How to make MY00 sound like a rally car!
01 November 2000, 05:34 PM
#31
In water pumpes systems, closing an outlet (ie throttle) quickly causes a reflected pressure wave back through the supply, so a surge protector or air damper is used to accumlate pressure in a vessel.
I know that air is compressible but hows about getting rid of the BoV and replacing with a damped vessel to 'hold' accumlated pressure.
When the throttle is opened again then boost pressure is maintained and the turbo has been protected from the pressure surge.
By the way, this will be patented unless its B*LL*cks- so feedback please.
I suppose the drawback is the volume that the accumulator has to hold and its size. Perhaps hide it behind the bumper?
Please no bad feedback as I hope this is a Dyson moment and I am on my way to millions....
I know that air is compressible but hows about getting rid of the BoV and replacing with a damped vessel to 'hold' accumlated pressure.
When the throttle is opened again then boost pressure is maintained and the turbo has been protected from the pressure surge.
By the way, this will be patented unless its B*LL*cks- so feedback please.
I suppose the drawback is the volume that the accumulator has to hold and its size. Perhaps hide it behind the bumper?
Please no bad feedback as I hope this is a Dyson moment and I am on my way to millions....
02 November 2000, 05:11 PM
#32
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Just tried this and I reckon were getting mixed up. The sound my car makes is absolutely nothing like the WRC "Chirp" that I think the original post relates to.
Its simply a slightly different venting noise, very similar indeed to a piston Dump Valve. As for driveability, not sure, didnt really trial it to any length.
Maybe some .WAV files should be employed here to demo the different noises as we're obviously all talking at cross purposes...or is this indeed the noise some of our cars make (the WRC related chirp/chatter/fluttery type noise on the overun and change up).
Richie
PS Ill be searching for some decent .wavs 2night
Its simply a slightly different venting noise, very similar indeed to a piston Dump Valve. As for driveability, not sure, didnt really trial it to any length.
Maybe some .WAV files should be employed here to demo the different noises as we're obviously all talking at cross purposes...or is this indeed the noise some of our cars make (the WRC related chirp/chatter/fluttery type noise on the overun and change up).
Richie
PS Ill be searching for some decent .wavs 2night
02 November 2000, 06:06 PM
#33
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RichieC
The noise I'm after is a chatter; not a whoosh or hiss. I'll look out for any .wav files you find.
My friend does a brilliant impression - I'll try and record it
or record it from a video.
Richard
The noise I'm after is a chatter; not a whoosh or hiss. I'll look out for any .wav files you find.
My friend does a brilliant impression - I'll try and record it
or record it from a video.Richard
02 November 2000, 07:02 PM
#34
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Yep not the nasty whoosh and hiss you get from R5 turbos etc but that fluttery chattery noise.
Play Colin McRae 2 on the PSX, drive the Focus and lift off at full throttle Ignore the noise of anti-lag and in the background is the noise you will get from a piston VTA BOV. If this is the sound your'e after, replace your airbox with an induction kit, or for a louder effect fit a piston dump valve (or better still do both!) This is also very similar to the noise I got from removing the OE BOV.
As far as that chirp we hear from the WRCs, anybody got any ideas?? Ive found an example in .wav format, how can I upload it??
Hope were getting nearer!.........
Rich
[This message has been edited by RichieC (edited 02 November 2000).]
Play Colin McRae 2 on the PSX, drive the Focus and lift off at full throttle
Ignore the noise of anti-lag and in the background is the noise you will get from a piston VTA BOV. If this is the sound your'e after, replace your airbox with an induction kit, or for a louder effect fit a piston dump valve (or better still do both!) This is also very similar to the noise I got from removing the OE BOV.As far as that chirp we hear from the WRCs, anybody got any ideas?? Ive found an example in .wav format, how can I upload it??
Hope were getting nearer!.........
Rich
[This message has been edited by RichieC (edited 02 November 2000).]
