Discussion and questions related to the course Practical Dyno Tuning
newbee here I was looking too know how to properly set up your lambda target for when the engine goes into load (full power run). In road tuning how do u determine your target lambda when u can’t see how the numbers effect power or going too rich?
General guidelines are provided in many places on this website. But you can choose 0.88 - 0.90 as a staring lambda for naturally aspirated engines are you will be be safe and very close to optimum. Often you can't measure much of a difference anywhere in that range.
So Say if Im tuning a 1jz gte with single turbo and 1000id injectors. I would roughly try a lambda target And then once going through a full power run if I have a lambda set too 0.85 and see engine going too lean. then I would simply change the lambda target too a richer mixture? Would this this be best way to get performance out of road tuning? Thanks for your reply
If the engine is going too lean (ie, Lambda greater than your target of 0.85), you change the fuel table to make it hit the target.
After the fuel table is tuned so it can hit the target at all RPMs, then you try a test where the target is a bit richer (say 0.83) and see if it makes more power (or the same power, but the coolant temp doesn't rise as much). You might try a bit leaner (say 0.87) and check the results -- make sure you don't see any knock. You might repeat this test with the coolant temp at the maximum end of the "normal" range -- to make sure you don't have any indications of knock as knock is more common at higher combustion temperatures.
That is how you pick a target lambda that makes the best power and keeps the engine safe.
Cheers lad I appreciate it all makes sense to me now