Jump to content
SAU Community

Recommended Posts

I ran my RB20 for over 3 years with no BOV. And the previous owner ran it like that as well, it was boosted for most of its life and handled backing off at 1 bar just fine. Chuffed like a mofo, and sounded great.

Got bored with the turbo and replaced it with an R33 S2 one, and continued running without a BOV. It was fine as well.

NO BOV = NO WORRIES. Anyone who tells you your turbo will blow up has been brainwashed by the "your car needs an aftermarket BOV for better performance (and more money in my hip pocket peddling junk to idiots)" brigade.

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588266
Share on other sites

i personally suggest running one. why would you want all that air slamming into your turbo fins then once you get back on the gas you got the little lag from you turbo slowing down. i kno people who ran no bov and their turbos are still ok then i know some that had their shit blow up. you never kno you could be next. id rather spend a couple hundred bucks on a bov versus buying a new turbo sooner than i have to

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588368
Share on other sites

I ran my RB20 for over 3 years with no BOV. And the previous owner ran it like that as well, it was boosted for most of its life and handled backing off at 1 bar just fine. Chuffed like a mofo, and sounded great.

Got bored with the turbo and replaced it with an R33 S2 one, and continued running without a BOV. It was fine as well.

NO BOV = NO WORRIES. Anyone who tells you your turbo will blow up has been brainwashed by the "your car needs an aftermarket BOV for better performance (and more money in my hip pocket peddling junk to idiots)" brigade.

no bov = stupid

yes its not going to "blow up" your turbo, bit it WILL create more lag in between gearchanges than necessary, i would never run any turbo car that i have without a bov. If you dont want the ptttch sound, plumb it back, easy.

search, this has been covered to death

Edited by R34GTFOUR
Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588463
Share on other sites

lol!

it does not created more lag between gear changes lol it does the opposite. nothing wrong with running no bov most drifters dont use bov, and i have personally seen many cars go for years without a bov and big power and no problem what so ever with their turbo.

its a urban myth ...

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588518
Share on other sites

cefiro's and other nissan family cars equipped with RB20DET's run no BOV's (plumb back or atmo) and have worked fine for their entire lives (all 17 years of it). Granted they always ran on stock boost on stock turbos. Once you start changing factory boost levels and turbos etc, it'd be wise to put one in.

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588522
Share on other sites

lol!

it does not created more lag between gear changes lol it does the opposite. nothing wrong with running no bov most drifters dont use bov, and i have personally seen many cars go for years without a bov and big power and no problem what so ever with their turbo.

its a urban myth ...

aahh wat??

your telling me air being forced back into a turbine thats spinning the other way wont slow that turbine down, then once that turbine's rpm has been reduced it doesnt take more time to spool up the turbo the the rpm which is would still be at if there was a bov there???

im the one lol

a mate of mine has a xr6t with no bov and the compressor surge is huge inbetween gearchanges when hes at 20psi, and there IS lag when he changes gears because of this. A bov in this situation WILL reduce spool up (or lag whatever you want to call it) time in between gearchanges when your on boost in the previous gear

its not a myth, its plain old physics

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588535
Share on other sites

aahh wat??

your telling me air being forced back into a turbine thats spinning the other way wont slow that turbine down, then once that turbine's rpm has been reduced it doesnt take more time to spool up the turbo the the rpm which is would still be at if there was a bov there???

im the one lol

a mate of mine has a xr6t with no bov and the compressor surge is huge inbetween gearchanges when hes at 20psi, and there IS lag when he changes gears because of this. A bov in this situation WILL reduce spool up (or lag whatever you want to call it) time in between gearchanges when your on boost in the previous gear

its not a myth, its plain old physics

where does the air go? if the air is not vented, it stays in the pipe. therefore once you jump onto the throttle again and the throttle body opens, and because the pipe is already fulled with air, it goes straight into the throttle body, unlike if you vent it.

this is one of the main reason why pro. drifters don't run bov as it helps with lag between gear changes *weather its noticeable or not is another issue*

also how fast is the turbo rotating/spinning ? 100,000rpm or more, do you think that the amount of air remaining in the pipe has enough force to slow down the turbine when it is speeding at such a high rate?

yes its physic, the air must apply a force on the turbine blades. the turbine blades are rotating which means they also have a force...

so we have:

Air:

F= ma

m= mass of the body (kg)

a = resultant acceleration of the body (m/s^2)

now because the turbine blades are rotating they have a torque.

