This might be a really sad question to ask but how does one go about making the wastegate chatter louder on a standard vRS?

Our other car - a remapped Smart with a K&N filter - can be heard clearly but I've never heard the vRS do it although a friend at work commented that he heard what he thought was a blow off valve when I drove past him changing gear. I can only assume this was the wastegate.

Your thoughts greatly appreciated!

James

it probably was the DV he heard, your car has a DV but it has a re-circ valve instead of a blow of valve, can stll be heard on a standard car, it was on my 1.8t

Do you mean the "pstsh" noise when lifting off accelerator or actual waste gate chatter?

If it's the later that's not a good idea....waste gate chatter is when boost is vented through the waste gate and this is bad for the turbo.

If the former then a replace Green Filter and an uprated dv will give some extra noise but for full fat "pstsh" a CAI is the way to go.

I fyou want the full wastegate chatter noise, blank off the dump valve. It will sound excellent for about 3 miles than you will need a new turbo

Steve

what is wastegate chatter, as I heard Tiff Neddle say 'wastegate chatter' when he was driving the Lotus and it went 'psssttttcchhhhhhhh',

If you want a psssstttccchhhh sound on the octy then fit an induction kit...

Thanks for your replies - the pstsh sound is the one I'm looking for! A Green Filter seems the way forward although I may well consider a full CAI.

It's interesting what SkodiRS says because the Smart vents its boost through the wastegate - there is no standard DV. Am I right in thinking that a DV stops the turbo from stalling, thereby improving pickup?

James

bingo

what is wastegate chatter' date=' as I heard Tiff Neddle say 'wastegate chatter' when he was driving the Lotus and it went 'psssttttcchhhhhhhh',

If you want a psssstttccchhhh sound on the octy then fit an induction kit...

AND

Thanks for your replies - the pstsh sound is the one I'm looking for! A Green Filter seems the way forward although I may well consider a full CAI.

It's interesting what SkodiRS says because the Smart vents its boost through the wastegate - there is no standard DV. Am I right in thinking that a DV stops the turbo from stalling, thereby improving pickup?

[/quote']

I posted this on another motoring bbs when someone asked about turbo noises. It may go someway to answering your question.

Most of you will have heard the chirping from the world rally cars and a few road cars as well as seing the flames. Everyone will have heard the pshhhh sound mainly on the boy racer turbo cars .

So what are these then?

You want the turbo to be upto speed and producing full boost as quicly as possible. Lets say our car produces maximum boost at 3000rpm. The exhaust gases are spinning the turbo as fast as it needs to go at full throttle with the engine spinning at 3000rpm.

As the engine revs rise further the turbo would continue to spin faster and probably destroy itself. For this reason the exhaust gas has two routes, either through the turbo or through a bypass straight down the exhaust . The direction of where the exhaust gasses go is controlled by a valve type actuator usually called a wastegate. At low revs the wastgate will channel all the gasses through the turbo then as max boost is nearing will allow gasses through the bypass, it will regulate this maintaining maximum boost.

On WRC cars and some high spec road cars running very high boost when you lift off the throttle the boost in the intake rises dramatically as it has no where to go, the wastegate slams open to allow the exhaust gases to bypass the turbo, the slamming open of the wastegate causes it to bounce (best I can think of to descibe it) this action causes the chirping sound

At the same time the turbo is spinning at around 120000rpm and the air has stopped moving, this shock loads the blades of the turbo as the turbo blades are cutting stalled air. This can sometimes be heard as a fluttering sound.

On a fast gear change the above is the best performance option as the intake is still pressurised and the turbo is still spinning when you come back on power. It is however a very hard life for the turbo and wastegate and only the highest spec turbo's with 360degree thrust bearings can withstand such a life.

Most roadcar setups use a dumpvalve or blowoff valve (Same thing different name). When the throttle is closed the pressurised air in the intake is released or dumped. This prevents the turbo being shock loaded and gives the wastegate an easier life. Most standard setups use a recirculting DV that dumps the air back into the airbox side of the turbo, doing it this way means you can't hear it as it's quitened by the cars intake system. You can replace these on some models with a vent to atmosphere type, when you lift off whith this type you get the Pssshhhh sound when it dumps the air pressure alternatively fitting an induction kit means you hear more of the recirc dump valve noise.

This however is not the performance option, dumping all or some of the air pressure means the intake has to be repressurised when you come back on throttle which increases lag.

For all the boy racers , a dump valve is there to protect the turbo and is not for added performance.

The ultimate has to be the antilag systems as used on WRC cars. With an ALS system when you lift off exhaust gasses are kept flowing through the turbo to keep it spinning at maximum boost all the time. This can be done a few ways, the simplest form is to keep the injectors fueling but with no cylinder spark when you lift off, the fuel is ignited in the exhaust manifold and thus keeps the turbo spinning. The latest systems use valve timing, when the accelerator is lifted the fueling and sparking continues but the exhaust valve timng alters so the engine power drops to minimum but the fuel is still burn't and sent to keep the turbo at maximim boost.

The most common systems and the sytems available for road turbo cars use extreme timing retardation. When you lift off fueling continues but you dont get a spark until the exhaust valve is opening thus all the power is sent straight out of the cylinder and used to spin up the turbo. The problem with using ALS on most road cars is that you loose servo assistance so a fancy brake setup is needed.

Obviuosly the turbo's with ALS don't last that long.

Cheers

Lee

Thanks for that informative post Lee - nice to now know exactly what a DV does

James

Thanks for that informative post Lee - nice to now know exactly what a DV does

James

It's amazing that even some Motoring Jurno's including Mr Clarkson and some ex-motorsport Jurno's don't know their wastegates from their dump valves.

Cheers

Lee