02 November 2000, 09:50 PM
#36
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Richard,
There is a very simple (and almost free) solution to your problem which you have already stumbled across:
1. Drive enthusiastically down your favourite stretch of road with your aforementioned friend in the passenger seat with some form of sound recording equipment.
2. Get your friend to make the noise at the appropriate moments.
3. When you want to be RB drive down the same stretch of road with the Tape/CD/MD/MP3 playing v. loudly.
Whilst this will not cause undue damage to your engine or invalidate your warranty in any way, I still wouldn't tell your dealer about it ;-)
AndrewC....
There is a very simple (and almost free) solution to your problem which you have already stumbled across:
1. Drive enthusiastically down your favourite stretch of road with your aforementioned friend in the passenger seat with some form of sound recording equipment.
2. Get your friend to make the noise at the appropriate moments.
3. When you want to be RB drive down the same stretch of road with the Tape/CD/MD/MP3 playing v. loudly.
Whilst this will not cause undue damage to your engine or invalidate your warranty in any way, I still wouldn't tell your dealer about it ;-)
AndrewC....
02 November 2000, 10:34 PM
#37
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LOL @ JohnF and AndrewC.
I was talking to Steve Lawson about this only a couple of weeks ago. But we kinda decided that if I did manage to reproduce the sound, it would get on my nerves after a while.
The whooshes and puffs and farts that other turbo cars make get on my nerves.
Play Sega Rally 2. That has the Chirping sound your after.
P.
I was talking to Steve Lawson about this only a couple of weeks ago. But we kinda decided that if I did manage to reproduce the sound, it would get on my nerves after a while.
The whooshes and puffs and farts that other turbo cars make get on my nerves.
Play Sega Rally 2. That has the Chirping sound your after.
P.
13 December 2000, 01:13 PM
#40
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John,
only one question.....
How come the BOV reduces throttle response?
I'd expect it to increase it - by keeping the turbo spinning.
The accepted wisdom at Cosworth (where I used to be a designer) was that the biggest factor in lag/lack of response was getting/keeping the turbo spinning.
Interesting (if you like that type of thing) to look at compressor maps and work out how much turbo would decelerate with/without BOV - without BOV, high pressure ratio, very low mass flow, - with BOV,low pressure ratio, higher mass flow.
Incidentally, the late (YBM?) Escort engines had a bypass valve integral to the compressor housing of the turbo.
What do you reckon?
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by johnfelstead:
<B>There is an awefull lot of bollix and misinformation floating around about dump valves. Must be the biggest single con by the tuning trade in the history of turbo tuning.
The reason car manufacturers fit BOV's is to prolong the life of the turbo, to allow them to get away with selling cars fitted with 300 degree thrust bearings.
Having a BOV on a turbo engine reduces throttle response, it allows boost that would be there to bleed away.
Fitting an aftermarket BOV that vents to atmosphere is bad news on an engine that uses a MAF sensor to meter airflow.
Removing a BOV from the system will give you better throttle response than having it there. Do this with a standard turbo and you will reduce its life.
If you want to run without a BOV to get better response then a good idea is to use an uprated turbo with a 360 degree thrust bearing. (I have run normal 300 degree bearing turbos without BOV's for over 12 months on track days and road without a problem.)
The only time it becomes esential to use a BOV is when you get to using turbos the size of an RS500 full race T4. Anything smaller than that and you do not have any problem whatsoever without a BOV.
No WRC car runs a BOV, WRC spec anti lag systems wont work with a BOV.
Turbo's of the size we use on our subaru's and cosworth's do not suffer from reverse pulses stalling the turbo, thats complete bollox. I have discussed this at length with WRC engine builders and they all agree this is not what happens.
The chatter is the sound of the exhaust gasses passing through the waste gate button in the turbo housing. You need very high exhaust gas speeds to cause the waste gate to chatter, this is something you only start to see when you run high boost. WRC engines run at 34PSI boost at low revs (3000rpm) and this is bled away as the revs rise to stop the air going supersonic as it passes through the 34mm turbo restrictor. This is why the chatter is more noticable at low speed transitions as the revs are lower and the boost is much higher on WRC cars.
