LT5 Ignition Systems Question??? - ZR-1 Net Registry Forums

Blue Flame Restorations · 02-26-2011

Hey guys, let's get Ron Wozniak involved here.

Here's the ???

How can we update the ignition system for a coil to plug (LS) type system?

It would be nice to update the technology with modern day parts that are accessible and may help to aid in HP gains.

Here you go, Ron!!!
Thanks!
Brett

Tyler Townsley · 02-27-2011

Can a Northstar dis module be used in place of the LT 5 dis module? Can the LT 5 dis module be rebuilt? If so how do you get it apart. I understand you have a lt 5 module with the cover off? Can you post a picture of it?

Tyler

LGAFF · 02-27-2011

What was the DIS system used on the two motors that were built to solicit potential business from Bentley/Rolls Royce? My undestanding was that it utilized a crank trigger system.

LGAFF · 02-27-2011

Well since the engine is gone, I will let the cat out of the bag. If you recall a motor being sold in MI recently....well a few weeks after it went up for sale, I bought the Thunder at Stillwater video. Amazing there was the gloss black engine shown during the plant tour, grey plug wires and all. I contacted a workers at Mercury and it was a test engine for a possible outsourcing of the LT-5 to Rolls, there was one other built with a crank trigger, and that was it.

Engine has apparently sold

XfireZ51 · 02-27-2011

Quote:

Originally Posted by todesengel

I found a more recent posting explaining the cop conversion on the 4g63. Just a little food for thought.

http://www.dsmtuners.com/forums/arti...tall-pics.html

Were it only that simple.

tomtom72 · 02-27-2011

I know I really don't belong posting in this thread because I don't understand this ignition stuff. I would like to ask a couple of questions. I'm sorry to clutter up this thread.

Why do we need to consider reconfiguring our OEM ignition system? Strictly because our parts are NLA, and no one is able to repair our OE DIS boxes?

Does a COP system allow tuning latitude specifically for ignition events? Our system does not allow any type of ignition tuning, right?

See how much I don't know! Sorry guys.

TIA

Tom

tomtom72 · 02-27-2011

Thank you Rob.

I am a bit less in the dark now. I wonder if in the LT5 application that our system was easier and less expensive to do than a COP system. I'm wondering if combustion chamber design, our vs the LSx motors', indicated that an LT5 could get away with using a waste spark system and not suffer?

Okay, I ask too many questions because I don't really get electronics at all. Sorry all.

Thank you for helping me to gain some knowledge!

XfireZ51 · 02-27-2011

Rob,

I was commenting on the article for comverting the Toyota motor you posted.
The issue that I and several others found is that the LT-5 ignition module acts more like a. co-ECM. It has it's own processor. Remember that the LT-5 ECM code is really a modified L98 code. Do with 8 injector drivers, they adapted it to run 16 by powering the secondaries thru the secondary injector relay. The primary injector provides the firing signal and so they fire in tandem. The L98 code assumes a distributor. That's why the crank signal feeds the ignition module and not the ECM. So we believe that parameters like coil dwell time are managed by the ignition module. The LSx coils have the PCM providing that control. These are the things that have me excited about LT5Ignition coming on board.

XfireZ51 · 02-27-2011

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.

LT5 Ignition · 02-28-2011

Hey is there a time limit for once you start writing? I just wrote about 5 paragraphs trying to help answer some of the questions and when I hit submit it said I was logged out and I lost the message.

Here is a shorter version:
If someone wanted to go to a coil per cylinder system like a Gen3 small block LS1, here are some challenges I can think of. The LT5 ECM is designed to receive a 4 ppr digital input REF for engine position sensing. It outputs a single 4 ppr EST signal that is pulse width controlled for coil on time (Dwell time) and phased for spark timing control. The ignition module is the go between that receives the 9 tooth VR signal and creates the REF signal.
It also receives the EST signal and splits it into 4 coil primary current drivers.

The Gen3 small block ECM receives a digital crank position signal and outputs 8 separate EST signals directly to Coils with internal drivers.

