Tuning 355 LT1 with 231/239 Cam & LE2 Heads

[Casey96SS]

Hi all, I have spent the last two years upgrading my 59k mile 96 Camaro SS. Current mods are in the sig. I have EEhack, TunerPro and an AEM wideband all setup working and logging great. I have spent numerous hours reading tons of threads and websites on tuning. Overall the car is in fairly pristine shape and the motor has about 400 miles on it after a complete rebuild. O2 sensors and injectors are brand new. I am fairly confident there are no exhaust leaks. I do not have any obvious intake leaks but I cannot be 100% certain on that there are no intake leaks at the manifold or TB. I do not believe there is an intake leak at this point.

Currently running closed loop with MAF. Not opposed to going to CLSD since this car is more of a weekend warrior now, but would certainly keep the MAF if I can.

As of right now I have a fairly basic tune in the car that I got from an email tuner. I made the following changes to that tune.

Turned off EGR, Air pump, AC, Stall Saver, Skip Shift, TC
Set injector flow rate and offsets correctly. Received data directly from Fuel Injector Connection
Made adjustments to O2 Swing voltage and Int Delay per @steveo website
Adjusted CORRCL Airflow %.
Changed idle timing to 32 and eliminated Idle Timing correction
Changed idle to 850 RPM.

The car feels like it idles better than it did and it is smoother taking off from a stop. MAP kpa dropped to 59.2 from 65.7 with the changes above.

The first issue I am having is that my BLM's are both showing +25% at idle during closed loop. Wideband shows high 14's during closed loop and 16-17 during open loop. Since it is driving better at idle should I worry anymore about the idle right now or just blame it on the cam?

Overall the car does not run too bad but I know it has a lot more left in it. It is showing lean during cruising and rich in PE mode. No knock.

Just hoping to get some advice on what my next steps should be. Should I continue to work on the idle or should I turn off PE and MAF and start running the Trimalyzer to dial in my VE tables?

I am attaching a log from a short run tonight if anyone want to take a look. Thanks for any input!

[Aroberson77]

I think you are ok with running lean cruising and rich in PE mode. What are your lambda values in PE mode? It wouldn't hurt to see what trimalyzer wants to change.

[Casey96SS]

I think you are ok with running lean cruising and rich in PE mode. What are your lambda values in PE mode? It wouldn't hurt to see what trimalyzer wants to change.

Thanks for the reply! I am attaching a couple screen shots of EEhack Analyzer for cruise and PE. I have read a lot but am new to all of this so I am not quite sure what direction to go next.

[Aroberson77]

The PE numbers I think are pretty useless since you don't have a wideband. I might richen the cruise a little bit but you probably don't have to. Richening idle probably won't hurt anything, just burn more fuel. Did the tune touch the timing at all?

[Casey96SS]

The PE numbers I think are pretty useless since you don't have a wideband. I might richen the cruise a little bit but you probably don't have to. Richening idle probably won't hurt anything, just burn more fuel. Did the tune touch the timing at all?

I have an AEM wideband 4.99V = 19.98 AFR. It is wired into pin D27. It seems to be logging pretty well in EEhack. The above PE screen shot is wideband data.

The tuner bumped the timing up a few degrees most areas. The tune I originally sent him was a premium gas performance tune for the stock configuration so I do not know how much the current tune varies from stock as far as timing. I was going to play with the timing after the air/fuel was dialed in.

[Aroberson77]

Doesn't a lower MAP kPA reading mean more efficient combustion? Did MAP go up after your changes?

Also you look rich in some spots at high load high RPM, can you see those AFR readings in lambda instead? I would shoot for .9-.93 lambda (AFR 12.69-13.1)