Hi all. I'm rather new to tuning but I understand the basics. I have been playing with the tune on my Cobalt SS/TC for about 3 months now. I have a tune that I am really liking, but I am getting some occasional KR and if I try real hard I can get it to throw a code. I have tried backing off the Desired Air Load but have seen guys running much more agressive Air Loads than myself. Was hoping that someone here could give me some advice.
Thanks!
You're tune is pretty similar to mine (2k8 Sky RL) as far as fueling and boost goes, and I see zero knock in similar weather conditions, and minor knock when it's in the 80's (2.5* at most). Have you tried switching gas stations? Are you using 93 octane or are you in an area with only 91 available?Originally Posted by Zven
Yeah, we only have 91 around here with one station that I know of with 92. I'll try that and see if it makes a difference, but would really like to figure out some more fuel but only at the points where I am needing it. I'm also thinking that my COT Lambda table might be playing a factor. I haven't messed with this at all yet.
Avoid Chevron gas if you think gas is your issue.
OK, I have run to empty and filled up with BP 92 octane which is the highest you can get in the KC area without stepping up to a race grade fuel. Still seeing KR sprinkled throughout with up to 3 degrees timing being pulled.
Like I said, I'm still rather new to this and I'm sure that there has to be a way to compensate. I'm still learning to tune using the log files as a reference.
Thanks again for your help.
How much boost are you getting after tuning the car?
I'm spiking to 25lbs and then it backs down and levels around 21-22lbs. I drove to Lexington, KY last weekend and ran the car completely empty (12.2 gal to fill up), then filled up with Shell 93. I didn't have the scanner connected but there did seem to be a difference in the smoothness of the car through the powerband. This could have been the cooler weather too though. Still seeing the problem back in KC this week.
Last edited by Zven; 03-02-2009 at 02:02 PM.
I don't know if you got this figured out yet or not, but thought i would drop in a few ideas... try richening your lambda (not the COT one, but the Power Enrichment one. this worked well for me. And, you can look at your logs, try to find a trend in the knock... I look at load and rpm mainly, and see what your wideband is telling you. I noticed that I was running just a hair lean, so I richened my lambda up a tad, and voila! No more knock!
For example... your first instance of knock, your wideband is at 15.xx... this is quite a bit too lean (in my opinion). It continues to be a bit lean while your load is at 50% to about 100%, so you could change the lambda in that range. Remember, the lower the lambda, the richer the mixture!
Last edited by mkriebs; 05-21-2009 at 05:26 PM.
I cannot read your file yet, but how many degrees of timing are you commanding and what is you lambda setting at that RPM and load? You might want to either richen it up a little or pull out 1 degree of timing in those areas.
Last edited by Terminator2; 05-23-2009 at 09:38 AM.
zven. send me your file please, i know of a few tricks to make it come alive
Care to share them? :Pzven. send me your file please, i know of a few tricks to make it come alive
x2, I want tricks
2002 Camaro SS - 556whp
2009 Cobalt SS/TC - ???whp
I dont think there is any way you are going to get Bryan (Area 47) to share his tuning secrets with you unless he knows you that is.x2, I want tricks
hmm, ok. Bryan, my name is Seth, I'm 25, I like beer and long walks on the beach... how bout now?I dont think there is any way you are going to get Bryan (Area 47) to share his tuning secrets with you unless he knows you that is.
2002 Camaro SS - 556whp
2009 Cobalt SS/TC - ???whp
run the afr that makes the most power and tune the knock to that. changing afr from a power making but safe afr just to reduce knock is more of a bandaid.
2000 Ford Mustang - Top Sportsman
hahaha, do you want to date me?
Share the tricks please!
after viewing the map. there is more work to be done just yet.
i'll be more than happy to help out a local guy if you want
On zevens yes. Mine still needs a few more changes too. I found a couple really good ones.after viewing the map. there is more work to be done just yet.
i'll be more than happy to help out a local guy if you want
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