LT1 with Tunercat...Can anyone help??
LT1 with Tunercat...Can anyone help?? I have just installed a cc306, etc..on my 94 LT1 and have been reprogramming the pcm with tunercat..well, right now at about 2000rpm with map between 54-60 I am getting some popping out the exhaust...is this too rich or what? Should I lean out the ve tables in that area? I have searched on this but there is such a discretion on using the ve tables(camaroz28.com)..some people say that is where the programming is at and others say that it doesn't do anything unless the maf isn't working...so now I am confused. That is why I came here to see if anyone else could help me out. The calculated AFR from the % chg to afr ratio tables is around 13.02 and I am wondering if maybe I should lean it out anymore. Also at idle there is a pretty stout smell from the exhaust. Thanks in advance for any help you can give.
TECH Regular
Joined: Apr 2003
Posts: 413
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From: Atlanta, GA
Originally Posted by TN94Z
I have just installed a cc306, etc..on my 94 LT1 and have been reprogramming the pcm with tunercat..well, right now at about 2000rpm with map between 54-60 I am getting some popping out the exhaust...is this too rich or what? Should I lean out the ve tables in that area? I have searched on this but there is such a discretion on using the ve tables(camaroz28.com)..some people say that is where the programming is at and others say that it doesn't do anything unless the maf isn't working...so now I am confused. That is why I came here to see if anyone else could help me out. The calculated AFR from the % chg to afr ratio tables is around 13.02 and I am wondering if maybe I should lean it out anymore. Also at idle there is a pretty stout smell from the exhaust. Thanks in advance for any help you can give.
What do you mean by popping? I have a very similar setup on my 94 LT1. It is basically a modified CC306 proifile custom grind lunati. The VE Table is where to modify it in this area depending on what your LTFT's are. Are you using TTS Datamaster to do your datalogging or Freescan?
I am using Datamaster at the moment. The popping is hard to explain...it is kinda like a misfire type pop, but it is not misfiring because it runs good in the higher rpms and idles good...it just does this during normal driving. It was doing this all of the time until I made some fuel changes in tunercat. I got a mail order tune that had my wot AFR at like 10.2. I changed it got it closer to 13.0. And I had to lean out my initial startup because it was way too rich also. So I am thinking that it is still a little rich. The popping seems to be around 2000rpm and 54-63 MAP. I leaned these areas out in the ve tables, but haven't had a chance to load it and try it out.
TECH Regular
Joined: Apr 2003
Posts: 413
Likes: 0
From: Atlanta, GA
Originally Posted by TN94Z
I am using Datamaster at the moment. The popping is hard to explain...it is kinda like a misfire type pop, but it is not misfiring because it runs good in the higher rpms and idles good...it just does this during normal driving. It was doing this all of the time until I made some fuel changes in tunercat. I got a mail order tune that had my wot AFR at like 10.2. I changed it got it closer to 13.0. And I had to lean out my initial startup because it was way too rich also. So I am thinking that it is still a little rich. The popping seems to be around 2000rpm and 54-63 MAP. I leaned these areas out in the ve tables, but haven't had a chance to load it and try it out.
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Are you sure its not leaning out??? Lean conditions will cause high HC's which will sometimes ignite in the hot exhaust system with a little air.
On another note, how do you like the tuner cat software??? I have been looking for something to do early cars with..
On another note, how do you like the tuner cat software??? I have been looking for something to do early cars with..
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Verdad Gallardo TECH Regular
Joined: Apr 2003
Posts: 413
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From: Atlanta, GA
I can understand why you say you are experiencing popping and hesitation. You are very rich from 800-2400 RPM based on the log file you sent me. Your LTFT's are -15.6 from 1500-2200 RPM. Look at the histogram display I attached and you will see where you need to pull some fuel in the VE table. I would do some smoothing so as to not just pull it in those cells only but the ones close to them by gradually decreasing the amount in those cells as well. If you want you can send me your .bin file and I can make the mods if you don't feel comfortable tweaking it but I would start off gradually decreasing the areas in your VE Table and doing some test runs of about 10-20 mins a piece until you can get your LTFT's in reason.
Ataylors>>>I think that it is just too rich. The mail order tune I got was very very rich, like 10.2. I've gotten a little better now except for the popping. As for the tunercat, I really like it. I would be great if I could get the real time programming but this is all I need for now.
Monodax>>>I really would appreciate it if you could do that for me. I'm afraid that I will get it all out of wack. I will send it to you. Thanks again.
Monodax>>>I really would appreciate it if you could do that for me. I'm afraid that I will get it all out of wack. I will send it to you. Thanks again.
Ataylors>>>I think that it is just too rich. The mail order tune I got was very very rich, like 10.2. I've gotten a little better now except for the popping. As for the tunercat, I really like it. I would be great if I could get the real time programming but this is all I need for now.
