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Air filter conduit
Posted: 12 Aug 2020, 14:00
by TONYT25T25
I have a rectangular shaped airbox where the breather tube goes at right angles into the side of the rear panel to receive air from the grille above. It is quite a tight fit in there and I am wondering if enough air is being allowed into the box, how close to the inside of the panel should the end of the funnel be in order to receive the correct flow of air. I am comparing it to a conventional front engine whereby air is allowed through the front grill of the vehicle.
Re: Air filter conduit
Posted: 12 Aug 2020, 22:34
by Mr Bean
TONYT25T25 wrote: ↑12 Aug 2020, 14:00
I have a rectangular shaped airbox where the breather tube goes at right angles into the side of the rear panel to receive air from the grille above. It is quite a tight fit in there and I am wondering if enough air is being allowed into the box, how close to the inside of the panel should the end of the funnel be in order to receive the correct flow of air. I am comparing it to a conventional front engine whereby air is allowed through the front grill of the vehicle.
By coincidence I have been poking about in that area on my 2.1 DJ WBX while looking for a more sensible home for my Idle valve controller than sitting on the over what is effectively the rear mudguard with it's connector and wires in contact with the floor which had been wet/damp at some time. I did have one fail and it had clearly got corroded around the connector.
I found the round flexible ducting unplugged from that plastic moulding hidden behind the grill and was surprised that in a downpour water had not be drawn into the air box via this ducting and interfere with the engine. I did manage to plug it back in and wedged it with a block of stiff foam as the metal sprang which I guess should hold it in place to stop it restricting air flow was not doing its job. I am confident that the area of the slot shaped aperture in the moulding would be adequate providing it was not impaired by the moulding being displaced and being pushed against the interior metal skin just aft of the vent. Once the weather cools down I may have another look at it.
Re: Air filter conduit
Posted: 13 Aug 2020, 08:11
by TONYT25T25
Hello, thanks for reply, my attention was drawn to this area whilst doing some repairs below and above the area which houses the latter part of the piping below the grille, obviously prone to water ingress in that area and behind the rear light cluster. I have managed to find an image on the internet of the unit, the bit I circled is what I was wondering about as when it is fitted it must be quite close to the inner skin of the panel and wondering if enough air is drawn in through it. The other end I understand is to gather warm air from the engine to aid cold starting, there is a bit of tatty alluminium piping attached to this which has deteriorated over the years.

Re: Air filter conduit
Posted: 13 Aug 2020, 17:09
by Mr Bean
Oh no! Mine is nothing like that. I was talking about the plastic moulding which terminates the round flexible conduit which hides behind the rear side grill. I will search for an image. Clearly the 2.1 DJ WBX is different - least ways mine is. Sorry about that.
Re: Air filter conduit
Posted: 13 Aug 2020, 17:24
by TONYT25T25
No problem, look forward to see what a different system looks like. Do not think anything is missing from mine apart from the loosely aluminium/paper pipes that hang off the bottom parts, need to source them if important and necessary.
Re: Air filter conduit
Posted: 13 Aug 2020, 21:17
by Mr Bean
TONYT25T25 wrote: ↑13 Aug 2020, 17:24
No problem, look forward to see what a different system looks like. Do not think anything is missing from mine apart from the loosely aluminium/paper pipes that hang off the bottom parts, need to source them if important and necessary.
Here are two of the components in my WBX:
https://www.brickwerks.co.uk/retainer-t ... -duct.html
The foam block squidges onto two tags within the aperture and secures the plastic moulding large end down upon which the vertical flexible conduit plugs to connect to the plastic moulded panel which separates the rear light cluster space from the engine bay. A short flexible conduit goes from there to the AFM etc. within the engine bay. I cannot find an image for this but it is clearly different from yours.
Hope this make it more clear.
Re: Air filter conduit
Posted: 14 Aug 2020, 11:28
by TONYT25T25
Thanks again, seen the image cannot see it suitable for my unit as you say. Maybe mine is as it should be, somebody will add some further information if needed.
Re: Air filter conduit
Posted: 15 Nov 2020, 22:18
by TONYT25T25
Still wondering if this is an issue with regards to air intake and mixture, the space it occupies (circled) which is below the grills. Has anybody got this same fitment or have they shortened it to allow more air into the conduit before it enters the air filter housing without affecting the hot/warm air uptakes.
Re: Air filter conduit
Posted: 15 Nov 2020, 22:56
by Aidan
1984 DG has the simple set up drawing air from the bottom of the grilled air intake area, part number 025 129 617, it should only fit together one way so if it's assembled correctly I wouldn't worry about it
the fuel injected models had a snorkel set up that MrBean has
Re: Air filter conduit
Posted: 15 Nov 2020, 23:25
by TONYT25T25
Thanks, just seemed a bit odd the way the conduit goes into the area behind the rear light cluster to draw air in from the intake above. mixture smells a bit rich att albeit on initial start up so trying to narrow down possible issues.