ECM and stuff (sorta) explained.....

My understanding is that the ECU knows which cylinder is inducing based on crank position and snapshots the MAP at the appropriate time to give the MAP reading per cylinder (Rocket III has 1 map sensor tubes to the 3 throttles).

Yes the PCV is spliced into the crank position sensor plug so this must be where its rpm reading comes from. I'd imagine might also uses this for crank position info as the add on ignition module can be used to alter timing (ignition module also has crank input but is apparently not used for Rocket III application)

So with all this info I'd imagine the PCV knows when to snapshot the MAP signal for pressure based fueling
can the PCV ignition module advance the timing?
 
I'm on my phone with fat fingers, please excuse brevity. Yes the R3 has low compression ratio, it is a high cylinder pressure engine however, same CCP as a late gsxr 1000 with 13.2 comp. It also has a twin plug combustion chamber, there is not much to be found on a stock engine in ignition. On our Aussie fuel anyway. And yes the dynojet ignition module is for altering timing.
 
I'm on my phone with fat fingers, please excuse brevity. Yes the R3 has low compression ratio, it is a high cylinder pressure engine however, same CCP as a late gsxr 1000 with 13.2 comp. It also has a twin plug combustion chamber, there is not much to be found on a stock engine in ignition. On our Aussie fuel anyway. And yes the dynojet ignition module is for altering timing.
Thanks for that. I've read much about fueling tables and adjustments but very little about timing adjustments. Good to hear from someone who has experimented with timing and can offer an informed opinion.
 
I'm on my phone with fat fingers, please excuse brevity. Yes the R3 has low compression ratio, it is a high cylinder pressure engine however, same CCP as a late gsxr 1000 with 13.2 comp. It also has a twin plug combustion chamber, there is not much to be found on a stock engine in ignition. On our Aussie fuel anyway. And yes the dynojet ignition module is for altering timing.
so early intake close. where could i find the info on the cam specs?
still question whether DJ PCV can only retard timing or is there some method to advance timing from what's in the ECM. in order to do that, it would need to know a bunch of things i think. retarding timing is easy, ignition pulse comes into PCV, lookup table says delay 2 deg, wait 2 deg based on knowing the CKP rpm, then let it out the other end.....
I'm on my phone with fat fingers, please excuse brevity. Yes the R3 has low compression ratio, it is a high cylinder pressure engine however, same CCP as a late gsxr 1000 with 13.2 comp. It also has a twin plug combustion chamber, there is not much to be found on a stock engine in ignition. On our Aussie fuel anyway. And yes the dynojet ignition module is for altering timing.
so it's got an early IVC point. (just out of curiosity, what is the CCP of a healthy stock R3? as an example on my HD engine with a static CR of 11.05:1, and and IVC of 47, my CCP is about 210psi).
does PCV ignition modules have the stock timing stored in them or do they read the timing map out at key-on? i've never really thought about it since they don't support HD with the ignition module....
 
still question whether DJ PCV can only retard timing or is there some method to advance timing from what's in the ECM. in order to do that, it would need to know a bunch of things i think. retarding timing is easy, ignition pulse comes into PCV, lookup table says delay 2 deg, wait 2 deg based on knowing the CKP rpm, then let it out the other end....

I don't know if the IM can be used to advance also, i've only ever had occasion to retard ignition from stock, even when editing the ECU ignition map.

The IM wires in between the coils and their supplies, and the PCV has CPS data, plus the ECU map timing by virtue of the ignition pulse timing, so is that enough to manage advancing also?
 
well that's what i'm wondering. maybe what they do is just simply sample the ignition timing from the ECM and then as they get the pulses as the engine is running they fill out the stock mapping as different points are hit. only then are they able to advance the timing. they can't make it earlier if they don't know when it is, right? so they'd either have to know it already or learn it every time.
stock advance say at a given rpm/map point is 35BTDC.... they'd have to wait and sample the ignition pulse for that RPM/MAP point at least once to know it's 35, right? only then can they add a couple and make it 37deg BTDC.... a couple of late spark pulses is probably not an issue. i've only just thought about this, but maybe that's the way it works. pretty clever, i guess. as far as regarding timing, well that's easy like i said. the retard settings can be applied right away since you just need to look at the ignition pulses.
can anyone confirm this is how it works?
 
oh, and before i forget, does the ignition module also read temp and have a table to adjust for temperatures too? that's pretty common, having a main spark table but also a secondary table to pull timing at some higher IATs or something.
 
DDT if you have a Harley with a 47 inlet close and 11:1 comp you would have over 230 psi?? Maybe something is off??. It will jump out of its skin with 11:1 if you put a cam in with a 55 or 57 inlet close. DJ IGN module can alter IGN each way plus or minus 20 degree from memory, and raise rpm. Good instructions on DJ site . Also R3 cam timing is in front pages of the workshop manual. The stock ECU may have timing reference to iat and engine temp, but we can't see it in tune ECU. I am a bit simple minded, while it's nice to know all the ins and outs of how the ECU works, I do not need to, I just adjust the bits they let me to get the bike to run as well as I can. The easiest way I've found with tune ECU l tables is to ride the bike on the dyno and note where they need changes, then do it. Takes a little while. If using live tune ,like PC v one can use the live torque gauge on dyno. Once again takes a while...... Oh hang on customer wants cheap, fast job... 🙂 .
 
Btw , just re read your post, all Harley pcv have had fuel and ignition for years, do I not understand correctly what you said ?
 
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