View Full Version : Turbo With External Wastegate.
novadose2009
01-06-11, 08:29 PM
im no mechanic i need to state that first.
i have a c20let engine for my nova that i have fitted a nissan 200sx tubular manifold and a evo6 td05 turbo which runs a internal wastegate.
i really like the sound of a wastegate and assumed that an external wastegate would give the chatter noise better and louder but the evo td05 turbo uses a internal wastegate do i need to get a different turbo so i can use a external wastegate?.
Also any tips on wastegates and how to get the loudest chatter.
thanks simon
Doin it for all the wrong reasons, and no just weld the gate shut.
Easiest way to get "wastegate chatter" is to have a decent turbo with no DV or recirc valve lol
isnt that actualy bad for the turbo though? or am i thinking something else
isnt that actualy bad for the turbo though? or am i thinking something else
Its not ideal but not the worst thing going, eventually the blades will fail due to stress from being stalled, losing the dump valve does mean more consistent boost though if you're on/off the throttle a lot. Not many drift cars run dump valves.
My S3 has been doing it for 90,000 miles and is still fine lol, wategate flutter is harmless as it takes place usually at spool up,
Turbo chatter when the already compressed air is forced back through the compressor is much louder and will damage the turbo much faster, usually this is the sound you hear on rally cars with anti lag or recirculation systems
No one mentioned wastegate flutter until you did bazil lol
losing the dump valve does mean more consistent boost though if you're on/off the throttle a lot.
Opposite actually - turbo stall jars the turbine into stopping, where as the DV will allow it to keep spinning. A quick gearchange will allow the turbo to keep some pressure going.
Opposite actually - turbo stall jars the turbine into stopping, where as the DV will allow it to keep spinning. A quick gearchange will allow the turbo to keep some pressure going.
Dump valve drops all the boost back to 0, whereas without it spikes a bit through the change, I know Simps said his was much more consistent to drive without the DV, and I'm assuming this is the reason most drifters don't run them
Hm, mine doesn't drop to 0, not unless you granny shift lol
Hm, mine doesn't drop to 0, not unless you granny shift lol
Your dump valve is fecked then lol
Just wonder if the op was on about the gentle ffftffftffft of flutter or the squirel in a blender chatter lol
craig green
02-06-11, 12:01 AM
External gates with a screamer pipe make a whole different sound altogether.
External gates with a screamer pipe make a whole different sound altogether.
Doesn't have to have a screamer if it's an external gate though.
craig green
02-06-11, 12:05 AM
But if you wanted chavvy noises it would have to be..
But if you wanted chavvy noises it would have to be..
Oh standard issue for people that like to be loud and irritating, less standard for those wanting to lose the exhaust flow that upsets the turbine spool in favour of a wastage exit further down the exhaust.
Just didn't want to give external wastegates a bad name lol
External gates with a screamer pipe make a whole different sound altogether.
Bingo. I reckon the OP is referring to a screamer pipe too.
Bingo. I reckon the OP is referring to a screamer pipe too.
Screamers don't 'chatter' though, they scream. Totally different, you can't get away with screaming in a cafe, or chatting at a boyzone concert.
edit: Or get away with attending a boyzone concert for that matter.
Dump valves only allow the turbo to spoil quicker after a gear change. If the boost pipes are full of pressure, the turbo stalls. If that pressure is released, it is allowed to spin freely.
But really, a sequential blow off valve is only any good in terms of performance. Your average dump valve doesn't operate quickly enough to make any real difference (other than making you look like a Barry!) :p
What he said lol
Your dump valve is fecked then lol
No its not. If you listen to a DV, they don't drop all the pressure in an instant, unless you have a huge one (and even then the turbo will still spin). Consider an inflatable matress, if I open the plug to release the air, it doesn't deflate to 0 as soon as I open the plug even with my fat girth jumping around on it lol
Thinking about it... throttle closes, turbo can't push air anywhere so it pressurizes the tract between compressor and throttle; that air pressure pushes back on the turbine and causes it to stall. At best, if you open the throttle quick enough, you might be able to drop that high pressure air into the inlet before the turbo stalls, but you risk running briefly very lean. Where as if the DV opens, the pressure is allowed to run off, so the compressor can continue to spin (albeit spooling down).
just get one of those exhaust pipe whistle things that are on ebay, it gives the authentic turbo sound but with none of the power....
