VVT Tuning Noise - ADDED: Comparison Video

[s2d4]

Originally Posted by regal

Sorry I thought you were an ecutek spammer till a saw your post count. To answer you question I ordered a tratrix 2.0 last week. Hopefully we will get good enough datalogging for poor folk out of that.

Yes, you can then analyse it and "confirm" if you have a problem rather than forever stating everyone else's problem is yours let alone if it's even a problem in the first place.

[regal]

Originally Posted by wparsons

The difference on an N/A engine is very noticeable, but with your supercharger adding power in that range already I doubt it's nearly as noticeable for you.

Exactly if this is chewing uo camshafts and bending valves we can pretty much forget GT-86 NA tuning scene.


I guess the next step is to find someone NA with an aggressive VVT who is installing the aftermarket turbo cams for a turbo install.


Mic those used NA cams and we should have our answer,


When I hear it is sounded like a slight manifold leak or exhaust air related which is usually benign unless the manifold cat is breaking down and the egr nature of the exhaust timing is the culprit.


I would expect that more on a stock car than a a catless headered tuned car. Maybe we need to really understand this egr like function and how to avoid it.

[Kodename47]

Originally Posted by regal

Do you log EGT that's another neglected but important one.

The car doesn't have an EGT sensor. It's a calculated value

[regal]

Originally Posted by Kodename47

The car doesn't have an EGT sensor. It's a calculated value

How useful is a calculated EGT? I seriously have no ide, seems like there would be too many variables (E5,E10,Head temp which we know is inaccurate.) add FI to the mix and I just don't know? This could be on or off topic I think more investigation is needed.

[Kodename47]

Originally Posted by regal

How useful is a calculated EGT? I seriously have no ide, seems like there would be too many variables (E5,E10,Head temp which we know is inaccurate.) add FI to the mix and I just don't know? This could be on or off topic I think more investigation is needed.

It's likely it is used by the ECU for cat and O2 warm up and control and is just output on a standard PID.

[arghx7]

Even for engines where it's not used for actual engine controls, you need at least a basic EGT model for the cold start strategy diagnostic monitor in California.

[Gostrider]

Originally Posted by Dezoris

THE ISSUE:
I have heard this is multiple tunes, including the Perrin, Vish, and Visconti.
Vish explained it's simply a large change in VVT timing in a small amount of RPMs. (5 to 40 degrees)

I'd like more technical information on what exactly is creating the noise. Perrin said its resonance, Vish said its "rasp." Sounds like shit, and like valvetrain noise to me. With all of the tuning drama recently...

I'd like a straight answer as to mechanically what is happening, because if the long term effects of reducing torque dip has mechanical implications I want the VVT timing cut back.

SOUNDS OF THE MODIFIED VVT TUNING TO REDUCE TORQUE DIP
Here are the logs to accompany the video:





New comparison video, stock VVT map vs aggressive VVT tune:

Noise can be heard here Perrin Tune: at time -31.00 and -23.00

http://www.freesound.org/people/dezoris/sounds/191194/



And here on Vish dyno: At 22 Seconds

At 22 Seconds


UPDATE: 3/11

Perrin modified my flash file to go back to a stockish VVT map from 2800-4200RPM range. After the flash the valve train noise is now gone.

The argument remains, tuners say the noise introduced from the optimal/aggressive VVT tuning is normal. Tuning VVT agressively can be done on FI or NA the same way, depends on the motor on how much noise it generates.

Given the unproven long term mechanical implications of those statements (if any) going back to a conservative VVT setting is good insurance for now.

I have been watching your YouTube videos they are very cool. After seeing the YouTube video FA20 VVT valaetrain noise I was very concerned with that spine chilling VVT noise. Wile searching the web I stumbled across this video by MRT Performance Australia on YouTube. Subaru has come across a problem with there VVT control system. Subaru are on there THIRD revision on the variable valve timing control assemble. After being tuned the VVT can advance to +40 causing something in the variable valve timing control assemble to fail. Witch causes the engine oil to bypass part of the VVT cams causing very low oil pressure. Check this YouTube Video out and see what you think fast forward to 4 minutes [ame]http://youtu.be/7iw1Pdln8eI?t=3m55s[/ame] .



Please email me on wot you think.

[regal]

Most important guage to have is an oil pressure gauge, yet so few on this forum have one because the car doesn't come with a sender just a switch. I personally can't imagine forced induction without an oil pressure gauge.

[xjohnx]

Originally Posted by Gostrider

I have been watching your YouTube videos they are very cool. After seeing the YouTube video FA20 VVT valaetrain noise I was very concerned with that spine chilling VVT noise. Wile searching the web I stumbled across this video by MRT Performance Australia on YouTube. Subaru has come across a problem with there VVT control system. Subaru are on there THIRD revision on the variable valve timing control assemble. After being tuned the VVT can advance to +40 causing something in the variable valve timing control assemble to fail. Witch causes the engine oil to bypass part of the VVT cams causing very low oil pressure. Check this YouTube Video out and see what you think fast forward to 4 minutes

.



Please email me on wot you think.

A little disappointing to see that someone who works for a respected shop like MRT doesn't know the difference between the RON octane ratings they use in Australia and the R+M/2 rating we use in the US. Really makes it hard to take anything else he says seriously.

[feldy]

I was doing some testing last night and flashed a stock rom. It really does sound more refined that's for sure. I also felt the loss of power

[feldy]

I was doing some testing last night and flashed a stock rom. It really does sound more refined that's for sure. I also felt the loss of power

[l0aded]

Installed my OFT today with STG 1 91octane. Injen+Catback and I heard the sound and thought my car was blowing up. Then I ran into this thread.. I agree that it is more pronounced in 3rd gear going up a hill at WOT as that is when I noticed it.

Here is the log for that pull if anyone cares.
http://datazap.me/u/l0aded/run2?log=0&data=1-2-5-6-9

Honestly a little sad to hear it as I really enjoy the extra kick but the sound is pretty annoying.

[vtmike]

Anyone on here have a delicious stage 1 or 2 na tune? Wondering if these have the quick change in cam phasing as some of these other tunes. I previously had another tune that created this noise that the stock tune did not. Not trying to buy another tune that creates the same potential problem.

Sent from my Nexus 7 using Tapatalk

[Luckrider]

This thread needs an update. It is scaring people to think that the noise from the cam phasing is going to cause damage or is bad for the car when it really isn't an issue unless there is a different issue (and it still hasn't proven to cause an issue other the fuel pressure pulsing as far as I know).