Russleh Posted October 5, 2009 Share Posted October 5, 2009 been looking about for the thread because mine is doing the same after fitting my filter. not that i mind chatter just wanna know why its not working. Quote Link to post Share on other sites
ste91 Posted October 5, 2009 Share Posted October 5, 2009 I really can't see the filter having anything to do with it... Quote Link to post Share on other sites
Russleh Posted October 5, 2009 Author Share Posted October 5, 2009 im not saying it is. im just saying that someone else recently fitted a blitz filter and just get chatter like me. was working before though. so im stuck. mostly just looking to see who it was so i can ask . Quote Link to post Share on other sites
Curtis Posted October 5, 2009 Share Posted October 5, 2009 what bov you running mate Quote Link to post Share on other sites
Russleh Posted October 5, 2009 Author Share Posted October 5, 2009 just a baileys one Quote Link to post Share on other sites
Curtis Posted October 5, 2009 Share Posted October 5, 2009 make sure where the vacuum pipe goes in the top of the valve is tight as the bailey ones can leak from there Quote Link to post Share on other sites
Russleh Posted October 5, 2009 Author Share Posted October 5, 2009 will have a look tomorrow and try that. Quote Link to post Share on other sites
Curtis Posted October 5, 2009 Share Posted October 5, 2009 i have a bailey and its exactly the same also what else are you running off that vacuum line because it sounds like a small leak.do you find with the bailey that it doesn't open when you want it to but when you are cruising down the bypass for instance the bloody thing wont stop whistling lol Quote Link to post Share on other sites
Russleh Posted October 5, 2009 Author Share Posted October 5, 2009 yeh when you put the foot a little on the accelerator it starts hissin at ya. pain in the arse one of the things i plan to change but am too much of a tight arse to part with my cash. Quote Link to post Share on other sites
Curtis Posted October 5, 2009 Share Posted October 5, 2009 lol i know what you mean, what i done to shut it up was to take the top cap off take the spring out and fit 3 washer on top of the piston and then put the spring and the top hat back on, that cured it. the springs in the baileys are way to weak. has it not dumped from the second you put on the blitz filter Quote Link to post Share on other sites
Russleh Posted October 5, 2009 Author Share Posted October 5, 2009 im pretty sure it stopped when i changed the filter. got me wondering if it was actually working before though. sounded like it used to. maybe ill just change it and if it works with a new one ill know its a shan bov . Quote Link to post Share on other sites
TBDevelopments Posted October 20, 2009 Share Posted October 20, 2009 are you comparing this to when you had the airbox fitted? as if the bov wasn't venting properly and causing lift off compressor surge then it wouldn't be auidable with the airbox in place but would be now with the filter fitting insteadTimTB Developments Quote Link to post Share on other sites
Russleh Posted October 20, 2009 Author Share Posted October 20, 2009 no it was a different filter i had on before but im gonna say because it was a smalled and worse filter it sounded less like chatter so i thought the bov was doin its job but i think its been like that since the start. just gonna get a new bov when funds allow. Quote Link to post Share on other sites
StarletRick Posted October 20, 2009 Share Posted October 20, 2009 it is working, your car will always chatter, just not you have an open filter you can hear it. Quote Link to post Share on other sites
TBDevelopments Posted October 20, 2009 Share Posted October 20, 2009 why will the car always chatter? (surge)i have a blitz filter on my car and a HKS bov and i get no compressor surge at all.TimTB Developments Quote Link to post Share on other sites
StarletRick Posted October 20, 2009 Share Posted October 20, 2009 1. it isnt compressor surge, thats something totally different/unrelated. 2. your bov is too loose in that case.a properly setup bov shouldnt open before about 4-5psi, thus causing some mild stall at lower boost levels. its perfectly fine and wont harm anything. Quote Link to post Share on other sites
TBDevelopments Posted October 20, 2009 Share Posted October 20, 2009 he decribed it as chatter through the airfilter. So if this isn't compressor surge upon lift off what is it? also the new generation hks bov's are none adjustable, so it can't be "to loose" the idea of bov preload is only just to compensate for the older type design where the boost is constantly trying to open the bov on boost, the hks design means this doesn't happen as the boost is trying to seal the bov instead of making it leak so you don't need to run such a strong spring.but i do agree with you that a "normal" style bov you will get a little surge below 4-5psi which is normal.TimTB Developments Quote Link to post Share on other sites
StarletRick Posted October 20, 2009 Share Posted October 20, 2009 youre getting confused mate...you mean compressor stall, not surge. and 99% of bovs are not efficient enough at releasing the pressure before it can come back through the turbo. i cant comment on the new hks ones, they may have cracked it. but most BOVs are pretty basic in design and cant do both jobs of holding higher pressure and releasing it fast enough. there is always a compromise, and the caveat of that is comp stall. Quote Link to post Share on other sites
