HOZZ4

Here's some info for people looking for the Northstar coilpack setup. By the way, the term "coilpack" refers to the 4 ignition coils and the base to which they are attached (which also happens to be the ignition module).

10458128 - Northstar Ignition Module
19056672 - Coil for Ignition Module (4 req'd)

As for the applications using these ignition modules & coils, look to 94-98 Cadillac Northstar and Olds Aurora V8 vehicles.

Pete

HOZZ4

Tom,
The ignition wires are custom-made by a major supplier for us. We have literally hundreds on the shelf, and they are available to re-order after they wear out. Price is $50 list, but $42.50 until we get a dealer network built.

By the way, I have pic's of an installed coilpack on a 1996 Vette if anyone is interested.


Pete


[IMG][/IMG]

ninetyfivevette

I'd love to see some pics!

Tom Piper

Hey Pete

By now, you probably think all I do is ask questions -- thanks for all the answers.

I'm sure you have a dependable product, but there is always a chance of a failure somewhere -- could even be my fault installing it.

My question now deals with diagnostics.
Correct me if I am wrong. As I see it, for the stage 1 product, there are really three systems here:
1) The OEM Opti-Spark optical signals -- the low-res and high-res pulses.
2) Delteq's "box" to decode the optical signals and enable the correct NorthStar ignition coil for the OEM EST signal to fire.
3) The NorthStar coil pack (this consists of a coil module and four coils).

It seems to me, the OEM ECM's diagnostics (trouble-codes) can still be used to determine if there is a problem with the Opti-Spark low-res or high-res pulse.
But, if the Opti-Spark signals are OK and I don't have spark, do you have any built-in diagnostic capabilities -- like LEDs to show pulses exist, etc?

I can see a need to determine if the problem lies in the NorthStar module or the Delteq box. I have a Corvette shop manual but not a Caddy or Olds.
For someone like me, that has an electronics background and test equipment (including multi-channel and storage O-scopes), it would be nice to have test points and what is expected at those points. Any diagnostic instructions would be a plus.
This is not something the average GM dealer's shop is going to know how to handle.

Tom Piper


[Modified by Tom Piper, 10:23 PM 12/12/2003]

Tom Piper

Hey Pete

Looking at the pictures of the installation that were recently posted reminded me of something.

The '92 to '96 Corvette has a tachometer and ASR (traction control) that needs a tach signal input.
The '96 has a dedicated square wave tach output signal from the ECM to drive the tach and ASR.
I don't know what year the change was made, but the '92 is different than the '96. The '92 derives the tach signal from the negative terminal of the OEM single coil. This signal goes through a tach filter that is part of the wiring harness to filter out the dampened oscillation from the coil and create a smoother square wave signal to drive the tach and ASR.

Any multi-coil setup is going to have to supply a composite tach signal to drive the tach and ASR on the '92. I'm guessing that the NorthStar coil driver module has a tach output signal. And, I'm guessing that that signal is a conditioned square wave. If this is true, that square wave signal is going to have to be connected after the tach filter in the wiring harness by the installer. I don't know of any existing external connection after the tach filter. It seems to me, this part will not be plug-and-play.

Any comment in this area?

Thanks


Tom Piper

Tom Piper

DOCTOR J

I seem to remember you mentioning the NorthStar system.

I don't have any information on that.

Does the NorthStar coil-pak have a tachometer output signal?

Thanks


Tom Piper

HOZZ4

Tom

Sorry I didn't answer your questions sooner. For the tachometer questions, I will sum it all up by saying that the tach and ASR work perfectly on both early and late coil LT1s. We actually custom-molded our own early LT1 coil connector to tap into the tach signal on these cars (no cutting/splicing the harness)! This item is included in the kits.

For the diagnostics, you are correct in saying that there are three main elements to the system.
1. a pair of Opti-Spark signals
2. our "Opti-Box" which mounts in place of the coil
3. the Northstar ignition module.

Your normal diagnostic methods will tell you if the opti spark signals are good. This would be check engine lights, trouble codes, or handheld diagnostic tools.

Our unit has a diagnostic LED (blue!) to tell you things about its status.

To diagnose the Northstar ignition module and coils, you basically approach it just like the LT1 ignition module and coil...except multiply it by 4! Just like every other ignition module and coil system, you basically diagnose it by seeing if it has:
1. Power
2. Signals
3. Spark
Since determining whether or not it has power and spark is easy, the only "hard part" is seeing if it has the proper signals going into it. Since this is a "higher level" diagnostic, I have not included it in the first revision of our manual. However, I will supply this info on demand. I will likely include it in the next manual revision as well.

