When do you need / not need a BOV?

[daniel_g]

This thread has just gotten waaaay too pedantic haha.

[AdamB]

I just said that the BOV's are modified with stiffer springs, and are generally used in conjunction with a solenoid valve.

Besides the only reason you use an external wastegate is because the turbo is poorly designed.

[ste91]

I just said that the BOV's are modified with stiffer springs, and are generally used in conjunction with a solenoid valve.

Besides the only reason you use an external wastegate is because the turbo is poorly designed.

An external wastegate is generally an upgrade over the internal one.

Are you now suggesting that almost all turbos are poorly designed?

[AdamB]

This thread has just gotten waaaay too pedantic haha.

The guy asked wether you can use a BOV instead of a wastegate and you all go jumping on the topgear bandwagon shit.

I'm just expressing my knowledge and opinion, maybe if people researched the methods used in the past which quite frank work and are still in use today you wouldn't all be wasting money on things you don't need.

[Phil]

The Sky is Blue Mate.

YEAH BUT THE GRASS IS FRIGGING GREEN.

Phil

[AdamB]

An external wastegate is generally an upgrade over the internal one.

Are you now suggesting that almost all turbos are poorly designed?

Go and have a browse at Borg Warners EFR series turbo's dude. Edited December 18, 2013 by AdamB

[daniel_g]

The guy asked wether you can use a BOV instead of a wastegate and you all go jumping on the topgear bandwagon shit.

I'm just expressing my knowledge and opinion, maybe if people researched the methods used in the past which quite frank work and are still in use today you wouldn't all be wasting money on things you don't need.

You didnt answer the OPs question, you just contradicted Ste91's description.

There was no bandwagon jumping, i only mentioned the Topgear thing as a laugh ok.

I never said you were pedantic, but by quoting me im your reply i'm guessing you realised your 1st reply was just a shallow dig at Ste.

Express your knowledge and opinion all ya like buddy.

[Phil]

Are you now suggesting that almost all turbos are poorly designed?

You didnt answer the OPs question, you just contradicted Ste91's description.

Since handbags have been drawn, ill address the BOV query.

Yes 90% of old turbos are poorly designed, especially the ones we tend to use a cheap upgrades, the internal gate systems is quite the blockage in the exhaust housing/flow. CT9/TD04/etc

there are some tidier designs used, im pretty sure garretts have long had exgate only turbo options for the gt series that removed the nasty internal gubbings.

that still doesnt address why a coldside control system may be better than a hot side one, and that simply comes down the modern ball bearing turbos not suffering from overspin as easily and therefore you can set a target max boost on the cold side using a BOV and then trim as much of the rev range to this boost as possible.

(in the coldside setup all parts/valves etc are only dealing with intake air therefore cold = big plus)

ex.gate works grand but you have to pressurize and release hot gas,via an anti-flow dynamic runner into ex.wg before the turbo, reducing speed of airflow and actually hampering the turbo to even spool straight off, as pressure is no more important than flow direction.

and ofcourse all parts are hot in this scenario so you need screamer/dump pipe and a safe area to release this air.

Phil

Edited December 18, 2013 by Philm

[Phil]

Go and have a browse at Borg Warners EFR series turbo's dude.

http://www.full-race.com/docs/WG_setpoint.pdf

Adam, not suggesting your mr innocent here, as you clearly accepted the opportunity to be involved in the little information tiff

but do you just read this stuff or are you in the industry? the borg warners boys are pretty fresh in the field with their stuff, especially to big hp applications.

too anyone about to slag the life out of me, i would qualify all of the above with this, BOV boost control is not a setup that your going to see from a starlet trader anytime soon lol

its not a good system to try with you greddy BOV and it really wont ever fit with the EP/jap world, 5 years maybe cold side boost control will be the norm for factory german turbo cars.

