Need help with timing under the curve/ whole timing map

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dj_smooth
240sx Wannabe
Posts: 196
Joined: Sun Aug 10, 2008 12:35 pm
Location: Guam-- Moore, Oklahoma

Need help with timing under the curve/ whole timing map

Post by dj_smooth »

The consensus seems to be subtract .75* per lb of boost and then add timing from there. .75* definitely feels laggy. I've been looking at a lot of the maps on here and they all seem to follow the same basic rule and be generally linear towards redline. However, my understanding is that timing increases with rpm in order to get closer towards that 15* or so past top dead center. How are people feeling comfortable adding timing on the street. Virtual dyno is a great tool. Maybe it's just me a little on the cautious side, but do those of you who use VD just keep adding timing and watching the torque curve? And once it makes no more power just backing it off a few degrees from there? Also how are you guys tuning power under full boost. Are you just looking at the stock timing map at atmosphere and then interpolating from 100kpa to your max boost level? Low boost doesn't push as much cfm through as high boost, so therefore would you be able to run a lot more timing on low boost? Kind of lost here and the car feels down on power because my timing doesn't seem to be high enough.

Megasquirt pnp 2
TD06 20G
550cc
91 octane

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cmj
240sx Wannabe
Posts: 129
Joined: Fri Jun 27, 2008 3:12 am

Re: Need help with timing under the curve/ whole timing map

Post by cmj »

Your ignition map looks very similar to mine and there is definitely more power in timing. You are now at a fulcrum of deciding to push timing without any real feedback or stay safe. I would suggest adding a knock module to your computer or rigging up some det cans. You can do this on the street if you have a good road where you aren't bothered and can replicate each run but I would definitely recommend getting a few hours of dyno time. Tuning for MBT on a dyno is very easy and pretty quick.
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