The boost curve is far more conventional on my own engine, that gives 26PSI boost at 3300rpm and then only drops 3psi till 6000rpm so i get chatter right accross the rev range.
Do i use a BOV? NO
Do i need one? NO
Does my turbo have a 360 degree bearing? Yes[/quote]
only one question.....
How come the BOV reduces throttle response?
I'd expect it to increase it - by keeping the turbo spinning.
The accepted wisdom at Cosworth (where I used to be a designer) was that the biggest factor in lag/lack of response was getting/keeping the turbo spinning.
Interesting (if you like that type of thing) to look at compressor maps and work out how much turbo would decelerate with/without BOV - without BOV, high pressure ratio, very low mass flow, - with BOV,low pressure ratio, higher mass flow.
Incidentally, the late (YBM?) Escort engines had a bypass valve integral to the compressor housing of the turbo.
What do you reckon?
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by johnfelstead:
<B>There is an awefull lot of bollix and misinformation floating around about dump valves. Must be the biggest single con by the tuning trade in the history of turbo tuning.
The reason car manufacturers fit BOV's is to prolong the life of the turbo, to allow them to get away with selling cars fitted with 300 degree thrust bearings.
Having a BOV on a turbo engine reduces throttle response, it allows boost that would be there to bleed away.
Fitting an aftermarket BOV that vents to atmosphere is bad news on an engine that uses a MAF sensor to meter airflow.
Removing a BOV from the system will give you better throttle response than having it there. Do this with a standard turbo and you will reduce its life.
If you want to run without a BOV to get better response then a good idea is to use an uprated turbo with a 360 degree thrust bearing. (I have run normal 300 degree bearing turbos without BOV's for over 12 months on track days and road without a problem.)
The only time it becomes esential to use a BOV is when you get to using turbos the size of an RS500 full race T4. Anything smaller than that and you do not have any problem whatsoever without a BOV.
No WRC car runs a BOV, WRC spec anti lag systems wont work with a BOV.
Turbo's of the size we use on our subaru's and cosworth's do not suffer from reverse pulses stalling the turbo, thats complete bollox. I have discussed this at length with WRC engine builders and they all agree this is not what happens.
The chatter is the sound of the exhaust gasses passing through the waste gate button in the turbo housing. You need very high exhaust gas speeds to cause the waste gate to chatter, this is something you only start to see when you run high boost. WRC engines run at 34PSI boost at low revs (3000rpm) and this is bled away as the revs rise to stop the air going supersonic as it passes through the 34mm turbo restrictor. This is why the chatter is more noticable at low speed transitions as the revs are lower and the boost is much higher on WRC cars.
The boost curve is far more conventional on my own engine, that gives 26PSI boost at 3300rpm and then only drops 3psi till 6000rpm so i get chatter right accross the rev range.
Do i use a BOV? NO
Do i need one? NO
Does my turbo have a 360 degree bearing? Yes[/quote]
13 December 2000, 10:35 PM
#41
You are quite correct in saying that keeping the turbo spinning is paramount to reducing lag. However your statement is implying that removing the BOV stops the turbo from spinning, it doesnt.
There is another factor to throttle response. That is what presure is in the system between the turbo outlet and the throttle butterfly when you open the throttle. If you have a BOV in the system, when you come off throttle the boost presure is bled away. What this means is that when you re-open the throttle buterfly the turbo has to build the boost back up.
You wont ever find a BOV on a competition engine except where you have huge turbo's running very high boost. The only cosworth that needs a BOV for example is an RS500 race spec engine running a large T4 turbo, in that app the BOV is there to protect the thrust bearing from being overloaded by such high presure/volume on throttle snapping shut. It isnt there for throttle response.
You wont find a BOV on a WRC engine either, in fact the anti-lag systems wont work with one installed.
BOV's on production engines are there purely for longevity of the turbo's, they reduce throttle response.
