How do you get that sound...

[dan.h]

i was at the last bluewater meet, and hopefully it wont be as cold at the next one!

[nutter]

Oh fair do's! Come and say hello next time then i'll be the one in the crappy old xr2 (mr2 has no engine at the mo)

thanks

Dean

[FizzyBlueMr2]

Well well - interesting evening!

I was discussing the sound my mates 200sx makes, and the guy I was speaking too described it as "waste gate flutter" sound? Sort of does the usual "whoosh" followed by rrrrrrrrttTT! (its the sort of noise I often seem to hear rally cars make?)..

Well, I decided to try reversing the plastic disk thingy on the standard toyota bov, to see if it does indeed sort out my "goose honk/farty" noise with the apexi....

....and lo and behold, it did!!! Not only that, but its started doing the same rrrrrrrrrtttTT! noise that my mates 200sx does!?!?!?!?

So, it looks as if that disk/valve thingy is in fact to help stablise/smooth out pressure changes to reduce the waste gate flutter? Its just that it reduces it to just the right frequency to resonate with the apexi...

Ok - anybody know if this noise/effect is harmfull to the standard toyota bov? (or ABV as I found its actually marked?). I want to be sure before I leave it this way....

[dan.h]

very interesting find... i would like too know more, i might try this trick myself...

[nutter]

I think what you've done is switched round the one way valve on the bov. That way the bov doesn't know when to open. Result? instead of excess boost being vented via the bov it is now going back through the wastgate. Apparently this is bad for the turbo someone told me because it puts alot of pressure on the blades. But i've yet to confirm that fact.

[dan.h]

does anyone have any good soundclips, of what noises we should be hearing with different mods????

Cheers.

[FizzyBlueMr2]

Well, done some reading on the net, and as you have mentioned, a lot of people see it as a bad thing..

Also, when you mention things like "doesn't know when to open" that doesn't inspire me with confidence either. So I have but it back as it was orginally now - as I think I said, Toyota must have had a reason to put it there!

Guess I'll have to look into some other way of getting rid of the honk. At least now I have a better idea of what my mates 200sx is up to to create that noise....

[karammander]

yeah its a very bad thing, thats why u only get the sound when u ease of the throttle gently, u keep the bov cloded forcing the built up boost to go backwards into the turbo causing compressor surge and stalling your turbo, plays xxxx with the bearings but sounds the dogs. ide say stick with the HKS SSQ and even with an uprated actuator the 2's dont realy have wastage chatter.

cheers karam

[TBDevelopments]

The sound your hearing is turbo stall.

This is where the air has no where to go when the throttle body butterfly is closed and travels back towards the turbo through the blades and out the air filter.

As someone said above this isn't very good for the turbo, although my blitz bov is very stiff and won't even vent till around 6+psi is reached. With the BOV closed on pressures under this i get the flutter sound of turbo stall.

There is no such things as wastegate chatter, its just a misconception of turbo stall, it has a very other names but the noise is not caused by the wastegate in any form. The varing sounds even in rally cars is caused by different levels of boost pressures and the very high pitched sounds from WRC cars is the antilag system keeping the turbo spooling while encountering this turbo stall.

Tim
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[TBDevelopments]

I also have a s13 200sx that used to make a lot of flutter, this is because the nissan 200sx doesn't come with a BOV or anti turbo stall device as standard. This is why the s13 is prone to turbo problems as it will stall at boosts upto 11psi in standard form causing alot of damage over time. Most 200sx go through turbo's ever 30-40k miles.

Tim
xxxx

[dan.h]

thanx for the info Tim,

i think i will try and get the hks ssqv, and try to keep back pressure to a minimum.

[TBDevelopments]

you can adjust the spring pressure on the HKS SSQV anyway so you will get this flutter upto say 5-6psi if you wanted. also it shouldn't decrease the turbo's life span. Like i said before my blitz bov does this and had no problems in the last 4 years.

Tim
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[nutter]

yep tim's right i have my ssqv adjust as hard as it will go, and i do get a bit of a flutter sound if i take it easy.

[jimGTS]

You need an HKS SSQV my friend! It's a replacement Blow off valve.

Like this :

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... eName=WDVW

are these genuine mate??

i thought these valves were £300-400???

i would well consider this if it was the real deal!

[nutter]

it is genuine but i don't think a fitting kit is included. I paid £150 for mine, it was meant for a golf turbo but i managed to retro fit it.