cosmetic.
Not if you separate the engine from the induction area. As far as I can see, I'm routing in air through the foglight hole into the boxed off area and out the vent.

I think they were originnally for rally cars when you weren't allowed to change panels from homolagated models...
Old 03 September 2005, 08:01 AM
  #11  
JTaylor
Scooby Regular
 
JTaylor's Avatar
 
Join Date: Jun 2005
Location: Home
Posts: 14,758
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by tath
Not if you separate the engine from the induction area. As far as I can see, I'm routing in air through the foglight hole into the boxed off area and out the vent.

I think they were originnally for rally cars when you weren't allowed to change panels from homolagated models...
If your air box is enclosed, great. This doesn't detract from the fact you're are drawing hot air toward the area, rather then letting cold air in which is the common conception.

P.S. I was considering routing from the foglight. I take it you've had no issues with water. This was a concern of a local tuner although I'm not convinced it'd be a problem.

J
Old 03 September 2005, 08:02 AM
  #12  
DaveC1
Scooby Regular
 
DaveC1's Avatar
 
Join Date: Jan 2005
Posts: 191
Likes: 0
Received 0 Likes on 0 Posts
Default

Correct, they are there for homolagation purposes and should not be removed as this can create hot spots
Old 03 September 2005, 11:05 AM
  #13  
tath
Scooby Regular
 
tath's Avatar
 
Join Date: Feb 2005
Location: Llandudno
Posts: 1,448
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by JTaylor
If your air box is enclosed, great. This doesn't detract from the fact you're are drawing hot air toward the area, rather then letting cold air in which is the common conception.

P.S. I was considering routing from the foglight. I take it you've had no issues with water. This was a concern of a local tuner although I'm not convinced it'd be a problem.

J
I've got a HKS induction partitioned off from the engine by tin sheet - this is the only way i'd remove it. Most importantly, with no cover you can hear the induction roar and snarfle

I don't understand what harm water will do if it does get in (apart from drawing in dirt if it's road water I suppose). It'll hit the airfilter and sit there for a few seconds until the high flow of air across it evaporates it. And even if it did get further what would it do? Cool my charge?

AFAIK the snorkle is there to prevent BIG amounts of water (e.g. when you're fording a river) entering.

At the moment I've only got one foglight cover, but I was considering getting the mesh ones of ebay that are designed to let light through - hopefully they'd also let air through.
Old 03 September 2005, 11:21 AM
  #14  
16vmarc
Scooby Regular
 
16vmarc's Avatar
 
Join Date: May 2004
Location: Shell Garage, York
Posts: 10,059
Likes: 0
Received 0 Likes on 0 Posts
Default

Getting water over electrics and MAF doesnt sound like a good idea! I remove mine in summer and replace them when the weather gets bad. I left them off a while during some bad weather - the engine got filthy.
Old 03 September 2005, 11:24 AM
  #15  
tath
Scooby Regular
 
tath's Avatar
 
Join Date: Feb 2005
Location: Llandudno
Posts: 1,448
Likes: 0
Received 0 Likes on 0 Posts
Default

Don't be a girl! Who said water and electrics don't mix?

Seriously, I would advise bagging the MAF. And if you've got an alarm siren down there you don't want it exposed to a) water and b) thieving pikies,
Old 03 September 2005, 01:14 PM
  #16  
Aztec Performance Ltd
Former Sponsor
iTrader: (234)
 
Aztec Performance Ltd's Avatar
 
Join Date: Jan 2003
Location: Over 500ft/lbs of torque @ just 1.1bar
Posts: 14,406
Likes: 0
Received 0 Likes on 0 Posts
Default

The water goes though the blanks anyway, just in a more directed manner.

Maf should be fine. Its a sealed unit. I have removed my drivers side vent blank, but run a CAK.



Bob
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
28
28 December 2015 11:07 PM
shorty87
Full Cars Breaking For Spares
19
22 December 2015 11:59 AM
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
buckerz69
Subaru Parts
3
08 October 2015 07:54 PM
Ganz1983
Subaru
5
02 October 2015 09:22 AM



Quick Reply: Bonnet Vents.



All times are GMT +1. The time now is 02:28 PM.