GM High Tech Performance
Nov 04
Pg 50

Interesting article about a *Delteq* igniton system for the LT1s.

The unit replaces the Otpispark with DIS.

The neat feature is this DIS module just uses the EST signal to fire the coils, and does it's own dwell calculation so that the coils don't run out of dwell time at higher RPM.

Related other reading.

http://www.jpteck.com/efi/northstar/
http://www.jpteck.com/efi/images/lt5_dis.jpg

Dr Jacobs Book on Igntion system is also a good read.

Then once you get the spark really good, you might be able to lean out the fuel some.

 

I've been eyeballing that Delteq system, myself. I'm thinking maybe use that setup with the vortec truck stuff? I know it wouldn't work as is, but shouldn't be that difficult to overcome, due to the signals, but the basis is there.....

Then, too, I haven't given up on the N* system with my own custom made trigger wheel....

 

It makes sence, hot spark can ignite a lean AFR. What would be nicer is a spark that jumped to the piston tops and had adjustable dwell (F1 is cool).
I bet running a lean cruise would be safer with the stronger spark.

 

Saab tried the spark to piston idea.
Downside is the spark liked to *find* ground thur the rings to cyliner bore, bore erosion was the reported problem.

Yes, if it meant reducing the advance needed.

 

What about said "Bailey Box" like Scott had on his Impy SS at the POW WOW's?

Wasnt that how he converted his LT1 to coil on plug?

later
Jeremy

 

That seems like what the obvious result would have been anyway.


-- Joe

 

F1 doesn't even use head gaskets so I'm sure their engines go through a rebuild often enough to not worry about the bore.
That's interesting that it would destroy the bore over time, I can see it happening but seems pretty extream considering spark plugs can last over 100,000 miles with smaller electrodes.

 

The electrodes are extremely non-erosive.

On a side note, the Audi Lemans engines are run on a dyno simulating Lemans, for 24 hours, then packaged up and sent to the track to be run in the race cars. Nothing is touched from the time they leave the dyno to when installed in the car.
Talk about a break-in........

Doc says it was his idea, going back to his original patents. But noone seems to be able to find any of his *alledged* patents.

PSS Happy's finger nails are growing in nicely......

 

Bruce?

What was Scott running on his Impala to go to the LS1 coils?

He had 8 individual coils when he drove it out there?

later
Jeremy

 

Bailey Box.. Bob

 

Shoot, I have four hand held fazers's here and can't find two more. Well, some day. . .

RBob.

 

Also known as the LTCC. My Impala has one too. I've been more than pleased with the results.

Bob Bailey once mentioned the idea of doing a "universal" version -- hopefully he hasn't forgotten about that.

 

Small or large connector?.
Doc

 

All he needs is about 49 hours a day.

The *big* thing nowadays for alot of projects is making it completely plug and play and still being able to make something on it. There seems to be alot of *stubborness* about learning to solder. The harnesses for the eDist and the like are just real stoppers for some items making it to market.

According to Doc

 

That's the reason I don't want to go any further than getting the N* DIS working for MY car, and letting others know how *I* am doing it. It also keeps from having legal issues, etc.....

 

I'd be happy with 36 hours. Send Bob to the north pole and I'm sure he'll find 49 hours of sunlight .
Honestly I'd be more than happy with a universal wasted spark DIS that used only a crank position sensor. That would be plenty of spark for a turbo charged V8.
I haven't asked this before but what are some cons associated with wasted spark? We run it on our little 4 cylinders at 15000rpm without a problem (COP though).

 

With a conventional dissy, you can set the min firing voltage with the air gap in the cap/rotor assembly. That means that on a cold start you guarantee a min firing voltage to keep the plugs clean. It's easier to foul a plug on DIS in cold weather. Emissions wise, you have to spin the motor over more, and risk a heavily rich startup. While on a dissy engine you can light the timing and fuel on the first DRP if you want, on a DIS car if you start the fuel on the first DRP you might have 2 revolutions of fuel puddling before any spark. You can see now, why DIS was rather late in coming, the expense in the electronics had to be justifable. And why the new stuff all does just about instant recognization for figuring out which cylinder to fire.

 

That (Rotor gap making a min firing voltage) makes sense why I've seen some DIS cars get towed into the shop in cold weather as a no-start. Throw plugs in it, and everything's fine.

On a DIS car, how can it send a DRP to the ECM if it doesn't even know when to fire? Example, the 4cyl/V6 trigger wheel. It has to make it to the 10* notch before it knows where #1 is, therefore it has no idea of which notches to look at, since it doesn't use them all. Not doubting what you're saying by any means, just trying to further understand the system!

 

Sactly.

As long as it's seeing a change at the cranksensor end, it knows the engine is spinning. While the timing is internal to the module below ~375 RPM, the ecm still needs to be able to count DRPs to figure out when to start pulsing (as well as a host of other things) the injectors.

 

Have a look-see:

http://picasso.org/mjlj/

Warning!!! Uses ford parts

 

That site is a stand alone device which means you can't use the GM knock sensor, maps, or any of that cool jazz. Instead you have a stand alone system that as it's name states, stands alone. That's why I wouldn't even consider it. Now if I were good at electronics I'd convert the GM voltage output (spark advance) to a pulsewidth signal to use the Ford edis, but I regress in my inability to design said circuit... .
In anycase I guess going with a CNP setup is all around a better idea, I just figured wasted spark would have been a happy medium.

 

Interesting. I noticed a post about using a makeshift crank trigger. Would something like an MSD flying magnet trigger work in an application like this? Wouldn't that be able to provide a pulse to the ECM to fire the correct coil pak?
Am I smoking crack?

 

It just needs to be able to interupt something like this.

http://www.jpteck.com/efi/northstar

 

So it looks like you could run the Lt5 DIS with a stock f-body ecm?! yes/no ? The DIS module, wheel, and sensor look like the only things that would be required?

 

A) The code's the same in the DIS to Distributor coded, in at least what I've found.

B) Yes, once you install everything, you've taken care of the hardware.

The ignition stuff all **seems** to be compatible, once you know what your looking for. ie like putting the late Quick Start set up on my GN. They inverted the shutter windows, but with using the correct module, it all worked. Not mention tracing back the history of the cam sensors/ecms to see if things were actually functionally the same.

 

The only downside I can see to the LT5 stuff is price and availability. The Northstar stuff is going to be more available. I can get the N* crank sensors for around $35 each (uses 2, will run with 1) The modules and coils can regularly be found on ebay for around $100 all together. I'm going to pick up a crank sensor soon to do more work on my bracketry. I still need to get some dimensions from a N* crank trigger wheel to make sure mine will work with the notch sizes I have used. Once I get more info, I will put up drawings with dimensions for the stuff you see on my page.