Help me with timing!!!!!!
Help me with timing!!!!!! First off I would like to say thanks to the many answers I find on this site. Now my issue is I have just put 600 miles on my 355 12.1 1.6rr forged piston stock rods and crank (email tune) the car is solid mount and long tube headers bmr everything with torque arm relocated slp subframes. The problem is knock counts through the roof what do I do I have checked everything and replaced knock sensor. The tune is a bit rich and timing upper 30s
First off I would like to say thanks to the many answers I find on this site. Now my issue is I have just put 600 miles on my 355 12.1 1.6rr forged piston stock rods and crank (email tune) the car is solid mount and long tube headers bmr everything with torque arm relocated slp subframes. The problem is knock counts through the roof what do I do I have checked everything and replaced knock sensor. The tune is a bit rich and timing upper 30s
TECH Regular
Joined: Dec 2011
Posts: 461
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From: Hastings, Nebraska
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Why in the world would anybody not just use stock mounts? Why even poly? Especially solid?
How much retard are you seeing? If you are not seeing any actual retard, ignore the knock counts. Your not going to get rid of them. They are just confusing you.
Some of you guys obsess over things you don't understand. 29 is too low.
How much retard are you seeing? If you are not seeing any actual retard, ignore the knock counts. Your not going to get rid of them. They are just confusing you.
Some of you guys obsess over things you don't understand. 29 is too low.
https://ls1tech.com/forums/17227973-post15.html
different chambers and setups need different timing, that said several of us have found the setup I have o want 29 degrees so that idea should not be dismissed. Plus both guys saying it is wrong are running aftermarket injection which will more accurately report the timing their engine sees.
Pat and I are saying what we use in Tunercat and specifically stating we know it gives it a few more degrees, on top of that who knows how much tolerance stacking there is, maybe there is another couple degrees there. At any rate when tuning with the factory pcm you are going to enter a lower number than what the pcm will see.
different chambers and setups need different timing, that said several of us have found the setup I have o want 29 degrees so that idea should not be dismissed. Plus both guys saying it is wrong are running aftermarket injection which will more accurately report the timing their engine sees.
Pat and I are saying what we use in Tunercat and specifically stating we know it gives it a few more degrees, on top of that who knows how much tolerance stacking there is, maybe there is another couple degrees there. At any rate when tuning with the factory pcm you are going to enter a lower number than what the pcm will see.
Btw, iron heads typically use less timing.
Last edited by Ed Wright; May 11, 2013 at 06:43 AM.
TECH Apprentice
Joined: Jun 2012
Posts: 372
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From: Mississauga Ontario Canada
Thats interesting because as I tuned my car i dropped the PCM tune to 28-29* (33 according to datamaster) at the upper RPMS and I have almost eliminated the knock. it only pulls .1-.5* sometimes now. knock counts still go up randomly but if most people are getting 36* I have some hp on the table that my knock sensor isent letting me get.
If it were false knock, pulling it back would not have effected. I doubt you have a knock sensor problem. Sounds like that is all it wants. Could be you have more compression than you think. If you didn't CC and everything you could have more than you think. Or, could be the fuel in your area. For example: Arizona and California has fuel with the same octane as the rest of us. But, their fuel is crap, and cars I tune in that area gets (depending on the combo) two to four degrees less timing that everywhere else. For got about Mexico, less timing down there too. Some of their's is actually just rated at 85 octane.
That E10 ethanol crap is a problem too.
I think you probably have your timing where it belongs.
Good luck.
That E10 ethanol crap is a problem too.
I think you probably have your timing where it belongs.
Good luck.
Launching!
Joined: Nov 2012
Posts: 253
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From: Midwest City, Ok
Don't even get me started on Ethanol...if you didn't build it for it. Don't run it.
TECH Apprentice
Joined: Jun 2012
Posts: 372
Likes: 0
From: Mississauga Ontario Canada
If it were false knock, pulling it back would not have effected. I doubt you have a knock sensor problem. Sounds like that is all it wants. Could be you have more compression than you think. If you didn't CC and everything you could have more than you think. Or, could be the fuel in your area. For example: Arizona and California has fuel with the same octane as the rest of us. But, their fuel is crap, and cars I tune in that area gets (depending on the combo) two to four degrees less timing that everywhere else. For got about Mexico, less timing down there too. Some of their's is actually just rated at 85 octane.
That E10 ethanol crap is a problem too.
I think you probably have your timing where it belongs.
Good luck.
That E10 ethanol crap is a problem too.
I think you probably have your timing where it belongs.
Good luck.
its still hitting 33* above 5000RPM so I dont think its to far off pace. apparently strong health motors need less timing advance, im not sure if that applies to the LT1 though.
One shop I talked to put a solid roller 355 on the dyno with aftermarket injection and ran timing from 31-40degrees and it did not knock but did not make any more power either on the higher timing. IMO the old idea that you want timing set just shy of detonation is outdated. Chamber design has come a long ways. If it makes power and goes down the track well at a "low" timing stting then that gives you some safety net shoukld you get poor quality fuel once or something else unexpected.
Really if you think about it in a perfect world spark would be at TDC, sparking before TDC has the expansion beginning to fight the rising piston, would be best if we could avoid that, but the flame takes time to travel and pressure to build which is why we need spark before TDC.
Really if you think about it in a perfect world spark would be at TDC, sparking before TDC has the expansion beginning to fight the rising piston, would be best if we could avoid that, but the flame takes time to travel and pressure to build which is why we need spark before TDC.