Pros & Cons Of Not Running A Bov

[Dose Pipe Sutututu]

but saying that, the speed of turbine is porportional to the speed of the exhaust turbine which propells the entire turbo unit, as long as there is x number of pressure exiting the motor through the exhaust, the speed of the turbine is proportional to the pressure that needs to drive the turbine.

BOV or no BOV from my understanding the difference is turbine speed is so neglgible. True the +ve pressure on the hot side "might" slow down the turbine's speed, but most of it exits back out the intake

[**RB2530**]

but saying that, the speed of turbine is porportional to the speed of the exhaust turbine which propells the entire turbo unit, as long as there is x number of pressure exiting the motor through the exhaust, the speed of the turbine is proportional to the pressure that needs to drive the turbine.

BOV or no BOV from my understanding the difference is turbine speed is so neglgible. True the +ve pressure on the hot side "might" slow down the turbine's speed, but most of it exits back out the intake

Sorry mate I am a little lost.

During the 'gear change' I am assuming that the exhaust gas pressure drop across the turbine (hot side) is very low and therefore very little energy is put into the exhaust wheel to keep it spinning.

On thinking about it some more the would be some windage across the turbine wheel which would act to slow the T/C rpm. I am not sure if this was what you were getting at?

The windage would be fairly low (I assume) due to the temperature of the exhaust gas (low viscosity) and also the smaller dia of the exhaust wheel when compared to the compressor wheel dia...

[08yannch]

why would the manufactures put BOV's on there cars if it is not needed. cars are designed by engineers and one major part of being a engineer is to keep the cost of a product as low as possible while still maintaining the products life and functionality. so if a BOV is not needed the engineers wouldn't have put it on.

how about we all get automatics.

auto = WOT 4 gear changes = BOV stays shut "right ?"

[l0WRB]

one thing bov's are good 4 paper weights

[**RB2530**]

one thing bov's are good 4 paper weights

They also make for exciting discussions on SAU..

[Harey]

why would the manufactures put BOV's on there cars if it is not needed. cars are designed by engineers and one major part of being a engineer is to keep the cost of a product as low as possible while still maintaining the products life and functionality. so if a BOV is not needed the engineers wouldn't have put it on.

how about we all get automatics.

auto = WOT 4 gear changes = BOV stays shut "right ?"

so cars dont have to meet emissions?

[75coupe]

So does this mean performance houses like PAC performance for instance are wrong by installing (as part of a build) a BOV on their own and their cuastomers cars, therse guys have been doing it a fair while now, I reckon they know how to make cars go fast and keep them going fast.

[.WILKO.]

I see my thread has created alot of controversy...

My understanding (and could be right or wrong) they was designed for emmision purposes... but compressor surge is not something i would like to happen...

If i dont run one will get the "DOSE" sound?? can anyone elebreate on "DOSE"?

I must admit i am still undecided but will run without, and add in if needed.

Edited March 25, 2010 by wilkor32gtr

[QWK32]

if you want to find out more about what "DOSE" is just search youtube, use search terms like "fully sick dose" or "vl dose" lol

also don't mistake compressor surge with dose, they are two different things.

[Harey]

So does this mean performance houses like PAC performance for instance are wrong by installing (as part of a build) a BOV on their own and their cuastomers cars, therse guys have been doing it a fair while now, I reckon they know how to make cars go fast and keep them going fast.

No one said that its wrong. The discussion is whether it is dangerous to the turbo to not run a bov, of course running a bov wont do any damage. I am of the opinion that bovs are not required and didnt run one on my previous car for 5+ years with no issues. Yes this is far from conclusive evidence but just my experience.

[R31Nismoid]

I see my thread has created alot of controversy...

My understanding (and could be right or wrong) they was designed for emmision purposes... but compressor surge is not something i would like to happen...

If i dont run one will get the "DOSE" sound?? can anyone elebreate on "DOSE"?

I must admit i am still undecided but will run without, and add in if needed.

People just waffling on about largely random stuff

Fact is you are running AFM - you need a BOV recirc to get it all working correctly as intended from el-factory.

