FAQ: All your Blow Off Valve & Diverter Valve / By-Pass Valve Questions!

[nateS4]

I could be mistaken but I'm quite sure the guy I bought my S4 from had the Forge 60/40 bov. After he blew up his K03's, he wondered if it was partly from this. Something about inappropriate backpressure on the turbo's... I can't remember for sure. Will try to ask him for more details.

Yeah, definitely let me know about that before I Fuk up my car

[Jung]

I could be mistaken but I'm quite sure the guy I bought my S4 from had the Forge 60/40 bov. After he blew up his K03's, he wondered if it was partly from this. Something about inappropriate backpressure on the turbo's... I can't remember for sure. Will try to ask him for more details.

It would not be solely because of this. k03s tend to catastrophically fail at the most inconvenient times. The only way he'd be getting backpressure is if the valves weren't doing anything or if one of the paths (atmosphere or intake) were blocked, which is unlikely. mileage, how hard the driver drives, warm up/cool down, etc.. the list goes on. these are all variables in when the turbo goes.

nate, the air from hte DVs aren't going into the MAF, the MAF is before this on the intake tract. like said before, some cars work well with splitters and blowoff valves, some do not. Just try it out and see how much different it works. You're not going to fuck up your car THAT much by running them for a little bit.

[nateS4]

^^^ It's tough to $320 and not be able to continue to use the part, but what is the plug for above the TBB called?

[Jung]

ahh the magic of ebay or the classifieds! you can use the part, but you won't have a perfectly running car!

[Tea Mandy]

Talked to the previous owner today...

Turns out he felt the diverter valve took out the turbo on his Golf, not the S4 (splitter valve was not able to blow-off 20psi)

He found though that the Forge splitters on the S4 had a bad effect on spool time, so it was still making the same power just a longer spool.

This is just what he found from his testing. And he thinks he probably blew his K03's from running them hard at 18psi. :)

Hope it helps!

[Jung]

the air does not get rushed into the intake, unlike diverter valves, which is why spool is longer. it just gets put into the atmosphere.

[awd2ks4]

i run a hks bov and one 710n with no problems what so ever. i know the hks sounds pretty gay but if you take out the fin insert it makes it sound totally different. Ko3s must be one of the worst turbos made(for failure). Tell you the truth my car is alot smoother and more easier to drive with the hks bov and one 710n. compared to two dv's

[Jung]

idk how it makes the car "easier to drive"...

[awd2ks4]

just like i said... it makes my 1-2 shift much smoother i have no idea why? when i had the 710ns in the 1-2 shift is more rough.

[will175]

Will that actually be okay to run it that way, one 710n and a BOV

[awd2ks4]

i beat a LS1 with it like that

[Jung]

wow that has to be one of the most non informative answers of all time.

[will175]

yah I know but its audizine...I was just wondering if it would do any harm to our car, I would think so but Im no expert.

[awd2ks4]

Well i did just find out the hks valve was throwing me into limp mode when i drove it for a long time along with lots high boost blow offs on the freeway, probably interpreted it as a boost leak and threw a positive deviation code. So no more valve, it was fun while it lasted but the 710N's going in for good.

[1997gtx]

^ Sorry you had to find out the hard way!
--Adam

[S-Power]

What is the noise made by the DV when your shifting on WOT ? ? ?

Like the little air sound ? ?

[1997gtx]

A little air sound is normal ... a lot could mean you have a boost leak or the DV is bad.
--Adam

[S-Power]

okay bro, but what if there is no air sound at all?

DV is bad ?

[S-Power]

IF you hear no air then the DV is bad or what ? ?

[Jung]

www.audidiy.com
under the b5 s4 part, there is DV testing.
do you have a boost gauge? If you go into boost and the boost doesn't dissipate really quickly, it maynot be functioning.

[Boosted-S4]

Im looking into the turbosmart compact...will there be a problem

[Jung]

its hard to say, dude.. some cars don't really react to them, some dislike them. it all depends on how you have them set up (recirc/ atmosphere). give them a shot and tell us. that woudl be the most helpful thing to do.