t=mr^2a

m=mass(kg)

r=radius(m)

a=angular acceleration (rad/s^2)

but that is assuming the turbine blades are a point mass system and we don't consider the mass moment of inertia

what im tring to get at is that one force will be alot larger than the other, so the impact of the small force on the larger force won't be that great....

also their are other issue to consider but its late and i can't remember this stuff off the top of my head would have to go grab my uni books and start quoting lines etc

just to summaries my point. the Force exerted by the air is not great enough the reduce/impact the turbine blades , due to the relative large force it creates (creates is not the best word but you get my point)

Edited by [Michael]
Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588553
Share on other sites

where does the air go? if the air is not vented, it stays in the pipe. therefore once you jump onto the throttle again and the throttle body opens, and because the pipe is already fulled with air, it goes straight into the throttle body, unlike if you vent it.

this is one of the main reason why pro. drifters don't run bov as it helps with lag between gear changes *weather its noticeable or not is another issue*

also how fast is the turbo rotating/spinning ? 100,000rpm or more, do you think that the amount of air remaining in the pipe has enough force to slow down the turbine when it is speeding at such a high rate?

yes its physic, the air must apply a force on the turbine blades. the turbine blades are rotating which means they also have a force...

so we have:

Air:

F= ma

m= mass of the body (kg)

a = resultant acceleration of the body (m/s^2)

now because the turbine blades are rotating they have a torque.

t=mr^2a

m=mass(kg)

r=radius(m)

a=angular acceleration (rad/s^2)

but that is assuming the turbine blades are a point mass system and we don't consider the mass moment of inertia

what im tring to get at is that one force will be alot larger than the other, so the impact of the small force on the larger force won't be that great....

also their are other issue to consider but its late and i can't remember this stuff off the top of my head would have to go grab my uni books and start quoting lines etc

maybe i've lost my point i was tring to get across but yeah

i know what your trying to get at, your thinking along the lines of the force required to slow down the turbine because of its weight cannot be produced by the force that the "trapped" pressurised air stuck in the intercooler piping, i studied physics aswell haha

But think along these lines,

The turbine is spooled from the load that the engine produces, no load = pretty much no boost as you would know with free reving (lets not get too technical and mention antilag)

I dont know why im saying this cause by the look of your post count you've been here for sometime and you know your stuff but anyway,

so when you get off that throttle and slam shut that throttle body butterfly, that compressor doesnt have the driving force from the exhaust turbine that it had when the throttle was on and the engine was under load, so the inlet charge WILL overwhelm the compressor wheel and slow it down. Theres not a matter of ifs or buts, the inlet charge will reduce the turbine rpm, maybe not all that noticeable at lower boost levels, but when the intake charge is up there, i've noticed a difference.

I've noticed with all my cars an instant improvement with a bov, atmo or plumbback. The same xr6t i mention above has a tad over 500rwhp and you can feel it slowing down in each gearchange, then have to spool again. Another mate had a stockish s14, no bov he ran a mid 13, nothing else changed expect a bov and he shaved .2 of a second off his time. If only every noticed nothing but improvements with a bov attached, and that why i stand by my original comment that i will never run a turbo car thats under my name without some sort of vent valve.

Its got abit off topic, and its late so im heading off haha

Edited by R34GTFOUR
Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588569
Share on other sites

i know what your trying to get at, your thinking along the lines of the force required to slow down the turbine because of its weight cannot be produced by the force that the "trapped" pressurised air stuck in the intercooler piping, i studied physics aswell haha

But think along these lines,

The turbine is spooled from the load that the engine produces, no load = pretty much no boost as you would know with free reving (lets not get too technical and mention antilag)

I dont know why im saying this cause by the look of your post count you've been here for sometime and you know your stuff but anyway,

so when you get off that throttle and slam shut that throttle body butterfly, that compressor doesnt have the driving force from the exhaust turbine that it had when the throttle was on and the engine was under load, so the inlet charge WILL overwhelm the compressor wheel and slow it down. Theres not a matter of ifs or buts, the inlet charge will reduce the turbine rpm, maybe not all that noticeable at lower boost levels, but when the intake charge is up there, if noticed a difference.

I've noticed with all my cars an instant improvement with a bov, atmo or plumbback. The same xr6t i mention above has a tad over 500rwhp and you can feel it slowing down in each gearchange, then have to spool again. Another mate had a stockish s14, no bov he ran a mid 13, nothing else changed expect a bov and he shaved .2 of a second off his time. If only every noticed nothing but improvements with a bov attached, and that why i stand by my original comment that i will never run a turbo car thats under my name without some sort of vent valve.