There is another factor to throttle response. That is what presure is in the system between the turbo outlet and the throttle butterfly when you open the throttle. If you have a BOV in the system, when you come off throttle the boost presure is bled away. What this means is that when you re-open the throttle buterfly the turbo has to build the boost back up.
You wont ever find a BOV on a competition engine except where you have huge turbo's running very high boost. The only cosworth that needs a BOV for example is an RS500 race spec engine running a large T4 turbo, in that app the BOV is there to protect the thrust bearing from being overloaded by such high presure/volume on throttle snapping shut. It isnt there for throttle response.
You wont find a BOV on a WRC engine either, in fact the anti-lag systems wont work with one installed.
BOV's on production engines are there purely for longevity of the turbo's, they reduce throttle response.
14 December 2000, 10:33 AM
#42
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A bit of evidence here ...
A friend of mine recently fitted his previously BOV-less 350 bhp Sapphire Cosworth with a shiny new Bailey BOV. Lo and behold, lag got worse!
<I>"But that's not what it said on the box ..."</I> 
Out of interest, without a BOV does any pressure blow back through the turbo? Or does that depend on the design of the compressor blades & housing?
Would running without a BOV be even more beneficial on a car with a larger (say front-mounted) intercooler with more pipework? (Seems like it would make even more sense to keep pressure up).
And does anyone know the expense & complexity of fitting an IHI turbo with a 360-degree thrust bearing? Just something I'd like to do to my next Impreza.
All good stuff though
Andrew.
(Wondering why he is working in the IT business when cars are much more fun!)
A friend of mine recently fitted his previously BOV-less 350 bhp Sapphire Cosworth with a shiny new Bailey BOV. Lo and behold, lag got worse!
<I>"But that's not what it said on the box ..."</I> Out of interest, without a BOV does any pressure blow back through the turbo? Or does that depend on the design of the compressor blades & housing?
Would running without a BOV be even more beneficial on a car with a larger (say front-mounted) intercooler with more pipework? (Seems like it would make even more sense to keep pressure up).
And does anyone know the expense & complexity of fitting an IHI turbo with a 360-degree thrust bearing? Just something I'd like to do to my next Impreza.
All good stuff though
Andrew.
(Wondering why he is working in the IT business when cars are much more fun!)
14 December 2000, 01:57 PM
#43
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Hi all!
just a thought, but has anyone considered that the sound could be made by the turbo going WAAAAY off the left hand side of its compressor map and into very unstable region, and therefore it's surging?
Curiously, my TD05H "chatters" under full throttle (along with a scream it develops above about 1 to 1.2 bar, gets quite intense at 1.5 to 1.6 bar!), but even without a BOV it doesn't "chirp" on lift off... IHI turbos seem to be better at "chirping" :-) All of this pales into insignificance compared to the sound of ALS and full throttle shift... the latter being MUCH louder than ALS and producing 4 foot blue flames out of the exhaust (god only knows how long the poor exhaust would last!). Don't think either are strictly legal on public roads! LOL
But seriously, without a BOV, as John has already stated, the pressure at the turbo exit rises rapidly (look at the compressor maps and follow a line of constant RPM, pressure ratio goes through the roof as mas flow falls) so this will be "hammering" the wastegate open, it may bounce around a little bit when there....
On my car I neither have a BOV nor a blocked off BOV pipe, the BOV pipe feeds the ISC, so that it is possible to feed the manifold with positive pressure without cracking open the throttle... just the thing you need when you want to "idle" with 1 bar of boost :-) Only problem is that the ECU can either do nice closed loop idle control OR open loop idle control and ALS, but not closed loof idle control and ALS... hmmmm, gotta talk to the guys at Pectel :-)
Cheers,
Pat.
just a thought, but has anyone considered that the sound could be made by the turbo going WAAAAY off the left hand side of its compressor map and into very unstable region, and therefore it's surging?