Screamers don't 'chatter' though, they scream. Totally different, you can't get away with screaming in a cafe, or chatting at a boyzone concert.
edit: Or get away with attending a boyzone concert for that matter.
I know, but the OP is thick as mince. lol
Maybe he does just want turbo stall n0ise bro! I reckon if he heard a screamer he would soon change his mind though!
"I want my car to sound like a Eurofighter plz"
What he said lol
No its not. If you listen to a DV, they don't drop all the pressure in an instant, unless you have a huge one (and even then the turbo will still spin). Consider an inflatable matress, if I open the plug to release the air, it doesn't deflate to 0 as soon as I open the plug even with my fat girth jumping around on it lol
Thinking about it... throttle closes, turbo can't push air anywhere so it pressurizes the tract between compressor and throttle; that air pressure pushes back on the turbine and causes it to stall. At best, if you open the throttle quick enough, you might be able to drop that high pressure air into the inlet before the turbo stalls, but you risk running briefly very lean. Where as if the DV opens, the pressure is allowed to run off, so the compressor can continue to spin (albeit spooling down).
here: http://www.lexusownersclub.co.uk/forum/index.php?showtopic=29047 explains a lot tbh, about halfway down it explains turbo stall, it's aerodynamic rather than physical stall, the turbo keeps spinning, which explains how it maintains boost.
The noise is actually cavitation apparently, which would explain why it's so damaging.
http://www.likeclockwork.biz/files/imagecache/product/files/MonkeyCymbal2Orange.gif (http://www.likeclockwork.biz/files/MonkeyCymbal2Orange.gif)
get one of these (http://www.google.co.uk/imgres?imgurl=http://www.likeclockwork.biz/files/MonkeyCymbal2Yellow.gif&imgrefurl=http://www.likeclockwork.biz/node/220&usg=__Je-b_d31hwRxzNDqUzQslbkXLko=&h=450&w=450&sz=73&hl=en&start=1&zoom=1&um=1&itbs=1&tbnid=CS1RMvOYKsmATM:&tbnh=127&tbnw=127&prev=/search%3Fq%3Dclockwork%2Bmonkey%2Bcymbal%26um%3D1% 26hl%3Den%26biw%3D1004%26bih%3D620%26tbm%3Disch&ei=B5HnTcPpE9Gu8QPk-qWHCg) for your dashboard... it will sound the same..
craig green
02-06-11, 03:33 PM
Fact of the matter is, you cant make a turbo or wastegate chatter IME. My 8v turbo used to have very audible chatter & a couple people I knew with turbo'd cars were a bit envious. One was an Escort series one RS & the other a 5GTturbo. All 3 had Garret's yet only mine had a noticeable chatter.
novadose2009
02-06-11, 05:36 PM
are screamer pipes legal and M.O.T Passable?
and i do prefer the wastegate chat then D.V blow off.
are screamer pipes legal and M.O.T Passable?
and i do prefer the wastegate chat then D.V blow off.
No, as it vents exhaust gas straight into the atmo. F@cks the world up bro!
Also, what Jack said is true. Your normal piston dump valve does not react quick enough to make any performance gain.
Craig - My Fiesta RS had massive chatter, but in comparison to a series 1 and R5GT, it uses different methods of fueling etc.
For the record, screamers are garbage. I shortly owned an s13 with a "wicked screamer brap brap" I never once thought it was cool.
If your going for the noise. It's dump flutter everytime
novadose2009
03-06-11, 05:20 PM
whats the best d.v to use on the tuned c20let engine anyone? does the trumped ones actually make the blow off louder as want a loud blow off.
thankyou everyone.
simon
The Simps
11-06-11, 10:45 PM
This gets argued about weekly on 200sx forums!
My 200 ran like shat with jumpy idle and jerkiness when holding the throttle at high revs, and thats with a proper sequential blitz. Removed that and now run no dv or recirc (pidgeon mod) and car is 10x nicer to drive.
