WHHHYYYY Do people get BOV's????

[vladr]

I have been wondering this for some time now, since I got my 1er......

Since our cars have diverter valves that recycle the air that is expelled when you decrease throttle pressure and are more efficient, why would people get blow off valves that simply expel that same are out into that atmosphere.

Is it really just for the sound? I would understand that (and I would probably get one myself), if it wasnt for the fact that they are worse than the original BMW design..


AM I way off base here? Or is this really the case?

Thanks --- No offense to anyone who has a BOV

[HondaGoneRogue]

Originally Posted by vladr

if it wasnt for the fact that they are worse than the original BMW design..

[APupNamedSmokey]

I would think a BOV would only be required when you are making above a certain amount of power in the 1 series. I'm positive the stock diverter valve is not meant to handle more than 400+ whp.

[vladr]

Never mind... got all I need from this:

http://jsalmi.com/bov/

Makes sense and confirms my assumption.



@APupNamedSmokey: I think this article agrees with your train of thought....

Now I see.."if you have a BOV, you better NEED one (you make a sh** load of power), otherwise...congratulations on wasting your money!"

Hahahahah

[oman135]

Sound!
getting a BOV with stock power is a waste !

[ES BMW]

Mostly sound. There are upgraded diverter valves from Forge and others that can handle the increased boost... but they don't make rice for you.

I'm with you. I can't stand BOVs!

[vladr]

At least I'm not the only one haha...

Ps now I'm thinking...if you have a chip, which increases the boost to like 12-13psi (depending on the chip) ...do you NEED to upgrade the stock diverter valves?

[Andrew@LutzPerformance]

Diverter valves are great for certain boost level's (pretty much all N54's fit this range). But when you get into higher boost levels 25+ on larger higher flowing turbo's, the Diverter valve setup probably wont be able to be efficient in protecting the turbo from compressor surge (air going in the opposite direction toward the turbo) compressor surge can cause some serious damage and drastically shorten the life of any turbo.

So IMO blow off valves are just to make a sound, but also have a specific purpose, now if you are using stock turbo's and under 20psi, then yes your argument has more basis. But for example if your running like an S54 with HPF's turbo setup, a PT67 and 16+ psi your going to want to run a blow off valve rather than diverter.

[ES BMW]

Don't they both work in the same way... there's a piston that's held in place with a spring and actuated by some kind of vacuum line to redirect built up pressure. They main difference is that the BOV vents to the atmosphere where the DV keeps it within the system.

The make stiffer DV springs for higher boost applications.

[romak47]

Well , id take that info into account too if he was talking about an N54 motor that has a MAF. But we dont have a MAF. MAF's are oil sensitive components, and dont apply well to our n54's (they love to recirculate the oil back into the charge pipe). So we dont have MAF's.. and therefore the "measured air" this dude talks about doesnt come into play for our engines and I highly doubt you will run rich by having a BOV vs DV in the n54.

and ..
use search yo..

http://www.1addicts.com/forums/showthread.php?t=378261

Originally Posted by vladr

Never mind... got all I need from this:

http://jsalmi.com/bov/

Makes sense and confirms my assumption.



@APupNamedSmokey: I think this article agrees with your train of thought....

Now I see.."if you have a BOV, you better NEED one (you make a sh** load of power), otherwise...congratulations on wasting your money!"

Hahahahah

[vladr]

Originally Posted by TrackRat

Yes you are correct diverter valves and BOV's operate exactly the same.

Some folks just like to make their BMW into a Honda, that's why they buy a BOV.

Hahahhahahahahha.....hahahahah

So does everyone agree with Andrew? Since tunes only make our cars go up to <15psi, it's ok to keep them stock?

[Luiggie135i]

I installed a BOV(Tial) because stock charge pipe blows off and broke by the secure clip so I ordered a Stett Perf. charge pipe which 100 times better than stock and it comes with TIAL BOV.