Curiously, my TD05H "chatters" under full throttle (along with a scream it develops above about 1 to 1.2 bar, gets quite intense at 1.5 to 1.6 bar!), but even without a BOV it doesn't "chirp" on lift off... IHI turbos seem to be better at "chirping" :-) All of this pales into insignificance compared to the sound of ALS and full throttle shift... the latter being MUCH louder than ALS and producing 4 foot blue flames out of the exhaust (god only knows how long the poor exhaust would last!). Don't think either are strictly legal on public roads! LOL
But seriously, without a BOV, as John has already stated, the pressure at the turbo exit rises rapidly (look at the compressor maps and follow a line of constant RPM, pressure ratio goes through the roof as mas flow falls) so this will be "hammering" the wastegate open, it may bounce around a little bit when there....
On my car I neither have a BOV nor a blocked off BOV pipe, the BOV pipe feeds the ISC, so that it is possible to feed the manifold with positive pressure without cracking open the throttle... just the thing you need when you want to "idle" with 1 bar of boost :-) Only problem is that the ECU can either do nice closed loop idle control OR open loop idle control and ALS, but not closed loof idle control and ALS... hmmmm, gotta talk to the guys at Pectel :-)
Cheers,
Pat.
10 November 2001, 11:00 AM
#44
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I've been warned by several abt removing the BOV, they all say the IHI turbos aren't sturdy enough to withstand the preassure when the throttle is being shut.
What do you gurus (Pat, Mark and so on
) think, would my 1.2-1.3 bar hurt my VF24?
I'm awfully tempted...that sound is soo sweet.
/J
What do you gurus (Pat, Mark and so on
) think, would my 1.2-1.3 bar hurt my VF24?I'm awfully tempted...that sound is soo sweet.
/J
10 November 2001, 11:20 AM
#45
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Hehe, a blast from the past, but one of my favorite threads.
Jerry, I'm not an expert, but of the 4 people I know with VF23s (including myself), two of them had a knackered VF23 after a few months (probably overshoot, impeller blades broken off). I was planning on removing the BOV myself, but hearing this has changed my mind. The damages may be totally unrelated (as John says, it's the bearing that will take the hit), but still it doesn't inspire confidence in the sturdyness of the VF23 (and probably VF24).
I have driven (for 3 months) with a mal functioning BOV that didn't open anymore, and the car felt quicker after (fast) gearchanges, and also "jerkier". The turbo did survive however.
So in short: I dunno
Jerry, I'm not an expert, but of the 4 people I know with VF23s (including myself), two of them had a knackered VF23 after a few months (probably overshoot, impeller blades broken off). I was planning on removing the BOV myself, but hearing this has changed my mind. The damages may be totally unrelated (as John says, it's the bearing that will take the hit), but still it doesn't inspire confidence in the sturdyness of the VF23 (and probably VF24).
I have driven (for 3 months) with a mal functioning BOV that didn't open anymore, and the car felt quicker after (fast) gearchanges, and also "jerkier". The turbo did survive however.
So in short: I dunno
10 November 2001, 11:24 AM
#46
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*lol* Theo....U didn't exactly help things much now did U. 
I *want* that sound...I think I'll take the chance...what needs to be done?
Blank off the IC outlet?
Plug off the hoses?
Cheers!
/J
I *want* that sound...I think I'll take the chance...what needs to be done?
Blank off the IC outlet?
Plug off the hoses?
Cheers!
/J
10 November 2001, 11:32 AM
#47
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FWIW, I never had the chirping sound ... I do have the "screaming" sound at half throttle (it goes away at full throttle). But no chirping, so I recorded an mp3 and played that once in a while 
I think we'd need even bigger turbo's and higher boost...
You need to have a blanking plate for the IC with a joint to make it airtight (like you have on the BOV). Remove the little hose from the manifold, and put a plug there. Plug off the recirc pipe or remove and plug at intake pipe.
I think we'd need even bigger turbo's and higher boost...You need to have a blanking plate for the IC with a joint to make it airtight (like you have on the BOV). Remove the little hose from the manifold, and put a plug there. Plug off the recirc pipe or remove and plug at intake pipe.
