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Location:
adelaide
Registered:
April 2003
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Re: BOV's
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Fri, 07 January 2005 07:11
 
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| Cool1 wrote on Fri, 07 January 2005 18:06 |
I also want to know about these F1 cars that you need to completely come off the throttle to change gears?
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watch some of the in car footage from the adelaide grand prixs and you will see with your own eyes
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 07:12
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| Cool1 wrote on Fri, 07 January 2005 17:11 |
If the throttle body comes to a complete close in an F1 car during a shift, something has broken.
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This goes for rally cars aswell.
And no matter how much wide world of sport you watch on TV, it wont make you know everything about race cars  
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Location:
Alice Springs
Registered:
February 2004
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Re: BOV's
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Fri, 07 January 2005 07:13
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Did any or all of the afore mentioned race cars run WOT shift or anti-lag which would make a BOV obsolete in terms of reducing lag?
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I Supported Toymods
Location:
Sydney
Registered:
December 2002
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Re: BOV's
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Fri, 07 January 2005 07:47
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I think that most of the arguements raised here are valid, however, it is hard to pick the point where installing a BOV or a turbo timer is pointless.
A BOV does have its uses, reducing compressor surge and noise being the main one, however, on a stock car they are pointless.
Even more so when a BOV is incorrectly adjusted to produce the fluttering sound many people seem to love you are doing more harm than good.
A turbo timer is a lazy mans device, however, it is good to have one installed if someone else is likely to ever drive your car.
We all know that turning the car off straight after giving it a big spool is a bad idea, however, without a turbo timer how can you be sure that your old man / old lady / brother etc. isn't going to thrash the car and then turn it straight off.
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Location:
Inside a giant turbo (syd...
Registered:
June 2002
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Re: BOV's
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Fri, 07 January 2005 07:58
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How does a turbo timer cool it down if say, you have not been boosting for 3 mins before your destination... wouldnt air from driving have cooled it down much more than when you stop and have no airflow over your radiator, oil cooler and such?
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Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 08:12
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| pro_ke wrote on Fri, 07 January 2005 16:57 |
but there are no other reasons, and i have never seen or heard of a hose blowing off on closed throttle (blow off hose?  )
sounds to me like you are a bov owner searching for justification of your ownership.
its ok there are groups that can help
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Yeah whatever.
My engine (2JZ-GTE) has a BOV from factory, and when it stopped working the intercooler hoses were popping off all the time - actually that's how I knew the BOV had stopped working! I also have friends who have experienced the same thing; VL turbos are known for doing this after installing a big front-mount and upping the boost, you need a BOV or they will pop hoses all the time.
So much for your assumptions eh?
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Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 08:13
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| Spanktown wrote on Fri, 07 January 2005 17:58 |
How does a turbo timer cool it down if say, you have not been boosting for 3 mins before your destination... wouldnt air from driving have cooled it down much more than when you stop and have no airflow over your radiator, oil cooler and such?
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Yes. As has already been pointed out several times in this thread, turbo timers are a complete waste of time on a street car for that very reason.
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 08:18
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| Spanktown wrote on Fri, 07 January 2005 17:58 |
How does a turbo timer cool it down if say, you have not been boosting for 3 mins before your destination... wouldnt air from driving have cooled it down much more than when you stop and have no airflow over your radiator, oil cooler and such?
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Most if not all new types calculate the cool down time depending on how you drive the car.
My girlfriends starlet has one fitted. By the time I get off the main drag, turn onto my road and do the 50kph to my house, the timer is at 0. So the engine just turns off.
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Location:
adelaide
Registered:
April 2003
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Re: BOV's
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Fri, 07 January 2005 10:51
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| Norbie wrote on Fri, 07 January 2005 19:12 |
| pro_ke wrote on Fri, 07 January 2005 16:57 |
but there are no other reasons, and i have never seen or heard of a hose blowing off on closed throttle (blow off hose? )
sounds to me like you are a bov owner searching for justification of your ownership.
its ok there are groups that can help
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Yeah whatever.
My engine (2JZ-GTE) has a BOV from factory, and when it stopped working the intercooler hoses were popping off all the time - actually that's how I knew the BOV had stopped working! I also have friends who have experienced the same thing; VL turbos are known for doing this after installing a big front-mount and upping the boost, you need a BOV or they will pop hoses all the time.