Its got abit off topic, and its late so im heading off haha

fair enough i can see where your coming from :P

from my personal experiences i notice no difference from running no bov to running a blitz bov (350rwhp @ 16psi), but then again it comes down to the car setup, driving style etc as every car is difference.

i understand what your saying about the turbine blade spinning but i was under the impression that even when idle or during gear change the turbine blades are still spinning at very high rpm. Also the reason why i stated the forumlas so show that torque was also affect by angular acceleration not just mass, and one would assume the angular acceleration to be a large number due to the rpm that the turbine blades are traveling at.

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588573
Share on other sites

sorry i cant quote, internet too slow.

but Micheal said where does the air go? if its not vented it stay in the pipe.

You're right where does it go? it pushes back to the turbo thats the only way it can go. if you got 12 psi in an enclosed area it going to go back the way it came. its just not going to stop and sit there and wait for the butterfly to open back up. the turbo is going to loose rpm then its going to have to spool again.

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588571
Share on other sites

sorry i cant quote, internet too slow.

but Micheal said where does the air go? if its not vented it stay in the pipe.

You're right where does it go? it pushes back to the turbo thats the only way it can go. if you got 12 psi in an enclosed area it going to go back the way it came. its just not going to stop and sit there and wait for the butterfly to open back up. the turbo is going to loose rpm then its going to have to spool again.

Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588574
Share on other sites

sorry i cant quote, internet too slow.

but Micheal said where does the air go? if its not vented it stay in the pipe.

You're right where does it go? it pushes back to the turbo thats the only way it can go. if you got 12 psi in an enclosed area it going to go back the way it came. its just not going to stop and sit there and wait for the butterfly to open back up. the turbo is going to loose rpm then its going to have to spool again.

correct :P the air will go back towards the turbo but how much of the air will hit the turbo. depending on what car you have and your intercooler piping setup will determine the length of pipe and how far the air will have to travel to reach the turbine of course some of the air will come into contact with the turbine blades, and theoretically impacting on the turbine rpm. the time between the throttle body closing and opening is maybe a second, depending on the speed the air is traveling, the amount of air in the pipe and the total distance between throttle body and turbine blades will determine how much air is transfer through the blades and how much air remains in the pipe.

also depending if the air flow is laminar or turbulent, will have an affect on things too.

Edited by [Michael]
Link to comment
https://www.sau.com.au/forums/topic/201983-is-this-bad/#findComment-3588575
Share on other sites

Guest
This topic is now closed to further replies.