Pete

DOCTOR J

Tom-
Thought I referred you to this info before - there is a long thread on
the TGO site about the Northstar unit:
http://www.thirdgen.org/techbb2/show...hreadid=193531

If not, the signal definitions I have are here:
http://temp.corvetteforum.net/c4/doc.../nstarsigs.jpg

There is a 4X ref pulse shown from the N* ICM to the ECM, but no
tach signal as such. Old tachs were typically driven by 12v.

At first blush, I'd say: If you want a tach drive off the N*, you will
need to grab the 4X ref pulse(5v), & buffer it so you have an
isolated signal, then use that to drive a 12v tach.


Hmmm, now that you mention it, you make a good point -
if I convert my L98 to a N* I'll still need an analog signal to
drive the tach and my data logger... Hadn't thought about
that. Adding a buffer shouldn't be a big deal, but I'll need to
look into it further...

Good catch.

DrJ

Tom Piper

Pete

Thanks again for all the information, sounds like an excellent product.

These questions are really unnecessary, but I am curious.

It appears that the Delteq "box" converts the Opti-Spark low-res and high-res pulses to the two crankshaft pulses and the one camshaft pulse that the N* module expects to see.

From the literature on the N* module, it sounds like it has a built-in "limp home" mode.
I believe this is supposed to allow the vehicle to still run if the EST signal is missing from the ECM. I would imagine it substitutes a triggering signal with a set advance.
I don't see why it wouldn't; but, does this function still work with your system?

I know this part really wouldn't be necessary (in fact, it could be called "nit picking"), but would be a nice feature.
I've never tried it, but the OEM LT1 system is supposed to still run with the Opti-Spark high-res pulse missing (at reduced performance).
How would this affect the Delteq conversion?
I imagine this is controlled by the Northstar module and how it responds to the signals.

Thanks

Tom Piper


[Modified by Tom Piper, 7:20 AM 12/18/2003]

MyX10sion

Any pictures yet? I think my Opti is going out and I may need this!

TIA

ericcer

Sorry I started a new thread a while ago. Search on Delteq and you should see the full thread. I included the pictures from that thread here.


Delteq module http://temp.corvetteforum.net/c4/ericcer/delteq01.jpg

Passenger side view http://temp.corvetteforum.net/c4/ericcer/delteq02.jpg

Coils closeup installed http://temp.corvetteforum.net/c4/ericcer/delteq03.jpg

Components minus Delteq module - uninstalled http://temp.corvetteforum.net/c4/ericcer/delteq04.jpg

Driver side view http://temp.corvetteforum.net/c4/ericcer/delteq05.jpg

SonnyinVA

i have a 96 with the crank trigger, and because i'm putting out well over 500hp i had my hub and balancer spin on the end of the crank, so i got it keyed.

so, is there a better option for me since i have the crank trigger and a keyed hub??

are you guys going to offer an improved opti-spark housing to use with the stage 2 kit? maybe something like a billet housing.

i hate to sound like a dummy, but i have no electrical background so can somebody explain in simple terms how much improvement this kit will make? for example, what kind of effect does this kit have on upper RPM limits? what kind of effect on power?

thanks!!

HOZZ4

Sonny,

Right now, we do not have a crank trigger option. Regardless of whether we came out with one or not, you will always need some sort of cam sync to run the LT1 fully sequential on the fuel. And no, we do not have an upgraded Opti housing either.

Basically, the main advantages of our stage 1 system are:
1. Elimination of cap and rotor wear, and the crossfiring that sometimes takes place on high-load engines (especially with Capacitive discharge ignitions).

2. High energy ignition without any coil dropoff. Even the fastest spinning LT1 doesn't even come close to causing a lack of coil charge time, since there are now 4 coils. In plain English, our system will provide full spark energy past 15,000 rpm.

3. Taking the cap and rotor out of the Opti tends to prolong the life of the sensors. The lack of possible high-voltage arcs into the sensor, and the lack of ozone buildup probably play the biggest role in helping the sensors live longer.

As for our stage 2 kit, we will be able to completely replace the stock sensors as well...stay tuned for that one.

