G
gaz_127
Guest
how do you get waste gate chatter when i get my next R i want the noise of that instead of the usual dumpvalve sound nice imo
M
Mr Overboooost
Guest
disconnect the blow off valve and plug up the two pipes which connect to your standard one but i dont recommend it as ive heard that it can f@ck your turbo in time.
i am sure someone will correct me if i am wrong
cheers
gary
i am sure someone will correct me if i am wrong
cheers
gary
Look here: http://forum.gtiroc.com/phpbb2/view...=chatter&sid=a3f21505c0845de15da52e4fca502981
I've done about 15,000 miles in my R with no dump valve
I've done about 15,000 miles in my R with no dump valve
S
Stoned
Guest
It's not wastegatter chatter :roll:
It's the turbo blades cutting up the air as it gets pushed back
It's the turbo blades cutting up the air as it gets pushed back
A
Anonymous
Guest
Actually you get the internal waste gate to chatter by fitting a much larger actuator. You shouldn't remove the dump valve really because it will hurt performance but slowing the turbo at throttle close. Another cool side effect to wastegate chatter is wastegate echo, this is a spooky sound you get when you slowly tease 1 - 3psi boost on and off.
:roll: :roll: :roll: I was waiting for you to say something :lol:kieron said:MarkTurbo said:And it dosent make one bit of difference to the performance either, especially as the engine hasn't run for months anyway
:lol:
Just you wait, it'll be running soon
Nad
Active Member
The word your all looking for is reciprocation. The effect can be amplified by having no dump/bov valve but can be heard if u have a metal air filter like the Blitz one. It is air backing up down the induction run and being forced over the blades of the inlet side of the turbo. This causes stalling which can increase lag and also cause damage in the long wrong. What is does do is save the car from overfuelling though if an atmospheric BOV is used.
Feel free to add other dis/advantages....
Nad
Feel free to add other dis/advantages....
Nad
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AndrewD
Guest
yeah your rightNad said:
listen up guys, heres a good one if you want your R to chatter, and even better to WINE (like indy cars as they spool) is to remove the current quad throttle bodies which are located post turbo (bummer) and and locate a single one BEFORE the turbo
this negates the need for a BOV (which is to relieve the stress on the turbine when throttle is closed)
alot of work but worth it
A
antilag
Guest
i had no dump valve on mine and as i was using quite a big turbo it was stalling and contributed to the turbo being shagged it stalled a few times and it wasnt pretty but in standard form i dont think u get this but will do damage in the long run so weigh up wat u prefure awesome chatter or longer life turbo lol id choose chatter all day long
To BOV or not to BOV, that is the question......
that comes up frequently on many car forums for many years.
The general concensus has always been
BOV's increase lag :shock: but help protect your turbo.
When the throttle closes, the BOV dumps the air and from the turbo through the intercooler to the throttle body. When you open the throttle again, you have to fill this gap before the engine starts working.
With no BOV, the throttle closes and the turbo is still forcing air. The pressure builds up and the air pushes back against the blades slowing them down and leaking through. As someone said, its the air leaking back through the blades that causes the noise, not the wastegate. When the throttle opens again, the remaining pressurised air floods into the engine and it starts working immediately.
If you have a turbo with 360deg race bearings, for the short/medium term you don't need a BOV at all . If you want to get 60K miles you might but other factors affect this anyway like boost and mechanical sympathy. I know of a few people who have run without BOV's on standard 270deg turbos but I wouldn't advise it.
If you're using 2Bar plus, the old touring car experience was fit the BOV again.
Me, I've fitted a 360deg turbo for the rebuild and will be losing my BOV at the earliest opportunity.
that comes up frequently on many car forums for many years.
The general concensus has always been
BOV's increase lag :shock: but help protect your turbo.
When the throttle closes, the BOV dumps the air and from the turbo through the intercooler to the throttle body. When you open the throttle again, you have to fill this gap before the engine starts working.
With no BOV, the throttle closes and the turbo is still forcing air. The pressure builds up and the air pushes back against the blades slowing them down and leaking through. As someone said, its the air leaking back through the blades that causes the noise, not the wastegate. When the throttle opens again, the remaining pressurised air floods into the engine and it starts working immediately.
If you have a turbo with 360deg race bearings, for the short/medium term you don't need a BOV at all . If you want to get 60K miles you might but other factors affect this anyway like boost and mechanical sympathy. I know of a few people who have run without BOV's on standard 270deg turbos but I wouldn't advise it.
If you're using 2Bar plus, the old touring car experience was fit the BOV again.
Me, I've fitted a 360deg turbo for the rebuild and will be losing my BOV at the earliest opportunity.
A
AndrewD
Guest
wrongcampbellju said:
its there to prevent lag!
and the air leaking past the compressor is bullshit also, its the pressure pulses created by the stalling of the compressor that you hear, which would only serve to INCREASE LAG
think of it this way, NO BOV
before the turbo is at ATMOSPHERIC pressure, after the turbo its ABOVE ATMOSPHERIC pressure, and we should all know that fluid flows in the direction of decreasing pressure!
so once the throttle is opened, the turbo has to do even more work to push air into the cylinders
now with a BOV,
both before and after turbo are at ATMOSPHERIC pressure, hence less work, less lag!
RIGHT :lol:
What you say is correct in that it will reduce turbo lag, effort to spin up again ... but it increases engine lag for the reason I previously stated.
Even in your answer you state
I don't think anyone will argue that having an oversized intercooler and extended pipe run from the turbo to throttle will increase overall lag all other things being equal. So why should having Atmos pressure in this same space cause less engine lag than positive pressure???
