Hi I just recently bought a 00 b5 s4 however after I bought it and started reading the forums I realized that the gfb stealth fx blow off valves on it are not only worthless but may be damaging my engine. I am not getting that stupid whoosh sound from em but have not messed around with it at all. I would just put in the stock stuff but I don't have it (I got it as a salvage with body damage). I have read with the right tune bov's can actually be beneficial to audi's and considering how expensive oem Audi parts are it may just cost the same to tune it. But besides the bov's everything else is stock. What do you guys think is my best option and how would I go about tuning it best companies etc. Thanks for any help and sorry for posting another blow off valve question.

 

first off get rid of those bov's and get two of these.

http://www.ecstuning.com/Audi-B5_S4-...iew_All/ES581/

 

Awesome thanks for the reply so that all I need to get rid of those damn things is to buy these right?

 

you should pick up some vacuum line at your local car parts store also to replace the old stuff. other than that you're all set. there are better diverter valves out there, but these will do just fine for up to stage 3 horse power.

here is the BOV set-up also for the 2.7t engine. if yours is plumbed correctly it shouldnt be a problem.

http://www.ecstuning.com/Audi-B5_S4-...HKS/ES2075267/

 

Hi Thanks so much for the help. I'm pretty new to the whole turbo world. So plume it back means recycle more of the air back from the bov's correct? Are you talking about how you can plume those specific bov's to be ok or any bov? Just because I will definitely get those diverter valves however I drove it over 200 miles to visit my parents for the holidays and have to go back just wondering if there was anything I can do to minimize damage. And also like I said before I dont get any wooosh from em so are they already plumed back?

 

the thing that makes bov's bad for our cars is that they release the backed up air into the atmosphere(the woosh sound) instead of diverting it back into the car. our cars, like evo's work on a closed loop system, so you can run bov's but they must be adapted to recirculate the built up air. i hope this helps i'm not the greatest when it comes to explaining these things.

have you had any issues with the car? post a pic of your car and the installed bov's if you get a chance. i also heard the same thing about needing a tune to run bov's properly.

 

Screw that stock stuff.... when I tune threw vast I had them purposely tune my car so it won't run lean when using bov instead of dv..... and before ppl starting say ing u can't run bov on a dv can...... just hold on cause 90 percent of all turbo maf cars are dv of some sort to begin with..... hks bov and other are so common now on audi that ecs tuning now carrys them... the only thing u will need is to find the right slip in add adapter on eb ay to slid down in ur factory pipes.... and some sort of plug. For ur inlet pipes to turbo wear the stock 710n vavle dv goes...... or if u still want to go with a semi stock route u can also use the greddy type s legit bov/dv vavle ( they an be hooked up either way to vent or reculate). Pnce again u will need a plate..... but there ability to hold back more pressure and and not fluter under high load... is well worth it...... I've built some nasty 2:7t and I have ever been conventional when building them.... yes bov of all nature can be used on dv 2.7t audi and right now I'm running the RFL's on mine ( lol however one of the factory plastics don't fit with it on there)..... also with factory 710n vavle u CAN NOT vent them to atmosphere cause at idle tthey are open just a light and let's just say u and ur maf will be fighting about who is rite and wrong

 

dont listen to slos4.. especially if you want to go back to stock. the 710n is a good buy and they work well, i have them on my stage 3. these cars are maf controlled, so the air that goes in needs to be used. so with a diverter valve, the air is rerouted back into the intake track and momentarily air no longer passes through the maf until the rerouted air is used and compensated for fuel wise. as to a bov, that just spouts the air out into the atmosphere. just trying to make it easy on you. fonzos giving good advice. hes been on here a while and helped many people... his option noted is the best/most economical out there..

 

yes if you want a stock dv then either use the bosch dv vavle or the 710n... i agree there and thats where i stop .... i have tried both ways and have dyno on both bov and dv and the air fuel curves dont change when tuned for them seeing as how the maf is just measuring tool for air... thus you can change it variables.. and tell it basically that it and other sensor that it does not need the air that would be rerouted back in to the system... i agreee with both of you if he wants stock then a 710n is the way to go way better then the stock bosch vavles

 

Thanks for all the replies I'm still kinda weighing my options of what to do. Just seems like kinda a waste to get rid of these 1000 bov's. Here are some pics of the car and engine bay. If I were to keep the bov's obviously get the tune and a type of slip in adaptor to slid down my factory pipes? If it starts getting 2 complicated i'll just go back to dv. And I know I need to replace all those frayed hoses.