Phil

Edited December 18, 2013 by Philm

[ste91]

So much contradiction here, one guy saying external wastegates are rubbish, another one saying there are turbos designed to work with external gates...

Regardless of what is "better" it stands that the vast majority of cars use a wastegate on the exhaust side to control boost, it doesn't matter what technical stuff you post on here, my original post explaining the difference between BOV and wastegate applies to 99% if not 100% of users on this forum and anything else after that just adds to the confusion.

Edited December 18, 2013 by ste91

[Phil]

So much contradiction here, one guy saying external wastegates are rubbish, another one saying there are turbos designed to work with external gates...

Ste91,

If the contradiction is something within my post feel free to elaborate and im happy to be clearer.

Though i dont see the contradiction in what you have said as its reasonable to say that there is better ways of controlling boost than wastegate and there are also turbos designed to work with external gates.

Regardless of what is "better" it stands that the vast majority of cars use a wastegate on the exhaust side to control boost, it doesn't matter what technical stuff you post on here, my original post explaining the difference between BOV and wastegate applies to 99% if not 100% of users on this forum and anything else after that just adds to the confusion.

If you really wanted to dismiss all thinking on the subject thats fine im not here to enlighten anyone, as i said the coldside control isnt applicable to normal starlet users. doesnt make any of the information wrong.

further you may be happy to remove yourself from the discussion now,

but you were the one posing some interesting questions..

Are you now suggesting that almost all turbos are poorly designed?

Are you seriously suggesting that having a massive boost leak is a better way of controlling boost than a proper external wastegate?

Sounds like a poor way of controlling boost to me, letting the turbo spin much faster than it would if it was controlled by a wastegate, would surely put the turbo out of it's efficiency range and then keeping the BOV open to release air you've essentially just got a massive boost leak...

im sorry you didn't like the answers.

it doesn't matter what technical stuff you post on here, my original post explaining the difference between BOV and wastegate applies to 99% if not 100% of users on this forum and anything else after that just adds to the confusion.

Again, happy to accept that people can be confused by information whether its right or wrong.

Phil

[ste91]

What the actual fuck are you going on about mate? You need to calm down and stop miss-reading things, I've said nothing against you (or anyone really, just expressed opinions) so why quote all of my posts?

[Phil]

What the actual fuck are you going on about mate? You need to calm down and stop miss-reading things, I've said nothing against you (or anyone really, just expressed opinions) so why quote all of my posts?

I didnt think i had mis-read anything but welcome to explain what you mean.

im perfectly calm from your post you seemed to think there was contradictory information, as i didnt see any wondered if you needed help understanding anything thats all.

Regarding the quoting of your posts, i thought it right to address your the questions you asked and are are now complaining about having received answers for.

I apologise genuinely that this seems to have upset you somewhat.

Phil

Edited December 18, 2013 by Philm

[daniel_g]

Thread of the week right here boys ;)

[ste91]

I didnt think i had mis-read anything but welcome to explain what you mean.

im perfectly calm from your post you seemed to think there was contradictory information, as i didnt see any wondered if you needed help understanding anything thats all.

Regarding the quoting of your posts, i thought it right to address your the questions you asked and are are now complaining about having received answers for.

I apologise genuinely that this seems to have upset you somewhat.

Phil

Are you for real?

"wondered if you needed help understanding anything" are you actually serious? Do not patronise me lol...

I haven't asked any "questions", my posts in reply to the other guy were rhetorical.

And after that I just skim read the replies and saw various things posted that contradicted eachother, from no one in particular.

I'm not sure why I'm even wasting my time, my earlier post was trying to be helpful and clear up confusion, this is why I rarely post on this forum anymore.

[daniel_g]

Wouldnt take notice Ste.

[Phil]

Are you for real?

"wondered if you needed help understanding anything" are you actually serious? Do not patronise me lol...

Nope not really lol,

the only truely serious part was the patronisation, that was real.

i was only winding you up because you were so annoyed at my quoted response.