You've already answered that question and its going to be a compromise between the time it takes for the turbo to spin up to full speed again compared to the time it takes to fill the space acting as a reservoir before the engine.
So if you had a massive intercooler and pipe run, a DV must increase lag, if you had no intercooler and a tiny pipe run, a DV must reduce lag.
In theory what you say is correct but in reality, the turbo doesn't stall and forget what its doing, the space in the middle acts as an air reservoir and off the engine jolly well goes the next time the throttle is opened. Less overall lag even though "turbo" lag will increase.
To re-iterate before anyone starts taking the DV off, I would not advise it for non-360deg turbos because of the reliability concern.
What you say is correct in that it will reduce turbo lag, effort to spin up again ... but it increases engine lag for the reason I previously stated.
Even in your answer you state
Meaning the space after the turbo is at +ve boost. 8)
I don't think anyone will argue that having an oversized intercooler and extended pipe run from the turbo to throttle will increase overall lag all other things being equal. So why should having Atmos pressure in this same space cause less engine lag than positive pressure???
You've already answered that question and its going to be a compromise between the time it takes for the turbo to spin up to full speed again compared to the time it takes to fill the space acting as a reservoir before the engine.
So if you had a massive intercooler and pipe run, a DV must increase lag, if you had no intercooler and a tiny pipe run, a DV must reduce lag.
In theory what you say is correct but in reality, the turbo doesn't stall and forget what its doing, the space in the middle acts as an air reservoir and off the engine jolly well goes the next time the throttle is opened. Less overall lag even though "turbo" lag will increase.
To re-iterate before anyone starts taking the DV off, I would not advise it for non-360deg turbos because of the reliability concern.
O
Odin
Guest
A
AndrewD
Guest
well if you honestly believe that then by all means go ahead an take it offcampbellju said:
no wonder there are so many broken R's cause there are tossers out there doing shit they dont understand to their cars, im going to start a poll
devylboi, read this Its taken from that link Rob put up.
Its taken from that link Rob put up.i would like to make a comment. the reversed airflow will not make the turbo spin backwards. if you think about it there is hardly any weight of this air that has no where to go. the blades are spinning in excess of 150,000 - 250,000 rpms. also, there is always more pressure coming from the exhaust side. definitely more so that what would be in the pipes having no where to go. bov's were not even around when some of the best turbo cars were around in le mans and other endurance car races. if you can find any of the older videos anywhere form the early 80's thru to early 90's of these races you will hear some beautiful wastegate flutter. doesnt sound like a turkey gobble. these are the same low-tech turbos alot of us use today and what usually comes factory. they would use these turbos at max boost in excess of 40psi. no bov. i will try to find a couple articles of professional engine builders explaining the nonsense of bov's. there are documented tests showing that in comparison of using and not using a bov there is no difference in propellor speed during shifts. i have driven a few cars without bovs and i love that sounds. i've seen turbos with thousands of miles on them from cars with no bov's and they have no shaft or side play. the only thing i know for sure is that the use of a bov can be bad sometimes. if it leaks you could spike in psi and possibly cause detonation. the only bov i would ever use (and actually do use) is the hks ssqv. so i'm not saying they're stupid, just pointing out that there is no REAL reason to use one other than that psssssst noise. if it eases your conscience then go for it
I must be one of those tossers then :roll: Like i said before i've done 15,000 miles in my R with no dump valve and it hasnt affected my turbodevylboi said:
[quote="devylboi]no wonder there are so many broken R's cause there are tossers out there doing s**t they dont understand to their cars, im going to start a poll[/quote]
I don't claim to be a turbo expert but the man who used to develop turbos for Garrett up until a year ago re-built my turbo. He matter of factly asked if I was going to take my DV off once it was re-built when handing me back the turbo.
From previous experience with friends, I know you get less lag on Subarus and Ford Saphire Cossies without a DV.
I have never tried it on a Sunny but given the past experience and other peoples knowledge I am more than willing to take the risk.
If my technical knowledge is incorrect, enlighten me but justify it, then maybe we can all learn something.
I'm off to start a poll on people who run out of intelligent things to say and rant off.
I don't claim to be a turbo expert but the man who used to develop turbos for Garrett up until a year ago re-built my turbo. He matter of factly asked if I was going to take my DV off once it was re-built when handing me back the turbo.
From previous experience with friends, I know you get less lag on Subarus and Ford Saphire Cossies without a DV.
I have never tried it on a Sunny but given the past experience and other peoples knowledge I am more than willing to take the risk.
If my technical knowledge is incorrect, enlighten me but justify it, then maybe we can all learn something.
I'm off to start a poll on people who run out of intelligent things to say and rant off.
Frrom the darkside
They did have a 100+ post thread a few years ago when the VTA DV's were defended and abused but 2002 had disappeared from their search engine ???. This is a more distilled version and unfrotunately less technical.
http://bbs.scoobynet.co.uk/showthread.php?t=338148&highlight=dump+valve+increase+lag
Again, using it on a 270 deg turbo long term is bad.
Using it with high boost is also bad (How high? the old touring cars ran at >2.0 Bar and used them)
As Dveliboy said, don't just take someone elses advice, research it yourself and post up.
They did have a 100+ post thread a few years ago when the VTA DV's were defended and abused but 2002 had disappeared from their search engine ???. This is a more distilled version and unfrotunately less technical.
http://bbs.scoobynet.co.uk/showthread.php?t=338148&highlight=dump+valve+increase+lag
Again, using it on a 270 deg turbo long term is bad.
Using it with high boost is also bad (How high? the old touring cars ran at >2.0 Bar and used them)
As Dveliboy said, don't just take someone elses advice, research it yourself and post up.