[Lazy-Bastard]

Lets consider for a minute the fact that most race cars don't run a BOV.

Lets consider for a minute the ONLY reason they were created was for emmisions reasons.

Lets consider for a minute the only people who started spouting about engine wear and turbo wear were the manufacturers of aftermarket BOVs...

The only thing they will do is remove "dose" (Which is perfectly fine, non damaging and doesn't slow the compressor down)

I run a MASSIVE fark off turbo, laggy as hell, and between shifts, it comes snapping back on full boost. The real way to setup a wastegate will prevent lag between shifts from not running a BOV...

These guys used one on their race car, I reckon they might have a fair idea what they are doing?....

[.WILKO.]

if you want to find out more about what "DOSE" is just search youtube, use search terms like "fully sick dose" or "vl dose" lol

also don't mistake compressor surge with dose, they are two different things.

haha after i posted that i went on youtube, typed in "dose found a few.... then went "fully hectic VL dose bro" and found like a million hits

I know its more commonly known with VL turbos? why is this? no BOV? no AFM? usually no pod? fully hectic owners?..

[Mr. Untouchable]

NO WAY..

I finally got around to fitting GTR BOV's to my car last weekend. I have previously run No bov and then a atmo blitz bov(due to laziness and not having GTR BOV's), the car is so much better to drive. No gay hektik noises going on.

much better between gears, no popping and over fueling and running like a hairy goat.

makes life with a large turbo on the street much more enjoyable. (AFM equipped anyway)

[.WILKO.]

People just waffling on about largely random stuff

Fact is you are running AFM - you need a BOV recirc to get it all working correctly as intended from el-factory.

Nismoid - are you saying IF i run a BOV its needs to be plumbed back not atmos vented becuase its AFM and will calculate fuel for air that never gets there becuase its vented or you sayying i need one plumbed back full stop as im running a factory ecu?

[rob82]

Reading this thread is like masturbating with a cheese grater - slightly amusing........ but mostly painful!!

[Dose Pipe Sutututu]

over fueling can be corrected, rows 1 to 2 on my map have the same amount of fuel as idle, there's no over fueling, pops or farts with my car between gear changes and the idle doesn't fall on its ass.

[Fordy85]

People just waffling on about largely random stuff

Fact is you are running AFM - you need a BOV recirc to get it all working correctly as intended from el-factory.

...or you move the afm and run whatever bov you like including none at all!

[aerofocker]

what a load of utter shit talk! its king of like getting 100 people to talk about neucleer reactors, 98 of the people have no scientific background what so ever and just like the sound of there voices 2 of the people are genuine scientists who know what they are talking about result: you cannot hear what the scientists have to say because of all the shit talkers, this thread is 98% full of shit and i dont know where to start,suggest deleeting the lot and starting agian!

[**RB2530**]

what a load of utter shit talk! its king of like getting 100 people to talk about neucleer reactors, 98 of the people have no scientific background what so ever and just like the sound of there voices 2 of the people are genuine scientists who know what they are talking about result: you cannot hear what the scientists have to say because of all the shit talkers, this thread is 98% full of shit and i dont know where to start,suggest deleeting the lot and starting agian!

Anto,

Well I am glad to read that you enjoyed this thread.

I see from your post that there may be some loss in translation possibly because you are not a local and although we all speak english, we use it in many different ways. I hope you don't mind but I have taken the liberty of rewording your post so it comes across a bit better when the average Aussie reads it.....

Hello all from Anto,

Well what an interesting topic!!

There is a lot information to get through. Its awesome to see threads like this where people from a range of differing academic backgrounds come together and relay their experiences to discuss a topic that we are all interested in...Unlike topics such as 'nuclear' (tricky word to spell...) reactors as not many people actually have these and those that do are probably scientists. The details would be way too complex for most of us to understand anyway...

There are not enough threads like this...98% of this thread brilliant and the remaining 2% (as usual) is from people butting in and making meaningless statements that do not relate to the topic at all. Wouldn't it great if people who had nothing constructive to say , actually didn't say anything at all...

Very kind regards,

Anto...