Vehicle weight

[TireFryer91]

I would like to hear peoples opinions on if you factor your vehicles weight in your tune? Ex: you take 400 pounds out, would you retune? I know its not a big factor at all but thinking in terms of making a vehicle lighter, it benefits the overall platform.
Im thinking in terms of timing under load would be where im headed with this
Thoughts please

[Dan Stewart]

Depends on whether or not timing is already maxed out based on knock limits or power limits.

Max timing isn't always just based on whether or not you've reached a limit where the load results in knock for a given octane, but also whether or not the engine simply makes or loses power beyond a certain amount of timing advance.

[TireFryer91]

thanks for the reply, my timing is close to being maxed for WOT, I see where you went with this. wouldn't the knock ceiling technically raise under part throttle and low load? and even slightly at WOT. given the motor will only eat so much timing before it wont make any more power. apart of what brings me to vehicle weight being a factor is the deference between a free revving engine with no load vs one under max load, eventually the vehicle weight will become a factor even if its very small. part throttle and lugging mode

[Dan Stewart]

That is correct. A lighter vehicle will be under less load with the same drivetrain as a heavier one, so it should be able to run more timing at both part-throttle and WOT. Manufacturers have retarded timing when sharing a car engine with a truck for that very reason.