So much for your assumptions eh?
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but was it not having a bov that caused your hoses to pop off?
because it is just more pressure, if you say wound up the boost 4 pounds would your hoses cope?
why dont turbosmart advertise 'stops your hoses popping off' instead of 'extra performance' if thats what they allegedly cure?
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Location:
Montrose, VIC
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 11:32
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Quite the argumentative ones here, aren't we A little too much red cordial, anyone??
If you're having issues of losing hoses that easily, then things obviously aren't very well anchored. While you will get an increase of a few PSI above normal when you close the throttle, it's not going to suddenly hit 150psi or anything like that, which suggests you're not using proper quality hoseclamps, proper silicone hose and pipes with rolled ends. To blow such a setup off would require, er, significant pressure!
If you are actually convinced your whooosh-valve is making your car quicker, hows about finding out? Go to the stip, or get a G-TECH, etc., run the car, then block off said valve, and try again. Isn't that slightly more effective than barstool talk?
Also, is there a need to get too excited about it? This is a free country, if you want to buy your $300+ shiny widget to make your car sound like an overaged jogger, do so. If you want to not, do so. As long as you're happy - the whole point of doing stuff to a car is to make YOU happy - and, for some, to kid them that they can pull chicks...........
(what else would they be pulling otherwise???)
Anyway, there's my whinge for the evening!
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Location:
Melbourne
Registered:
October 2003
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Re: BOV's
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Fri, 07 January 2005 11:33
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The turbo bearings were designed to cope with the shaft loadings and force to allow the turbo to spool in a time X, and hold the force from the wheels caused by the pressure on both the intake and exhast side. So with some backpressure slowing the turbo to a stop in a time possibly longer than X should be well within the design limits.
To sum that up, the shaft loads from backflow are nothing compared to the shaft loads from the turbo in operation.
Remember when the foot is off the pedal, shit all exhausts gas
is trying to keep the turbo spinning in the forward direction
so this slowing of the comp wheel is not too stressful.
I do think a BOV would be useful in saving pipes/hoses..
I was running 2-3 pounds when my turbo wasn't spooling due to
a dodgy wastegate, and I was cheking for leaks by moving my
gauge around and observed spikes of around 9-10psi that fluttered downto 5psi in sync with the noise. Basicly 9-10psi
of flutter-pressure off only 2-3psi boost. I never saw what it got upto when i was running 17psi, but i'd image something
like 30psi possibly more. I always lost hoses letting off the
pedal..
But rather than go and buy a bov i'd just spend the cash on better intake pipes or something that will deliver more go per $.
I don't know how many of you will agree with this, but i think not running a BOV can be a performance advantage. There is a point with your intake tract, depending on overall volume where the air will act like a spring compressing. Catch it before it bouces back with an open throttle, and you'll get a nice big pressure wave straigt into the manifold. I don't know if it's the shoddy tuning of my engine, but with some specially timed
gear changes i get a burst of torque down low where the turbo
isn't normally spooled. If i leave it a split second too long i loose it all.
Lastly, about the turbo timer, heat soak from an idle car is nothing compared to a turbo at 800deg C. But the few times I would be in this situation i could handle sitting in the car for a bit... but there are some who would rather not, and i guess it's up to them.
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Location:
Inside a giant turbo (syd...
Registered:
June 2002
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Re: BOV's
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Fri, 07 January 2005 11:59
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norbie it was aimed in reply to the chuckster who was saying the opposite then saying the same... hah, i should learn to quote people, anyhow...........
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Location:
wangaratta
Registered:
May 2004
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Re: BOV's
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Fri, 07 January 2005 12:21
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the point has already been raised, but i might just chuck it in here for good measure. . . .
a turbo spinning at around 70 to 100,000 RPM suddenly backing off to around 10,000 RPM because of the massive pressure build up in the intake when the throttle closes cannot be a good thing for turbo life ( bearings and shafts etc ). . . .
thats not all that much different to driving a car in 5th gear at 100 KPH, then chucking it in 1st gear. the rotating components and all mounting hardware associated with them undergoes a massive 'pressure' build up because of VERY sudden decelleration.
is someone going to try and tell me that that doesnt hurt gearboxes and other drivetrain parts????