02-26-2011	#1
Blue Flame Restorations Join Date: Feb 2010 Location: Pendleton, IN Posts: 3,904	LT5 Ignition Systems Question??? Hey guys, let's get Ron Wozniak involved here. Here's the ??? How can we update the ignition system for a coil to plug (LS) type system? It would be nice to update the technology with modern day parts that are accessible and may help to aid in HP gains. Here you go, Ron!!! Thanks! Brett __________________ 1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project

02-27-2011	#2
Tyler Townsley Join Date: May 2005 Location: Nichols, FL Posts: 615	Re: LT5 Ignition Systems Question??? Can a Northstar dis module be used in place of the LT 5 dis module? Can the LT 5 dis module be rebuilt? If so how do you get it apart. I understand you have a lt 5 module with the cover off? Can you post a picture of it? Tyler __________________ 55 Polo White (Project) 61 Jewel Blue (Sold to buy above) 66 Nassau Blue 68 Torch Red 88 ZR1 Blue 90 ZR1 White

02-27-2011	#3
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: LT5 Ignition Systems Question??? What was the DIS system used on the two motors that were built to solicit potential business from Bentley/Rolls Royce? My undestanding was that it utilized a crank trigger system. __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

02-27-2011	#4
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,194	Re: LT5 Ignition Systems Question??? Well since the engine is gone, I will let the cat out of the bag. If you recall a motor being sold in MI recently....well a few weeks after it went up for sale, I bought the Thunder at Stillwater video. Amazing there was the gloss black engine shown during the plant tour, grey plug wires and all. I contacted a workers at Mercury and it was a test engine for a possible outsourcing of the LT-5 to Rolls, there was one other built with a crank trigger, and that was it. Engine has apparently sold __________________ LGAFF 90 #966-150K miles-sold 92 #234-sold 1987 Callaway TT #17 1991 ZR-1 #1359

02-27-2011	#6
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: LT5 Ignition Systems Question??? I know I really don't belong posting in this thread because I don't understand this ignition stuff. I would like to ask a couple of questions. I'm sorry to clutter up this thread. Why do we need to consider reconfiguring our OEM ignition system? Strictly because our parts are NLA, and no one is able to repair our OE DIS boxes? Does a COP system allow tuning latitude specifically for ignition events? Our system does not allow any type of ignition tuning, right? See how much I don't know! Sorry guys. TIA Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

02-27-2011	#8
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,696	Re: LT5 Ignition Systems Question??? Rob, I was commenting on the article for comverting the Toyota motor you posted. The issue that I and several others found is that the LT-5 ignition module acts more like a. co-ECM. It has it's own processor. Remember that the LT-5 ECM code is really a modified L98 code. Do with 8 injector drivers, they adapted it to run 16 by powering the secondaries thru the secondary injector relay. The primary injector provides the firing signal and so they fire in tandem. The L98 code assumes a distributor. That's why the crank signal feeds the ignition module and not the ECM. So we believe that parameters like coil dwell time are managed by the ignition module. The LSx coils have the PCM providing that control. These are the things that have me excited about LT5Ignition coming on board.

02-28-2011	#10
LT5 Ignition Join Date: Feb 2011 Location: Sterling Heights, MI Posts: 11	Re: LT5 Ignition Systems Question??? Hey is there a time limit for once you start writing? I just wrote about 5 paragraphs trying to help answer some of the questions and when I hit submit it said I was logged out and I lost the message. Here is a shorter version: If someone wanted to go to a coil per cylinder system like a Gen3 small block LS1, here are some challenges I can think of. The LT5 ECM is designed to receive a 4 ppr digital input REF for engine position sensing. It outputs a single 4 ppr EST signal that is pulse width controlled for coil on time (Dwell time) and phased for spark timing control. The ignition module is the go between that receives the 9 tooth VR signal and creates the REF signal. It also receives the EST signal and splits it into 4 coil primary current drivers. The Gen3 small block ECM receives a digital crank position signal and outputs 8 separate EST signals directly to Coils with internal drivers.