LT5 Ignition Systems Question???

[XfireZ51]

Rob,

I was commenting on the article of COP conversion for the Toyota motor not on what you plan on doing. eficonnections provides a complete conversion for both early and opti-spark motors for conversion to CNP.
The LT-5 ECM code is a derivative of the L98 code. So no secondary injector drivers, no ignition coil controls. That's why the secondary injectors have their own power thru the 2ndary injector relay and are triggered by the primary injector. The L98 assumes a distributor. So it handles timing but not much else. The LT-5 is a more intelligent ignition module acting almost as a co-ECM.
That's why the crank signal goes to the IM and not the ECM. The IM has it's own processor. So we believe parameters like coil dwell are embedded in the IM firmware. That's why I am excited to have LT5Ignition on the forum. Maybe he can shed some light on this whole topic.

[Tyler Townsley]

Originally Posted by todesengel

. It would still be a batch fire, but would allow changing the control module. .

It is not a batch fire system. The efi is sequential and spark is wasted spark.. The lt 5 ecm/dis is a little more advanced than you give it credit for. The ecm code is not just modified l98 code, it is far more flexible and with Tod Ps definition files there is no need for any other ecm system up to about 600 rwhp. The turbo applications use an additional fuel injector with a link setup but it is fuel only. There is no reason to change out the waste spark method. Besides if you go cop you clutter up the best looking underhood engine out there.

The issue is the dis module. It is sensitive to heat and if installed without the correct grease it will overheat and fail. I have 3 dead modules and if we could get a rebuild capability it would sure help those who discover the hard way that the correct grease matters.

With Moats tuning aids and current software you can tune on the fly.

Tyler

[tomtom72]

Tyler, the FSM says if you r&r the DIS to use di-electric grease as the heat sink interface. What is the correct grease to use?

I was thinking that the same grease that is used to bed a PC's processor to it's heat sink would be a better choice than di-electric grease?

TIA

Tom

[Tyler Townsley]

Originally Posted by todesengel

I never said the injection was batch fire. If you read my post you will see batch was thrown in with wasted spark talking about the ignition. In some circles you will hear batch thrown in with wasted spark, which is why it was placed there, but I never once said the injection on this motor was batch.

The system may be more advanced than credit given I suppose, but it is also overly complicated, and does nto seem very flexible, imho.

So you are saying there is no benefit from an upgrade to the ecu in this car?

Batch fire applies to fuel, it means all the injectors fire at once, it does not apply to spark. So when you used it I assumed you were refering to fuel. EFI is inherently complicated or sophisticated depending on your point of view. A lt 5 in stock or modified form to about 550 rwhp will not benefit from another fuel/spark system. You need the right tools and an understanding of the tuner definition files, no small task but there are a couple of folks on the forum who have mastered this tuning and can do a calibration quickly and accurately.

Tyler

[Tyler Townsley]

Originally Posted by tomtom72

Tyler, the FSM says if you r&r the DIS to use di-electric grease as the heat sink interface. What is the correct grease to use?

I was thinking that the same grease that is used to bed a PC's processor to it's heat sink would be a better choice than di-electric grease?

TIA

Tom

There was some discussion about this in the past and I think we decided you are correct. We felt the FSM referred to the wrong stuff. What is needed is a substance the conducts heat to the plenum where the incomming air cools the plenum base and indirectly the module.

Tyler

[Tyler Townsley]

Originally Posted by todesengel

Once this car is complete I am taking it down for a day with Corey, and we are going to test it in a lot of different configurations. We are going to test it from stock all the way down to the plenum, tb, and airhorn to ported plenum, ih's, tb, air horn, headers, etc. I have a egt in each runner, as well as multiple temperature sensors. It should result in some useful information, no matter which side of the fence you are on.

If you get the chance take a tuning ride with Cory in a stock ecm car and his tuning equipment and software. I believe he used the stock setup in the Bonniville car and did not run into problems until trying to get the last 2/3 mph to break the record. I think it was about 650-700 rwhp at 7900-8000 rpm where the ecm momentarly reset for some reason we still do not understand.

EGTs are good but a wideband is better.

As a side note Jerry Watts said they had an efi system in the early 80s that had the same afr for all cyl but a new manager did not like its looks and stopped development and went to the 'tuned port' setup that never achieved what they were able to do with the earlier setup.

Tyler

[Blue Flame Restorations]

I just emailed Ron Wozniak. I'm in Little Rock, traveling from SW TX. Picked up a 35 Auburn Botattail Speedster to retsore this year.

Hopefully, Ron will login to this discussion.

[Hog]

Originally Posted by Tyler Townsley

If you get the chance take a tuning ride with Cory in a stock ecm car and his tuning equipment and software. I believe he used the stock setup in the Bonniville car and did not run into problems until trying to get the last 2/3 mph to break the record. I think it was about 650-700 rwhp at 7900-8000 rpm where the ecm momentarly reset for some reason we still do not understand.

EGTs are good but a wideband is better.

As a side note Jerry Watts said they had an efi system in the early 80s that had the same afr for all cyl but a new manager did not like its looks and stopped development and went to the 'tuned port' setup that never achieved what they were able to do with the earlier setup.

Tyler

I believe there are other parameters other than WOT power that could benefit from a more modern processor. Driveability being one. The LT5 was ahead of its time so far as part/WOT transitioning, esp. controlling the 8, then 16 injectors.

I do agree that there is not much to be done ignition wise, or fuel wise when talking about WOT power. The WOT tuning is the "easy" part.

I am wondering if you could eliminate, the secondaries (easy enough) then simply plug the injector holes in the injector housings and fuel rails. The use a larger injector to compensate, with a more modern ECM/PCM, heck you could even incorporate a MAF.
These MAF react better to mods than speed-density does.
I'm just thinking aloud.


EGT's are just another way of determining the a/f ratio of a cylinder. I would rather have a thermocouple in each cylinder's exhaust than a wideband O2 sensor in each bank, esp. if I have a means of adjusting a/f ratio's on a cylinder per cylinder bases.


Todesengel, I understood what you were meaning about the "batch fire" ignition comment.

peace
Hog

[Tyler Townsley]

Originally Posted by todesengel

Tyler,
I have two wide band's, and two narrow band sensors placed in the headers as well, at the collector area. The haltech can use this information to adjust the afr to keep it's set target. The egt sensors are to give me a cylinder by cylinder breakdown of what is happening throughout the process. This will illuminate the design flaws, if any, with both the stock, and dropped/siamiesed plenum. I am interested to seewhich cylinders are getting more airflow depending on plunum used. I plan to use this information to fabricate my own plenum when I go tt.

I have the same. According to the Lotus engineers the most compromised part of the stock plenum is the placement of the injectors. Cory relocated/changed this on the Bonniville car and should be able to give you valuable pointers on what changes work and which do not. You want to make a plenum? Take a Mustang GT 500 s/c and graft it to the lt 5 plenum THAT would be real HP improvement.

My current project is putting a 2001 lightning motor in a 65 fairlane. Got it positioned and it will require some slight hood modification.LOL

Tyler

[Tyler Townsley]

Originally Posted by todesengel

I think we are all on the same page now. I do not mind being slapped around when I cannot articulate myself properly. I am typically rushed when I post, and my brain runs faster than my fingers can type.

Sorry if I was a bit short. These posts are read by a lot of people who do not have a grasp on the correct terminology and it was more an attempt to keep it straight in thier minds. I agree with your assement of MAF vs MAP.

Tyler