Bank 1 / 2 LT FT / VE Notable variation

[TheBlazer24]

Hello all, I am relatively new to tuning, (I've tuned a couple chevys and stock ish Dodges) but I am currently having a problem tuning my NGC3 / 5.7 (Pre Eagle) swapped Challenger. Motor is pretty simple, It has Eagle Heads and Pistons, (10.5 CR) 224 234 cam, 6.1/Eagle injectors and LTH.

The main problem I am having is the Bank 1 / 2 are about 10% off each other on VE and LT Fuel trims. The car is also backfiring / Popping out the exhaust.

I have swapped coil packs and plugs around, I have swapped injectors with a spare set, I have swapped intake manifold with one of my spares, and still the same problem.

I did have the motor running about 6 months ago before I did the 4 link rear end.
I do not recall it having this issue; I DID swap PCMs (to another 06 NGC3) in that time; Could that be the issue?
(Now that I mention it, I may try swapping the old one back in)

The motor sounds fine while idling, no notable sound, besides the backfire/ popping. Video attached.
I don't believe it is a mechanical issue, but I may also pop open a VC to check.

Attached is a couple logs of it idling, and you can see in the warm log how the VE / LT split apart.

Just looking for any insight, appreciate any help; Thanks!
COLD idling b1 vs b2.hpl
warm idling b1 vs b2 LT TRIMS.hpl

Tune file (its a lil messy)
RACECAR MOD v4.hpt


https://www.youtube.com/shorts/3lW1CFGBrn0

[LilSick]

you put the motor and trans in a car from the 60's but you still have electronic stability control enabled

and what is up with the friction loss base?

ECM [12882]

[TheBlazer24]

Hey; body is actually a 2010 so I left it as is for now; I haven't really focused too much on the fine details until I can find the root of the problem at hand; I was playing with the friction table to help reduce the rev hang on these motors, again though, just was spitballing with it, nothing set in stone

[PurpleRam]

check your O2s

[PurpleRam]

check your O2s

Oh and YOU'll LOVE that 4 link swap, I run a 4 link with Williams 9in in my 09 DP car, knocked .10 off my 60 ft times and the car is more stable above 125MPH , some times the slightest cross breeze would give the 09 that GM'G-body shuffle" going in to the traps, but now it's one finger on the steering wheel smooth.

There's a good chance that while the car sat, something happened with the 02 sensors , either small critter munched on the wiring or corrosion on the connection.

I have a 75 4x2 Ramchager that sat from OCT 2020 till Apr 2022, NGC3& 5.7 out of an 04 , acted the same as what you're dealing with, swapped o2s from side to side and the problem stayed on the D-side, I pulled wiring out and the connector on the rear o2 was discolored( only way to think about describing it) changed the connector and it was fine afterwards.

[TheBlazer24]

Oh and YOU'll LOVE that 4 link swap, I run a 4 link with Williams 9in in my 09 DP car, knocked .10 off my 60 ft times and the car is more stable above 125MPH , some times the slightest cross breeze would give the 09 that GM'G-body shuffle" going in to the traps, but now it's one finger on the steering wheel smooth.

There's a good chance that while the car sat, something happened with the 02 sensors , either small critter munched on the wiring or corrosion on the connection.

I have a 75 4x2 Ramchager that sat from OCT 2020 till Apr 2022, NGC3& 5.7 out of an 04 , acted the same as what you're dealing with, swapped o2s from side to side and the problem stayed on the D-side, I pulled wiring out and the connector on the rear o2 was discolored( only way to think about describing it) changed the connector and it was fine afterwards.

Thanks!, Yes I am excited to get this thing out for some Test n tunes. Built and designed the 4 link myself, roughly based on the Gen1 Dragpaks with more adjustability.

I actually forgot to mention, but I did pull the o2s out, and swap them side to side, with no change. (Same VE drop on B2)

However, now that you mention it, the Passenger side connector (From the o2 wiring extenders) had fallen on the Header at one point, and was half melted.
The pins seemed fine, but I suppose it could certainly have effected it.

I'll drop an order for some new extensions, and swap with a couple spare OEM o2s I have hanging around, ones in the car are NTKs.

Thanks for the suggestion Rick

[PurpleRam]

the kid I sold my 19 1320 Challenger to, backed half the car with a 4 link , no more squat to pee , that thing leaves the line like a 60 era Super Stocker.

[TheBlazer24]

Well, I ended up testing each injector to make sure they were all firing, and I swapped the o2 sensor extensions, and... still has the same problem.

Last thing I'm going to try is swapping the PCM back to the old one, before popping open the valve covers to look inside.

[edcmat-l1]

Popping in the exhaust is raw fuel being lit in the pipe. Almost always caused by a misfire. The raw fuel from the misfire is lit but hot gases from another cylinder.

First thing you need to do is check the header tube temps with an infrared temp gun. If you don't have one they're cheap at your local Harbor Freight or Northern tool.

Need to make sure you hit each tube at the back of the bend. If you're hitting different tubes in different spots your temps will look like they're all over the place. The backside of the first bend out of the head is going to be the hottest spot for each tube.

The O2 problem could be the result of the misfire. Finding and fixing that may fix the O2s.

I would also pull each O2 connector one at a time while it's running to make sure they're connected to the proper side of the engine.

[fumanchu182]

VE Bank 2 is currently disabled. Please enable and try that. Also kudos for actually using the notes section in HP Tuners, very rare to see notes.

[TheBlazer24]

Update gentlemen, I believe to have tracked down the issue.

I did end up pulling the valve covers off, and cranked the motor over, and sure enough, 1 and 7 both seemed to not open all the way... great, lol. Pulled the head off.

It gunna sound really stupid, and 100% my fault, but when I assembled this motor, the 2006 large bearing lifters were still in great shape, so I opted to reuse them, however being an 06 motor, it had MDS on 1 4 6 7.

I have talked with others about this, and others that have gutted the inside of the lifter and inserted a solid bushing, essentially locking them out. What I had done was tack weld the MDS pins to do the same thing, (lock them out). sure enough, the tack weld cracked, and I believe they had started to collapse; therefore not letting the valve(s) open all the way. This makes sense completely, as when I had first assembled the motor, it had no misfire.

Anyway, I went ahead and ordered a full set of Non MDS lifters, and I'll get them dropped in, and will post an update for ya'll once they show up.

fumanchu182; yeah, in my last ditch effort I disable B2 VE in attempt to make sure they were 100% the same, which obviously did nothing, lol, good eyes though,