Mac Dog
Leaving Skid Marks
don't start the bov/no bov debate......
p.s - no bov's 4 lyf yO!
p.s - no bov's 4 lyf yO!
POD FILTER's I need help people, please!!!!!!!!!!!!
- Thread starter millsy
- Start date
Kenneth
1 AYC Bar
Steve, if you don't know how Mitsubishi AFMs work, you should not be giving advice about pod filters.
VR-4s have very small turbos (and therefore small bearings) and run at close on 200,000 RPM. You WILL significantly shorten their lifespan by not using a BOV.
If you don't care that your turbos won't last as long as they should, then don't use a BOV... It does sound cool.
VR-4s have very small turbos (and therefore small bearings) and run at close on 200,000 RPM. You WILL significantly shorten their lifespan by not using a BOV.
If you don't care that your turbos won't last as long as they should, then don't use a BOV... It does sound cool.
i fail to see how the size of the turbo/bearings or rpm have any impact on the life span of the turbo when comparing bov vs no bov.
like whats been stated, we dont need another one of these threads. but bov or not, and whatever u believe works, the dimensions and specs of the turbo will have a much profound impact of the lifespan of a turbo than using a bov or not.
like whats been stated, we dont need another one of these threads. but bov or not, and whatever u believe works, the dimensions and specs of the turbo will have a much profound impact of the lifespan of a turbo than using a bov or not.
Kenneth
1 AYC Bar
Thats where we differ Steve, it isn't what I believe (obviously in your case, it is) it is what the manufacturers state. Garrett for instance, have published that you need to use a BOV to prevent premature failure due to excessive thrust loads caused by compressor surge.
Bearing size, shaft size any size for that matter, has a profound impact. It is called stress, bigger objects of the same material (in this case alloys) can absorb much more stress (heat, impact etc) without deforming.
A small metal shaft running at 200,000 RPM, inside a small metal bearing, at high temperatures, running on a thin film of oil doesn't require much to start causing damage.
As I said, if you don't care, thats fine. But to tell others that it doesn't matter is just plain wrong.
Unless you have some actual proof? A pair of VR-4 turbos which have been running 150,000km without a BOV would be enough for me.
Bearing size, shaft size any size for that matter, has a profound impact. It is called stress, bigger objects of the same material (in this case alloys) can absorb much more stress (heat, impact etc) without deforming.
A small metal shaft running at 200,000 RPM, inside a small metal bearing, at high temperatures, running on a thin film of oil doesn't require much to start causing damage.
As I said, if you don't care, thats fine. But to tell others that it doesn't matter is just plain wrong.
Unless you have some actual proof? A pair of VR-4 turbos which have been running 150,000km without a BOV would be enough for me.
bradc
1 AYC Bar
It should be pointed out that this is coming from the same person suggesting pod filters will provide a benefit on a VR-4.
right next to the part where putting 235's on a 7" rim is advised
BAH. HA. HA.
I quite enjoyed that.
I have an HKS Super Powerflow pod on my car and as far as I know it hasn't given me cancer or resulted (even indirectly) in the eating of any babies.
Macca
Showing some Leg.
Just on the question on stock airboxes, I got mine from kempys the link for the site is somewhere on the forum. I payed $100 for it.
And just on BOV's I can't say I have looked into it for cars but almost all jet turbine engines have a "pressure relief valve" which is basically a BOV for jet engines and considering jet engines are basically giant turbos I think they might be important.
Rolls Royce have been making aircarft engines for a while. Just my 2c.
And just on BOV's I can't say I have looked into it for cars but almost all jet turbine engines have a "pressure relief valve" which is basically a BOV for jet engines and considering jet engines are basically giant turbos I think they might be important.
Rolls Royce have been making aircarft engines for a while. Just my 2c.
bradc
1 AYC Bar
Just less power and more fuel usage
godzilla
1 AYC Bar
- Location
- QLD / Tweed Coast
- First Name
- Trevor
- Drive
- 1/19 2002 FL Legnum Type 'S' Manual in Black with Suede Recaro's!
