Headling 0 Posted April 11, 2008 Sorry to sound a bit of a boy racer, but got my 2.0 turbo 205 going and fitted it with a nice noisy bailey dump valve. I was watching rally cross at lydden hill and loved the turbo beast they have there, i know they are prob £10k + engines etc, but my question is how to get that chirp/burble noise? Is it the waste gate making this noise? Is it a case of buying a upgraded wastegate, is this a part you can buy for the std pug turbo? Share this post Link to post Share on other sites
welshpug 1,626 Posted April 11, 2008 (edited) its the turbo stalling when the throttle snaps shut for a split second, happens quite a lot when you run more boost. Edited April 11, 2008 by welshpug Share this post Link to post Share on other sites
sonofsam 5 Posted April 11, 2008 Nope its not the wastegate! Its compressor stall, air being chopped up back through the turbine blades! Take the dumop valve off, fit a cone filter and you shall hear it Share this post Link to post Share on other sites
Headling 0 Posted April 11, 2008 oh right got you now, is there any gain fitting an uprated waste gate? check this out some good chirpming going on! and some good music!!!! Share this post Link to post Share on other sites
whizzer71 0 Posted April 11, 2008 Not very good for the turbo though !,puts extra strain on the impellor and its shaft,hence the fitment of dump/blow off valves. Share this post Link to post Share on other sites
Tom Fenton 1,526 Posted April 11, 2008 As above its bad for the turbo, when I hear it I wince. If you don't like the rude boy whoosh noise then a recirc dump valve looks after the turbo and is not too noisy. Share this post Link to post Share on other sites
sonofsam 5 Posted April 11, 2008 As above its bad for the turbo, when I hear it I wince. If you don't like the rude boy whoosh noise then a recirc dump valve looks after the turbo and is not too noisy. Plenty of 406 sri's, xm's etc run no BOV for the entire lifespan of the Turbo and there fine! Mine actually runs better without one! if you're running higher than stock boost it might warrant one though. "is there any gain fitting an uprated waste gate?" Yes, if you've got an uber mental jap racing wagon External or divorced wastegates will allow the gasses to exit at different points equally less turbulence by the blades equally quicker spool up I guess, just extra bling mate really. An uprated wastegate actuator though will allow higher boost setttings than stock but you can bet your bottom dollar the ECU will throw a spanner Share this post Link to post Share on other sites
Headling 0 Posted April 11, 2008 i kind of like the whoosh noise! i know i should grow up! im 28 for gods sake! but just wanted to get some other noises going on hence the questions of the wastegates. what do you reckon on the video? group B cars are so so awesome! got to love the T16 Share this post Link to post Share on other sites
whizzer71 0 Posted April 11, 2008 (edited) Plenty of 406 sri's, xm's etc run no BOV for the entire lifespan of the Turbo and there fine! Mine actually runs better without one! if you're running higher than stock boost it might warrant one though. Yep agreed if youre only running .5 bar std,a BIG must if youre running higher boost ,as mentioned if you don't like wooshing noise of the compressed air being dumped off then a recirc valve is more than fine. Edited April 11, 2008 by whizzer71 Share this post Link to post Share on other sites
bales 1 Posted April 11, 2008 (edited) I know a lot of people disagree with this but I run mine at 1bar without a dv and it has been absolutely fine for quite a while now.... I prefer the noise, but its up to you if you want to take the chance, there are lots of supposed turbo failures due to this but I personally have never heard of one failing from this and have been told that it is very rare so I take the chance. If were gonna be really pedantic compressor surge is actually when you run a centrifugal pump in a high load situation on the very far left of the compressor map and is completely out of the effcciency island. This causes pressure pulses in the volute that can stall the compressor wheel and even roatate it the opposite way.... So if you ever have a massive turbo and put your foot down in 5th at low revs and it explodes you know why... Only really applies to industrial scale stuff though, not enough inertia in an automotive turbo. Anyway thats enough geekiness Edited April 11, 2008 by bales Share this post Link to post Share on other sites
