Originally posted by: DSNUT
Here are tonights dyno runs. the first is on straight alky. The next is 10% NM then 20%NM then 30% NM

Notice we are making slightly more hp on straight Alky with the HP4's than we did with the 109's w/ 20%NM. Hmmmm.

Notice the first 10% increased hp by about 11 hp. The second 10% only added about 5 hp and the third 10% also only added about 5 hp.

I wonder if the extreme timing advance isn't responsible for the motor posting weak numbers on straight Alky. I think the timing advance is almost optimal for 10% NM........that is why we see the biggest gain when adding the first 10% of NM. We are getting more power by adding more but the incremental gains are cut in half. We might need more advance to optimize running more than 10% NM. Tonight is a bit colder than last night, that might account for the 2 hp loss at 20% from what we ran last night.

The other thing that might be holding the 20% and 30% back is lack of sufficient fuel delivery. We might be looking at a loss of carburator efficiency past 10% NM also...............Interesting stuff, huh?

Dyno Runs