Discussion and questions related to the course Practical Dyno Tuning
i get the idea of tuning the steady state ignition tuning using the dyno, but what about when im tuning on the road?
i have a few question here:-
1. how can i get the maximum torque from advancing the timing when im on the road tuning?
2. how do i know when to stop advancing the timing when im on the road tuning?
3. is there a way that i can know how to roughly estimate the optimum advance timing that i should put at every cell?
4. is it safe to advance the timing on every cell until i hear a knock and then only i retard by 2 degrees?
Hi Madnoor, unfortunately when we're tuning on the road there are a few limitations on what we can achieve compared to being on a dyno. The key one of course is we have no feedback for engine torque so optimising the timing can be challenging. If we're tuning an engine that is knock limited however the knock threshold is the limiting factor for how much timing we can use regardless whether we're on the dyno or the road, so in this case we can achieve broadly identical results. Where things get more tricky is if you're tuning on a race gas or an ethanol blend where the engine may not knock. In this case it pays to err on the side of caution and be a little conservative with timing. Understand that you may not be able to make the engine knock at light loads so it's not a case of advancing every cell until the engine knocks. I generally do this under high load and then make my changes to the entire rpm column in the ignition table.
I understand that the evo 9 4G63 is knock limited on the upper limited of the rev range, but can we employ what u stated in the above for the lower and mid rpm ranges? Say 2k - 4.5k rpm?
i understand that nothing replaces the dyno but sometimes It’s hard to get dyno time for every mod that’s done