Difference in throttle percentage

[black bandit]

Thanks for the explanation guys. I think I got a better grasp on it now.
[MENTION=4577]TK-421[/MENTION] sorry for your loss. Let us know if you need anything.

 

[Alin]

[MENTION=4577]TK-421[/MENTION] damn man my condolences.

Your previous explanation with the flutter... I have that flutter! Sounds like a plusating surge and never knew why it happened. Theres another noise that appears to be coming from the turbo area and ill try to explain in a little bit.

 

[IGOTASTi]

Sorry to hear about you loss. Will be praying for you and your family.

 

[Alin]

Ok so on higher loads, such ad saturday. 80% throttle or so at 20 psi in 5th gear around 4.5-5k rpm, a metal banging noise came from what i thought was in the turbo region. Nothing was affected by it, just the noise occured. Not the first time its happened so thats why i wasnt concerned. What can this metal banging noise be coming from?

 

[HolyCrapItsFast]

off topic,but sorry to hear about your gramma.

 

[HolyCrapItsFast]

Ok so on higher loads, such ad saturday. 80% throttle or so at 20 psi in 5th gear around 4.5-5k rpm, a metal banging noise came from what i thought was in the turbo region. Nothing was affected by it, just the noise occured. Not the first time its happened so thats why i wasnt concerned. What can this metal banging noise be coming from?

Say What! :shock:

Send me a log immediately please... Knock sounds like someone banging on the block with a ball peen hammer. does it sound like that?

 

[Alin]

I dont know what that noise sounds like. :lol:

What parameters and situation do you want logged?

 

[HolyCrapItsFast]

Also your last dyno plot doesn't show any adverse boost issues so I can't explain the flutter you are hearing.

Perhaps it's time you took a visit.

 

[Alin]

We discussed the turbo surge. I didnt use the word flutter, i used surge. I suppose flutter is indeed a better word to use to describe that.

Again, this metal knock noise only occurred in 5th. 1-4 are fine regardless of throttle percentage.

6th you can forget about it cause i dont think ive ever WOT in 6th.

 

[HolyCrapItsFast]

I dont know what that noise sounds like. :lol:

What parameters and situation do you want logged?

Log...

Engine Speed
Engine Load
Throttle Position
Manifold Relative Pressure
Waste Gate Duty Cycle
Feedback Knock Correction
Fine Learned Knock Correction
IAM
Boost Error
Wideband AFR Gauge

Do one WOT run in 4th gear from 2500-6500 rpm. Watch for lean AFR's and Knock and abort the run at any sign of a problem and send me what you have.

 

[Alin]

Ok. Do you want it today? 50s and rain.

I have only taken the car out on friday and saturday nights in the past 3 months.

 

[HolyCrapItsFast]

We discussed the turbo surge. I didnt use the word flutter, i used surge. I suppose flutter is indeed a better word to use to describe that.

Again, this metal knock noise only occurred in 5th. 1-4 are fine regardless of throttle percentage.

6th you can forget about it cause i dont think ive ever WOT in 6th.

It might be hitting a load cel that we didn't touch. I never tune for WOT in any gear higher than 4th. I will leave it up to you if you want to log and recreate the condition you are seeing. Use the same parameters as previously suggested.

 

[HolyCrapItsFast]

Ok. Do you want it today? 50s and rain.

I have only taken the car out on friday and saturday nights in the past 3 months.

When ever you fell it is safe to do so.

 

[Alin]

I decided ill wait for the weekend. 60s and sunny.

When i drove on sat night it was raining lightly but enough to get the roads wet. The tires i have arent too fond of wet roads because i was spinning all 4 around 4k rpm on WOT in 3rd gear. :tard:

So ill do the log friday evening or saturday morning. :tup:

Ill be doing your 4th gear and if the log looks sound, ill try and replicate the 5th gear condition.

 

[TK-421]

All of you guys a freaking amazing! Thanks for the kind kind words.

