Thread: knock knock

couple things i want to verify on a 1g

#1 about how tight should the knock sensor be?? I have read some things that say barely more than hand tight,, tooo tight causes exagerated levels of knock?

#2 Fuel Pressure should be 38psi w/o vaccum on??

#3 Around what voltage should the stock o2 read when when running stoich (I know I know I need a wideband!).. Looks like as my tps goes to 100% I knock instantly up to around 20 counts, but that can be at nearly any RPM and and boost level it knocks usually around .85 volts on my o2, also I am getting some random knock also when i see ~ .85v, on a rare occasions when the car will pull hard and not knock my o2 will be around .78 to .82v

Ben you are running chevron right??? I have been running 76, I think im going to switch for tuning purposes atleast

Ben

No Im not flaming you here but here is the way i see it...


The dyno is going to do shit for me as far as knocking goes, my narrowband should be able to get me in the neighborhood and outside of knock territory (For Fuel Related issues). Im not going to go to dyno untill im ready to fine tune... Right now its a simple as go full throttle knock pull timing and im screwed.

I want to find my safe thresholds that I can work with b4 i go to the dyno, when i go to the dyno it will be to fine tune a/f and timing for max hp within those boundaries, not for problem diagnostics that i can do on my own w/ the butt dyno, data logger. and a perfectly good enough for basic tuning narrow band. After that I will progress to a wide band to more finely tune out the a/f which I will not be able to do much with in the 1st place because I only have SAFC right now.

Keep in mind, this turbo is temporary, and this ECU is tempory and my MAF is temporary therefor all tuning is only temporary untill AEM EMS and MAP, which will come before the 35r.

So the point is I need to resolve the Issue of knocking and make sure the essentials air / fuel / spark are all dialed into a rough tune that is actually drivable without damaging anything.

Also if you can drive 20psi at your compression rate is roughly the equivalent of 17psi at my compression rate.... now this is obvoisly roughtly speaking but that said I should atleast be a bit lower knock than you @ ~15psi. but then again I flow more than you with cams but again I should be able to run ~17psi to match you drop 2 psi for cams i should still be in the neighborhood.

also as far as my up and down idle I highly doubt that lifters can be blamed for that,,, I could see it making it sound like it has a miss, but not surging up and down by ~150rpm w/ no isc movement only Inj Pw changes.

anyways I found this

Volts -- A/F ratio
0.250 V - 15.0 : 1
0.375 V - 14.5 : 1
0.500 V - 14.0 : 1
0.625 V - 13.5 : 1
0.750 V - 13.0 : 1
0.875 V - 12.5 : 1
1.000 V - 12.0 : 1
__________________

on dsm talk

peep this thread and let me know what you all think

http://www.dsmtalk.com/forums/showth...op+temperature

are they going rich as possible here for knock reasons? I would have thought you would stay more around a 14.1:1 mixture right?

you guys must be best friends.

Ben

#1 My lifters are not out of that 2g,,, I used to lifters out of the head the "Overheated" according to dirty. I did compare them to the 2g ones and also cleaned the shiiiiznit out of them, It also had a few that were seized that i had to replace with ones out of the head that was in the 1g when i got it,,, all were identical lifters. I also checked each one of the lifters by hand,,,, it is easy to tell which ones are flat and which ones are seized.


#2 I WIll replace my lifters when it t-belt time. @ arount 15 - 20k Im getting a better belt remember??


#3 Again I do not want to go to the Dyno for problem diagnostics,,,,,,,

#4 your are 7.8:1 I am 9:1 so what that just means you have to have a larger volume of air to reach the same combustion chamber pressures as i do at a lower volume. Hmm although I just thought I am looking at PSI not at flow,, I have larger cams so more of a chance for the pressure to neutralize during an intake event, which could mean a higher volume for me,,,, MR Engineer Ben do the Fing math on that, I might have just corrected myself here, Mah Bad..

#5 What you say about flow still makes no sence to me at all,,, the way I look at it is,,, at sea level you have a 10 ounce jar both pressureized with 10 psi,, they would both have the same volume of air... lets take 2 identical engines and 2 different turbo's at lets say 3k rpms and 10psi bewst, the bigger turbo will be spinning slower to maintain the appropraite amount of flow to produce the appropraite amount of volume of air for 10psi,,, keep in mind both motors are identical in every single way therefor the volume of air that will be removed from the intake for every intake event is identical. so then the smaller turbo will have to be spinning faster to produce the same amount of flow to produce the same amount of volume of air it takes to maintain 10psi. so looking at it this way the bigger turbo is NOT flowing more,, it is flowing the same at a lower RPM which would make it more efficient. I would say your turbo can flow more than mine at the top of its efficiency but at 10 psi it is not flowing more than mine, On identical engines of course,,, in our case at 10psi My turbo would be flowing more than your turbo because my intake events take a larger volume of air from the intake there for my turbo has to flow more to maintain a volume of air that = 10psi, but obviously my turbo would be much closer to the top of its effeciency range than yours.