BOV's are put there for far more serious reasons than 'reducing the noise of compressor surge'
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Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 12:56
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| pro_ke wrote on Fri, 07 January 2005 20:51 |
but was it not having a bov that caused your hoses to pop off?
because it is just more pressure, if you say wound up the boost 4 pounds would your hoses cope?
why dont turbosmart advertise 'stops your hoses popping off' instead of 'extra performance' if thats what they allegedly cure?
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The BOV stopped working and then the hoses started popping off... I put them back on and they kept coming off until I got a new BOV, and since then there have been no issues. This is harldly rocket science now is it?
And how gives a shit what TurboSmart say in their advertisements? They'll say whatever shifts their product.
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Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 13:03
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| mrshin wrote on Fri, 07 January 2005 21:32 |
If you're having issues of losing hoses that easily, then things obviously aren't very well anchored. While you will get an increase of a few PSI above normal when you close the throttle, it's not going to suddenly hit 150psi or anything like that, which suggests you're not using proper quality hoseclamps, proper silicone hose and pipes with rolled ends. To blow such a setup off would require, er, significant pressure!
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I'm not sure if you're aiming this at me, but there is nothing wrong with my setup (yes I have proper hoseclamps, silicone hose etc) and as I just mentioned the problem went away when I installed a new (working) BOV. Maybe it was just a coincidence though?
Note that my setup is far from stock though, and this is much less likely to be an issue on a stock 2JZ, but with ~400hp worth of air at up to 20psi going through a very large intercooler, I dare say the pressure spikes can be quite significant under certain conditions.
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If you are actually convinced your whooosh-valve is making your car quicker, hows about finding out? Go to the stip, or get a G-TECH, etc., run the car, then block off said valve, and try again. Isn't that slightly more effective than barstool talk?
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At no point did I say a BOV makes my car faster, and I certainly don't believe that to be the case. I do however believe it has other benefits, which is why I have no intention of removing it just because certain people don't like them.
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Location:
Montrose, VIC
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 13:12
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Norbie - I wasn't aiming anything at you as such, just saying that I find this surprising. Have you stuck a gauge on there and measured the pressure spikes? I'm curious as to how big they're getting.
And if you want to have one, I don't mind I'm going to put one on my car again (when it's going again soon...) for the simple purpose of killing the noise.
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Location:
adelaide
Registered:
April 2003
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Re: BOV's
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Fri, 07 January 2005 16:28
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mrshin = voice of reason
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Location:
On your mum!
Registered:
May 2002
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Re: BOV's
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Fri, 07 January 2005 22:14
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mrshin - here is an example of measured boost spike sans BOV
| hemi twofifteen turbo wrote on Fri, 07 January 2005 22:33 |
I do think a BOV would be useful in saving pipes/hoses..
I was running 2-3 pounds when my turbo wasn't spooling due to
a dodgy wastegate, and I was cheking for leaks by moving my
gauge around and observed spikes of around 9-10psi that fluttered downto 5psi in sync with the noise. Basicly 9-10psi
of flutter-pressure off only 2-3psi boost. I never saw what it got upto when i was running 17psi, but i'd image something
like 30psi possibly more. I always lost hoses letting off the
pedal..
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Location:
Brisbane
Registered:
May 2002
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Re: BOV's
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Sat, 08 January 2005 01:29
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| mrshin wrote on Fri, 07 January 2005 23:12 |
Norbie - I wasn't aiming anything at you as such, just saying that I find this surprising. Have you stuck a gauge on there and measured the pressure spikes? I'm curious as to how big they're getting.
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I haven't bothered to actually check the magnitude of the pressure spikes; once I installed the new (inexapensive and non-shiny  ) BOV it was no longer an issue.
Having said that, when I first turned the boost up to 20psi there was enough pressure in the system to crack the end tanks of my intercooler wide open 3 times before I added extra strengthening. Admittedly the end tank design of my cooling-brick isn't the best, but even so it clearly demonstrates we're talking about non-trivial amounts of pressure here!
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