engine knock q sr20 blacktop - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

*kenshinS14sks* · 05-27-2009, 02:04 AM

Subject:
SR20DET s14 black top (no internal mods)
basic mods - blitz fmic, apexi n1 exhaust, stock turbo, blitz bov

on the apexi power fc there's a feature in which you can gauge your engine knocks
i dont hear any noticeable knocking under idle or fot but on the fc commander it says there are. . . so~

what would be considered a safe range under normal driving versus fot?

*slider2828* · 05-27-2009, 10:59 AM

PFC knock sensor is a POS.... You gotta get a wideband, but knock for stock should be under 40 max knock.... Anything more you are really detonating. Check your spark plugs...

*landins13* · 05-27-2009, 11:17 AM

^^^ pretty much

djcobra · 05-27-2009, 01:41 PM

I have to agree with slider2828 also... as long as your car is stock ie, internals, turbo etc... then knock levels should be below 40. However, if your car has upgraded internals ie, cams, valve springs, head gasket, turbo, etc... then knock readings will be wierd or high even though you don't hear any knock.

My knock readings are stupid, on idle i get about 1-5 knock, on light load/cruise i get about 25-30 and if i start to give her it can go high as 60 yet there is no audible ping/knock. Car has been dyno'd with good AFR also with a conservative tune.

Mods include, HKS Step 2 cams, 256in/264ex, Apexi head gasket, HKS Valve Springs, Retainers, GT28RS, HKS 555cc injectors bleh bleh bleh.... RPS Max Street clutch.

Heck, even a clutch could be picked up as knock, due to its harmonic crap... lots of variables especially if your not stock like me.

Anyawys, hope this helps.

Steve.

*slider2828* · 05-27-2009, 01:49 PM

Yup I have about the same, but like 15 on light cruise and 60 or 70 on load, but I think that is cause of the tranny, but my motor is built so 60 max knock ain't so bad.

*kenshinS14sks* · 05-27-2009, 02:23 PM

thanks a lot guys this really helps. . i know im running lean but one time i saw that my knock was upwards at 86 and my jaw just =OOOO and ive been meaning to get my engine tuned so hope that'll do the trick

*slider2828* · 05-27-2009, 03:28 PM

2 things you can do, dial back timing at peak knock / power which is around 4500- 5500. I think that is where you knock is.... Sometime enriching the mixture does work either....

05-27-2009, 02:04 AM	#1
kenshinS14sks Premium Member Join Date: Feb 2003 Location: bellflower, ca Age: 29 Posts: 465 Trader Rating: (0)	engine knock q sr20 blacktop Subject: SR20DET s14 black top (no internal mods) basic mods - blitz fmic, apexi n1 exhaust, stock turbo, blitz bov on the apexi power fc there's a feature in which you can gauge your engine knocks i dont hear any noticeable knocking under idle or fot but on the fc commander it says there are. . . so~ what would be considered a safe range under normal driving versus fot?

05-27-2009, 10:59 AM	#2
slider2828 Premium Member Join Date: Oct 2004 Location: San Francisco, CA Posts: 3,457 Trader Rating: (8)	PFC knock sensor is a POS.... You gotta get a wideband, but knock for stock should be under 40 max knock.... Anything more you are really detonating. Check your spark plugs... __________________ Turn and Burn!

05-27-2009, 11:17 AM	#3
landins13 You love to hate me! Join Date: Jan 2008 Location: Baltimore Posts: 532 Trader Rating: (2)	^^^ pretty much __________________ turbo lag is my way of giving you a head start !!NO HANDS IN PANTS!!

05-27-2009, 01:41 PM	#4
djcobra Zilvia Member Join Date: Aug 2006 Location: Calgary Age: 31 Posts: 236 Trader Rating: (1)	I have to agree with slider2828 also... as long as your car is stock ie, internals, turbo etc... then knock levels should be below 40. However, if your car has upgraded internals ie, cams, valve springs, head gasket, turbo, etc... then knock readings will be wierd or high even though you don't hear any knock. My knock readings are stupid, on idle i get about 1-5 knock, on light load/cruise i get about 25-30 and if i start to give her it can go high as 60 yet there is no audible ping/knock. Car has been dyno'd with good AFR also with a conservative tune. Mods include, HKS Step 2 cams, 256in/264ex, Apexi head gasket, HKS Valve Springs, Retainers, GT28RS, HKS 555cc injectors bleh bleh bleh.... RPS Max Street clutch. Heck, even a clutch could be picked up as knock, due to its harmonic crap... lots of variables especially if your not stock like me. Anyawys, hope this helps. Steve. __________________ S14 326 whp, 311 tq @ 15 psi HKS F-CON V-PRO

05-27-2009, 01:49 PM	#5
slider2828 Premium Member Join Date: Oct 2004 Location: San Francisco, CA Posts: 3,457 Trader Rating: (8)	Yup I have about the same, but like 15 on light cruise and 60 or 70 on load, but I think that is cause of the tranny, but my motor is built so 60 max knock ain't so bad. __________________ Turn and Burn!

05-27-2009, 02:23 PM	#6
kenshinS14sks Premium Member Join Date: Feb 2003 Location: bellflower, ca Age: 29 Posts: 465 Trader Rating: (0)	thanks a lot guys this really helps. . i know im running lean but one time i saw that my knock was upwards at 86 and my jaw just =OOOO and ive been meaning to get my engine tuned so hope that'll do the trick

05-27-2009, 03:28 PM	#7
slider2828 Premium Member Join Date: Oct 2004 Location: San Francisco, CA Posts: 3,457 Trader Rating: (8)	2 things you can do, dial back timing at peak knock / power which is around 4500- 5500. I think that is where you knock is.... Sometime enriching the mixture does work either.... __________________ Turn and Burn!

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