how to tune timing?
 

what are the ways to tune timing, i know listening to the engine and pyrometer(EGT) does. Does the WB02 tune/say anything for timing as well? if so how? I do not have a knock sensor but i think i will be able to hear knock, and for the EGT doesn't that take a long time to tune with it since its electronic and temp changes slow? ohh one more thing what should the range of timing be in the high revs on vacum and boost, somehow i think the timing should be under 40 in vacum and under 25 in boost at high revs, correct me please.

Re:how to tune timing?
 

Tuning timing is really best done on a dyno. Some forms of knock are not audible but will show up in the power band on your torque line. Exact ignition timing depends on your motor size, dohc or sohc, available octane, amount of boost, temp of the charge air, and etc. It is really best left to do on a dyno. But u can see major detonation in the a/f readings if there are rapid spikes but then u should also be able to hear it and feel it very easily. Basically u want a nice smooth flat torque curve with decent afr's. After u get that u can just highlight the entire boost section and up the timing by .25 -.5 degrees at a time till ur either too scared to add in more or u start to see signs of detonation.

Re:how to tune timing?
 

You could also use a step retard that is dependant on the amount of boost. That would be a better idea.

Re:how to tune timing?
 

As stated above you will not be able to hear the detonation, so you cannot tune this way. But the best thing is to deffinitley get it done on the dyno. I usually don't go with a step retard just because I didn't get a chace to get a car on a dyno, I believe for smaller motors you should go with a little more advance and with larger displacement motors you can go with a little less, b/c of the heat dispertion maybe like (.9 vs .8) Someone might be able to clear this parts up a little more. It makes perfect sense to me though.

Re:how to tune timing?
 

http://www.efi101.com/forum/viewtopic.php?t=7

http://www.efi101.com/forum/viewtopic.php?t=101

http://www.efi101.com/forum/viewtopic.php?t=272

http://www.efi101.com/forum/viewtopic.php?t=126

http://www.efi101.com/forum/viewtopic.php?t=22

Some good links about timing...be prepared to read.

Re:how to tune timing?
 

a step retard is still a type of ign. 'basemap' so to speak, it's by no means a tuned ign. map and it will still need attention, but it's a better start than an overly conservative linear retard and will give you a better tip in to boost. as far as smaller and larger bore engine, you can run 'more' timing on larger bore because of the larger cylinder diamter. as far as tuning ign., there's a lot to it if you want to do it properly with the best results as far as power, but for begninning tuners, a good afr and mildly agressive timing map is a good goal ;)

Re:how to tune timing?
 

The larger bore is because there is more heat dispertion b/c of the area. Also you have to make sure your ignition is retarded at the motor's peak TQ. You can tell this by where the motor uses the most fuel. There will almost always be a big dip in the fuel tables, assuming that the map is tuned to a consistant A/F. Peak Tq usually happens right after peak fuel consumption, just something to keep in mind, when you are onthe dyno.

Oh and I do agree witht the step retard, but I am into running conservative untill I hit a dyno.

Re:how to tune timing?
 

smaller bore = smaller diameter = less distance for teh flame to travel before reaching the cylinder wall = less timing :P

Re:how to tune timing?
 

peak fuel comsumption and where your timing map should see its least amount of advance is generally at peak torwue for your motor

generally you take away a little fuel and add timing back in after peak torque.

Re:how to tune timing?
 

peak fuel comsumption and where your timing map should see its least amount of advance is generally at peak torwue for your motor

generally you take away a little fuel and add timing back in after peak torque.
You guys are just better with words. :P