Knock Volts? - SRT Forums

csufdrew · 01-20-2008, 11:09 AM

Assuming everything on the car is working OK, what should this be during cruise and WOT?

thanks

moreause · 01-20-2008, 08:10 PM

the lesser the better

but i have seen value below 1 V and never checked when engine knocked, but if i look into my sct table knock is beginneing at around 1.5 volts depending on rpm

but what really matters is knock degree...so that way you get value filtered by the pcm

Simon.Starkie · 01-20-2008, 08:15 PM

My car has a KR of 0 or -1 on 91-octane pump gas from Union 76.
Interestingly enough, the KR is -5 or -6 on other brands of 91-octane including Chevron, Shell, Torco, etc.
I know it sounds like fantasy, but it's totally true and totally reproducible.
So I always try to use Union 76.

csufdrew · 01-20-2008, 09:17 PM

Quote: Originally Posted by Simon.Starkie

My car has a KR of 0 or -1 on 91-octane pump gas from Union 76.
Interestingly enough, the KR is -5 or -6 on other brands of 91-octane including Chevron, Shell, Torco, etc.
I know it sounds like fantasy, but it's totally true and totally reproducible.
So I always try to use Union 76.

i was asking about VOLTS not RETARD.

Its been known that 76 and shell have better gas.

Simon.Starkie · 01-20-2008, 09:23 PM

Quote: Originally Posted by csufdrew

i was asking about VOLTS not RETARD.

Its been known that 76 and shell have better gas.

My bad, I misread you op.
I'll see if I can get you the voltage tomorrow.
Cruising at 65 in 4th OK?

FWIW my car gets the same KR issue with Shell.
Only Union 76 gets the lower KR.

csufdrew · 01-21-2008, 01:16 AM

Quote: Originally Posted by Simon.Starkie

My bad, I misread you op.
I'll see if I can get you the voltage tomorrow.
Cruising at 65 in 4th OK?

FWIW my car gets the same KR issue with Shell.
Only Union 76 gets the lower KR.

thats cool. Mine is like always bouncing from 0.3-0.7 even just crusing...dont know what that means. getting ZERO kr on the gauge.

SNOOPALOOP · 01-21-2008, 02:52 AM

76 and Chevron with Techron FTW

Simon.Starkie · 01-21-2008, 09:56 AM

CSU:
Cruising at 55-60 (traffic) was fairly stable with voltage averaging 0.4 most of the time.
Cruising at 65 or above the voltage was all over the place from 0.3 thru 1.3 but no idea why,

SNOOP:
Chevron Premium (with Techron) also causes KR of -5 or -6.
Again, I've found that out of all the brands, only Union 76 produces a KR of 0 or -1.

csufdrew · 01-21-2008, 11:55 AM

thanks simon. i guess its normal then.

Simon.Starkie · 01-21-2008, 12:26 PM

Np .

MonsterLemon · 01-21-2008, 12:40 PM

Quote: Originally Posted by Simon.Starkie

CSU:
Cruising at 55-60 (traffic) was fairly stable with voltage averaging 0.4 most of the time.
Cruising at 65 or above the voltage was all over the place from 0.3 thru 1.3 but no idea why,

SNOOP:
Chevron Premium (with Techron) also causes KR of -5 or -6.
Again, I've found that out of all the brands, only Union 76 produces a KR of 0 or -1.

been preaching that for awhile and nobody believes me when I tell them

Simon.Starkie · 01-21-2008, 01:12 PM

Quote: Originally Posted by MonsterLemon

been preaching that for awhile and nobody believes me when I tell them

OK, but why?

forcefedjunkie · 01-27-2008, 03:44 PM

The raw knock sensor voltage is difficult to interpret because the sensor picks up a lot of noise besides true knock. The raw output is filtered in the PCM to eliminate normal engine noise.

Todd

Simon.Starkie · 01-27-2008, 03:52 PM

^^^
Yeah, I know.
I was actually more interested in finding out why Union 76 Premium is so much better at reducing KR than the other brands.
Maybe there is no simple answer though, so I'll just take it for what it's worth.
And the result is repeatable, at least on my car, so I guess the performance improvement is worth something.