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Knock in High Boost with Right AFR

Old Nov 30, 2008 | 05:56 AM
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Knock in High Boost with Right AFR

Hi everyone. I have encounter a problem I need some advise. Or
Knowleadge on why, how to solve, and what cause it.

I am driving a 4G63 with Stroker Kit 2.2L*Billet Crank, Forged Rod,
JE Piston) 264in 272ex HKS Cam, larger intercooler...etc, I am using
a TD06 20G Greddy Kits with 850cc Injector Sard*. I am trying to make
about 400HP.

I had install PFC with Innova* LC1 Wideband. All items are setup and
connected.

As I try to boost up the Turbo 1.5Bar. I see knock*(70~80) WTO in the
3rd Gear 4800RPM. But I get a AFR (LC1) of (10.80~11.20). the Timing
on that Cell is 8.

Can any one suggest what I should do? Retrad the Timing again? which
I have retrad the Timing from 11 to 8. still get Knock at that range.

Why did I still get knock for the RIGH Air Fuel?
Should I decrease the Fuel. with Less timing?
what cause the Knocking as I Logged the File, and found out that
where before it reach 4800(3rd grea) with 4400Rpm with 1.5Bar(Boost)
timing is 11 and only knock (7). when it reach 4800(3rd Gear) with
Timing 8 and the knock start to go up to 70?. Any suggestion what
happen and why.

Thanks in advance for helping up with the infor and suggestion.
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Old Nov 30, 2008 | 06:48 AM
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Too much fuel will cause knock. Poor detonation. What is your target a/f? Get it to around that level with low timing, then add timing till you start to see knock. Once you see 1/2counts in areas back off 1 degree.

What are you using to tune?
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Old Nov 30, 2008 | 07:47 AM
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if the afr is good and the boost is reasonable then it's time to retart the timing 1* at a time until it's clean
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Old Nov 30, 2008 | 05:23 PM
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I have using Apexi POWER FC. to tune it.
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Old Nov 30, 2008 | 05:24 PM
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Is 11.5 will be too lean for Turbo Car? my Target AFR is 11.5
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Old Nov 30, 2008 | 05:45 PM
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11.5 is fine. You'll want to stop with fuel once you reach around 11.3 then add timing till it knocks. That's one angle, different ways to reach 11.5 with timing/fuel...each car is different. You just have to play with it, one step at a time.
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Old Dec 1, 2008 | 12:05 AM
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Originally Posted by Evoryder
11.5 is fine. You'll want to stop with fuel once you reach around 11.3 then add timing till it knocks. That's one angle, different ways to reach 11.5 with timing/fuel...each car is different. You just have to play with it, one step at a time.
Is timing at 8 is too low? or not as many ppl tell me that if u Retrad the timing u will have high exhaust Temp. can cause Turbo damage?

before adjustment it was 11 at 4800 rpm with 1.5Bar. now is 8 at 4800rpm
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Old Dec 1, 2008 | 07:42 AM
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I've seen some cars on 87 octane with pitiful timing values and they never had a problem.
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Old Dec 1, 2008 | 04:31 PM
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Originally Posted by Mellon Tuning
I've seen some cars on 87 octane with pitiful timing values and they never had a problem.
Hmm.. ok than I will try to reduce more timing and see how.. will keep this post update.

Hope I don't Blow my engine( since is Just build up with some Strong Internal)

will show some pic Soon...
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Old Dec 1, 2008 | 05:14 PM
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Originally Posted by gtm_maxwell
Hmm.. ok than I will try to reduce more timing and see how.. will keep this post update.

Hope I don't Blow my engine( since is Just build up with some Strong Internal)

will show some pic Soon...
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Old Dec 3, 2008 | 03:40 PM
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Anyone who have ideal or want to share what they think also can post here about Ignition timing vs AFR
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Old Dec 4, 2008 | 01:14 AM
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hey im running power fc d jetro since last 2 years ...
it has been running gr8 ..
i doo often see 80 knock on my comander but that is false knock ...normaly i see 20 max ....and my peak ign timing on the comander showz 44 ....
actually its the tuner who have tuned my car so i dun know wat the exact figures shud be, but wat ive been told that 80 is the false knock and i actually see 80 knock when im lanuching or hiting the rev limiter so its due to vibration in car i think ...
i cud be wrong though but my afr at 1.9 bar boost is 11.9 ,12 ...

now u tell me that once u see knock does ur check engine lite blink ?if not than its false knock if yes than uve to check ur tune ...
gud luck and keep us updated .
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Old Dec 4, 2008 | 03:33 PM
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Originally Posted by haseeb
hey im running power fc d jetro since last 2 years ...
it has been running gr8 ..
i doo often see 80 knock on my comander but that is false knock ...normaly i see 20 max ....and my peak ign timing on the comander showz 44 ....
actually its the tuner who have tuned my car so i dun know wat the exact figures shud be, but wat ive been told that 80 is the false knock and i actually see 80 knock when im lanuching or hiting the rev limiter so its due to vibration in car i think ...
i cud be wrong though but my afr at 1.9 bar boost is 11.9 ,12 ...

now u tell me that once u see knock does ur check engine lite blink ?if not than its false knock if yes than uve to check ur tune ...
gud luck and keep us updated .

The engine Lite Blink.. so I will try to reduce the timing this week end.. And do u mind tell me what is your timing at 5400rpm when u reach 1.9bar? as I try to make sure i don't go too low on the timing.. if u want my timing and fuel I can pm u too..
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Old Dec 5, 2008 | 12:26 AM
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i heavnt checked my timing at 5400 rpm but the max i see at wot till 8k rpm is 45 and 44 in my comander ....
pm me wats ur at wot ....
my lite never blinks but i alwaz see 80 knock when i launch and hitting rev limiter ,but ive been told that this is the false knock cause when i go wot widout lanuching and not hittng my rev limiter i only see 25 max knock ...
if ur cel is blinking than u shud definatly check ur tune ...
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Old Dec 5, 2008 | 12:28 AM
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btw does any 1 know the actual language of power fc ... like wat does the
44 degree timing means? and wat does 80 knock actually means ?
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