Dillz Three pedals are better then two.. Donating Members 15,637 Member For: 17y 8m 16d Gender: Male Location: Melbourne Posted 26/03/08 06:31 AM Share Posted 26/03/08 06:31 AM (edited) The small one, you would need a pretty narly screw to block up the other hoses. Edited 26/03/08 06:32 AM by XRTPSI Link to comment Share on other sites More sharing options...
R-SPEC You are a dead set goose Silver Donating Members 3,968 Member For: 19y 2m 12d Gender: Male Location: Melbourne Posted 26/03/08 06:33 AM Share Posted 26/03/08 06:33 AM What's the hose that goes into the top of the engine? That came off the other day and I didn't have a clue. Is that the one you're talkin about? Link to comment Share on other sites More sharing options...
R-SPEC You are a dead set goose Silver Donating Members 3,968 Member For: 19y 2m 12d Gender: Male Location: Melbourne Posted 26/03/08 07:52 AM Share Posted 26/03/08 07:52 AM If you put an aftermarket BOV on and vent to atmosphere, does it still flutter or dose? Or is the dose caused by the plumb back pressure going over the splines thus not existing with an atmospheric BOV? Link to comment Share on other sites More sharing options...
PURVIE Sexy Member Donating Members 524 Member For: 18y 2m 1d Gender: Male Location: Berwick, VIC Posted 26/03/08 09:37 AM Share Posted 26/03/08 09:37 AM (edited) Venting a bov regardless of whether its aftermarket or not will not allow you to dose or flutter. Very quickly, the bov vents\dumps the unneeded air pressure whereas blocking it up, it will flow back through the turbine (compressor surge) and that's how u get a dose or flutter. This has been covered in MANY topics before...Rspec I sent u a pm! Edited 26/03/08 09:50 AM by PURVIE Link to comment Share on other sites More sharing options...
R-SPEC You are a dead set goose Silver Donating Members 3,968 Member For: 19y 2m 12d Gender: Male Location: Melbourne Posted 26/03/08 11:12 AM Share Posted 26/03/08 11:12 AM that's what I thought. I might try the chair stop thing and see how that sounds maybe... Link to comment Share on other sites More sharing options...
dule Donating Members 1,180 Member For: 17y 9m 26d Gender: Male Location: Sydney Posted 26/03/08 11:31 AM Share Posted 26/03/08 11:31 AM Try and let us know what you think. I liked the sound with blocked BOV but it took longer for the turbo to spool up between gear changes. Link to comment Share on other sites More sharing options...
Dillz Three pedals are better then two.. Donating Members 15,637 Member For: 17y 8m 16d Gender: Male Location: Melbourne Posted 26/03/08 10:29 PM Share Posted 26/03/08 10:29 PM Venting a bov regardless of whether its aftermarket or not will not allow you to dose or flutter. Very quickly, the bov vents\dumps the unneeded air pressure whereas blocking it up, it will flow back through the turbine (compressor surge) and that's how u get a dose or flutter. This has been covered in MANY topics before...Rspec I sent u a pm!Mate are you sure, I've always thought dose was another name for when the BOV vents excess air and the Ptchh sound it makes in doing so. I think I'm starting to understand why all the new guys are getting confused, everyone is telling them different things. Link to comment Share on other sites More sharing options...
R-SPEC You are a dead set goose Silver Donating Members 3,968 Member For: 19y 2m 12d Gender: Male Location: Melbourne Posted 26/03/08 11:59 PM Share Posted 26/03/08 11:59 PM I found this.... This explains it quite well...Now that there's a whole intake system full of compressed air with nowhere to go, and the compressor is not being driven by the turbine - so it can't hold the same air pressure that it did while spinning flat out. The air will start to flow the other way, which means going backwards through the still spinning compressor. This is where compressor surge comes into play. The compressor is still trying to pump air, but at the speed it's going it can't provide as much pressure as there already is in the pipe. This causes the compressor to "stall". Stall is a misleading turn used here, because it doesn't mean stall as in to stop spinning. It's the aerodynamic stall, like a plane that's tried to climb too steeply, or has slowed down too much to maintain lift. The smooth air flow through the compressor blades is broken up, and some of the air will flow back out through the compressor, making a hissing noise. Centrifugal compressors work on a "squared" relationship for speed vs flow / pressure, so if the turbo slows down to half speed it will only be able to hold a quarter of the boost pressure. The "chopping" or "fluttering" sound is caused by the accoustic effects in the intake system, determined by the size and length of the piping / cooler. Rather than air constantly flowing back out of the turbo it tends to come out in bursts, triggered by pressure waves in the piping hitting the compressor. Generally though the flutter is the sound of the pressure wave cause by the throttle closing bouncing back and forth between the turbo and the throttle plate (the longer the pipes the slower the flutter). Every time the wave hits the turbo it causes the compressor to cavitate, which makes the noise. It's not the blades chopping the air making the flutter. Since the blades are spinning at 80000+rpm you wouldn't be able to hear the individual "chops" If you listen closely you'll actually hear a more constant hiss sound at higher boost levels and rpm when backing off. (ie, a "whooosh" rather than a "chop chop chop") The loudest flutter tends to occur at lower rpm and boost levels of only slightly above atmospheric pressure (0psi). This is partly because the sound is "chopped" up more noticeably, and partly because the rest of the car is making less noise at lower speeds. This is also where it's least damaging. Car manufacturers don't like weird noises from the intake system, so they use restrictive airboxes designed to muffle the sound, and more recently (SR20 onwards) used a Blow Off Valve. If you wanna read the rest, go here:http://www.lexusownersclub.co.uk/forum/ind...showtopic=29047 Link to comment Share on other sites More sharing options...
ROLMDL role model Member 1,111 Member For: 18y 11m 1d Gender: Male Location: Melbourne,S.E Posted 27/03/08 06:27 AM Share Posted 27/03/08 06:27 AM (edited) Mate are you sure, I've always thought dose was another name for when the BOV vents excess air and the Ptchh sound it makes in doing so. I think I'm starting to understand why all the new guys are getting confused, everyone is telling them different things.DOSE = VL TURBO noise which makes a suttututu sound.DOSEFLUTTER = uncompressed air coming out of the cooler & air intake which makes a cha cha cha soundlike so A bov will still flutter a little bit depending on what boost you are running and what thetension is on the BOV is.PS: hope michael doesnt mine me using his car for an example Edited 27/03/08 06:34 AM by UNV3ME Link to comment Share on other sites More sharing options...
Dillz Three pedals are better then two.. Donating Members 15,637 Member For: 17y 8m 16d Gender: Male Location: Melbourne Posted 27/03/08 06:41 AM Share Posted 27/03/08 06:41 AM (edited) I agree mate, they sound similar in those clips.I really like rexs and the like that just have a loud Ptchhh and that's it, no flutter. People say it's just the type of bov but I'm yet to hear a T that has no flutter. Edited 27/03/08 07:01 AM by XRTPSI Link to comment Share on other sites More sharing options...
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