Rough idle with forced induction

jwick · 08-22-2014, 11:24 AM

Quote:

Originally Posted by nomodsjk

The only thing I'm sure of is I spent too much time and money to have my car sound like its broken

Word!

nomodsjk · 08-22-2014, 12:11 PM

I guess there is some solace in the fact that galeforce is having the same issue. Not to be taken negatively. If he's having this issue with his extensive knowledge and experience with modifying 370s then I don't feel so bad

Mitco39 · 08-22-2014, 12:31 PM

Quote:

Originally Posted by nomodsjk

I guess there is some solace in the fact that galeforce is having the same issue. Not to be taken negatively. If he's having this issue with his extensive knowledge and experience with modifying 370s then I don't feel so bad

I guess ill just stop contributing to this topic. I will get to the bottom of this idle, I have a bunch of theories but I am limited by what I have to work with what tables Uprev gives their "non pro tuners".

Jason, how much you pay this guy? lol.

jwick · 08-22-2014, 12:38 PM

Quote:

Originally Posted by Mitco39

I guess ill just stop contributing to this topic. I will get to the bottom of this idle, I have a bunch of theories but I am limited by what I have to work with what tables Uprev gives their "non pro tuners".

Jason, how much you pay this guy? lol.

No Mitch please don't. Some of us know the truth

Mitco39 · 08-22-2014, 12:45 PM

Quote:

Originally Posted by jwick

No Mitch please don't. Some of us know the truth

lol, it just rubbed me the wrong way. Hopefully ill get some time to play with the car this weekend. I would like to wait for the boost tubes from Sasha before tweaking with the tune. I was thinking of pulling the bottom of the tubes off the intercooler and just letting it suck air like it otherwise would and see if its the restriction causing these issues.

Its clear to everyone that its bouncing. Which means that the natural frequency of the O2s to switch from rich to lean is getting close to to natural frequency of the intake system. I suspect thats whats happening. That would cause the hunt, and if we tap back in the crankcase pressure lines with a PCV valve (to protect the bottom end under boost) this would allow the system to operate at a vacuum and change the natural frequency of the system.

One way to find out, lol it just involves tapping into my boost tubes, but hey if im getting new ones anyways I might as well give it a shot.

jwick · 08-22-2014, 12:52 PM

Quote:

Originally Posted by Mitco39

lol, it just rubbed me the wrong way. Hopefully ill get some time to play with the car this weekend. I would like to wait for the boost tubes from Sasha before tweaking with the tune. I was thinking of pulling the bottom of the tubes off the intercooler and just letting it suck air like it otherwise would and see if its the restriction causing these issues.

Its clear to everyone that its bouncing. Which means that the natural frequency of the O2s to switch from rich to lean is getting close to to natural frequency of the intake system. I suspect thats whats happening. That would cause the hunt, and if we tap back in the crankcase pressure lines with a PCV valve (to protect the bottom end under boost) this would allow the system to operate at a vacuum and change the natural frequency of the system.

One way to find out, lol it just involves tapping into my boost tubes, but hey if im getting new ones anyways I might as well give it a shot.

I hear you! Other than us providing alternate data points you are the driver of what's going on in the progress of a solution

My man!

Question - Can you route the PCV back into the intake tubes? The only reason I ask this is because the GTM TT kit has them routed in the air filter tubes pre-turbo. From the experience I have with those kits, they aren't having the issues we are.

That being said, I don't know how we do that since the filter is clamped directly to the compressor inlet.

I'm definitely down for a solution. I'd happily tap my intake piping for the PCV system if it'll take care of the hiccup.

nomodsjk · 08-22-2014, 01:12 PM

[QUOTE=Mitco39;2939877]lol, it just rubbed me the wrong way. Hopefully ill get some time to play with the car this weekend. I would like to wait for the boost tubes from Sasha before tweaking with the tune. I was thinking of pulling the bottom of the tubes off the intercooler and just letting it suck air like it otherwise would and see if its the restriction causing these issues.

Its clear to everyone that its bouncing. Which means that the natural frequency of the O2s to switch from rich to lean is getting close to to natural frequency of the intake system. I suspect thats whats happening. That would cause the hunt, and if we tap back in the crankcase pressure lines with a PCV valve (to protect the bottom end under boost) this would allow the system to operate at a vacuum and change the natural frequency of the system.

One way to find out, lol it just involves tapping into my boost tubes, but hey if im getting new ones anyways I might as well give it a shot.[/QUOTfE]

Apparently I missed something. I'm guessing I rubbed you the wrong way. I mentioned Jason in my post because he was the op of this particular thread even though he just quoted you. Didn't mean to belittle your efforts or rub you in any way..

GaleForce · 08-22-2014, 04:34 PM

Quote:

Originally Posted by nomodsjk

I guess there is some solace in the fact that galeforce is having the same issue. Not to be taken negatively. If he's having this issue with his extensive knowledge and experience with modifying 370s then I don't feel so bad

I just started the thread, and put the question out there. Mitch is the brains. I don't have a clue when it comes to tuning. I'm learning from everything Mitch, Phunk, Jwick, et al, are saying in the other thread..

Quote:

Originally Posted by Mitco39

I guess ill just stop contributing to this topic. I will get to the bottom of this idle, I have a bunch of theories but I am limited by what I have to work with what tables Uprev gives their "non pro tuners".

Jason, how much you pay this guy? lol.

Don't stop Mitch, you are an incredible resource! I'm learning so much reading your posts.