[Boosted-S4]

from turbosmart specs that DV/BOV can do 3 things...full diverter valve,diverter/atmospheric or 100 atmospheric...they say that both first and second options are perfect for the car but the thirs is use at own risk...i searched forge and they have a similar one....also a buddy of mine who owns a 1.8t is running the turbosmart and he loves it...it produces the bov sound but not as loud!!!
im gonna take a chance and ill keep u guys posted!!!
thanx for the info!!!

[1997gtx]

Good luck!

To the poster asking about "no sound" -- that would be normal.
--Adam

[S-Power]

How Important is it to Re-grease the DV's ?

How Often Should it be done?

What are side effects, if they arent greased ?

Thanks ! ! !

[nateS4]

^ Please try it and let us know how it goes. Most people don't wanna spend the money on a split, but i'm glad someone is :)
--Adam

Well, when I was @ H2O I bought 2 Forge Hybrid Bypass/Recirc Vales and so far so good, no codes! Now the only way you hear the woossh sound is to have the sunroof cracked and the music down pretty much, so its definitely recirculating most of the air. Oh and I couldn't pass up the deal they gave me $100 each. for Forge, and on a side note they are probably going to become an Advertiser on here.

[S-Power]

How Important is it to Re-grease the DV's ?

How Often Should it be done?

What are side effects, if they arent greased ?

Thanks ! ! !

Can someone help me out

[DraxeofDclan]

Why does almost everyone use piston type DV....I use APR R1s, no maintenance needed and from what I understand diaphram based are better...yes-no?

[1997gtx]

People had some issues with the R1 when it first came out. I believe they tweaked the design, but many people were hesitant to go with it afterwards. Glad to hear it's going well.

Should be re-greased once a year. Bad part would be old and worn out rubber gaskets and pistons -- would eventually lead to small boost leaks.

Forge is already an advertiser on the forum.
--Adam

[S-Power]

People had some issues with the R1 when it first came out. I believe they tweaked the design, but many people were hesitant to go with it afterwards. Glad to hear it's going well.

Should be re-greased once a year. Bad part would be old and worn out rubber gaskets and pistons -- would eventually lead to small boost leaks.

Forge is already an advertiser on the forum.
--Adam

Thanks Adam! Much Appreciated

[1997gtx]

=)

[RitchS4 914]

which DVs combined with what intake gives the best sound... not expecting anything major like a BOV sound but just curious... thanks

[Jung]

My Forges with the Darintake mod makes some sound, but not a lot.. I've heard some Bailey's without the darintake and they were actually a little more loud than mine. Try those with the EVO intake and you will probably get some good sound. But It's REALLY a waste of moeny for an intake... our intakes are pretty much as good as they can get stock.

[dennisS4]

the extra boost flows through a piece of cloth wrapped rubber and its prone to being brittle over time, what is the best replacement? Will a standard Samco vacuum line work in 3mm??

[1997gtx]

Yep -- any line will be fine.
--Adam

[Ianxcom]

I was at a local shop today and i asked about 710n's running on a stage 1 s4. The shop employee said that they are crap and that they are the same as a stock DV only with a stiffer spring and that they will still take a dump. I dont know if he was trying to push another more expensive product that i dont need or if he really believes that. Makes me wonder if its only the springs that suck on the stock DV or the whole thing.

Thoughts?

[AudiSon]

hey I'm tryin to find some inexpensive blow off valves to replace the stockys where should i look?

[Jung]

I was at a local shop today and i asked about 710n's running on a stage 1 s4. The shop employee said that they are crap and that they are the same as a stock DV only with a stiffer spring and that they will still take a dump. I dont know if he was trying to push another more expensive product that i dont need or if he really believes that. Makes me wonder if its only the springs that suck on the stock DV or the whole thing.

Thoughts?

well, he clearly didn't know anything about the 710N. There are a LOT of stage III S4s running 710Ns just fine for many miles under high boost. it's a proven fact that 710Ns can handle from stock to stage 3. I believe he was just trying to make you spend more money.

[1997gtx]

hey I'm tryin to find some inexpensive blow off valves to replace the stockys where should i look?

Look no further than 710N's ... They are the stock DV's off an Audi TT.
--Adam

[Ianxcom]

well, he clearly didn't know anything about the 710N. There are a LOT of stage III S4s running 710Ns just fine for many miles under high boost. it's a proven fact that 710Ns can handle from stock to stage 3. I believe he was just trying to make you spend more money.

Thanks. Thats what i figured.