Timing and RPMs

In the upper rpms would the nitrous need more or less timing, and would this help your et if there was a way to vary the timing? Would a small second shot (50hp) on top of a 125 shot need to retard the timing even more? Thanks.

Any time you add more nitrous, it's better to play it safe and pull some additional timing. Typically, a motor requires less timing at higher rpms due to the fact that it is operating more efficiently while at those higher rpms. There are some gains to be made by retarding timing at higher rpms without spraying the motor.

Any time you add more nitrous, it's better to play it safe and pull some additional timing. Typically, a motor requires less timing at higher rpms due to the fact that it is operating more efficiently while at those higher rpms. There are some gains to be made by retarding timing at higher rpms without spraying the motor.

I don't doubt that pulling timing is a good idea when running nitrous from what I have read and have been told by people in the buisness. Your last couple of sentenses confuse me though. (Not hard to do) So let me put this another way. I have a NA tune that might have a few more degrees of timing than stock. Say 2 degrees, (I really don't know), plus with the 125 shot I need to retard the timing 4 degrees, so lets say 6 degrees total need to be taken out. My question is, with another 50 shot on a second stage, once the car is in second gear and the rpms are up should I retard the timing another 2 degrees, 4 degrees, or none? Thanks for any insite on this, Rick.

if you pull 6 deg out that should be fine for both stages.keep an eye on your knock count with a datalogger to make sure.im on a 100 dry shot with 38 deg at higher rpms and i just run unleaded 100.your prob going to just have to try it.maybe go with 50/50 blend of race gas and pump gas on the first pull just to make sure,if its ok then try it on pump gas.

if you pull 6 deg out that should be fine for both stages.keep an eye on your knock count with a datalogger to make sure.im on a 100 dry shot with 38 deg at higher rpms and i just run unleaded 100.your prob going to just have to try it.maybe go with 50/50 blend of race gas and pump gas on the first pull just to make sure,if its ok then try it on pump gas.

I guess I'm having a hard time being clear with my question. If the tune is perfect for the 125 shot, do I really have to retard the timing any more with the 2nd stage, since the motor will be in the upper rpms and not really able to digest much nitrous with that kind of piston speed? And if I do have to retard it some more, would it be less than the 2 degees per 50hp that seems to be the norm? Thanks again, Rick.

each car is different...but I would reccomend pulling timing for the combined shot...or there are multi stage retard boxes that can pul timing as each stage comes in.