I had my LS6 intake and an ASP underdrive pulley (crank pulley only) and belts installed last week and everything feels/runs perfectly. No dyno tuning done though.
On Saturday I happened to 'open it up' a bit with a short impromptu stoplight race with a Cobra and I heard a slight pinging at the upper rev ranges. I tried to duplicate it later on that night and it didn't seem to happen again, or at least I couldn't hear it.
My question is, is it possible that the intake change through off the tuning that much as to actually change the A/F ratio that radically?
And if so is it possible that the computer already 'learned it out'/corrected it so to speak and that's why it only happened once?
Removed EGR and AIR as well which I know could be a factor.
I doubt it's the pulley (newer style ASP, stock timing chain, stock internals/exhaust too for that matter) but those were the only two changes made to the car other than a Hawker lightweight battery.
I want to race the car if the track is open this weekend but don't want to hurt the motor.
Not sure if this really belongs in the 'External section' only or not, if so please just delete it for it's already posted there.
Thanks in advance.

 

It is probably not because of a change in your AF ratio. That should be fine. The problem is probably that you did not disable EGR in your PCM, and you should also zero out the EGR Spark table. The PCM adds additional timing when your EGR is (should be) active. Additionally, you may need to remove some. EGR dilutes the intake charge and helps prevent detonation. This allows your car to run increased timing. Now that the EGR is gone you will be more prone to detonation. Cammed cars do not suffer from this as much due to increased overlap, resulting in an "EGR effect" because it allows exhaust gas to stay behind and dilute the mixture.

 

It is possible that your timing is slightly too aggressive in certain areas but are you sure it is not a tank of poor quality fuel? Do you also have any tuning software or autotap/efi live? This would be the exact method to determining true pinging vs just some random noise.

 

egr shouldnt be running at wot anyways so was that the real problem about the timing table?? are you shure it wasnt the other car you where racing?? ive done that before, looked thru all my logs trying to figure out why my car made all that racket and then finnally the guy came to pay me the money i won and said that his car was pinging like crazy.. ??? it just sounded like it was from my car. if you have a log or the file currently in your car, we can look thru it for you and see more of what is going on, the egr timing table is only active while egr is on or supposed to be on, but even the new cars that dont have egr still have the egr timing tables in them.. sorry , jes

 

Thanks for the responses.
I don't have Autotap or EFI Live or anything but I can have a friend maybe do it...the EGR/timing thing could be a factor because I haven't deleted the EGR code in the PCM yet and I do know that from a prior ATAP a few years ago that my car was making some serious timing when near stock, nearly 29*.
I wonder if that's my issue.
Now assuming it was pinging from that, is it possible that it could've 'fixed itself' or adjusted itself (added fuel?) out enough to cause it to now stop?

 

That's a possibility as well and I did think of that but I only use Amoco Ultimate from a busy/active station so I kind of ruled that out.
The car does sit sometimes up to 3 weeks between drives and did have some roughly 2 week old fuel in it when this happened, again still quality 93 octane only.
Also, living in the Northeast they do mandate the use of oxygenated fuel in the winter time if that could have any effect at all.

 

0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 1 3 4 2 2 0 0 0 0 0 0
0 0 3 5 6 5 3 0 0 0 0 0 0
0 0 6 7 7 5 2 0 0 0 0 0 0
0 0 4 5 6 4 2 1 0 0 0 0 0
0 0 2 2 5 3 3 1 0 0 0 0 0
0 0 0 0 2 2 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0



i now this is a crappy copy and paste but that is the egr adder table, the rpm limit that it is adding is 2800 at that furthest point and the furthest load is .6 so at wot it is not a factor. there is a whole other table missing that hp doesnt have in there editor yet, i think it is a multiplier table that tells that table when to add or subtract or even be on for that matter.. anything more than 0 in the table is on. 1 is 100% of the table .5 is half the table ect...

 

Yeah I better get it ATAP'd before racing it.

 

It isn't necessarily the EGR adder table. A lot of the lower values are more aggressive on the earlier year cars. I have an ugly spot on mine where I get KR now that my EGR is gone. It isn't much though. Even stock you get pinging if you hit the gas too hard at too low of an RPM. What conditions does this happen? What RPM, and how much throttle?

 

Going from a stop from a light, basically WOT once it hooked up, 45 degrees out at night, not sure what rpms but it was just a little bit of pinging at around 70mph.
I tried nailing it again on the highway later on that night and it didn't seem to happen again so I'm thinking the PCM corrected for it if that is possible.

 

Absolutely. That is what the low-octane table is for. You need to A-tap it, or log it with HPTuners.

 

I can tell you from my experience that the A/F does get leaner, at least I have seen this on every occasion when an LSX intake was installed. The A/F went a full point leaner on all three vehicles. I am not sure how much of an affect the LS6 intake would cause to the A/F but I am sure that it did lean it out a bit, enough to make it ping ??? don't know for sure.....