Truck is a 1500hd, so right around 5500lbs. Only running 5 psi so far and 4-6 degrees of timing in boost. Afr is rich at 10.2-10.5. Stock everything. Stock head gaskets, stock ring gap etc. Starts making boost at 2200-2400 rpms and reaches full boost at 3200. Shifts at 5200. Gt45, intercooled, 80lbs, 450 lph, br7ef, only 93 octane. Stock timing was super low up top even in N/A. What is a safe timing number to be at under boost in this heavy truck? And what boost can I up this to safely?
Start with a safe NA timing curve for your application, then retard the timing 1.2-1.4 degrees per pound of boost. In your application, you'll find that removing 6-7 degrees from your total timing will be plenty safe. So, for yours around 23 degrees total and subtract 7 degrees puts your around 16 degrees total.
Agreed, 14-16 degrees of timing with that low of boost is just fine.
Lean out the fueling too, aim for low to mid 11's.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
Reply With Quote