Discussion
I could suggest gently swinging the flap through its range of travel to make sure it's not sticking or rough anywhere.
But I won't, because everyone else says leave it alone
An if you DO find anything wrong with it, AFM-paranoia will set in and you'll wonder whether a second-hand one off a BMW 3-Series that your mate wrapped round a tree will work any better...
But I won't, because everyone else says leave it alone
An if you DO find anything wrong with it, AFM-paranoia will set in and you'll wonder whether a second-hand one off a BMW 3-Series that your mate wrapped round a tree will work any better...
Replaced air intake hose a couple of months ago. My surprise was the the throttle body and AFM are not in the same horizontal plane! And the silicon hose is not very flexible. Seems that flappers like the AFM sort of to be horizontal (hotwire no issue) to avoid potential issues. Ended up to unbolt AFM from the wing, put the hose on, and remount AFM to wing with some spacers etc.
Thing mentioned on backfire. Thought that hotwire setups are more prone to damage (wire damaged, or even gone!) from it. Think that flappers are quite sturdy.
Rob
Thing mentioned on backfire. Thought that hotwire setups are more prone to damage (wire damaged, or even gone!) from it. Think that flappers are quite sturdy.
Rob
350zwelgje said:
Replaced air intake hose a couple of months ago. My surprise was the the throttle body and AFM are not in the same horizontal plane! And the silicon hose is not very flexible. Seems that flappers like the AFM sort of to be horizontal (hotwire no issue) to avoid potential issues. Ended up to unbolt AFM from the wing, put the hose on, and remount AFM to wing with some spacers etc.
Rob
Found the same myself but found the hose to be too flexible and didn't like the way it kinked seemed almost closed, so I have used a bend from guttering down pipe and it seems to have done the biz just need to get 3 new clips to finish then will post some piccy'sRob
andy390se said:
i fitted the act pipe on my 390(flapper) and to get it on without kinking i unbolted the afm and had to angle it downwards slightly. do they need to be level to work properly or will the slight decline hinder it will take pic tommoroe and post to show.
ta
Should be OK. Some cars with the Bosch AFM (even though it says Lucas on it ta
) had it mounted sideways-on or even upside-down.
Umm, don't look as prity as I would have liked, many be not a good idea, as I have a flapper and as you say they don't like not being stright. may be look better with a nice SS or ali bend in the middle. or maybe worth moving the AFM so it the same height as the Plem. Do you remember the cost, and if they do Blue, or just black.
Wedg1e said:
andy390se said:
i fitted the act pipe on my 390(flapper) and to get it on without kinking i unbolted the afm and had to angle it downwards slightly. do they need to be level to work properly or will the slight decline hinder it will take pic tommoroe and post to show.
ta
Should be OK. Some cars with the Bosch AFM (even though it says Lucas on it ta
) had it mounted sideways-on or even upside-down.Or is the flap and counterweight on it specifically balanced to nullify the effect of any acceleration?
[/quote]
[/quote]Should be OK. Some cars with the Bosch AFM (even though it says Lucas on it
) had it mounted sideways-on or even upside-down.[/quote]
That's an interesting point. When launching a normal wedge, the flapper is pointing forwards. A heatlthy launch will induce positive g's, which will possibly tend to open the flap more?
Or is the flap and counterweight on it specifically balanced to nullify the effect of any acceleration?
[/quote]
Within reason, mounting the AFM in various attitudes will not make any significant difference to its operation because the flap is actually two flaps fixed at right-angles, one of them inside a damping chamber.
The flaps are stabilised throughout the speed range. When the throttle is opened pressure in the intake tunnel falls due to the depression in the manifold and atmospheric pressure at the intake moves the measuring flap against the spring tension as more air enters the engine.
At the same time air in the damping chamber is momentarily compressed, damping the rate of movement of both flaps.
If the throttle is now held steady, the air pressure in the damping chamber will also fall until it is equal to the pressure at the intake area. This balance of pressure on each side of the damper flap ensures that the flap unit remains stable at any throttle opening.
A neat design feature takes advantage of flap momentum as it overshoots its position of equilibrium during acceleration to briefly signal an even higher airflow and boost the mixture. Upon deceleration a similar effect occurs to reduce mixture and aid the braking effect. Both these effects give good throttle response.
So between both these actions, balanced air pressure between the intake area and the damping chamber, and, constant resistance of the flap spring trying to prevent the flap opening too far, the flap and it damping partner are relatively immune from then effects of gravity or location.
I doubt, however that the flaps would respond correctly if, in the unlikely event, the AFM was mounted in a vertical plane, because there would be some gravity effect on the right-angled pair of flaps.
heres the pics of the new pipe angled slightly down seems to be ok?
also can anyone tell me what the cutout just beloe the screen is for air flow to cabin or drainhole into cabin?
looks a bit diy to me should i cover it?
[pic]http://ph.uncle-dave.co.uk/upload/images/pictures%20373.jpg[pic]
[pic]http://ph.uncle-dave.co.uk/upload/images/pictures%20375.jpg[pic]
also can anyone tell me what the cutout just beloe the screen is for air flow to cabin or drainhole into cabin?
looks a bit diy to me should i cover it?
[pic]http://ph.uncle-dave.co.uk/upload/images/pictures%20373.jpg[pic]
[pic]http://ph.uncle-dave.co.uk/upload/images/pictures%20375.jpg[pic]
Gassing Station | Wedges | Top of Page | What's New | My Stuff