TWO MAJOR PROBLEMS WITH TURBO SETUP

[hass]

hi guys
i have 2 problems my my turboed 325i
the specs:
standard 25 m20 with oversized h/g
t34 turbo
42ib injectors
volvo i/c
m/s
right firstly
got my car back from ants yesterday and i was adviced to change my custom nissan pulsa intercooler.
so got the car up on the ramp and took off the i/c
put the volvo one on and remade all my boost pipes from 2.5" stanlessteel piping
all good
the car has been transformed.

but....
i never put the dumpvalve on left it off (didnt have enogh time to drill and wheld the port)

but my car sound like i have a dumpvalve
does anyone know what this could be.

number 2 problem
now ant is looking into this problem but i thought i have a word with you guys to see if anyone has come across this problem before.
when im driving and i come to a stop the idle drops right down and the car starts to hunt and run very poor.but soon as i rev it up it clears.
like i said ant is looking into it but all the help will help.

guys thanks for your time and i hope i can sort these problems out with ur help.

thanks hass

[FlappySocks]

What Idle Control Valve is being used? Could be just a setting in MS. Took me a while to get mine right, and it's still not perfect.

[hass]

not using any icv

[FlappySocks]

Hmm...probably something that needs tweaking then. Fuel cut maybe, or idle advance. Best wait for Ant.

[hass]

yea i guess so

any other opions on the misterious dump valve noise

[FlappySocks]

Forced induction is where my knowledge ends unfortunately.

[appletree]

Is it a noise like you hear from the rally cars? could be waste gate chatter? or the turbo stalling as the air in the pipes hits the closed throttle body??

[tylerma]

I was also thinking wastegate flutter
mine used to do this and that never had a dump valve fitted

[FlappySocks]

If you feel inclined, try data logging your idle problem. I was having issues recently with a new MS install I did. It was immediately obvious from the graphs my TPS signal was noisy (crap secondhand TPS from ebay). You can learn a lot by analysing the graphs.

The TPS was causing the mixture to go rich, which caused a missfire. My JAW wideband saw this as a lean mixture, and instructed MS to dump even more fuel in, and made it even richer still Still, at least with MS you get all the right tools at your disposal to fix it. Try deducing that problem from a closed system... you would have to swap out parts until you found the cause.

[Wiseman]

WASTEGATE CHATTER/FLUTTER ? PLEASE? do you know what a waste gate does? noob
Put a dump valve on though, it sounds mint without it but will reduce the life of your turbo, the pressure from your compressor wheel has nowhere to go when you come off of throttle so it burps backward through your intercooler, charge pipes etc..
then hits the blades on the compressor side of your turbo, the noise comes through your air filter.
it will also cause slight lag on your turbo because you slow it down with the boost reversing back into it. it sounds a bit like squirrels gettin sucked into the turbo.

www.andrewgallacher.com
worlds fastest focus

[SPADGE]

WASTEGATE CHATTER/FLUTTER ? PLEASE? do you know what a waste gate does? noob
Put a dump valve on though, it sounds mint without it but will reduce the life of your turbo, the pressure from your compressor wheel has nowhere to go when you come off of throttle so it burps backward through your intercooler, charge pipes etc..
then hits the blades on the compressor side of your turbo, the noise comes through your air filter.
it will also cause slight lag on your turbo because you slow it down with the boost reversing back into it. it sounds a bit like squirrels gettin sucked into the turbo.

www.andrewgallacher.com
worlds fastest focus

Lol everyone calls it 'wastegate chatter' but as you say it has sod all to do with the wastegate

[Wiseman]

Thanks finally someone who will agree on something wi me. Sorry but im not offen on here and when i am all ive had is sheere cheek. everyone does call it that tho.

[stonesie]

Everybody knows 'that noise' as wastegate flutter and thinks it's a good thing.... Few understand that it's compressor stall and is like smacking the turbo with a hammer, eventually somthing is going to let go and mince the turbo, maby the engine, depending how many bits get through.

[appletree]

WASTEGATE CHATTER/FLUTTER ? PLEASE? do you know what a waste gate does? noob
Put a dump valve on though, it sounds mint without it but will reduce the life of your turbo, the pressure from your compressor wheel has nowhere to go when you come off of throttle so it burps backward through your intercooler, charge pipes etc..
then hits the blades on the compressor side of your turbo, the noise comes through your air filter.
it will also cause slight lag on your turbo because you slow it down with the boost reversing back into it. it sounds a bit like squirrels gettin sucked into the turbo.

www.andrewgallacher.com
worlds fastest focus

Thats what i said in the first post i made! all be it in a less detail! i said about the air hitting the closed throttle pettle and stalling the turbo, but to try and help the guy out i though it would be easyier to call it what everyone calls it and then he could go on youtube, type in wastegate chatter and hear the noise, then if its the same as the noise hes got we can work out how to help him.


Hears a more detailed description from wiki

There is a common myth in the automotive world about so called "wastegate chatter" or "turbo flutter", a noise created on lifting off the throttle in a turbocharged car. The sound is commonly described as a chipmunk or a rattlesnake and is often stated incorrectly as being a result of the turbo's wastegate closing.

The noise is in fact the air compressed by the turbo passing back through the compressor wheel of the turbo after the airflow is abruptly halted by the throttle plate closing, called compressor surge. However, in some cases, i.e. where the throttle plate doesn't open fast enough or is set up to only react to high boost, some chatter will remain. Surge can occur on diesels when the turbo is attempting to pressurize the air at a higher pressure ratio than the compressor wheel can flow at a given speed. Diesels have no use for a Blow off Valve as they do not have a throttle plate.

The chatter noise is very noticeable on World Rally Cars, where anti-lag is used.

Bear in mind that a compressor stall like this causes huge amounts of wear on turbochargers and should be avoided in order to prevent damage to the wheel shaft and ball bearings, if the unit is equipped with them

[Wiseman]

Aww feel better now that you've copy/paste something that you wish you had done first.

[fowler]

Aww feel better now that you've copy/paste something that you wish you had done first.

LOL
easy fella you will get a warning for things like that on here just a heads up

[Wiseman]

here just jestin you. What would life be like if you didnt
Thanks tho fowler

[fowler]

wise man where are you based ?????