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Registered:
December 2002
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Blow off valve 'pshshhhhh'
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Wed, 26 February 2003 08:05
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hehe, anyway, i cant for the life of me figure out why when I have my FAULTY(yes thats right, my faulty vacume leaking BOV, still works, opens, just car gets a little jumpy at low revs) BOV on, i get boost at 2,700(this is in second gear, without ringing out 1st gear) and it hammers all the way to about 6k (Stock CT20) -=- But with no blow off valve at all.. i dont get boost till about 3,500 and it doesnt get strong till about 4k, with the faulty BOV on, its strong at 3k
Blowoff valves really make this much difference? and how? if im not thrashing it in 1st(aka no boost, no backspin or reverse spin for that matter), and the turbo isnt charged up anyway, how can 2nd still see boost at 2,700, when with NO BOV i dont see boost till 4k
This is a easy take off, then into 2nd, and foot down.
ANd this is a 3t-gteu with the stock ct20.. I've checked for leaks etc, everything under the sun, the faulty BOV is sucking air.. i assume it has a fucked diaphram(a hole in it) - although it sucking air shouldnt have much to do with it, because it makes it idle really shitty, aned at low revs the car jumps . SO to conclude this long ass thread, its eithe rthe vacume leak causing the turbo to charge up quicker, or its the BOV causing the turbo to charge up quicker(BUT HOW?)
[Updated on: Wed, 26 February 2003 08:12]
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Registered:
December 2002
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Re: Blow off valve 'pshshhhhh'
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Wed, 26 February 2003 08:20
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What effects have others experienced going from no BOV to BOV?
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Location:
Central Coast, NSW
Registered:
May 2002
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Re: Blow off valve 'pshshhhhh'
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Wed, 26 February 2003 22:00
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I don't have a BOV at the moment and i'm a bit naive about the whole situation. I'd love to know if someone can tell me exactly what the advantages of having one are? I know they expel all the "dirty" warm air from the chamber so that new air can be sucked in through the air intake??
The BOV i'm thinking of getting is the HKS Super Sequential.
as soon as i've gotten this ELiTeHaYDeN i can actually answer this thread for ya haha 
Thanks
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Location:
newcastle
Registered:
June 2002
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Re: Blow off valve 'pshshhhhh'
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Wed, 26 February 2003 23:21
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blow off valves do work .(otherwise known as wanker valves) 
BUT think of them this way all they do is vent the build up pressure between the turbo and the throttle body so the next time you come on boost the turbo doesnt have to spool up against the pressure
so basically it reduces your spool up time
Many toyota turbo engines have factory blow off valves anyway .So unless the factory one is leaking then a blow off valve is a complete waste of time .
The reason a big gain was experienced in this case is more likely due to a compressor surge issue .Or the turbo is quite small and relative to the huge volume of plumbing a noticeable gain was experienced
AFTERMARKET VENTING BLOW OF VALVES ARE A BAD IDEA ON AIRFLOW METER ENGINES
The airflow meter has already measured a given amount of air before it even enters the turbo .You then vent that air to atmosphere .The amount of air that has enetered the intake prior to the throttle body is actually FAR less than the ecu belivies is there
This can have all kinds of effects on mixtures and airflow (there are many other more complicated reasons this is just a simple way to look at it).
Put simply for airflow metered engines use a blow off valve that returns to the vented air into the intake AFTER the airflow meter ..or leave the factory one on
So if you fit a return blow off valve to an airflow metered car you wont get a pshhhht sound 
AND venting blow off valves are now illegal in NSW
so dont fit a blow off valve for performance.
A good boost control system is 10 times better gain in spoolup time
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Location:
Central Coast, NSW
Registered:
May 2002
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Re: Blow off valve 'pshshhhhh'
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Wed, 26 February 2003 23:34
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Got ya
while you've been writing that massive reply i've been pricing Turbosmart Dual Stage Gated boost controllers. Is this the go?