From what i can fathom from the jap world, people either run pigeoned or a good quality recirc. On a 200 the std recirc isnt reliable enough over 1 bar boost so it gets removed or replaced.
There's variouz arguements of what damage running pigeoned does but the logical suggestions are its minimal and less running serious boost. The air pushing back through the turbo iz what you hear, not the turbo stalling.
right, ive seen this on the audi forum too,
WASTEGATE FLUTTER and TURBO CHATTER are 2 totally different things caused by 2 different areas of the turbo
wastegate flutter is found at low engine speeds when lifting of the throttle, usually its the sound of the wastegate opening and closing ( bouncing if you will ) at low boost due to actuator strength.
turbo chatter is as simps says, usually found at lift off on high boost due to already compressed air re-entering the compressor.
the thing is, flutter is not a big issue but usually chatter means something isnt working as it should ( usually on a recirc system like my vag engine ) anti lag systems chatter as they are designed to retain as much pressurised air as possable.
if im wrong then my turbo should have died about 6 years ago.
The Simps
11-06-11, 11:48 PM
I noticed the other day driving a nissan juke 1.6 turbo it had a little pidgeon coo. Even with my blitz there still was a coo. It depends at what pressure the dv is set to dump or recirc. If it does it too low down you lose throttle response cause you've got the void to fill. Most cars do it at high revs because you are then normally changing gear so by the time you're back on throttle its all boosted back up again. But imagine just driving through town normally in the same gear and everytime u let of the gas the dv dumped it would be a nightmare.
You wont be damaging the turbo blades, if anything it'll be the bearings but that will take a long time depending on the kinda of boost you're running.
my audi has flutter, its done it for 8 years and 100,000 miles, but on higher boost it dumps boost fine.
as you say setting pressure, i see lads on the audi forum use forge recirc valves, some who run high boost run different coloured springs from those who run lower boost, some have better knowlage than others and some are muppets or have been ill informed.
its still a learning curve for me and as they say " everyday is a school day"
I noticed the other day driving a nissan juke 1.6 turbo it had a little pidgeon coo. Even with my blitz there still was a coo. It depends at what pressure the dv is set to dump or recirc. If it does it too low down you lose throttle response cause you've got the void to fill. Most cars do it at high revs because you are then normally changing gear so by the time you're back on throttle its all boosted back up again. But imagine just driving through town normally in the same gear and everytime u let of the gas the dv dumped it would be a nightmare.
You wont be damaging the turbo blades, if anything it'll be the bearings but that will take a long time depending on the kinda of boost you're running.
srsly, wtf? you drove a nissan juke? lol
The Simps
12-06-11, 12:01 AM
srsly, wtf? you drove a nissan juke? lol
Was at a nissan garage getting something done to the 200 and was bored. I have to be honest - it drove really well! Pulled well, handled well for a big car. Its just the looks are marmite.
theres one round here that has big eyelash's on it lol
The Simps
12-06-11, 12:20 AM
"Surge in a lift-off situation arises due to instantaneously operating to the left of the surge line, (throttle closed: zero flow, increasing pressure) but in this scenario, reverse flow occurs until pressure in the system is equalised and the flow across the compressor blade is stabilised. There is no real-world reliability or performance issue with this, hence "pigeon" is fine. Some people refer to this as stall/chatter/flutter, whatever. Every turbo will experience this when the throttle is closed.
Surge under load is due to using a compresor too large for the application in question, i.e. an inherent design flaw or poor choice of component. The engine simply cannot ingest the amount of air that the compressor is forcing through the cylinders. At WOT, this is detrimental to your turbo, there is much higher flow instability. Once in surge, there's not a lot you can do, as lifting off compounds the problem by further reducing flow in the system to zero at an even higher pressure. Everyone knows & refers to this as 'surge', unlike 'lift-off surge'/chatter/flutter/pigeon. Surge under load can be avoided by using ported compressor housings to recirculate diverted flow and partially venting relief valves which operate during states of low flow. Very useful for BB turbochargers with large compressors and low boost thresholds, that would otherwise surge at low RPM, yet provide high pressure at high RPMs (BIG powahz)."