Pete





[Modified by HOZZ4, 9:56 PM 12/30/2003]

steelwindmachine

this sure seems very similar to Bob Bailey's LTCC LS1 coil conversion which has been out for a while...

from: http://www.turbocharged.net/twinturbo/

Installed Pics: http://turbocharged.net/twinturbo/rebuild2003/ltcc/

Over on the Turbo Buick side of the fence, he's invented the Translator, Scanmaster and Extender chips ...

The Delteg system looks great too :) Nothing better then some competition :)

I work at Dynotech Performance in Manville, NJ ... we do quite a bit of work on the LT1 vehicles, we carry Bob's stuff, but we'd be interested to get more info on your products too.

Can you email us info? eric@dynotechperformance.com

check out our site to see what we do: http://www.dynotechperformance.com

also, take note everyone, these guys really are cool, taking the time, at length, to explain everything about their system. no big mysteries about the money you're spending on what could be considering a "black box".

Excellent customer relations :)

ericcer

I don't know why someone would consider the LTCC a "plug and play" system because you have to fabricate the coil brackets and I have heard that wires can be long on the Vette. When I installed the Delteq system it came with everything I needed and it took about 3 hours to install.

I like the LTCC system and it certainly can look really cool once installed but it is certainly takes a lot more time to get it hooked up and looking professional.

SonnyinVA

thanks for the answer, and that leads to my next question... i don't ever plan on spinning 15,000 RPM, so at what point does the stock opti and coil start having coil dropoff, and how can i be sure that i am having that and that it is what is causing my high rpm scattering in my dyno graph? is it basically a change-it-out-and-see-if-it-goes-away kind of thing?
thanks again,
sonny

Tom Piper

The articles I've read say the stock single coil systems start dropping off at about 3K rpms. But, the stock system is capable of reliable ignition up to about 6K rpms on a reasonably modified engine.

Tom Piper

HOZZ4

Basically, the point at which a stock ignition starts "falling off" is fairly easy to calculate...if you know how long it takes a coil to saturate. For ~most~ late-model GM coils (such as the 2nd design LT1 coil), the charge time to saturation is somewhere in the 2.0-3.0millisecond range.

So what is saturation? Basically, when you plot coil current versus time, you get a diagonal line from 0amps to "x" amps, and you typically turn off the coil at "x" amps. The "x" is the point at which the line begins to go vertical rather than diagonal. At this point, continuing to input more charge to the coil is simply not adding more energy...the coil is "fully saturated." Most modern low impedance coils saturate somewhere between 5 and 10 amps of current.

Back to the question at hand, if it takes between 2 and 3 milliseconds for an LT1 coil to saturate (let's say 2.5ms for this calculation), the coil will experience a decrease in charge time starting at about 6000 rpm. This is because it takes 10 milliseconds for one engine revolution at 6000rpm, and the coil needs to be charged 4 times during this period. (10/4 = 2.5ms).

If the coil currents start falling too much, a noticable drop in spark energy will be realized. The decrease is most noticable under high load situations because it takes a lot of voltage to jump the spark plug gap and a high amount of current to maintain the arc.

I don't remember the exact numbers that the LT1 coil uses for saturation. If memory serves correct, the early one was over 2.5ms, and the late coil was slightly less than 2.5ms. I will throw an oscilloscope on my car one of these days and report back...

-Pete



[Modified by HOZZ4, 9:26 PM 1/2/2004]

DOCTOR J

It's been a lot of years :) since I had a EE course, but I use this (simplified) equation to look at
coil saturation - which makes it a function of the variables below:

[ t = - LN(1 - (IR/V)) * (L/R) ]

where t = time
LN = Natural Log
I = current (pick a max value)
R = coil primary resistance
V = Voltage (can vary, especially during starting)
L = coil primary inductance


It seems to match up pretty well with the simulator here:
http://www.bgsoflex.com/igncoil.html

However, if there is a better way to evaluate Coil sat I'd be inetersted in seeing it - I know
that equation has no allowance for coil capacitance.

And, if you are going to be running your O-scope, I have been meaning to measure the
current limit built into a GM 7-pin HEI module, and the newer LT4 module. Could you
measure those too? I'd be interested in seeing the result.


FWIW, I'd take the benefit of multi-coil ignition to be both the increased time available for
saturation, as well as eliminating the (second) arc in the distributor housing. That arc
elimination by itself probably doubles the efficiency of the Kettering-type design, and I
presume does good things for spark latency.

DrJ

Tom Piper

Although I don't think either is detrimental, it would be interesting to see a comparison of the losses between the distributor arc and the "waste spark" of the cylinder on the exhaust stroke.

Tom Piper