i know im new to audis but im not to turbo cars and i put 2 bov's on my 2000 s4 and it runs fine lost a little mpg but o well and it runs better down the highway the rmps dont surge anymore because the stiffer spring in the aftermarket bov's dont leak boost

 

What BOV' did you put on? The issue is just that the MAF meters the air as it enters the intake. The ECU uses this to decide how much fuel to add, when you vent this pre measured charged air into the atmosphere it messed up your ECU. Even if the effects arent obviously negative to you, you MAY pay the price later on replacing sensors and such.

 

HKS SSQ recerc?

 

Its been touched on a couple times allready on this page. If it is 100% recirculation it wont cause problems. Hybrid valves will be less of an issue, but problems can still occur. And complete vent to atmpsphere is not supposto be used in this car. Sure you can install it and your car will run but the s4 is programmed to have DV's not BOV's and you will more than likely be doing damage to your vehicle, even if it is not immedietly apparrent to you

 

HAHAHAHA!

 

Yeah me too I read the topic heading for this post, and started laughing...

Any BOV's for Any Audi is just not good.
BOV's are for the fast, and furious crowd....

 

what is the diferance between S4 closed loop system different than the A4 closed loop system system?

 

Here is a brilliant idea... Instead of wasting money on VTA BOV's which will hurt your car later down the road why dont people just invest in some bigger turbos? Exhaust? 710N's? and MAYBE a chip... and instead of a woosh noise. People would hear a loud whistle and then a quick little snap from the dv. BRILLIANT

 

FWIW, the UrS world doesn't really go for the BOV approach either. Most of us stick with Diveter valves.

Allthough, i have seen some HIGH HP AAN applications where a BOV is used but that's usually in conjunction w/ some uber crazy setup....

 

http://www.034motorsport.com/product...roducts_id=685


034 has the idea lolz