Forum » Practical Reflash Tuning » Optimizing Timing With FI

Optimizing Timing With FI

Practical Reflash Tuning

Discussion and questions related to the course Reflashing


Page 1
Author
92 Views

So just curious, I'm very much biased and accustomed you can say, to tuning ignition and fuel maps with standalones. So just curious what is the best way to optimize timing on say HP tuners when converting over to SD on a turbocharged application? I figure the 0-100kpa is going to be fairly close already-ish. So just curious about this because i'm beginning my build now with a 5.3 all that's going to be done to it for now is a cam basically. It will be turbocharged on e85. Cam will be around 600ish lift, so not sure if that will require to add more timing than what's already in the stock map that i will pull from the ecu on first set up/start. Also not sure how to optimize the ignition then for the boosted areas 105 kpa on up? Any help would be greatly appreciated.

Only going with HP tuners because my buddy said that if i pick up a PSI conversion harness for $500 he will allow me to use his HP tuners as long as i buy the credits. So this is going to save me $500 that i was going to save up extra to purchase the Terminator X from holley, or $650 from buying my own HP tuners. Which then i can put the $500 into a better turbo etc.

The downside of reflashing is that you can't generally make your tuning changes live so you can't make a spark sweep test to find MBT in steady state for each cell. That's not generally as much of a problem as people think though. You're right that the off boost areas are probably going to be there or thereabouts so usually this area is best left stock unless you're picking up some knock retard. I'd then start by filling out the boosted areas of the timing with some conservative numbers (you're probably going to be immune from knock on E85 anyway so not too much to worry about). You can then optimise the timing table at wastegate boost by doing ramp runs - Perform a run, check your results, add say 2 degrees through the regions you accessed and repeat until you see no gain in power (or knock).

You're likely to then end up with a region between 100 kPa and your wastegate boost level that you haven't accessed. I'd suggest just hand blending or interpolating this area. This will be sufficient to get you optimal results under WOT conditions and you're likely to be 80-90% of the way there in the cruise/transition areas without wasting a huge amount of your time.