LTx VS LSx Timing

[EvilOptiZ28]

Hey guys I have a 97 Camaro Z28. I installed the new TorqHead 24x conversion and I'm using the 0411 PCM. My question is about the numerical value used in the tune for the timing. I had the car dyno tuned and the tuner said the car made the most power at 24 total timing I think it was. Don't have access to my computer at the moment to look at the tune. I know the LT1 usually likes high 30 to low 40 on total timing. I also know that the LTx pcm and 0411 pcm uses different values in the timing tables. So with all that said if someone converted the values in a LTx pcm (ex 38) to 0411 pcm RPM x Air Mass would it convert over to the lower number like 24? If need be I can post a copy of my tune once I get home but I'm just wondering if I need to look into my timing more and see about adjusting it.

[Ben Charles]

Needs a lot more then 24 degrees at WOT... I think you're tuner is full of shit

[LSxpwrdZ]

Yes completely full of it. I've done quite a few of these LTx conversions and as a starting point I would start around 31deg around pk tq and ramp up to 32 at pk pwr. Work your way up from that until it doesn't gain more than 5hp.

Most that have come through my shop on 93oct and 1000' elevation like roughly 33-34deg timing. The LS PCM is much better at controlling spark than the original PCM and Opti was. There could be a +/- 3-4deg swing with the old PCM/Opti setup which is how some people were getting 38-40deg timing in them. Real measured timing I've never seen an LT1 want that much.

[Fast4.7]

The LT1 heads are not much different than the Vortec heads on my Express van when it comes to timing/afr. Running the Lunati Bare Bones version of the Hotcam, .015" compressed head gaskets and 906 Vortec heads milled .020" for close to 10:1 compression, mine likes about 12 on the throttle hit, 20 by 1,600 rpm, 24 from 2,000-3,600 and works its way up to 30 by 5,000 at 5,800 it is running 32. Running 12:1 on E10 fuel. 14.1 stoich and PE multiplier of 1.175 from 2,400 to redline. PE adds between 1* and 6* depending on the air/fuel ratio and RPM. The maximum total heavy throttle timing in my main spark table is 26* and it is flat lined from 0.64 gm/cyl and above. PE has 0 delay in both RPM and TIme and the decay value is basically as quick as it can happen. I have it set to come in at about 60% throttle. I have PE set to run about 13:1 under 2,400 rpm and quickly transitions to the 12:1 by 3,200. I run 93 octane and tow heavy trailers with those timing/fuel settings in the heat of summer. I run the stock GM 4.3 B82 2,200 stall torque converter in the 4L80E and 4.56 gears. I am also running 24x with the truck coils that have heat sinks. D585 IIRC. As well as 8.1 DBW. I had a whole 8.1 setup from a Van and just felt like playing with a DBW setup so I converted it when I did the 24x conversion.