Thanks to MisMyS on this https://www.s2ki.com/s2000/topic/815...#entry19448484.

Here's a brief walk through in checking the ignition timing sync at the crank and the AEM EMS.

The timing gun coil sensor is not able to pick up a signal on the S2000 ignition coil. What I did was grab an old used Honda Civic coil and removed the ends. Then attach one end into Cylinder #1 spark plug and the other end jamming it into the ignition coil. Clamp the timing gun sensor onto the Civic coil wire. Start the car and check for misfire. Open the ignition timing sync wizard in the software and lock the ignition at 5.1 BTDC. Flash the timing light on the crank at 5 degrees on the timing gun. The white mark on the crank pully should line with with the arrow on the block. If not, click on the Advance/Retard timing arrows in the EMS until the white mark lines up with the crank pully. Adjust the timing gun to 0 degree and the red line on the crank pully should line up with the arrow. Stock S2000 idle at 5 degrees BTDC (think I read that somewhere). A second check is to lock the ignition to 15 degrees in the EMS and then set 15 degrees on the timing light. The white mark on the crank pully should line up with the arrow on the block.

Here's the pic....




For etuners, it is essential to dial in the ignition timing with the crank.

Next up is the difference in knock between 2 degrees of timing at full throttle on ~15psi. 12 degrees seems to give minimal knock voltage spike at 15psi. The last graph is 12 degrees at 13psi.

Knock volts in black



The question of the day is... Which is better? Running high boost low timing or low boost high timing? Does the 2001 theory of high compression engine 7psi max boost still applies today?

Here's the screen shot of the street dyno.
Green line = 15psi at 16 degrees ignition
Orange line = 15psi at 12 degrees ignition
Blue line = 13psi at 12 degrees ignition.

 

Nice..!

 

In essence low boost more timing and high boost less timing are both achieving the same thing...by that I mean consistant cylinder pressures which remain under the knock limit. Obviously retarding ignition timing reduces peak cylinder pressure due to the piston being closer to TDC when the spark occurs, and therefore further down the cylinder (after top dead center) when peak cylinder pressures arrive. and the reduction in cylinder pressure in the other (low boost high timing) scenario is purely from the lower boost pressures.

One key advantage of running with lower boost and more ignition timing is lower exhaust gas temperatures for the exhaust valves to cope with.

With regards to running boost your timing is always going to be knock limited (as apposed to hitting the torque plateau) at WOT as the timing is already retarded from standard. So you should always be aiming to get as close to that knock limit as is reasonable and safe to do so to provide as higher peak cylinder pressures as possible and therefore more power..Theres no point in chucking in tons of boost and having your timing retard miles back (apart from during anti-lag) before the point at which knock occurs, all that is going to provide is worse fuel economy and burnt valves (it will provide a slightly quicker turbo spool up time though).

Dan

 

it depends alot on the turbo setup.

I usually like to keep the boost as low as possible to make the power you want. Running less than ideal timing is bad, running more than ideal timing is bad.

 

The Ptuning kit boost creep up to ~15psi without the boost regulator disc. What the boost regulator does is restrict the exhaust flow to 2.25" or 2.5" ID. Also, I am limited to 91oct. By running high boost and low timing, I essentially don't have to worry about boost creep. I also get my money's worth in running the 3" exhaust. I can see and feel more power with the increase in boost. Like Dan said, the timing is already knock limited, but how far can the timing be retarded until it is detrimental?

The next thing on my to do list is get an EGT sensor post turbo to monitor how timing changes effect exhaust gas.

 

Great write up, while your at it don't forget to check the MAP calibration it was wrong on my car and others so I don't trust the Wizard calibrations anymore.

BTW have you figured out the breakup issue? If not don't hesitate to call me.