that actually makes pefect sense to a problem a forum member was describimg on audi forum, i shall return with a link in a mo!
flutter or chatter lol
http://www.youtube.com/watch?v=mciE5W1bjY4&feature=player_embedded
The Simps
12-06-11, 12:29 AM
True Compressor Surge - http://www.youtube.com/watch?v=nCj6Spwl1CU&feature=youtube_gdata_player
It's the blades that suffer damage it seems Simps, air forced back through the turbo cause cavitation. Cavitation is seriously damaging, it's basically small implosions against the blade, can tear apart industrial machinery when it's pumping water, air is a tad softer though lol
The Simps
12-06-11, 12:30 AM
flutter or chatter lol
http://www.youtube.com/watch?v=mciE5W1bjY4&feature=player_embedded
Its a short vid but sounds vid to me. You only hear the chatter on lift-off not WOT.
True Compressor Surge - http://www.youtube.com/watch?v=nCj6Spwl1CU&feature=youtube_gdata_player
sounds like the compressed air is tripping over itself, i know that sounds stoopid but it is laymen terms lol
The Simps
12-06-11, 12:33 AM
It's the blades that suffer damage it seems Simps, air forced back through the turbo cause cavitation. Cavitation is seriously damaging, it's basically small implosions against the blade, can tear apart industrial machinery when it's pumping water, air is a tad softer though lol
I dont disagree but its very minor unless running SERIOUS boost ie 2 bar +. But tben its still a very slow gradual cause.
Its a short vid but sounds vid to me. You only hear the chatter on lift-off not WOT.
crap vid but defo not surge compared to your post.
The Simps
12-06-11, 12:35 AM
sounds like the compressed air is tripping over itself, i know that sounds stoopid but it is laymen terms lol
Its trying to force more in than the engine can take so it just getting pushed straight back.
like a hamster falling in its wheel?
( fcuk im bad at this lol )
Its trying to force more in than the engine can take so it just getting pushed straight back.
More to do with turbo spec than the engine, but pretty much, surge line is the top line on a compressor map iirc.
The Simps
12-06-11, 12:40 AM
like a hamster falling in its wheel?
( fcuk im bad at this lol )
Imagine MK999 giving his usual head and when you blow he cant swallow it all so some sneaks out and he dribbles.
Imagine MK999 giving his usual head and when you blow he cant swallow it all so some sneaks out and he dribbles.
FCUKINGlol lol lol lol lol lol
Not that Simps would know, wouldn't touch it with a barge pole attached to a barge pole.
The Simps
12-06-11, 12:51 AM
Lol
so surge happens on boost, so what is the pigeon sound on lift of?
harmless?
The Simps
12-06-11, 01:07 AM
Surge is the sound of the air passing back across the blades. Lift-off surge is what most people hear is relatively harmless. In that skyline vid air is blowing back out the turbo even tho its a full throttle. The turbo is trying to push more air in that the engine can handle. The pressure builds to a point where the turbo cant sustain it so it blows back through the blades. Sorta stalling it. It will then boost up and try again. That wrecks turbos & engines as the forces are much greater.
The Simps
12-06-11, 01:07 AM
Double post
The Simps
12-06-11, 01:10 AM
P.S. Under load its a constant pushing & pulling. On lift-off is all one way (as such)
cool, what ill need to do now is check my DV is actually working as it should, i dont have surge on boost ( thank **** ) but may have boost leaking back into the compressor if the DV is weak ( recirc system on audi APY engine ).
The Simps
12-06-11, 01:16 AM
You've only got a problem mate if the dv is leaking off boost wen its not meant to. Ie spring is too weak for the bost level. Thats the job of the boost control.
interesting, according to some fat americans you dont need a dump valve or a wastegate if you run the correct compressor map. as anyone who isnt a yank knows, thats utter bollocks, but the **** up ive seen due to this are hilarious. makes a big mess too.....
The Simps
12-06-11, 03:59 AM
Surely every turbo needs some form of wastegate??
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