  • Similar Content

  • Latest Posts

    • My experience with Rising Sun Exports Before agreeing to the sale I tried to do as much research as I could (obviously), his Facebook reviews are 98% and he goes Live at least once or twice a week. I contacted 2 people in the UK who had used him for their imports, both had positive feedback. His explanation and talk through of the import process was thorough, answering any query no matter how stupid it was. It felt as soon as the money was sent, communication dropped off. I asked for shipping updates every 2 weeks or so, not wanting to pester him, he never had any updates. I wasn't informed the car had been dropped off at the port, I only found out by his Facebook story. I asked for the photos taken at the port, knowing he would need some for insurance purposes. I received a few 5 second clips and that's it. When asked again, he said his staff had them. Weeks later I asked again, he tells me he doesn't have any, but does have 50 photos from the original advert. I never received them. I eventually got the documents sent via WhatsApp after I mentioned the port was requesting them. I purchased a CarVX report, to find out the vehicle is a Grade R with recorded accident damage, first recorded in 2017 when it was first auctioned. He never told me the grade, then again I didn't ask. His response was "Grade R means nothing, it wasn't chassis damage". Still, I would have liked to have been informed about it. Jon prides himself on being open and honest when it comes to inspecting cars, it's his main job doing so at the auctions for customers. When the vehicle arrived in the UK I noticed a few little cosmetic issues. It's a 21 year old car so it wasn't going to be mint condition. The side skirts are cracked on each corner and the sealant is failing. The front grill on the bonnet/hood isn't secured very well, mounting studs are missing. Both minor things, but again, it would have been nice to be told. During a Facebook Live walk around video of the vehicle, he mentioned it has a front Whiteline anti roll bar/sway bar. While on the inspection ramp, I noticed the stock item has been installed. When first questioned, his response was "the ARB? Switched? Since when, it never had them". Since sending video and photo evidence I've not received a response. I'm probably being over critical of the overall condition of an old car, but all I wanted was honesty (which he claims to have). I'm aware I wasn't his only customer, he's busy doing XYZ but other reviews praise him for great communication with regular updates and photos, I felt I didn't receive the same treatment. 
    • I was able to get some underside photos while the car was on the ramp The suspension is all Altezza/IS200/IS300 so getting part's will hopefully be less of a headache
    • Welcome to my 2004 Toyota Mark ii IR-V Fortuna (series 2) With a 1JZ-GTE powerplant under the bonnet (hood) it'll give me plenty of scope for power upgrades. For those who aren't familiar with imports, the 1JZ-GTE is a 2.5L 6 cylinder VVTi engine with a single turbocharger. This has the factory R154 5 speed gearbox, along with a aftermarket 2 way LSD differential (brand unknown). Under the arches are a set of CST Zero 1 alloys, 18x9 +30 225/40 up front and 18x9.5 +15 265/35 on the rear. The car was quite low in Japan and there's evidence of the wheels catching the rolled arches/fenders. The tyre's aren't great so I'm in two minds whether to replace both or just the tyres and put up with the wider wheels on the rear. The car still uses stock brakes with the addition of some braided hoses. The exterior is stock with the exception of a BN Sports front bumper and a replacement Fortuna grill  Moving to the interior, the steering wheel has been replaced with a dished MOMO steering wheel (which will get swapped for my Momo Tuner for the time being) Defi Link Gauges are mounted above the climate controls and on the A pillar, the Oil Temp,Oil Pressure,Water Temp and Boost gauges should help with spirited and track driving  The stock seats have been replaced with some retrimmed Recaro bucket seats. Being a larger build these are a little snug, unfortunately the orange isn't for me so I'll look into replacing these down the line. Other modifications include a twin plate clutch, Blitz intercooler, Evolve alloy radiator, a stainless exhaust with decat, HKS EVC-S boost controller and coil overs
    • Apologies for the long read My R34 GTT was up for sale at the beginning of spring due to a few repairs creeping up. The strut tops needed replacing, roof and bonnet (hood) painting (yay for 3 stage pearl) and the underside stripped and treated. I sold the car which allowed me to be in a much better place financially. Leading up to the sale I was already thinking about the replacement. In an ideal world it needed to be a good all-rounder. Something I can mess around with, modify, do track days, do the school run, go on long drives etc.  Options included but not limited to... Laurel C35, Evo 8/9, Civic FD2, Impreza Hawkeye, Aristo and even an Audi S4 Avant (I've already got the Mazda 6 wagon). But there was always one car at the top of the list The Toyota Mark ii JZX110 I found an advert on a Facebook group for an example in Japan, from a seller called Jon at Rising Sun Exports. A few messages back and forth and Jon calls me from Yokohama one morning (or afternoon in his case). He briefly explained the import process, the costs involved and a repeat of the advert. After much deliberation, the price was agreed and the sale was locked in. I've never imported a vehicle so I jumped into the unknown head first. The money transfer was completed through wise.com (fees apply), very easy to use and the money was with him within a day or two.  The car suspension was raised for the vessel and the car dropped off at the port. It was 7 weeks later when the bill of lading was received and the freight invoice sent to me, followed by the export certificate a couple of days after (both digital copies) In the mean time the port had been in contact. I needed an agent to deal with the NOVA (notification of vehicle arrival) along with the tax/duty invoice, this was £75.00. The port also had a fee of £100, I'm guessing to cover the cost of the 10 day 'free storage' and for moving the car off the boat etc. They need a copy of the vehicle invoice, freight invoice and export certificate to allow the vehicle to pass through customs. The vessel arrived on Tuesday 5th August, the tax/duty invoice was generated and sent over. This is generally tax 20% and duty 10% of the vehicle value. Although the invoice came in at a higher amount than I had calculated. Once HMRC had received the payment the vehicle could be released from customs. I thought once the tax/duty was paid you could collect at any point, that's not the case. Your agent will need to book a collection slot, I requested Thursday 7th which was accepted, with a 9:00am slot allocated. It was a 5:00am start from Norfolk heading to Southampton. We eventually found the compound, upon presenting the bill of lading and some ID they released the car (they drove it out of the compound to the front ready for us to load up). The email from the port stated each slot had a 10 minute window, which seemed abit farfetched but the staff said it's not a strict rule. We were there for approx. 30-40 mins in total. A week prior to collecting I contacted my garage and explained the situation, I was able to get an inspection slot that afternoon. For the registration, DVLA require the car to be insured, for this I used a company called Adrian Flux who can insure the vehicle using the VIN number. 
    • Hey guys, looking for these side skirts if anyone can help me out. 
×
×
  • Create New...