ok, here's the story... the car runs fine... but when at full throttle, and near .8bar (12psi)... there's a sharp metal noise... it's almost as if there is a loose bolt in the the piping and being thrown around in there... besides the noise, i can sometime feel the vibration in my shift ****... i got a new engine in about 6k miles ago... n it's been doing that ever since.... it almost feels like something is being torn apart or something under there...it's definitely coming from under the car... i know i blew my cat out in feb., but never took it off and cleaned it... could it be something in the cat? anybody have a similar experience? any help is greatly appreciated...

Eddie

 

I have heard weird noises while boosting at high levels (15 PSI)also. I think what I heard was detonation due to the fact that I was running on a stock ECU without any timing advance.

 

I'm pretty shure 12PSI on the stock turbo is pushing it. That could be detonation true.

 

How many miles on the turbo? If you are boosting the stock turbo up that high with quite a few miles, it might have some shaft play in it and boosting at that high a level can cause the turbine blades to "contact" the housing. Or so I've heard at least, if thats what it is time for a rebuild or upgrade

 

Just a thought...but maybe under that high loading something is getting of the way of the fan. Something under load could be hitting the fan.

James

 

Detonation and the turbine shaft are very possible. without some type of additional fuel and a very good intercooler 12 psi is going to kill the stock motor quickly. detonation can quickly destroy the motor, I blew a brand new motor the first day of testing with a couple of runs at high boost. be careful and watch the A/F ratio at high boost. I have also found that 10 psi seems to be the high end of effectiveness for the stock turbo. it will make more boost but it is very inefficient. please be careful.

 

i appreciate all you guys' comments... but i don't have a stock turbo... greddy td06sh 20g... all my mods r listed in my sig.... also, i know i have enough fuel.. well pretty sure i fried the wires for my A/F meter tryin to put a switch in... i was boostin 14psi-22psi fine on my old engine(stock) during the past winter....never had this symptom... i have probably 35-40k on the da turbo... i've been inclined to think that turbine blades are messed up.. but i'm not a mechanic......newayz, ne more ideas? anything i can do to locate the prob? or do i need to take it to a shop? thanks

Eddie

 

either way, if you get enough shaft play on a turbo making that much boost, like you said, the turbine blades could be messed up, possibly from contacting the housing. I would take off your TID, check for play and see if the blades look damaged at all. Oh, and next time I'll look more carefully at the sig