knock
knock
I have a K20A3 with the jackson race kit. I downloaded the map for the jackson racing, 440cc injector and 4"pulley and I'm getting around 75 knock counts on a quarter mile. Is this normal. I tried to mess with the ignition but didnt do a whole lot. Is this normal. Theres plenty of fuel too, its around high 11. Is there a certain limit , like under 2 mv or something that the knock level is normal or should it be at 0. Please help i'm new at this. thanks.
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BoostedK20A
- Posts: 10
- Joined: Thu Jun 30, 2005 3:58 pm
knocks
right now I'm using #9 plugs, which is pretty cold. As far as the octane is concern, I live in canada so 91 octane is the highest I can get. its fucked up. But am I going to lose a shit load of power by detuning the car for 91 octane. I tried backing the ignition but didnt help a whole lot. what should I do? Someone help.
Re: knocks
Upload the datalog of what happened and your calibration. Are the knocks wide open throttle knocks or are they part throttle or 'transition' knocks?unrated wrote:right now I'm using #9 plugs, which is pretty cold. As far as the octane is concern, I live in canada so 91 octane is the highest I can get. its fucked up. But am I going to lose a shit load of power by detuning the car for 91 octane. I tried backing the ignition but didnt help a whole lot. what should I do? Someone help.
When I tuned for N/A, my car knocked like crazy when I'd tap the gas -- I ended up needing to remove some ignition from mostly column 7 in the 2000 - 3500.
75 knocks is a LOT of knock for just a quartermile. I had around 13 - 20 after driving a good 10 miles when I just needed to back off the part throttle area.
I'm betting you have some physical cause for knock -- have you troubleshot the classic causes of engine knock outside of tuning?
Wayne
knocks
I tried it tonight, I took 4 degrees off the base map and its still knocking. I lost like 20whp all throught the graph. My a/f is 11.5 which is way to rich, thats why with the timing backed off by 4 and with the amount of fuel there is no reason for it to knock like that. I still had like 30 knock counts. You can hear em too. I think thats what i'm hearing anyways. Is it because here in canada we only have 91 octane? What else could i do?Spunkster wrote:Try removing 4-5 degrees of timing from the areas where it is knocking. If it still shows klnock you are getting false readings...like noise form the blower itself.
Re: knocks
Wow, I'm no engine mechanic, so standard disclaimer applies -- I just installed my JRSC and I'm going to be tuning very soon. If I had unexplainable knock, I would check my spark plugs to see if they were installed correctly. The NGK plugs I used (which were 8s, that I gapped to .32 initially) came with a little diagram on the box that told how far to turn the wrench after being hand tight. In my case it was 1/2 to 2/3 of a turn to crush the little crush washer. I've never seen it happen, but I've heard that having your plugs not torqued down to spec will cause a massive loss of heat dissipation. In short, if the plugs aren't tight enough, heat will not leave the plug through the head and get cooled by the coolant -- eventually the plug gets so hot it will start pre-igniting your mixture.unrated wrote:I tried it tonight, I took 4 degrees off the base map and its still knocking. I lost like 20whp all throught the graph. My a/f is 11.5 which is way to rich, thats why with the timing backed off by 4 and with the amount of fuel there is no reason for it to knock like that. I still had like 30 knock counts. You can hear em too. I think thats what i'm hearing anyways. Is it because here in canada we only have 91 octane? What else could i do?Spunkster wrote:Try removing 4-5 degrees of timing from the areas where it is knocking. If it still shows klnock you are getting false readings...like noise form the blower itself.
Once again, I'm not a mechanic -- but that's at least an idea.
Correct me if I'm off base here guys.
Additionally -- if you do check your plugs -- remember that if you had a crush washer thing on your plugs like my NGK's, you should not try turning it a full 1/2 turn again on re-insertion or re-tightening. You should turn it much less. Generally speaking, the instructions for the ones without crush washers are closer to what you should turn them. If in doubt, look up the torque specs from your plug maker and use a torque wrench. I really doubt this is your issue btw.
plugs
I know what you mean but the plugs are tighten correctly. I did what it said to do, hand tight and then 1/2 a turn like it said in the instructions. But thanks anyways. I think my problem is not enough octane. I'm going to try racing unleaded fuel tomorrow and if that cures it well then its water injection time.
Re: plugs
Assuming your 91 is the same octane as our 91, then you should be fine I would think. There are people running 11 pounds with 91 or 92 without water injection with no nocking problems. Perhaps you just got some bad gas.unrated wrote:I know what you mean but the plugs are tighten correctly. I did what it said to do, hand tight and then 1/2 a turn like it said in the instructions. But thanks anyways. I think my problem is not enough octane. I'm going to try racing unleaded fuel tomorrow and if that cures it well then its water injection time.