Back on topic, [MENTION=9]HolyCrapItsFast[/MENTION], It might be possible that this is a mechanical situation, regarding his noise. He did mention the cracked wastegate. I have experienced a slight metal knocking noise on a few WRX's and STi's on the dyno along with the Evo 8 as well, upon investigation it's led to it being the actual wastegate flapper in the exhaust turbine housing that has become somewhat "loose" and creates a metal knocking/pinging sound. Not all of them turned out to be this way, but it was pretty pro dominate in the cars that had a bell mouth catless downpipe, and most Evo 8's that had the dual puck wastegate outlets. But then again it could be the tune, until you see the logs, but if the logs show things to be of the norm, I would look into a mechanical issue such as the wastegate flapper in the turbine housing [MENTION=1172]Alin[/MENTION]

 

[Alin]

[MENTION=4577]TK-421[/MENTION] well i do have an open bellmouth catless downpipe. :lol:

So with the crack and 20 psi, the flapper cant do its job correctly?

 

[TK-421]

@TK-421 well i do have an open bellmouth catless downpipe. :lol:

So with the crack and 20 psi, the flapper cant do its job correctly?

Its not necessarily the flapper that malfunctions, it's the actuating mechanism that the wastegate arm attaches to that becomes loose, I bet if you pull the cotter pin holding the wastegate arm to the actuator, and then wiggle the actuator that goes into the turbine housing you will notice free play. There's a couple of ways around this, 1 buy a new turbo, 2 buy a exhaust housing, 3 get the turbosmart, AVO, or any other equivalent IWG that has pretension load adjustability, on the older td04 WRX's the wastegate was adjustable, they got rid of the adjustability with the STi and newer WRX. The wastegate issue like I said can be pretty common when the car has boost creep, which is a mechanical issue, most of the time you will hear in subaru's that loud fluctuating fluttering sound under hard accel at higher boost levels, that's the wastegate flapper opening and closing with the BCS controlling that IWG which regulates that flapper. Most don't notice it with light boost or if they are on a stock downpipe and stock tune. I was planning on doing a install write up this weekend on the Turbosmart IWG actuator and taking a video to compare and contrast the differences between the stock unit and aftermarket, and to differentiate the noise differences with the flutter sound, and small metal pinging sounds most experience with the stock unit. But unfortunately those plans have been pushed back.

Still take some logs, but if you have the chance, check that wastegate flapper by disconnecting the wastegate arm, and if you can feel free play and you hear the flapper smacking around and being real noisy when you swing the arm, I wouldn't be surprised if that's where your mysterious noise originates from [MENTION=1172]Alin[/MENTION]

 

[Alin]

Well everything you said is exactly what ive been experiencing. I will take a look at the wastegate flap to see if its loose. Most likely. The flutter, the bang/ping.

I already have the remedy with a nee turbo but that wont be going in until spring time.

From your experience, does the flutter and ping/bang noise affect anything/keep the turbo from doing its job in harmony?

 

[HolyCrapItsFast]

Well everything you said is exactly what ive been experiencing. I will take a look at the wastegate flap to see if its loose. Most likely. The flutter, the bang/ping.

I already have the remedy with a nee turbo but that wont be going in until spring time.

From your experience, does the flutter and ping/bang noise affect anything/keep the turbo from doing its job in harmony?

The ECU can easily mistake this for knock and reduce your timing to the point where power begins to drop off. This is what I am looking to see with the logs. And if there is any observed knock then we can determine that easily enough by removing timing and seeing if it is impacted or not.

I also want to observe any noticeable difference from the new log versus the old ones that I have on file from your car. That will help to troubleshoot any issues that may have arrived since your tune. Try to log on the same stretch of road you logged with that last time.

 

[Alin]

The ECU can easily mistake this for knock and reduce your timing to the point where power begins to drop off. This is what I am looking to see with the logs. And if there is any observed knock then we can determine that easily enough by removing timing and seeing if it is impacted or not.

I also want to observe any noticeable difference from the new log versus the old ones that I have on file from your car. That will help to troubleshoot any issues that may have arrived since your tune. Try to log on the same stretch of road you logged with that last time.

Absolutely. Same exact strip. 25 to 55 mph at that traffic light. :tup: