wastgate chatter

[RedRummy]

thank you! this is an interesting discussion, but at last someone has answered my question as to why i have both!

Mine chatters on low boost (I mean if I lift off early, rather than control the boost) but sounds like a normal psssssshhhhhtt when driving hard..  

no idea if its OK to do that though...  :confused:

[Jimjitsu]

well ok if it does not do to much damage to the to4e then ill leave it i kinda like the noise and my bov is working i have the pffffff and fffffftthththththt

[Jimjitsu]

mine does it at any level of boost if i let off the throttle quick i get the hannibal if i let it off easy i get the bus putting its brakes on

[Kash_]

I\'ve got a to4e and been running 0.85 bar without a BOV/ dump valve for over a year and had no probs... plus the wastegate chatter sound is intoxicating

[Jimjitsu]

I\'ve got a to4e and been running 0.85 bar without a BOV/ dump valve for over a year and had no probs... plus the wastegate chatter sound is intoxicating

Good enough answer for me i like the noise so it stays :Thumbsup!

[FLAT4MATT]

I\'ve got a to4e and been running 0.85 bar without a BOV/ dump valve for over a year and had no probs... plus the wastegate chatter sound is intoxicating

Mine\'s sweet as a nut with no BOV (Pip didn\'t fit one when he fitted my single - Not got much good to say about them either...) t04e @ 0.87bar (389.9@flywheel) ran a 12.54 despite terrible starts all day due to the stock clutch, tired stock suspension, 30PSI in the tyres, a full tank of fuel and no diff bracing.

AND...

It\'s my daily car and has been for 18months ! :driving

[andysmee]

does the stock car have a BOV?

[strange_days_uk]

Stock FD has a recirulating bov for each turbo.

My greddy bov is adjusted so that at low boost I get a little chatter, but at good boost levels it will all vent to atmosphere.

Good thread !

[stocky]

i had a series 2 rs with a t3 that was at 20psi with a dump valve decided to bin it for the chatter had no problems whatsoever with the turbo and that was always driven hard then after that a s13 origionally a 1.8 with t25 ran that with no bov with no problems then swapped to sr20det with t28 again with no bov and no probs (except for the w"£$y variable valve timing)
the one thing i noticed with the escort was it was slightly quicker picking up
also if i remember right a magazine (maybe fast car/max power?) did a test on the new-at the time mk4 golf turbo that was dyno\'d which HAD more power and response without the bov

[turbotoaster]

havent had time to read past page one up to yet but for reference about why rally cars dont have BOVs, theres a good reason for this, its not to save the turbo or anything like that, its because they run anti-lag, when the driver lifts off the throttle instead of the engine taking no more charged air and it either being \'dumped\' or passing back through the blades it is continually pumped into the engine, the ignition is timed right back so the fuel is almost ignited as it leaves the cylinder head hence expanding and keeping the turbo spinning so when the throttle is opened the timing is adjusted back and full boost is avaliable instantly.

If a BOV was installed all that pressure would be lost and anti-lag wouldnt work, since most people run without anti-lag i can see the benefits of having it

the times when isnt as efficient on a road car is in extreme full throttle times when the car is running a large cooler and pipe work.

Its been mentioned that the loss of pressure will cause a lag in full boost between gear changes, now this is all down to the driver to be fair and how fast he changes gear.

It takes longer for the pressure to escape back through the turbo and the system to revert back to zero pressure/vacuum than it will through a BOV as it has two options on how to get out and will use both.

If the driver is very slow on gear change then most likely the pressure will fully escape through either the turbo or if a BOV is fitted before full throttle is applied

If no BOV he will just slow the turbo down which will then take a very small amount of time to spool back to full speed, if hes running a blow off valve obviously the turbo will be slowing down but not at the rate of which is was without a BOV.

So it does depend on the situation the driver is in, very fast full throttle changes i would advise not to run a BOV(drag, maybe some circuit) but for street use id advise to run one as the benefits out weigh the potential negatives as you wont be able to tell enough for it to make a difference

hope this helps, any questions or comments im happy to discuss:Talking1