My car's 7M-GTE does have a factory air flow meter. I'm guessing i would most likely bodge it up by sticking a BOV on there? the car does have a standard internal waste gate that makes the lovely "fluttering" sound when i back off.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: Blow off valve 'pshshhhhh'
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Thu, 27 February 2003 00:13
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The 7M-GTE already has a factory recirculating BOV anyway doesn't it? And yes, fitting an aftermarket BOV would stuff up things 
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Location:
newcastle
Registered:
June 2002
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Location:
Sydney
Registered:
May 2002
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Re: Blow off valve 'pshshhhhh'
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Fri, 28 February 2003 11:34
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man you got to tell me more about your boost controller celicamad...pm me...
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Location:
Wollongong
Registered:
May 2002
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Re: Blow off valve 'pshshhhhh'
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Fri, 28 February 2003 13:19
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Go to Celicamad's website (Google: celicamad)
He's got graphs of his 1JZ doing power runs... look at how steep the curves are ! Almost straight up 
I imagine that he is using his own kit 
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Location:
newcastle
Registered:
June 2002
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Re: Blow off valve 'pshshhhhh'
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Fri, 28 February 2003 23:38
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Mx 83 i have sent a Pm
The graphs on my site(link at bottom of page) .
are based on using a bleed volume overboost setup.this gives awesome results with good driveability
And yes it my own kit .i just hate paying companies like turbosmart $90 for a $20 valve .
their dual stage kit is a wank.why not just set the boost to a stable reliable maximum and be able to turn it down on hot days or trips or when your grandma is driving(mine would turn it up )
And their gated system leaks like holy shit
im working on new setup which is about a week away incorporates the whole deal .But i have tried it with awesome results
A fuel map control module (this changes the ENTIRE map and give average fuel ratio of 12.1 and will also control fuel cut
And a system using 3 pneumatic valves that has awesome control over boost(same boost in all gears)
And also has a variable wastegate control .the wastegate can be set so that it simply stays dead shut until max boost .
Boost comes on twice as fast as the volume overboost system
It will be about $250 BUT this about the price of a Fuel cut defender by itself (new).And you get a FCD and a boost controll and a mixture control all in one
results
..a good 1j (auto )no twin pipes factory cooler 5.3 0-100(16 psi)Cressida,supra..sorry havent tested soarer yet!!
twin pipes factory cooler 4.8-5.0(0-100) (depending on traction)290 rwhp (216 rwkw)
with a big FMIC and plumbing mods 4.5 is possible
The reason i dont quote times for manual is it depends who is driving but at best add about .3
for anyone that wants to try and make the system themselves there will be a diagram on my webpage in few weeks that explains how to do it yourself .But he hardware will cost you around $300 off the shelf but your welcome to the design anyway
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Location:
Wollongong
Registered:
May 2002
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Re: Blow off valve 'pshshhhhh'
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Sat, 01 March 2003 00:47
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OOOOOOhhhh this sounds sweet Celicamad.
I'm interested to see the diagrams cos I love knowing how things work. I have so many little ideas for projects, just no time to do them.
I really want to make a small controller that lets me have a sequential gearbox setup with 2 buttons (and takes into account current RPM). Parts are ~$100, but no time to get it together.
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Location:
Lismore, NSW
Registered:
February 2003
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Re: Blow off valve 'pshshhhhh'
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Mon, 03 March 2003 04:39
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I own a supra MA70 with the 7MGTE, im using the Turbosmart single stage boost controller. After reading celicamad's opinion im writing to say that I cant control boost when i've got the thing switched on, the engine no matter what goes into fuel cut ive tried screwing the boost controller to bring the boost down but it still fuel cuts on me. Im going outside right now to remove the bloody thing.
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Location:
newcastle
Registered:
June 2002
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Re: Blow off valve 'pshshhhhh'
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Mon, 03 March 2003 09:13
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do you have a fuel cut defender fitted ??
If not then this is your problem .the setup is VERY important on the turbosmart dual stage .But it shouldnt do this .They still work Just not as good as other setups
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