Basically,

1. How are they related?

2. If you have capability to alter ecu timing map (Hondata, PowerFC, ect.), what do changes via distributor do to the whole equation?

3. Do you tune using both methods, or one over the other?

I've never really understood the differences. Thanks for your help.

-Shawn

Just read:https://honda-tech.com/zerothread?id=201640 and it still didn't answer my questions.


[Modified by GReddyB18C, 3:41 PM 7/5/2002]

 

1. distributor timing is sometimes referred to as base timing. ecu timing adds or takes away from this based on various other things... it's not uncommon for 16 degrees of base timing to be something like 36 degrees of timing on the ecu at 8000rpms. (just a loose example)

2. changes made to base timing affect the entire timing map.

3. tuning via ecu is always preferred - as you can manipulate individual cells of the timing map without affecting the entire timing map. such cannot be said for the distributor timing method.


-the r0cker, who still knows relatively little and just needs to go ahead and get his hondata stage 4 up and running.....

 

Distributor = mechanical advance
ecu = electronic advance

 

THe hondata I ran was set at 45 degrees of timing at 8000 rpms just as an FYI.

 

well, if the ecu is set at 36 and there is 16 base then the total timing is 52

 

So, if you advance the base timing from 16 deg. to 18 deg. the whole timing map will effectively be advanced 2 deg. as well?

-Shawn

 

correct

 

But I thought the firing of each plug (timing and duration) was determined by when the contact on the rotor hits the cap contact for each plug. Does the ECU control the coil for the moment that the rotor is in contact with the cap? I don't have a rotor handy Looks like the contact is about 10 degrees in duration?

 

The rotor allows for a certain "window" of spark firing.
By turning the distributor, you change the location of the sensor which will in
essence tell the ecu the engine is at a different degree than it actually is which
is why the timing can be advanced or retarded manually. The 96+ h22a do not
do this because the sensor that controlls this is on the crankshaft and not the
distributor. The coil does not automatically release the charge when the rotor
touches the contact point on the distributor, rather it is controlled by the ECU.

 

How is timing tuned via ECU manipulation? For instance, when tuning fuel, the A/F ratio is used as a guage. What is the "guage" for tuning timing?

 

Very good info

 

i think sgT was born from a motor, just plooped right out of the header or something.

 

a/f is NOT a gauge for tuning fuel. its only to see that what you are doing is
ACTUALLY doing something. gauge for fuel is HP. same with timing except
you also have to use detonation to see your limits as well.

 

Sgt is right, a/f is not the ultimate gauge to tune fuel, hp is. However, I tune the fuel on my car with an eye on a/f as well. When I tune my fuel to make maximum power without any regard for the a/f ratio, my car runs too lean. I don't think it's safe to tune fuel on the dyno right up to the point where detonation occurs without also keeping an eye on the a/f ratio. I may lean out my fuel and not get detonation on the dyno, but that doesn't mean the a/f ratio is "safe" for all driving conditions where air temperatures, atmospheric pressures, and other factors can cause detonation that didn't occur on the dyno. Maybe I'm too cautious with my tuning, but I don't want to risk uncontrolled detonation. Also, my opinion on tuning is somewhat skewed because I have a jrsc.