Timing has a mind of its own???
01-26-2004, 01:47 AM
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Timing has a mind of its own??? I am tuning a 99 turbo vette, has plently of fuel 11:1 AFR, I am trying to get the timning to come down but the car is not responding at all, no matter what it stay at 21.5 degrees and knocks horribly, pulling 15 degrees timing at about 3600 or so, boost level is about 6 psi.
I have put both the low octane and high octane tables from .56 all the way to 1.2 G/cyl to 10 degrees, and checked all the other timing adder tables except the new one found in the latest ls1edit v 1.3H but supposidly these tables are zeroed out on 2001 and earlier pcms..... why can't I get a control on timing this is rediculous!?!?! any ideas? and where can I get 1.3H Ken shoulda sent this to me I think lol.
I have put both the low octane and high octane tables from .56 all the way to 1.2 G/cyl to 10 degrees, and checked all the other timing adder tables except the new one found in the latest ls1edit v 1.3H but supposidly these tables are zeroed out on 2001 and earlier pcms..... why can't I get a control on timing this is rediculous!?!?! any ideas? and where can I get 1.3H Ken shoulda sent this to me I think lol.
01-26-2004, 04:32 AM
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ok folks, I figured this one out, lol I am not the first person to tune this car, I have tuned about ~7 of these cars after this tuner, and he does some very disturbing things to a cars PCM not allowing the car to pull the neccessary timing that it wants to pull!!!
setting max KR to a very very low number, I know false knock is a bad thing but this is a really bad way to go about it not allowing the car to pull the timing is just crazy to me.
in this specific case I thought I had undone everything this person had done, but I missed one table, spark retard limit, I thought this was another table that was a limiter on spark retard from total timing instead its just a actual number that is the lowest possible timing the PCM will allow, this specific number set was also very disturbing, if owners ever wanted to put some forced induction on thier car, it is setup for a total nuclear meltdown!
anyway I will finally get to fix this car up for my customer like I promised I know he will be one happy camper tommorrow! can't wait to see what the car puts down!
setting max KR to a very very low number, I know false knock is a bad thing but this is a really bad way to go about it not allowing the car to pull the timing is just crazy to me.
in this specific case I thought I had undone everything this person had done, but I missed one table, spark retard limit, I thought this was another table that was a limiter on spark retard from total timing instead its just a actual number that is the lowest possible timing the PCM will allow, this specific number set was also very disturbing, if owners ever wanted to put some forced induction on thier car, it is setup for a total nuclear meltdown!
anyway I will finally get to fix this car up for my customer like I promised I know he will be one happy camper tommorrow! can't wait to see what the car puts down!
01-26-2004, 08:44 AM
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KR is trying to save the motor, we run maybe 30
advance at the top end with no boost. Ask the
Forced Induction guys what they see, I bet low
to mid 20s at most. Fooling the PCM into allowing
continuous detonation is not a survival strategy.
Especially while still tuning mixture / timing. I'd
say to use the amount of timing pulled-to by KR
as a guide to what the engine can stand, and go
there for a new starting point.
Seems like 11:1 fuel with more spark than the
engine can stand, might not be as good for output
as a closer-in mixture and max tolerable spark <for
that mix>.
advance at the top end with no boost. Ask the
Forced Induction guys what they see, I bet low
to mid 20s at most. Fooling the PCM into allowing
continuous detonation is not a survival strategy.
Especially while still tuning mixture / timing. I'd
say to use the amount of timing pulled-to by KR
as a guide to what the engine can stand, and go
there for a new starting point.
Seems like 11:1 fuel with more spark than the
engine can stand, might not be as good for output
as a closer-in mixture and max tolerable spark <for
that mix>.
01-26-2004, 11:26 AM
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I am fully aware of KR is there for, and I am not so ignorant as to completely "handcuff" the pcm is to not allowing the timing to be pulled.
FYI 5 psi low 20s at the most up top, with this specific car the turbos are quite small so full boost hits at 2500 rpm, I need timing around 8-10 at this specific point im thinking we'll see.
FYI 5 psi low 20s at the most up top, with this specific car the turbos are quite small so full boost hits at 2500 rpm, I need timing around 8-10 at this specific point im thinking we'll see.
01-28-2004, 07:16 PM
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Hey nick, sounds like I'm in for a treat as well since Team--- errr I mean -----ZR1 tuned my car previously as well. Hit me up in AIM when you get a chance so I can ask you a few things about an initial tune.