Knock problems (boosted)

Martijn_b · 04-01-2019, 11:11 AM

Problems solved.

Rusty · 04-01-2019, 07:06 PM

ByThaBay · 04-02-2019, 05:18 AM

If you’re running cats you might have an exhaust restriction. Have you checked backpressure? When the knock happens, which cylinder(s) are making noise? What is the engine load at which the knock is occurring? What is the calculated timing vs the actual timing?

All good places to look for clues.

sirnixalot · 04-02-2019, 07:12 AM

Did you check the passages of the turbo manifolds?

https://www.gtrlife.com/forums/topic...-the-findings/

Spooler · 04-02-2019, 10:48 AM

Quote:

Originally Posted by sirnixalot

Did you check the passages of the turbo manifolds?

https://www.gtrlife.com/forums/topic...-the-findings/

LOL, that was hilarious..... What a junk manifold. This doesn't surprise me at all.

Spooler · 04-02-2019, 10:51 AM

Here is the picture of the blockage.

Martijn_b · 04-02-2019, 02:46 PM

WOW on that manifold. My set is pre-used though, i bought it on here from a forum owner which made over 600whp with it and ran it successfully. I will keep it in mind.

I can drive the car with just the downpipes to exclude a blocked exhaust. I do not run catalic converters. Knock mainly on cyl 3 and 4

Because i was achieving knock with boost, i disconnected the wastegate flappers and drove without boost.

Here is a low RPM example, no boost and timing pull:

Here is a run started at higher RPM, with about 10psi of boost and a bit more timing. There is no timing pull here. As long as I start my runs in higher RPM ranges like 4500rpm+ i get no timing pull)

sirnixalot · 04-02-2019, 04:11 PM

can You swap the knock sensors around and see if the knock changes cylinders? Maybe a bad sensor?

Martijn_b · 04-02-2019, 04:33 PM

It's something I can do, but i think to have "validated" the knock with my Link Knockbox (audible).

For the audio file, check and listen for the typical tin can/shaking change sound: https://drive.google.com/open?id=1pm...smo-NJwlxDleUY

370zbeast · 04-02-2019, 04:40 PM

Quote:

Originally Posted by Spooler

Here is the picture of the blockage.

Im sorry what am i looking at ? is that a AAM manifold thats been cut open ???and why ? Im missing something im sure.

Spooler · 04-02-2019, 04:46 PM

Quote:

Originally Posted by 370zbeast

Im sorry what am i looking at ? is that a AAM manifold thats been cut open ???and why ? Im missing something im sure.

That is casting slag in the middle of the pipe closing off cylinder 3 by 80 to 90%. That's not supposed to be there. Follow the link above for more pictures.

Spooler · 04-02-2019, 04:48 PM

Quote:

Originally Posted by Martijn_b

WOW on that manifold. My set is pre-used though, i bought it on here from a forum owner which made over 600whp with it and ran it successfully. I will keep it in mind.

I can drive the car with just the downpipes to exclude a blocked exhaust. I do not run catalic converters. Knock mainly on cyl 3 and 4

Because i was achieving knock with boost, i disconnected the wastegate flappers and drove without boost.

Here is a low RPM example, no boost and timing pull:

Here is a run started at higher RPM, with about 10psi of boost and a bit more timing. There is no timing pull here. As long as I start my runs in higher RPM ranges like 4500rpm+ i get no timing pull)

Did you replace the injectors with new ones or used? It is showing you have issues on Cylinder 1 and 3 as you know. You may need to take those out and have them cleaned and tested.

Martijn_b · 04-02-2019, 05:05 PM

Yes i replaced injectors by IDx1050s. Used set, not tested.

Heres pictures of my spark plugs, car is running a bit rich but didnt see anything out of the ordenary:

Verstuurd vanaf mijn SM-G950F met Tapatalk

Spooler · 04-02-2019, 05:18 PM

Pull all the injectors and have them cleaned and tested since you used used ones that were not tested.

Rusty · 04-02-2019, 05:51 PM

Quote:

Originally Posted by sirnixalot

Did you check the passages of the turbo manifolds?

https://www.gtrlife.com/forums/topic...-the-findings/

Holy crap!

