Ignition Impulse @ Balancer/Dampner

[VetteVet]

Paul,

The 411 PCM swap is a good one if we could get it to work on the LT5. The third gen F-body guys are doing this swap and reporting improved driveability, power and fuel economy. The tuning is much easier and there are third party code mods available for forced induction, nitrous, launch control and wide band O2 support. Going to COP or CNP would get rid of the Ignition Control Module that is getting harder and harder to find. Hell we could even implement Electronic Throttle Control with the torque management that would make possible. Also 4L60E and 4L80E transmissions would be on the table.

I've been looking at this for the last couple of weeks and it looks really promising. If we could only get past the 16 injector issue, this would be a no-brainer for me.

Jep

[XfireZ51]

Originally Posted by Paul Workman

Aside from an alternate ignition system, tell me again what problem you;re trying to solve with the CNP?


P.

I guess you could ask why GM would bother if it wasn't worth it. CnP is credited with providing some of the power increase for the LSx motors.
We have 4 coils that fire in "waste spark" mode. So even tho we have 4 times as many coils as an LT-1/L98 motor, the coils fire only half as many times as a single coil, not 1/4. One coil per plug means one coil's full power per cylinder, therefore longer dwell times for charging the coil, ie more power. More power equals better burn on less fuel. Now instead of our coils which fire twice per revolution, imagine a coil only needing to fire once. The coil has twice the amount of time to fire and at 7000rpm, time is something that is very valuable. CnP also minimzes the resistive losses due to the length of the conductor. Higher voltage, hotter spark and more accurate timing. Less advance needed. My blue car only ran for about 30-45 sec with CnP but the idle was noticeably smoother and quieter.
Basically what GM did with CnP was eliminate the need for an ignition module. The tasks the module performed were distributed between the
coils and the PCM. The PCM determines the firing order, the coils manage the actual firing (which in the LT-5 is done by the IM). The 24 tooth reluctor provides nearly 3x better timing resolution than our reluctor.
Obviously with what Jerry has, someone was thinking it could be a better alternative.

[VetteVet]

Well said, Dominic!!

[Tyler Townsley]

Originally Posted by VetteVet

Paul,
.

I've been looking at this for the last couple of weeks and it looks really promising. If we could only get past the 16 injector issue, this would be a no-brainer for me.

Jep

This a non issue, pull the secondaries and fire them togeather. Thats what I do with a stock ecm and no secondaries.

Tyler

[-=Jeff=-]

Well doesn't the Stock Ecm have all the injectors on 8 ports anyway? the injector modules allow to run 16 injectors but I believe the Ecm has only 8 outputs

Also keep in mind if you solve the issue of running a LT5 with a LSx PCM. you also need to make the CCM happy

[VetteVet]

Tyler,

I have done the secondary delete. Are you running all 16 injectors at idle? I was under the impression that pulse widths got too short at idle to fire all 16 injectors reliably enough for smooth idle.

Also, I'm not sure that the 411 injector drivers could handle the current required to drive two injectors per driver, which could mean an add-on driver circuit to handle the exra current.

I think that the mods could be made to the 411 code, the hard part is getting the code hacked. I've started disassembling it, but it's a lot more complex than the P4 code.

One interesting note: the Motorola 68332 processor has table lookup instructions as part of the instruction set. Instead of having to execute a routine for lookups, it just takes a couple of instructions to load the registers and then execute the lookup instruction.

The 411 PCM code has adaptive octane control with high and low octane spark maps with interpolation between the two. The PCM basically maintains an effective octane rating variable that is used for the interpolation between the two tables. It also has shift light control that can be set independently for each gear. All of the tables extend up to 8000 RPM. It also uses an adaptive idle strategy, although I'm still trying to figure out exactly what that is.

The really cool thing is that the code is divided into segments. My understanding so far is that segments can be mixed and matched and features can be turned on and off. If you want air pump functionality, click the mouse and you have it. If you don't, click the mouse and that code is not executed. If you're using electronic throttle, click and it's turned on in the code. Cable throttle? Click and those routines are made active and the electronic throttle routines are disabled. The alternator excitation can be controlled by the PCM if you enable it. The alternator is de-excited at WOT to make the extra power available.

I've just started digging into the 411 PCM, but so far I'm pretty impressed.

[XfireZ51]

Originally Posted by -=Jeff=-

Well doesn't the Stock Ecm have all the injectors on 8 ports anyway? the injector modules allow to run 16 injectors but I believe the Ecm has only 8 outputs

Also keep in mind if you solve the issue of running a LT5 with a LSx PCM. you also need to make the CCM happy

There are only 8 injector drivers. Remember the LT5 code is a derivative of the L98. GM didn't move on to the 2nd Gen LT-5 because of the need to develop and certify a new ECM and code.
The firing for the secondaries is piggybacked from the primaries with the power for the secondaries provided thru the secondary relays. The secondaries shut off at 0 throttle and use the VE Port Closed tables at that point. You can see that in a data log with the ECM switching from Port Open to Port Closed.
By the way that goes for the SA tables as well. And then there is the question of the CCM.

[-=Jeff=-]

Originally Posted by XfireZ51

There are only 8 injector drivers. Remember the LT5 code is a derivative of the L98. GM didn't move on to the 2nd Gen LT-5 because of the need to develop and certify a new ECM and code.
The firing for the secondaries is piggybacked from the primaries with the power for the secondaries provided thru the secondary relays. The secondaries shut off at 0 throttle and use the VE Port Closed tables at that point. You can see that in a data log with the ECM switching from Port Open to Port Closed.
By the way that goes for the SA tables as well. And then there is the question of the CCM.

Okay..

my point was is that couldn't those 2ndary driver modules be used with the LSx PCM?

[A26B]

If 16 injectors are a problem, why not just ditch 8 of them and simplify?
Here's a solution, work-in-progress......

[XfireZ51]

Originally Posted by -=Jeff=-

Okay..

my point was is that couldn't those 2ndary driver modules be used with the LSx PCM?

Yes but you still need to have 2 sets of VE and SA tables to do that. One way of having both injectors operate constantly, including idle, and still have a controllable pulsewidth would be to vary the fuel pressure. That would eliminate the need for the Port Closed tables but then you would need a regulator that varies pressure and some code to deal with the changing the variable base pulsewidth constant similar to what EBL (www.dynamicefi.com) does now and what I believe the C6 ZR-1 also does. The 2nd Gen LT-5 was going to use single injectors and I wonder if Lotus was thinking along those same lines?