m42racer

I have the Link G3 and I looked at my numbers on another engine. I run the Idle in closed Loop with a stepper Motor, so the numbers could be different again. On this engine I have some real agressive cams, so the idle is not so smooth either. Dave, they have used the 4D map and have isolated the cells wher the engine Idles and have blown this up into its own fuel map. It helped a bunch. My map is not limited to 16 x 16 either so maybe the cells around the idle have more span and do rely on interploation as much. This may help in the cell numbers too. I looked at my fuel values at Idle and I am lower than you, more in line with the others but I have real big injectors. I asked and was told, the Fuel Injector size, Fuel Pressure and Master value all factor into the final pulse width, along with all corrections. Trying to compare pulse widths bewteen systems could be very difficult. What one engine wants another does not.

Duke

Trying to compare pulse widths between systems could be very difficult, but it doesn't have to as long as you compare the actual pulse width and not the fuel map values since that is different between systems.

I've used many stand alone systems and some use VE map combined with a lambda map, some use a percentage of a master pulse width and some just have the whole fuel map in raw pulse width ms. (pluse many more variants of course..)
But in the end those are just different ways of calculating a certain pulse width and those numbers don't vary too much when you calculate engine displacement, fuel injector size, fuel pressure and ve (and air mass depending on boost but we're talking idle here).

DanG

While everyone is chiming in with some standalone EMS info, anyone care to share some complete baseline fuel & spark maps? Obviously fuel will vary a bit depending on the specific setup of the user, but spark maps should be pretty easy to compare. The engine is going to respond to 35 degrees of advance at a specific load/rpm point regardless of whether its being run by a Motec or a Megasquirt. Taking someone's well developed spark map and dialing it back X degrees might make a safe but helpful start for someone starting from nothing.

adrial

For timing maps, I've collected a few but I would love to see any others. Especially the cars that have been tuned close to the edge, so that I can do exactly what Dan G mentioned.

I found both of these on Rennlist. I have both listed as stock 26/6 maps, though the maxtronic version is a few degrees more advanced across the board.

adrial

And here is a big turbo TEC3 map, though I don't think it was tuned with knock sensing.

adrial

According to the website I linked at the beginning of the thread (http://www.rbracing-rsr.com/calcinjpulse.html):
95# (1000cc) injectors should idle at about 1.19ms
72# injectors should idle at about 1.25ms
36# injectors should idle at about 1.5ms.

All those numbers are for a 2.5L
That correlates at least somewhat to the numbers listed in this thread aside for evil 944t since the Link G3 doesn't appear to use raw injection time in the map.

So I definetely can't just scale my map up or down linearly. 3ms will probably be way too much fuel, I'll dial the map down and then edge it up if it doesn't fire.

dand86951

Give 1.75ms a try to start. Mine seems to like a bit richer mixture on start up. If it doesn't start, don't worry about it try a higher number, or lower if you can smell any fuel, until you get some fire in the hole. Once you get it to start then you can fine tune it.
Just to eliminate problems make sure you are getting spark prior to worrying about fuel. The last thing you want to do is keep adding fuel until you have the cylinders completely flooded. It will probably start and run within a pretty wide range of ms values.

adrial

Thanks for the tips. I'm mostly worried about getting that initial fire and confirming that I actually wired everything correctly and got all the settings correct.

Here is the timing map that I extracted from the E6k. ~18 degrees of advance at 15psi. Only 30 degrees max at very low vacum with a 7 degree retard soon as you get into any boost. It seems like the map could use some smoothing, some more timing at low boost/vacum and maybe a little less once on boost, but not too bad overall? I'll be running pump 93 and 15-16psi.

Definetely looking forward to doing some tuning ... I've got the MBC dialed allll the way back with the stock wastegate so I shouldn't get much boost at all until I decide it's ready for it.

dand86951

As a starting point and for safety sake, I would pull 3-4 degrees timing out of the above map in the 2500-5000rpm range(High torque) at anything above 8psi. If you look at the factory wide open throttle maps you posted they don't have advance nearly as high as your map is. Also, even though you don't plan to be up there, think about lowering the ign advance in the higher boost range as a safety feature. If you lose a wastegate hose and your boost spikes is there a boost limiter somewhere in the system? If not cutting the timing back might save an engine if it overboosts.

adrial

You make a good point Dan ... I'll dial it back to the stock maps.

Eventually I hope to have the Haltech control boost ... which does have an overboost protection, but if I lose a wastegate hose ... there won't be anything it can do. I'll dial that back as well.

I extracted the fuel maps also ... not sure what there is to learn here, except that it looks like the injectors may have been maxed at redline and 15psi. It's kinda interesting that at 15psi, thru the rev range ... fueling doesn't change much. That indicates a very flat torque curve, no?

dand86951

Having a relatively consistent fuel map across the rpm range at a given manifold pressure wouldn't necessarily mean a flat torque curve. Unless you know what the engine's volumetric efficiency at each the rpm segments is it doesn't tell you much about the torque curve. If it was a 2 valve engine then probably not a flat torque curve. If it was a 4 valve engine it certainly could be much flatter without having to have a lot of other modified components such as headers, intake, and valve port work, turbo etc required to get a 2 valve head to flow at the higher rpm range as efficiently as a 4 valve.

My fuel map is fairly consistent across the rpm range at 15psi also, but the torque curve is anything but flat. Keep in mind that each combustion event with 15 psi manifold pressure will, as long as the intake and exhaust system can flow the amount of air required to keep the pressure at 15psi, and the intake temps are constant, then the same volume of air goes in regardless of rpm, so the same amount of fuel is required.

The fuel map needs to be different only where the volumetric efficiency at a given rpm changes. In your map above the 3500-4500rpm shows a slightly higher fuel flow and in most of our engines that is where our torque peak occurs.

Chris White

15 degrees at high boost = really high EGT. and I mean REALLY high.

dand86951

Higher EGT or Higher detonation safety margin when doing intitial tuning? How high do you think EGT's would be at those settings?

Chris White

1800+ f

Duke

Higher EGT means higher detonation safety margin.
Lower ignition values and higher EGT is definatly better to start with than low EGT and a detonating engine!