04-01-2019, 11:11 AM	#1 (permalink)
Martijn_b Enthusiast Member Join Date: Jan 2018 Location: Netherlands Posts: 280 Drives: 2010 370z MB 6MT Rep Power: 3786	Knock problems (boosted) Problems solved. __________________ Instagram: Boosted_Fairlady Last edited by Martijn_b; 06-04-2022 at 05:10 PM.

04-01-2019, 07:06 PM	#2 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 68 Posts: 35,218 Drives: 2011 Nismo GM 6M Rep Power: 2684438	__________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

04-02-2019, 05:18 AM	#3 (permalink)
ByThaBay Base Member Join Date: Aug 2011 Location: Bay Area, CA Posts: 239 Drives: 2015 370z Rep Power: 10080	If you’re running cats you might have an exhaust restriction. Have you checked backpressure? When the knock happens, which cylinder(s) are making noise? What is the engine load at which the knock is occurring? What is the calculated timing vs the actual timing? All good places to look for clues. Martijn_b likes this.

04-02-2019, 07:12 AM	#4 (permalink)
sirnixalot Track Member Join Date: May 2017 Location: Cayman Islands Posts: 685 Drives: 2010 370Z Rep Power: 57454	Did you check the passages of the turbo manifolds? https://www.gtrlife.com/forums/topic...-the-findings/ JARblue, wideglideleon and Martijn_b like this. __________________ 2010 Sport - LS3 swap loading 2012 Frontier - BTWTuning VK56DE swap

04-02-2019, 02:46 PM	#7 (permalink)
Martijn_b Enthusiast Member Join Date: Jan 2018 Location: Netherlands Posts: 280 Drives: 2010 370z MB 6MT Rep Power: 3786	WOW on that manifold. My set is pre-used though, i bought it on here from a forum owner which made over 600whp with it and ran it successfully. I will keep it in mind. I can drive the car with just the downpipes to exclude a blocked exhaust. I do not run catalic converters. Knock mainly on cyl 3 and 4 Because i was achieving knock with boost, i disconnected the wastegate flappers and drove without boost. Here is a low RPM example, no boost and timing pull: Here is a run started at higher RPM, with about 10psi of boost and a bit more timing. There is no timing pull here. As long as I start my runs in higher RPM ranges like 4500rpm+ i get no timing pull) __________________ Instagram: Boosted_Fairlady

04-02-2019, 10:51 AM	#6 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,834 Drives: 2013 Nismo 370z Rep Power: 2684392	Here is the picture of the blockage.

04-02-2019, 04:11 PM	#8 (permalink)
sirnixalot Track Member Join Date: May 2017 Location: Cayman Islands Posts: 685 Drives: 2010 370Z Rep Power: 57454	can You swap the knock sensors around and see if the knock changes cylinders? Maybe a bad sensor? Martijn_b likes this. __________________ 2010 Sport - LS3 swap loading 2012 Frontier - BTWTuning VK56DE swap

04-02-2019, 04:33 PM	#9 (permalink)
Martijn_b Enthusiast Member Join Date: Jan 2018 Location: Netherlands Posts: 280 Drives: 2010 370z MB 6MT Rep Power: 3786	It's something I can do, but i think to have "validated" the knock with my Link Knockbox (audible). For the audio file, check and listen for the typical tin can/shaking change sound: https://drive.google.com/open?id=1pm...smo-NJwlxDleUY __________________ Instagram: Boosted_Fairlady

04-02-2019, 05:05 PM	#13 (permalink)
Martijn_b Enthusiast Member Join Date: Jan 2018 Location: Netherlands Posts: 280 Drives: 2010 370z MB 6MT Rep Power: 3786	Yes i replaced injectors by IDx1050s. Used set, not tested. Heres pictures of my spark plugs, car is running a bit rich but didnt see anything out of the ordenary: Verstuurd vanaf mijn SM-G950F met Tapatalk __________________ Instagram: Boosted_Fairlady

04-02-2019, 05:18 PM	#14 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,834 Drives: 2013 Nismo 370z Rep Power: 2684392	Pull all the injectors and have them cleaned and tested since you used used ones that were not tested.

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