Tuning 304 11p 424

[immortality]

I I've also noticed dyno shops often don't tune spark, only fuel, I guess because they want to see cars go out the shop performing better, which they will with better fueling, and not take the risk on spark. In general the shape of the spark map should be similar to the VE table and if you know things like RPM that has peak toque there are calculators online that can give you a generated spark map. This is often a good way to get good usable timing on an engine conversion without taking the risk to find the absolutely best spark everywhere in the map.

I know of one dyno shop that used to run some serious timing to get a good dyno graph and then dial it back before it went out the door.

[immortality]

Do you know your compression ratio? Have you checked cranking pressure?

The stock eco mode timing map isn't a bad starting point on these except around the 3200-4400rpm it drops out the timing. I'd put the whole lot at 28° if you are running decent fuel. The power map is very weak so I'd copy the eco mode timing map into that as the base.

A stock or mild 304 will take 28° timing at WOT all day long with a good exhaust system unless you have some serious compression just keep the AFR's on the rich side as these things run high intake temps with the stock banana's manifold on them.

But follow the advice above, add in a degree of timing and take it for a run and see what happens, if it improves then good, if no change then you are probably close to where you want to be and don't want any more.

I was watching a engine dyno video the other day and they have a Chev 383 on the dyno with some ridiculous amount of timing in it and they were going to add a 100 shot of nitrous so they knocked 4 degrees of timing out of it and ran the engine again without the nitrous to get a before run but it made basically the same power as before when it had the extra 4 degrees in it so in reality the lower timing number was the correct timing for the engine.

[delcowizzid]

You can't remove the timing dip at 3500 to 4500 it's the bananas being very efficient at that point if tried on the dyno many times