SAFC 2 raw knock levels
- Thread starter Rev
- Start date
Javier Wilde
Fresh Recruit
Did you set the knock sensor. U have to rev up to 1450 rpm and set the low knock and the go to 3500 rpm and set the high knock. U should do that often.
No havent set it yet because I find conflicting advice.
My tuner said dont bother they dont work well but I am in hot climate and found posts saying if you set in cold weather it picks up the knock sound much better.
Other posts say set it a the middle temperature and now you are saying do it often ... I guess at different temperatures.
WIth the raw figure it shows all sounds the microphone picks up but some posts say this is also helpful i wondered how it worked.
Given that It seems to be picking up the the raw figures ok I guess you are right I should set it up properly but what I am also doing with the raw figures is checking a few rattles I have like my intercooler pipes are rattleing too much with the raw figure I can see if the rattle is getting picked up by the knock mic. as this can effect timing.
My tuner said dont bother they dont work well but I am in hot climate and found posts saying if you set in cold weather it picks up the knock sound much better.
Other posts say set it a the middle temperature and now you are saying do it often ... I guess at different temperatures.
WIth the raw figure it shows all sounds the microphone picks up but some posts say this is also helpful i wondered how it worked.
Given that It seems to be picking up the the raw figures ok I guess you are right I should set it up properly but what I am also doing with the raw figures is checking a few rattles I have like my intercooler pipes are rattleing too much with the raw figure I can see if the rattle is getting picked up by the knock mic. as this can effect timing.
Javier Wilde
Fresh Recruit
I set it very time i get to high readings.
MARK@CMBAUTOS
Trader
Iv always been told ur aloud high 50's
Mine shows 54 bouncing the limiter that's on a apexi pfc
iv only ever seen it higher than that but that's cause my bottom end was knocking its brains out
Get ur fueling checked or try measure engine debt that will cause high readings
Mine shows 54 bouncing the limiter that's on a apexi pfc
iv only ever seen it higher than that but that's cause my bottom end was knocking its brains out
Get ur fueling checked or try measure engine debt that will cause high readings
Thanks for the input here's a small update.
I waited for the colder temps, tonight around 16.5deg C I setup the safc2 knock rpm settings both rpm settings had raw knock 150
with 98 ron fuel.
10 Knock at idle start
15 idle in auto reverse gear due to load.
10-11 knock when backing off the throttle
0 knock at 17psi on the flat
0 knock up a hill load 17 psi
5 knock when gear changes under hill load from 2nd to 3rd at 17 psi
1 after the 5 knock occured normal driving knock is now 1 not 0
11-12 knock when backing off the throttle
0 knock up a hill load at 18 psi 2nd gear about 3800 rpm
Ok I guess i will have to wait for hot weather and a bigger hill to test further.
I waited for the colder temps, tonight around 16.5deg C I setup the safc2 knock rpm settings both rpm settings had raw knock 150
with 98 ron fuel.
10 Knock at idle start
15 idle in auto reverse gear due to load.
10-11 knock when backing off the throttle
0 knock at 17psi on the flat
0 knock up a hill load 17 psi
5 knock when gear changes under hill load from 2nd to 3rd at 17 psi
1 after the 5 knock occured normal driving knock is now 1 not 0
11-12 knock when backing off the throttle
0 knock up a hill load at 18 psi 2nd gear about 3800 rpm
Ok I guess i will have to wait for hot weather and a bigger hill to test further.
Last edited:
dac69er
Super Moderator
im super safe and look to keep it below 30 on my power fc.
Good info chaps.
For safc on the nismo forum they say audible knock is 175-200 and they have luckily survived with no damage at 230.
I find this an interesting idea to check your sensor numbers against audible knock whether safc or power FC but with respect to Iain actual failure numbers are priceless of course.
For safc on the nismo forum they say audible knock is 175-200 and they have luckily survived with no damage at 230.
I find this an interesting idea to check your sensor numbers against audible knock whether safc or power FC but with respect to Iain actual failure numbers are priceless of course.
Last edited:
dac69er
Super Moderator
all engines are different so you cant go by forum info if its not about your particular type of engine.
as you said. always best to listen for audible knock when tuning and just use the knock reading as a guide/warning.
ive been lazy and not got any det cans, that is why i am extra safe with the knock levels on my car as i mapped it on the road myself. will get round to doing it properly one day.
as you said. always best to listen for audible knock when tuning and just use the knock reading as a guide/warning.
ive been lazy and not got any det cans, that is why i am extra safe with the knock levels on my car as i mapped it on the road myself. will get round to doing it properly one day.