TBDevelopments Posted October 20, 2009 Share Posted October 20, 2009 i design and build my own turbochargers and i'm a garrett agent, i know what i'm talking about ;)stall and surge are the same thing. Surge is normally refered to as full throttle surge, which is the most damaging but when you lift off this is also surge, it does the same thing its just less destructive, all its doing is adding an increasing load on the turbocharger that mores the flow point into the right sector of the compressor map (the surge area) this is sometimes wrongly refered to as stall or wastegate chatter, when in fact there all the same thing.but i do aggree with what your saying about most bov's, like you said it has to seal on high pressure so needs a spring + boost pressure to do this, and the spring load stops it being very effective at low pressures. now with the hks the boost comes up behind the piston and forces it down onto the seals, instead of hte old style where it trys to lift the piston off the seals. because of this you don't need the high spring pressure to hold it down, so you can use a very soft inital piston for very low pressures. the hks will actually open and very when you've only taken it to atmospheric equalisation pressures inside the engine.TimTB Developments Quote Link to post Share on other sites
StarletRick Posted October 20, 2009 Share Posted October 20, 2009 thats nice ;) but it isnt the same. when you lift off the throttle and it makes that nice chattering sound, it isnt compressor surge, its compressor stall. they are 2 totally different things, and the way they happen are from 2 totally different circumstances. you may be a garret dealer, but that doesnt make you right. at least we agree on the bov thing ^^ Quote Link to post Share on other sites
TBDevelopments Posted October 20, 2009 Share Posted October 20, 2009 i'm open to listen to others so please explain what the differences are and why they happen.TimTB Developments Quote Link to post Share on other sites
StarletRick Posted October 20, 2009 Share Posted October 20, 2009 stall: when the butterfly closes, and the pressure has nowhere to go (be it a poor bov or no bov at all). the only way the pressure can vent is back through the turbo, even though the turbo is still spinning. this is what causes the chopping noise. alot of people call this "wastegate chatter" which is also wrong. surge: this is when the compressor produces more boost than the inducer/engine can cope with. the engine can only "breathe"so much air, and if the turbo is flowing more CFM than the engine can process, then you have a problem. thats why you get surge protectors on the bigger turbos (those holes that are drilled into the intakes)its feels sort of like a horrible missfire when it happens and the turbo makes a horrible stammering noise, totally different from the chips you get when it stalls. thats about as basic as i can explain it. 99% of people dont know what surge is, as they never see or experience it, as it only happens way up the tuning ladder. that, coupled with alot of ill-informed people has sort of marred the definition and everyone calls every noise a turbo makes "surge" Quote Link to post Share on other sites
ste91 Posted October 20, 2009 Share Posted October 20, 2009 Also, isn't wastegate chatter when you are hovering around the point of full boost, and then you get "wastegate chatter" as the wastegate is quickly opening and closing on/off?Or something like that anyway. Quote Link to post Share on other sites
StarletRick Posted October 20, 2009 Share Posted October 20, 2009 no mate, wastegates dont make any noises appart from regular old exhaust gas noise when opened. no chattering or anything. that terms is just what nubs say who think they know what they are talking about ^^ Quote Link to post Share on other sites
TBDevelopments Posted October 20, 2009 Share Posted October 20, 2009 oooo so close,you are spot on regarding compressor surge, its basically a back pressure on the turbocharger as the engine can't consume anymore air being provided, so load increases. and yes this is very bad for the turbocharger. It sounds so aggressive because the engine is at full power and gas flow.Now this is where your slightly incorrect, the stall is actually exactly the same thing. Think about what you've said in your own description, even on lift off the turbocharger is still being powered by the exhaust as that will never stop spinning and driving the compressor, so with the throttle body butterfly closed its basically pumping into a closed container, very similar to an engine that can't consume anymore air flow. So again this pushes the gas flow into the surge part of the compressor map. This back pressure is what causes the flutter or chatter you hear upon lift off, but because the engine is basically returning to an idle state when you close the throttle body its much less damaging as the gases driving the turbocharger is dropping off so force spinning the compressor against this back pressure is also falling away. if you connect a boost gauge to the actual compressor housing you can see these pressure spikes exactly the same way as you can see the boost gauge jump around when you see surge at full throttle, its just much less aggressive, but still damaging all the same to the thrust bearings on the turbochagerThe holes your talking about is called an anti-surge housing, its basically a pressure releace from halfway down the compressor blades to allow the pressure to escape the inducer parts of the compressor blades.TimTB Developments Quote Link to post Share on other sites
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