11 November 2002, 03:44 PM
#48
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I occasionally get the screaming sound at part throttle on my turbo. What causes it? It doesn't sound too healthy to me?
As for chatter it sounded like I got quite a lot of chatter with a Motorsport BOV with the orignal red spring. However I have sinced changed it to a blue spring and now get more psschhh noise then chatter.
As for chatter it sounded like I got quite a lot of chatter with a Motorsport BOV with the orignal red spring. However I have sinced changed it to a blue spring and now get more psschhh noise then chatter.
19 February 2003, 01:33 PM
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Heres a cupla things i posted in the past that might help....
ABOUT CHATTER---
EDIT!- Why the hell does it cram it together like that in a quote? Its spaced out in the editing screen here??? Sorry about that!
ABOUT ANTI-LAG (ALS)--- http://bbs.rsownersclub.co.uk/showthread.php?s=&threadid=8634
UMMM the link dont seem to work, duno why. Easy enough to find tho, jus go to the FAQ section of the rsoc bb and look for "Anti-Lag, Whay is it?" its about 10pages long!
BTW antilag/ALS is the best mod ever, id never own a turbo car without it now.
Cheers, Steve
[Edited by Steve3drALS - 2/19/2003 1:37:51 PM]
ABOUT CHATTER---
the flutter/chatter noise is whats called "wastegate chatter" even tho its not the wastegate in any way, its air coming out the turbo compressor inlet when the throttle is snapped shut on boost. "Impeller stall" is another more accurate name but no1 knows wat u on about if u say that, lol. "turbo chatter" id call it.
ANYWAY...
NO DUMPVALVE makes that noise, thas jus rumour etc thas spread over the years (even by tuners, before i had a clue, Torque Developments told me the HKS SQV valve made that noise "depending on your induction pipework" but no ANY turbo makes that noise "depending on induction pipework" ESP if no dumpvalve at all).
Let me explain...
Like i said earlier its the noise of pressurised air (from being on boost) escaping back out of the turbo compressor inlet when the throttle is shut. The MAIN reason for std factory fit recirulating dumpvalves like most turbo cars have is to STOP any "chatter" as they decide that it might put customers off (same reason for nigh on silent std exhausts n induction, i even saw a review of the old Ibiza GTi where they COMPLAINED that you could hear induction noise...).
The reason dumpvalves help stop chatter is because it gives soewhere else for the air to escape.
People say its to keep the turbo reliable, well if it IS on a scooby then their turbos must be VERY crap, as 99% of turbos that are specced to do so are fine to 25/30 psi with no reliabilty changes without a dumpvalve, you never see a turbo listed as "can run 2bar of boost, ONLY with a dumpvalve" as its jus legend thas spread across the bloody world (Ive ran without a dumpvalve for 2yrs now, with boost ranging from 25psi peak/22psi held, to 36psi peak/30psi held, and ive had no reliablilty issues with it).
Other things that muffle the sound is the airbox (jus fit a cone), airflow meters, and long induction piping.
These people saying "chatter on street cars is nothing to do with chatter on rally cars" are wrong, it EXACTLY the same thing. "my chatters because i got a stronger spring in my dumpvalve so my dumpvalve makes the noise" thas HALF right, having the stronger spring is stopping the dumpvalve opening partially or completley as the cars vacumn isnt strong enough to open it so most/all the air has nowhere to go but back out turbo, so TWTWTWOOOOOO, fookin chatter laddy.
So to sum it up, take off std resirc dumpvalve n plug the pipes, fit an induction kit, n go booting up down the road to the sound of chatter.
Dumpvalve woooshes are a bit gay anyway, kinda old news.
Cheers, Steve
Oh,BTW dumpvalves have no noticable effect on reducing lag between gearchanges either, thas another old wives tale, btu it you got a massive turbo with very long compressor blades (T4 or bigger) then a dumpvalve might be good for very high boost (30psi+) as longer blades are mre likely to snap when turbo stopping suddenly.