sonofsam 5 Posted April 11, 2008 I know a lot of people disagree with this but I run mine at 1bar without a dv and it has been absolutely fine for quite a while now.... I prefer the noise, but its up to you if you want to take the chance, there are lots of supposed turbo failures due to this but I personally have never heard of one failing from this and have been told that it is very rare so I take the chance. If were gonna be really pedantic compressor surge is actually when you run a centrifugal pump in a high load situation on the very far left of the compressor map and is completely out of the effcciency island. This causes pressure pulses in the volute that can stall the compressor wheel and even roatate it the opposite way.... So if you ever have a massive turbo and put your foot down in 5th at low revs and it explodes you know why... Only really applies to industrial scale stuff though, not enough inertia in an automotive turbo. Anyway thats enough geekiness No carry on I was enjoying that Compressor surge and compressor stall the same thing then?! Share this post Link to post Share on other sites
bales 1 Posted April 11, 2008 No carry on I was enjoying that Compressor surge and compressor stall the same thing then?! In the realms of talkin about cars everyone uses the term compressor surge for the reversing of the air through compressor, just like people still talk about wastegate chatter! So yes I would say that they are the same thing. I am talking from a industrial pump sort of sense, my last job involved a lot of sizing of centrifugal pumps for specific flow rates etc...and whether they will suffer from cavitation if they run pressurised or if they run dry for periods of time. For every pump you always have a compressor map with lots of different islands depending on what pressure ratio you run at. At the bottom left of every compressor map is a "surge" area that you are always warned to keep well away from. So you have to very careful of when the pump is speeding up and slowing down, and depending what your flow rate is and what the density of the fluid is and if it is going to change during operation say if the viscosity changes. This would then change the load and if it is struggling and the rpm's drop down then you can get in the surge area and thats when problems happen. It has been known for the pressure pulses to be so strong on even something like a slurry pump to shear shafts and rip blades off as the waves can be so violent. Then there's issues with cavitation if you run a pump deep underwater and it gets air in and the water starts to "boil" around the impellers, the bubbles implode and can rip chunks out of stainless steel blades!! So erm...yeah you can get in lots of s*it if you don't size appropriately - not like the fact that you just drop off boost in a car That enough info I have bored myself Share this post Link to post Share on other sites
base-1 17 Posted April 12, 2008 I used to work on one of the Supercars you were probably watching at Lydden. Dump valves are a load of gay, if surge/stall REALLY killed turbos, then they would have been fitted from the factory when turbos started to be fitted from the factory. Yet even on 20 year old cars original turbos are still going strong, or the bearings have given up. They would also be fitted to all massively expensive race engines, but they're not. You don't get wastegate chatter because wastegates are plumbed back into the exhaust, unless it's some mental drag car perhaps, or some chavved up P.O.S. Or perhaps some company demo car that just wants attention, but screamer pipes (open wastegate exits) sound gash. Share this post Link to post Share on other sites
whizzer71 0 Posted April 12, 2008 I had an Evo with a screamer pipe on it,bloody awfull thing it was one of my first jobs to remove it ! Share this post Link to post Share on other sites
sonofsam 5 Posted April 12, 2008 A divorced wastegate would be fun to engineer onto a 205 Turbo! Share this post Link to post Share on other sites
whizzer71 0 Posted April 12, 2008 A divorced wastegate would be fun to engineer onto a 205 Turbo! Thats a nice bit of kit Sam where did you find that ? Share this post Link to post Share on other sites
sonofsam 5 Posted April 12, 2008 Thats a nice bit of kit Sam where did you find that ? google image search "divorced wastegate" bought up that, think it was www.scoobytuner.com! I think you maybe able to buy discharge flanges with a built in "seperator"?-may have a look later Share this post Link to post Share on other sites
craig f90 0 Posted April 14, 2008 Sorry for dragging this up. But Turbo technics recommend using a Dump valve if you are running 1bar+ Thanks, Craig. Share this post Link to post Share on other sites
inferno 1 Posted April 14, 2008 (edited) I built my 205 turbo with a T34 hybrid and Tial external wastegate. The idea of the wastegate was to take control away from the ecu. The gate opens at a specific boost pressure, and can run as low as 3psi. The way they work helps to eliminate boost creep and overboosting situations. Well worth looking at for the power ill be running Bought a T3 flange on ebay, some 3 inch pipe for the dpipe, and some 38mm pipe for the waste gas pipe. Have piccys somewhere. (yes for those that remember... the one i gave up on is coming back ) Edited April 14, 2008 by inferno Share this post Link to post Share on other sites
