Currently have a dart 331 with 10. To 1 compression and water meth. Looking to see how much timing to take out per lb of boost or what to run around 12 psi?

thanks

 

Heads? cam?

 

Afr 205s customer hydraulic roller from Ed curtis

 

Heres 2 diff tables from my 351w,93 pump and W/M.Had TFS Heads. Scaled in PSIA. I don't remember what I was doing when making changes between the two - been a while - but will give you something to look at.

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Can generally run NA timing to 4psi or so to help get it “lit”. Then flatline it to 10* 5psi and on. Run new plugs and pull to redline at your desired boost level. Pull the plugs and look for the leanest cylinder. Tune off that cylinder’s ground strap reading going FWD bumping IGN up 1 degree at a time until the heat mark is around the middle of the plug strap. That’s considered “safe” And the only way to do it properly IMO. Anything else is guessing. Assuming yourtiming is spot on and sync’d correctly… you’ll likely end up around 15-18* @ 12psi.

I’ve seen 12* offset in sync from ECU to actual timing and everything in between though. That’s why you shouldn’t ever just plug in someone else numbers. Start at a known low amount, work your way up watching plugs.

 

Testing on the engine and preferably at a track is the only way to know for sure what timing the engine will like. I've had SBF not tolerate more than 16* at 9#, and another that likes 32* at 14#. Way too many variables for someone on the internet to spit out a number that is perfect. Like Forcefed said, start low and work up to it while reading plugs and power all the way.