I haven't asked any "questions", my posts in reply to the other guy were rhetorical.

Rhetorical is fine, if the question makes the right point, im quite sure yours didnt, but i daren't say anymore about whats right or wrong eh.

And after that I just skim read the replies and saw various things posted that contradicted eachother, from no one in particular.

Thats fine, you may be able to understand my response in light of the fact that despite your 'skim' approach, one of the random things you felt was contradictory was posted my me.

and it wasn't in fact contradictory.

Apologies again for the multi-quote usage.

Phil

Edited December 18, 2013 by Philm

[Phil]

this is why I rarely post on this forum anymore.

You shouldnt take it like that, the thread started off airy fairy, 2+2 does a bov give me more power crap.

then admittedly AdamB took the opportunity to take a point to task regarding boost control systems.

you then asked questions like

Are you seriously suggesting that having a massive boost leak is a better way of controlling boost than a proper external wastegate?

Despite you rhetorical designs the answer is pretty much yes.

and

Are you now suggesting that almost all turbos are poorly designed?

And again despite you intentions the answer is compared to today technologies turbos we use are poorly designed.

Nobody is saying the spitfire cant fly, just that it is poorly designed compared to a modern fighter jet.

Phil

Edited December 18, 2013 by Philm

[Chris Green]

[Phil]

Haha true though I argue with my shadow in reality too lol

Phil

Edited December 18, 2013 by Philm

[Xpect]

Would it be possible to have the high boost 'dump' recirculate rather than dump to atmosphere?

I like the chatter, but don't really want the 'WOOSH' on high boost...

Yes, that's exactly what most factory turbo setups do. It gives you less lag, less noise and (as far as I read) a longer turbo life as chatter really hurts the bearings and everything movin in the turbo casing (well, the german word would be "Welle", litterally also meaning "wave" but in this context would be the gear going through intake and exhaust wheel connecting them). The pressurized air when closing the throttle with no blow off (or dump valve) will not actually cause the turbo to stall as mostly there still is some air exiting the exhaust because the engine still runs. But there is much stress on the components as on one end the air is slightly trying to move the turbo backwards while on the other side (exhaust) the air is still forcing the turbo to move forward. This can (not must) lead to a broken gear between them both and thus a broken turbo. But mostly it will "only" lead to fast wear of seals and bearings and thus early turbo aging.

Damn, I know most engine and car parts names better in english than German but some others I just have to explain as I have no translation.

Edited December 20, 2013 by Xpect

[smithyithy]

You shouldnt take it like that, the thread started off airy fairy, 2+2 does a bov give me more power crap.

It started off as a genuine technical question, that spiralled into petty arguing, actually..

Thanks for the relevant replies though guys, all I wanted to know is whether they're really needed on aftermarket turbo setups.. I'll be going down the TD04 route soon(ish) and I'm not overly bothered about having the car go WOOSH all the time, so I just wanted to check if I'll actually need to buy an aftermarket BOV or not.

If I do, I'll just recirculate it, same as the screamer pipe, depending on which turbo kit I end up buying.

[Phil]

It started off as a genuine technical question, that spiralled into petty arguing, actually..

Thanks for the relevant replies though guys, all I wanted to know is whether they're really needed on aftermarket turbo setups.. I'll be going down the TD04 route soon(ish) and I'm not overly bothered about having the car go WOOSH all the time, so I just wanted to check if I'll actually need to buy an aftermarket BOV or not.

If I do, I'll just recirculate it, same as the screamer pipe, depending on which turbo kit I end up buying.

Aye sorry to hijack your thread mate, hope you got whatever answers you were looking.

Phil

[smithyithy]

Aye sorry to hijack your thread mate, hope you got whatever answers you were looking.

Phil

Naa it's alright dude, I did actually learn a bit from different people's inputs

[Xpect]

Well for reliability and long life a BOV would be good (to put my other post in few words).