Guys, I need some advice on tuning my truck. Please keep in mind my location (Medellin-Colombia) and the limited access that I have for some performance parts specially with COVID19 thing out. I know the 0411 PCM and wideband is by far the way to go and I'll do it later, but I want to play with what I have now on hand.
1998 C1500 truck (4x2) 5.7L Vortec - K&N complete CAI - MSD 6A ignition/MSD spark plug cables - Long headers - magnaflow 200 cells cats - Flowmaster super50 2in/2out - 4L60E recently rebuilt - Stock tq converter - Deleted EGR/EVAP - upgraded spider injector MPFI - I believe someone put before a high flow MAF or modified the stock one (doesn't have the hive cells).
I recently took apart 90% of the engine (with the crankshaft and block on the truck) and this was added: Compcams 08-501-8 cam Adv Int/exh Dur: 264/269 LSA:112 Int/exh Duration at .050: 212/218 Int/Exh Lift: 0.488/0.495 - Valve springs, seals and spring retainers to accomodate the new cam lift on the stock heads - Ported stock heads and resurfaced valve seats. New piston rings, rod bearings, gaskets, seals, timing gears and chain, etc.
While we're in quarantine in my City we're just allowed to go out 2 days/week with a lot of restrictions, I'm not able to do much testing on the truck. I've felt a low end power/tq loss (I believe because of the new config) and because of the region is very altitude variant (lot of mountains, etc) I want to try to re-gain with software what I have lost with the new hardware. I've included the stock tune, modified (last version) and 2 logs of my short runs. My comments:
- I've seen another VE tables in this Gen3 thread and everyone has regular values in percentage 40-50-70-90% If you see my table is in different range. I added +10% of the values in the main region to see how it goes, but no noticeable changes on the engine behavior.
- In engine airflow tab, I've read a lot and seen videos about failing MAF to fill VE and running MAF only to fill MAF tables but since I'm not able to hook a WB and be out in the street making some runs, is there any general rule or someone have tried doing this in a similar year/engine/trans config that can share the airflow tables (VE and MAF) to give it a try?
- I've not made any changes on engine timing. Any advice here based on my config?
- In one of my short runs last week I felt like the trans was slipping a little in 1st/2nd gear WOT. As you can see in my files I give the trans a little pressure increment. Any advice is welcomed since I want firmer shifts.
- I read that the 1998 PCM black connector pin 9 (dark blue) is labeled as Auxiliary Electric Cooling Fan and engine cooling fan feature available in the tune. Has someone tried using that pin to control engine cooling fans? I already did the electric fan conversion with electric thermostat.