Bypass Valve Routing Question

[jimothy]

I've been looking through several of the routing possibilities that people on the forum have used for their turbo bypass valves. It seems that many of the older installs have the valve venting to the air filter. Only Hamleto has the vent going into the tube before the turbo but after the air flow sensor. Please correct me if I am wrong but I thought the whole reason to recirculate the vented air was to keep it in the system and not foul the reading of the air flow sensor. I've read elsewhere, and it seems to make sense, that if the air is vented to the atmosphere, as in a BOV then the ecu thinks there is more air than there actually is and so creates a rich condition, which over time can foul plugs and other things. Keeping in mind that this only happens for fractions of a second it probably doesn't matter.

So is it fair to say that the people reciculating the vented air back into the air filter, before the maf sensor, are doing it for purely acoustic reasons.

Thanks

[Doug]

what you say is true for newer cars that have a mass air flow sensor -- the Elan DOES NOT have one, thus you can vent the BOV anywhere you want and it will not change the running of the engine.

[jimothy]

If I had my shop manual in front of me I could answer my own question but what then are the two connections just after the garbage can on the pipe to the turbo inlet?

[Doug]

they are emissions related vents:

one is the bleed line back from the Boost Solenoid Valve
the other is the vent from the oil separater area