Sell the airbox Tim, just name your price and the minions will pay!
are u sure its Garrett making these claims and not bov manfacturers? because anyone trying to push a product they sell and make money from is going to be pro-bov in their reasoning. however with such claims have u seen any proof of a life span of a turbo with and without a bov. i sure havnt and ive been looking for a long time. if u any evidence at all, i would love to see it.
u say a small metal shalf spinning at 200,000 rpm at high temp is tempremental to damage. well they seem to last well over 100,000kms on cars under extreme pressure and heat. and ur saying that releasing the air 'gradually' will have any affect what so ever. please, if u got some evidence, share it with us.
doesnt it seem funny so many cars ran no bov's and everything seemed to run miraculously sweet before emmision became more stringent.
im not trying to say ur wrong, but where is the evidence. any manufacture can make claims to help push their sales, and most do. i mean the ab-fab machines will give u rock hard abs, but not only that, help u lose weight with no regard to diet, but also give u a tan and the ability to rip apart ur shirt when chicks walk past. thats gota be true right, i mean i saw it in a commercial and i dont think companies would be so undermining to falsely advertise something that has little benefit.. would they.
like i said previously, high powered and boosted drag cars (in excess of 40psi) dont use bovs and their turbos seem to work, hmm weird hey. and most drifters dont use bov's either and they defiantly give their cars a thrashing.
none of my cars have ever run bov's and so far im not responsible for global warming, aids or the war on terror. amazing hey.
thats the wastegate, all turbos have that and it regulates pressure to prevent over boosting. hardly a bov.
Kenneth
1 AYC Bar
First of all, here is a link: http://www.turbobygarrett.com/tech_center/turbo_tech101.html
Here is even a quote: "We will explore exhaust manifolds in more detail in subsequent tutorials; however, it is important to understand the need for a compressor bypass valve (commonly referred to as a Blow-Off valve) on the intake tract and a Wastegate for the exhaust flow"
In the linked text, it VERY CLEARLY says that a BOV is needed to prevent the compressor going into surge and the thrust loads associated with it.
I didn't say the turbos are prone to damage, I said their resistance to out of specification behaviour is made less due to the fact they are small.
Yes, turbos work without a BOV, no arguments there. It IS bad for their lifespan though.
A competition car is another story and not relevant here, unless you have a VR-4 which is involved in competitive racing of some sort. Do you? Does anyone here?
The reason you cannot compare a competition car is because a competition vehicle doesn't measure success in service life other than if they managed to have the part in question last until its next scheduled replacement. Go do some research on Rallying or any other racing where they use Turbos. Go find out how many KMs the do before replacing their turbos.
What proof do you need? I have one VR-4 at close to 140,000km on standard turbos without any issues. Most standard turbos which run with a BOV last this long or longer.
Have yet to see anyone who can say they have run any great distance with no BOV. So we know that standard turbos last a long time. Can you prove they last a long time without?
Here is even a quote: "We will explore exhaust manifolds in more detail in subsequent tutorials; however, it is important to understand the need for a compressor bypass valve (commonly referred to as a Blow-Off valve) on the intake tract and a Wastegate for the exhaust flow"
In the linked text, it VERY CLEARLY says that a BOV is needed to prevent the compressor going into surge and the thrust loads associated with it.
I didn't say the turbos are prone to damage, I said their resistance to out of specification behaviour is made less due to the fact they are small.
Yes, turbos work without a BOV, no arguments there. It IS bad for their lifespan though.
A competition car is another story and not relevant here, unless you have a VR-4 which is involved in competitive racing of some sort. Do you? Does anyone here?
The reason you cannot compare a competition car is because a competition vehicle doesn't measure success in service life other than if they managed to have the part in question last until its next scheduled replacement. Go do some research on Rallying or any other racing where they use Turbos. Go find out how many KMs the do before replacing their turbos.
What proof do you need? I have one VR-4 at close to 140,000km on standard turbos without any issues. Most standard turbos which run with a BOV last this long or longer.