And rallycars etc dont run dumpvalves becasue, 1- no need, and 2- it makes the anti-lag not work as well as the air escapes out the dumpvalve when u let off which is exactly what you DONT want it to do when running ALS (belive me i got it n i tried it).
ANYWAY...
NO DUMPVALVE makes that noise, thas jus rumour etc thas spread over the years (even by tuners, before i had a clue, Torque Developments told me the HKS SQV valve made that noise "depending on your induction pipework" but no ANY turbo makes that noise "depending on induction pipework" ESP if no dumpvalve at all).
Let me explain...
Like i said earlier its the noise of pressurised air (from being on boost) escaping back out of the turbo compressor inlet when the throttle is shut. The MAIN reason for std factory fit recirulating dumpvalves like most turbo cars have is to STOP any "chatter" as they decide that it might put customers off (same reason for nigh on silent std exhausts n induction, i even saw a review of the old Ibiza GTi where they COMPLAINED that you could hear induction noise...).
The reason dumpvalves help stop chatter is because it gives soewhere else for the air to escape.
People say its to keep the turbo reliable, well if it IS on a scooby then their turbos must be VERY crap, as 99% of turbos that are specced to do so are fine to 25/30 psi with no reliabilty changes without a dumpvalve, you never see a turbo listed as "can run 2bar of boost, ONLY with a dumpvalve" as its jus legend thas spread across the bloody world (Ive ran without a dumpvalve for 2yrs now, with boost ranging from 25psi peak/22psi held, to 36psi peak/30psi held, and ive had no reliablilty issues with it).
Other things that muffle the sound is the airbox (jus fit a cone), airflow meters, and long induction piping.
These people saying "chatter on street cars is nothing to do with chatter on rally cars" are wrong, it EXACTLY the same thing. "my chatters because i got a stronger spring in my dumpvalve so my dumpvalve makes the noise" thas HALF right, having the stronger spring is stopping the dumpvalve opening partially or completley as the cars vacumn isnt strong enough to open it so most/all the air has nowhere to go but back out turbo, so TWTWTWOOOOOO, fookin chatter laddy.
So to sum it up, take off std resirc dumpvalve n plug the pipes, fit an induction kit, n go booting up down the road to the sound of chatter.
Dumpvalve woooshes are a bit gay anyway, kinda old news.
Cheers, Steve
Oh,BTW dumpvalves have no noticable effect on reducing lag between gearchanges either, thas another old wives tale, btu it you got a massive turbo with very long compressor blades (T4 or bigger) then a dumpvalve might be good for very high boost (30psi+) as longer blades are mre likely to snap when turbo stopping suddenly.
And rallycars etc dont run dumpvalves becasue, 1- no need, and 2- it makes the anti-lag not work as well as the air escapes out the dumpvalve when u let off which is exactly what you DONT want it to do when running ALS (belive me i got it n i tried it).
ABOUT ANTI-LAG (ALS)--- http://bbs.rsownersclub.co.uk/showthread.php?s=&threadid=8634
UMMM the link dont seem to work, duno why. Easy enough to find tho, jus go to the FAQ section of the rsoc bb and look for "Anti-Lag, Whay is it?" its about 10pages long!
BTW antilag/ALS is the best mod ever, id never own a turbo car without it now.
Cheers, Steve
[Edited by Steve3drALS - 2/19/2003 1:37:51 PM]
19 February 2003, 01:49 PM
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Tell u what heres a BETTER link, to a edited version of somthing i wrote for a website about anti-lag---
http://www.wrc-cosworth.org/tech/tuning/antilag.html
and heres the RSOC post-
http://bbs.rsownersclub.co.uk/showthread.php?s=&threadid=8634&perpage=20&pagenum ber=2
http://www.wrc-cosworth.org/tech/tuning/antilag.html
and heres the RSOC post-
http://bbs.rsownersclub.co.uk/showthread.php?s=&threadid=8634&perpage=20&pagenum ber=2
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