Alfa Romeo Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
39 Posts
Discussion Starter #1
Hi Hope someone out there can help ! ,
I am building a special useing a 164 24 Valve V6,I am running into space problems for mounting Bosch air fow meter, I need to know will it run ok on its side instead of flat as in standard position.
Thanks for looking Mick.
 

·
Premium Member
Joined
·
26,814 Posts
Hi Hope someone out there can help ! ,
I am building a special useing a 164 24 Valve V6,I am running into space problems for mounting Bosch air fow meter, I need to know will it run ok on its side instead of flat as in standard position.
Thanks for looking Mick.

It should as that is how they are mounted in the 80-85 Lancia Beta cars.
 

·
Registered
Joined
·
3,506 Posts
Do you get a choice of whether gravity helps open the flap or holds it closed? It might make little difference, but it might be worth thinking about.
 

·
Registered
Joined
·
549 Posts
Do you get a choice of whether gravity helps open the flap or holds it closed? It might make little difference, but it might be worth thinking about.
In theory, that would be a concern, but from a practical matter, it's really not an issue. A bigger concern would be that you dampen the mounting of the meter, or you'll likely get some unwanted output hysteresis from vibration.
 

·
Registered
Joined
·
3,506 Posts
_Good_ point, Brad. Like I guess I said, "It might be worth thinking about." I guess it is worth thinking about. The vibration issue would do ugly things to the flap setting if it isn't well-balanced.
 

·
Premium Member
Joined
·
26,814 Posts
Lancia used some rubber bushings with steel inserts for bolts and Bosch AFM housing was threaded to take three bolts. It worked fine on its side.
 

·
Registered
Joined
·
549 Posts
Lancia used some rubber bushings with steel inserts for bolts and Bosch AFM housing was threaded to take three bolts. It worked fine on its side.
At the risk of taking the counter-point for the sport of it.... :D The Lancia was undoubtedly calibrated with the AFM in this upright position, whilst the 164 was undoubtedly calibrated with the meter in the stock "horizontal" position. Thus, your argument is flawed. :p

Again, from a practical standpoint however, any difference is neglible at best - the door spring is what the air-flow is being measured against, not gravity. Bear in mind too, the Motronic logic is adaptive, and thus it's designed to re-learn sensor output, should it change small amounts (say, as a result of the spring weakening a tiny bit over time).

Oh, and FWIW, I've run a Bosch AFM "upright" on another application where it was designed to run "flat", and there was no discernible difference at all.
 

·
Registered
Joined
·
3,506 Posts
My point was that if the AFM is working on a vertical axis, it might not have had to be balanced against gravity and the (smaller) force of turns. If one then took an unbalanced unit and mounted its axis horizontally, gravity (and bumps in the road) would affect it much more. Autos don't have left/right transients nearly as strongly as they have up/down transients. Just a comment on the sign of the effect, not whether it's significant. But the AFM flapper is probably balanced for the reason that it is the proper thing to do to make it insensitive to such forces.
 

·
Registered
Joined
·
1,233 Posts
The AFM is designed with a counter weight on the other side of the flap so it should be pretty well balanced against the axis of rotation. The counter weight (inside flap) also provide some buffering to smooth out the swing of the air flap so the signal to ECU is not as erratic. If the weight of the flap is balanced (which I think it is), gravity should have very little effect on the AFM operation whichever way it is mounted.
 

·
Premium Member
Joined
·
26,814 Posts
Sometimes we (me included) beat a subject well past the point of sudden or slow death IMHO!
 
1 - 11 of 11 Posts
Top