Have yet to see anyone who can say they have run any great distance with no BOV. So we know that standard turbos last a long time. Can you prove they last a long time without?
mine has been off the car for the last 15,000 kms. time will tell. but ive had my silvia for 4 years racking up nearly 100,000 kms and no failures.
if u have evidence and testing, great, id love to see it and for u to prove me wrong.
however i always hear the generic auto barn high school kids reply which irritates me. something along the lines of.. 'im not sure exactly of the long term affects, but its just safer to run one just in case'. now thats a piss poor excuse. hell, i may as well carry around 4 spares with me 'just in case'.
like u posted urself, saying it will reduce the lifespan. says who? people seem to hear this with no evidence and regurgitate it at every opportunity. actually, who ever sees their turbo thru to the end of its life anyway.
anyway so u may be thinking, well if a bov isnt necessary, then whats the point of removing it anyway. better performance. seeing the turbos dont need to spool up again, the boost is already on tap. many people have noticed this increase in performance when removing their bov.
so i guess play it safe, dont bother to fully understand the affect bov's have, and give the technical auto barn advice. and maybe in the long run in 150,000 kms (with no evidence), u may get what, another 5-10K kms out of ur turbo. and where did i pull those numbers from? absolutely no where, seeing hard facts and testing has no place in the realm of car talk and hype.
btw im very aware of competition cars and their replacements. hell, even some drag cars rebuild their engine after every run. i wasnt trying to show that they dont use them due to the long term affects. but if there was any gain what so ever with a bov, they would indeed use them to get that edge over the competition. and guess what, they dont use them.
if u have evidence and testing, great, id love to see it and for u to prove me wrong.
however i always hear the generic auto barn high school kids reply which irritates me. something along the lines of.. 'im not sure exactly of the long term affects, but its just safer to run one just in case'. now thats a piss poor excuse. hell, i may as well carry around 4 spares with me 'just in case'.
like u posted urself, saying it will reduce the lifespan. says who? people seem to hear this with no evidence and regurgitate it at every opportunity. actually, who ever sees their turbo thru to the end of its life anyway.
anyway so u may be thinking, well if a bov isnt necessary, then whats the point of removing it anyway. better performance. seeing the turbos dont need to spool up again, the boost is already on tap. many people have noticed this increase in performance when removing their bov.
so i guess play it safe, dont bother to fully understand the affect bov's have, and give the technical auto barn advice. and maybe in the long run in 150,000 kms (with no evidence), u may get what, another 5-10K kms out of ur turbo. and where did i pull those numbers from? absolutely no where, seeing hard facts and testing has no place in the realm of car talk and hype.
btw im very aware of competition cars and their replacements. hell, even some drag cars rebuild their engine after every run. i wasnt trying to show that they dont use them due to the long term affects. but if there was any gain what so ever with a bov, they would indeed use them to get that edge over the competition. and guess what, they dont use them.
bradc
1 AYC Bar
Let me rephrase that last line for you
"but if there was any gain IN POWER what so ever with a bov, they would indeed use them to get that edge over the competition"
"but if there was any gain IN POWER what so ever with a bov, they would indeed use them to get that edge over the competition"
Macca
Showing some Leg.
Ahhh, nope it's for the compressor stage of the engine and as such is "like" a bov for a jet engine. There is also sometimes a relief valve or "wastegate" for the exhaust but not often as it's the intake gasses which are regulated.
I'm an aircarft technician and work on turbo shaft engines and helicopters for a living and was simply saying jet engines have something "like" a bov and they wouldn't have them if they didn't need them and considering jet engines are basically giant turbos I would think that turbos may be prone to the same loads and damages.
But like I also said, havnt looked into it for cars just an observation I've made. Everyone is entitled to their own opinion but I'll be keeping mine on.
Macca
Showing some Leg.
Too many tools putting the really loud ones on their WRX's and Skylines, oh and VL's too. Hahaha. Well maybe that's just Canberra. It's like chrome wheels went out because too many people where putting them on their barinas and Mazda 2's. I guess car parts are like fashion for some people.
As a side note I have nothing against the above mentioned cars and parts just the tool drivers which of course isn't all of them just a select few.
As a side note I have nothing against the above mentioned cars and parts just the tool drivers which of course isn't all of them just a select few.
Macca
Showing some Leg.
ROFLMAO. Don't suppose you could put a pic up of that?
