R5FORD

iTrader: (1)

well i was geting a fluttering noise from around the turbo, and as adviced changed the spring iin my d/v..now i drove it down the road, it hit 18psi and then staggred like loosing boost, and im still getting the fluttering noise..

CAN ANYONE HELP ME AND TELL ME WHAT THAT BLOODY FLUTTERING NOISE IS

thanks

Mike Rainbird

iTrader: (3)

If it's on acceleration, then it is surge.

R5FORD

iTrader: (1)

its when i come off acelleration tho

xr4x4rs

iTrader: (5)

its the air coming back through the turbo and being chopped up by the blades

if your dump valave isnt working then the spring is too strong or seized

but i dont runa dump valave and would rather have the flutter

Gary F

iTrader: (1)

Just sell up mate

SimonT

Chatter. Wicked. Dont do anything about it!

R5FORD

iTrader: (1)

seriously thinking about it mate



How can that work, i drove it with the new spring in and it didnt flutter than after about 7mins it started to flutter again

Gary F

iTrader: (1)

Just the dv off mate the chatter sounds better anyway

R5FORD

iTrader: (1)

but heard the chatter cant be that good for my turbo, especally when peaking at 28psi and the turbo is a roller bearing one

Mike Rainbird

iTrader: (3)

Try swapping with a dump valve that you know to be working fine and see what happens.

R5FORD

iTrader: (1)

its a brand new d/v mike..

thats what i cant understand

Mike Rainbird

iTrader: (3)

So why did you change the spring?

Did you change it for one harder or softer?

What size is the d/v outlet - normal 25mm Cosworth?

RickyLee53

Isn't it normal to loose boost when you come off the throttle

Sounds like you've put a harder spring in the DV, so its not opening at lower boost and the air's going back through your turbo causing chatter.

R5FORD

iTrader: (1)

changed it because i thouught it may stop the fluttering and it did for about 5 mins and then the fluttering came back..i changed it for a softer spring.. outlet is..25mm

Mike Rainbird

iTrader: (3)

What make dump valve?

R5FORD

iTrader: (1)

forge dual piston ram dump valve

Rickeylee53, i said it feels like loosing boost, didnt say i was not accelerating, i said it flutters when iv accelerated and then depressed the clutch

Mike Rainbird

iTrader: (3)

If it flutters while you are accelerating and feels like it is loosing boost THAT IS SURGE!

Sounds to me like you have a completely mismatched turbo.

What rpm does it do it at?

No amount of dump valve changing will cure surge - you have to either cap the boost at the point it is surging or fit a smaller compressor or a larger turbine. You could also play with the cam timing to help allow the engine to "breath" better at the current surge point.

R5FORD

iTrader: (1)

yh maybe that could be it, my turbo is a roller baering turbo, kicks in around 300rpm.. is there anyway i could get my turbo matched with my ecu,etc?

Mike Rainbird

iTrader: (3)

Yes, the boost curve can be mapped to rpm. However, you're in OZ, so the only way you could do it is to buy one of the good Jap controllers that allow this. Make sure the fuelling is good for each rpm / boost increment.

Spiky

iTrader: (1)

matched to you engine spec, not ecu

R5FORD

iTrader: (1)

so if i brought a jap boost controller, would i be able to set it up myself? or best to go proffesional?

also mike do you mean mis matched as the compressor wheel is to big for the turbin or visa versa

Mike Rainbird

iTrader: (3)

Did you not read my reply ? The fuelling needs to be checked at each rpm / boost point as your chip was designed to run a completely different turbo - so what do you think?

Yes, the compressor is too big for the turbine.

R5FORD

iTrader: (1)

lol i get you mate..so i need a boost controller and setup profesionally.

or change the turbo again

R5FORD

iTrader: (1)

would be easier if i could just get stu to re write my chip to match my turbo, but doubt thats going to happeen

Mike Rainbird

iTrader: (3)

Would be easier to put the turbo on the car the chip was written for .

R5FORD

iTrader: (1)

well i had a t34.48 and stu wrote me a chip for that turbo,, but that turbo didnt last 5mins literally..so hadto get a new one made up..

would it be possible for stu to write a new chip to match my spec or not?

Oranoco

Only way to find out is to ask.

R5FORD

iTrader: (1)

yh i know..just getting the phone this min

Mike Rainbird

iTrader: (3)

Unlikely, as the turbo sounds like some bastard hybrid using Pulsar GTiR internals etc. But you never know.

Vic

what size rear housing is it?

what ever you do DONT keep you foot into it while it surges!

R5FORD

iTrader: (1)

its a 0.48 but has been machined..so not sure

Vic

There lies your problem mate, get a 0.63 to 0.70 rear housing. This will free up horsepower (at the expense of some lag) and will get rid of a LOT of surge. (but not knowing what compressor you have I cant guarentee it'll get rid of it all)

Basically you need to spend some more cash