Quote:

Originally Posted by jwick

No Mitch please don't. Some of us know the truth

jwick · 08-22-2014, 12:39 PM

Quote:

Originally Posted by Mitco39

I guess ill just stop contributing to this topic. I will get to the bottom of this idle, I have a bunch of theories but I am limited by what I have to work with what tables Uprev gives their "non pro tuners".

Jason, how much you pay this guy? lol.

And

09 Nismo#400 · 08-22-2014, 01:04 PM

Mitco39, I am guessing your thinking of adding something like this: mpx_check_valve then route the PCV back into the intakes, kind of like the OEM intakes do?

jwick · 08-22-2014, 01:06 PM

Quote:

Originally Posted by 09 Nismo#400

Mitco39, I am guessing your thinking of adding something like this: mpx_check_valve then route the PCV back into the intakes, kind of like the OEM intakes do?

That's my working understanding too. You need the check since we would be tying in where you can see positive pressure. Treadstone makes something similar.

Mitco39 · 08-22-2014, 01:16 PM

Quote:

Originally Posted by 09 Nismo#400

Mitco39, I am guessing your thinking of adding something like this: mpx_check_valve then route the PCV back into the intakes, kind of like the OEM intakes do?

Thats what I was thinking of at first yes. And might still have to try something like that. Or might just delete the PVC system all together, although then its a question of what to do with the oily mess it leaves.

Mitco39 · 08-22-2014, 01:14 PM

Upon looking at it more closely I have a check I am going to try. I am just going to pull off what I refer to as the primary circuit and vent it to atm. That will stop any chance of this sort of thing happening. Right now I believe all the kits keep this circuit so that they are not blowing out oily emissions all down the car.

What I am referring to as the primary circuit is the purple highlight, green is the secondary with the filters on it currently.

jwick · 08-22-2014, 01:30 PM

Quote:

Originally Posted by Mitco39

Upon looking at it more closely I have a check I am going to try. I am just going to pull off what I refer to as the primary circuit and vent it to atm. That will stop any chance of this sort of thing happening. Right now I believe all the kits keep this circuit so that they are not blowing out oily emissions all down the car.

What I am referring to as the primary circuit is the purple highlight, green is the secondary with the filters on it currently.

See the pic tells a thousand words. So the primary is the two that tie into the IM right where we tapped for the BOV feed. That must not have as much of an effect on the system as the secondary because all the kits I know of keep that setup.

Mitco39 · 08-22-2014, 01:41 PM

Quote:

Originally Posted by jwick

See the pic tells a thousand words. So the primary is the two that tie into the IM right where we tapped for the BOV feed. That must not have as much of an effect on the system as the secondary because all the kits I know of keep that setup.

yes they tie in there and under idle the manifold is under a vacuum that sucks in crankcase vapors. Now before the kit the crankcase would be filled with air from the intake between the maf and the throttle body. But now this air is just entering the system through those two fiilters and straight into the intake at idle.

08-22-2014, 01:12 PM	#7 (permalink)
nomodsjk Premium Member Join Date: Apr 2014 Location: martinsburg wv Posts: 2,073 Drives: 2011 370z MB/7at Rep Power: 19962	[QUOTE=Mitco39;2939877]lol, it just rubbed me the wrong way. Hopefully ill get some time to play with the car this weekend. I would like to wait for the boost tubes from Sasha before tweaking with the tune. I was thinking of pulling the bottom of the tubes off the intercooler and just letting it suck air like it otherwise would and see if its the restriction causing these issues. Its clear to everyone that its bouncing. Which means that the natural frequency of the O2s to switch from rich to lean is getting close to to natural frequency of the intake system. I suspect thats whats happening. That would cause the hunt, and if we tap back in the crankcase pressure lines with a PCV valve (to protect the bottom end under boost) this would allow the system to operate at a vacuum and change the natural frequency of the system. One way to find out, lol it just involves tapping into my boost tubes, but hey if im getting new ones anyways I might as well give it a shot.[/QUOTfE] Apparently I missed something. I'm guessing I rubbed you the wrong way. I mentioned Jason in my post because he was the op of this particular thread even though he just quoted you. Didn't mean to belittle your efforts or rub you in any way.. GaleForce likes this.

08-22-2014, 01:14 PM	#13 (permalink)
Mitco39 A True Z Fanatic Join Date: Aug 2012 Location: Edmonton Alberta Canada Posts: 2,089 Drives: 40th 370z Rep Power: 132	Upon looking at it more closely I have a check I am going to try. I am just going to pull off what I refer to as the primary circuit and vent it to atm. That will stop any chance of this sort of thing happening. Right now I believe all the kits keep this circuit so that they are not blowing out oily emissions all down the car. What I am referring to as the primary circuit is the purple highlight, green is the secondary with the filters on it currently. __________________ 2007 Chevy Duramax - EFILive Tuned By Me 2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her My Build --> http://www.the370z.com/members-370z-...39s-build.html

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08-22-2014, 12:11 PM	#2 (permalink)
nomodsjk Premium Member Join Date: Apr 2014 Location: martinsburg wv Posts: 2,073 Drives: 2011 370z MB/7at Rep Power: 19962	I guess there is some solace in the fact that galeforce is having the same issue. Not to be taken negatively. If he's having this issue with his extensive knowledge and experience with modifying 370s then I don't feel so bad

08-22-2014, 01:04 PM	#10 (permalink)
09 Nismo#400 Base Member Join Date: Mar 2012 Location: North Dakota Posts: 25 Drives: 09 370z Nismo T Rep Power: 14	Mitco39, I am guessing your thinking of adding something like this: mpx_check_valve then route the PCV back into the intakes, kind of like the OEM intakes do?