Hel!p look at this log please ( Cammed 5.3 truck)

[Slowrc]

This is a log of a cammed 5.3 . Recent mods include a 4.8 to 5.3 swap, 3k converter, shift kit, and some tuning. Look at the rpm on the 1 -2 shift. The owner complains of a sluggish off the line condition and says it just soes not pull as strong as it use to and now he has more cubes. I have not logged the off the line condition because thats at the track only. Still spins on the street. Any ideas? I'll save mine till someone hits on it. Thanks.

[5.7ute]

Why is it only commanding an AFR of 14.63 under WOT conditions? That and high timing for a that mix wouldnt be helping at all.

[5.7ute]

That lean spike at frame 463 could well be a detonation issue not being picked up by the knock sensors.
Do you have any logs of the previous combo. Trans or convertor issues I wouldnt think would affect both rpm & mph, unless the trans was loading up internally. Was the car frying the tyres in this area?

[joecar]

+1... I agree with Mick... needs to command richer at load/WOT and with less timing...

Even if you don't hear knock/detonation, combustion chamber temps would be going very high (which may cause damage and greatly increases knock/damage potential).

You need to richen CFOL and PE... and make sure PE enables...

Also, being too lean may be the reason why it may be sluggish.

Looks like you're running OLSD (no MAF, no LTFT)... and have gotten BEN's close to converging...

Lean spike might be knock, but not for 7 seconds... that might be the wideband resetting itself or something.

30° timing advance thru peak torque is too much advance... if you don't hear it knocking then the other problem is cylinder pressure would be peaking a bit early (i.e. piston-rod angle is not at optimum angle to make the best torque... i.e. piston is still too close to TDC where it is not moving down very much yet).

My understanding of the LS1 family cylinder heads is that they are a fast-burn design, so you don't need as much timing advance.

$0.02.

[5.7ute]

I was just looking at the spike at frame 463.
Joe, what do you make of the drop in RPM & mph from 410 to 430.

[5.7ute]

Also I just noticed it is either an arctic winter, or the IAT sensor is an open circuit or not plugged in.(Reading -39deg C)

[joecar]

The other problem you have is the IAT pid is pegged at -38°F like Mick said... the IAT sensor might be disconnected;

(my comment on this is that at -38°F I would have expected the commanded AFR to be much richer, something like 11.7-12.5).

[5.7ute]

Joe, I believe it is a custom OS with stoich commanded. Wideband AFR is fluctuating like STFT are active.

[joecar]

I was just looking at the spike at frame 463.

Ah, I see it, yes maybe it's due to knock...

Joe, what do you make of the drop in RPM & mph from 410 to 430.

That looks maybe like his spinning tires are slowly/progressively gaining traction and at the same time the engine is starting to experience increasing load (from increasing traction and insufficient torque).

[joecar]

Joe, I believe it is a custom OS with stoich commanded. Wideband AFR is fluctuating like STFT are active.

Ah, I see that too, now.