Digitial CPC from MSD?

I was looking at improving the 351W as best i can and i came across the CPC ignition from MSD
Whats interesting here is that i can get rid of the distributor which makes way for a larger air box or just a cleaner look out back.

Did anyone purchase one of these units yet? Just wondering what you thought of it?

Syd.

 

[David Briggs]

I have the MSD 7600 digital ignition on my 40, it has 8 individual coils, is crank fired, has a cam synchroniser in place of the dist. You program it with a laptop(you can vary the timing cyl to cyl if you have unlimited dyno access and patience). I am very happy with this unit and the support from MSD. If we are talking about the same unit you will like it.

 

Yup that would be the one i am talking about...I used MSD in all my race cars before with great sucess. But i never used the CPC (7600) before.

Thanks for the reply..

Syd.

 

[Bill Musarra]

Syd,
You might want to consider the Electromotive XDI electronic ignition or TEC3r for total engine management for fuel injected setups as well. I am planning on using the EFI unit for my 351. Should have it by the first of the year.

web page

Bill

 

[Chris Duncan]

Little bit on the spendy side, goes for about a grand. Depending on your engine management system you may be duplicating some tasks. If it's carburated then...nevermind.

If you're running a programmable ECU like the Accel Gen7 it already has fully adjustable ignition. Then you just have to add on something like the Fast Edist which takes the already timed signal from the Accel and separates it into 4 waste spark or 8 sequential signals so you can be distributorless.

I used the Fast Edist distributorless system. It costs about $300 and works best with LS1 coils which can usually be found new on Ebay for about $200.

Don't forget also that these systems need a crank trigger signal ($200 to $300), and if run fully sequential, a cam sync signal. Summit says a distributor plug must be purchased separately for the MSD, which is another $75 to $150, although it shows a dist plug in the picture.

Accel has just introduced a similar system to the MSD although I can't find a price it's probably close to the same.

Some of the programmable ECU's like Electromotive include distributorless ignition capabilities but the coil packs are extra.

 

Okay, this is all new to me, no distributor? Shame on me I need a boost. This system looks great but I do not know of any one running besides the responses on this post. Does this work with a carb. system or is not worth the trouble? I allready have my MSD dist. and coil . Should I go into the new century with this or or stay "old school" ? Kevin

 

[Sandy]

I looked at the MSD CPC as well, and decided that you end up spending a ton of cash for it and what it really should be is a complete EFI system. It does have one very nice thing for the GT40 in that you can run a distributer 'plug' which helps with the tight fit. The cost from Summit is about $975, then add mag pickup and wheel, coils x8, dist plug, and you are in for a good amount of $$. You could have a Haltech E8 (Topend has them for about $1400) and for a couple hundred more and be ready for injection. The cost of the coils, pickup/wheel is a wash.

I keep waiting for the complete EFI/COP Ignition from MSD as I love the stuff they make, but just hasn't happened. I also thought about how well the MSD 6 Digital works on my other car and found it hard to do much better.

I ended up going (will go) with a Haltech 6x for fuel and a MSD 6 Digital for ign. Easy, not too much fuss. Does lack the cool factor of the COP however...

Sandy

 

[Chris Duncan]

Ouch, your right, coils are purchased separately. Every picture I've seen of the thing shows coils and the dist plug, sort of misleading.

Just recieved my LS1 coils, came in 2 working days from Ohio via priority mail, that beats UPS by a substantial amount.

They look good and are supposed to be very hot spark. $220 with shipping, brand new in the bag with harness/weatherpack connectors and stock bracket. The bracket looks crap though and is very heavy 1/8" thick steel. Aluminum here we come.

 

[Sandy]

Kalun -

Yep, all extra. $220 for 8 coils seems like a very good deal. Are those coils only or a coil/ignitor package?

Kevin -

The 'Old' school works fine, Nascar is running over 9000 rpm on MSD 6's 700+hp, so you should be good to go. Can the COP deliver a hotter spark, more then likely. What it all means would depend on many factors, RPM, compression, fuel mixture etc. For the most part for us 'Hot Rodders' does not matter all that much as long as you have good premium matched components all around.

One other thing I think that was an issue is that the MSD CPC has 2 control boxes, more wires, more space.

Sandy

 

Well to reply to your post. Yes coil on plug produces a hotter spark it also delivers a long spark with more current...(Amperage). If you consider that at 9000 rpm lets say. you have to cycle that coil on an off 72000 times a minute which leaves you about 8.3 milli-seconds to charge and fire that coil. Where if you use a single coil per plug you now only cycle it 9000 times which now gives you 66.4 milli-seconds to charge and fire that coil. Ultimately that is why i decided to go for a coil on plug solution to my delima.

For systems that are DIS remember they function under a wasted spark concept. They would have a charge time of 33.2 milli-seconds @ 9000 rpm.

But seeing that a 351w works best around say 6500 to maybe if your lucky (spend a lot on pistons and rods that can take that speed) 7800 rpm or so DIS is more than adequate.

I just prefere using a coil per plug. Kinda got used to it. At the school that i teach at my students are rebuilding Chevy new gen. 5.3L with coil per plug. Its a clean installation. Which ultimately i am looking after.

Oh yes i almost forgot. If any of your are into numbers. what you could do to see exactly how much power you are using you can use Ohms Law with the simple formulas

E= I x R and then to find watts P = I x E Where P is power rated in watts
I is current in Amps
E is Voltage.

 

[Sandy]

The total available charge time is not how long the coil is ultimatly charged. I don't have all the numbers and can't say what is enough as it depends on coil, ign voltage, etc. Many of the newer coils like the MSD E-Core style have very low impedance, as this help reduce the time to charge to saturation which helps with fast saturation, etc. You only need to start charging to saturate the coil and then any more is wasted in heat in the coil and associated drivers. Essentially either you have to raise the voltage to charge faster or lower the coils primary impedance (or both).

Again, not sure of all the numbers for the actual dwell time required to saturate specific coils but having 100ms to charge a coil when 25ms is the time to saturate it is of no value to charge any longer then 25ms. Some EFI and Ignitions do calculate that based on the positional aspect of the engine, some rely on the drive to get it right based on some simple sampled analog parameters that the ignition driver chips handle ala GM's Older HEI's as one for an example.

I don't know if the reason for using COP on production vehicles has all the same values as I'm looking for. I would expect that the order is big from emissions, fuel economy, then power. I'm ok to waste the first two for my toys /ubbthreads/images/graemlins/smile.gif.

Now after all that, _YES_ I definitly like the COP, it get's rid of a ton of crap and can light up most anything, But I would like to have it as part of my EFI controller as many now do. Some do waste spark which I hate as it still has some of the clutter and not as clean as COP. I think all the Electromotive EFI/Ign's do waste spark as well as a few others. It does still work pretty well, just not as neat as the cop.

Sandy

 

OK i had a look at the MSD website the coil that they provide for the 7600 has 570mA and 37000 peak volts. and they give a interesting piece of information 130Us spark duration.

Which will give you in watts for that 130Us duration 37000V x .57A = 21090 Watts.. Compared to say a distributor ignition set up of say a MSD 6AL and HVC coil. 42000V x .3A = 12600 Watts.

So it looks like twice as much energy to ignite what ever you choose to use. Which will be benifical for higher octane fuels which are harder to ignite.


Syd.

 

LS1 cnp coils have the igniters built in. They are fired by a 5 volt, logic level signal with a maximum dwell of about 10ms at high rpm. If the coil stays charge much longer than that, it fires itself off anyways so it wont cook. If you want a good, cheap efi controller with wb sensing, auto learning, full sequential ign and the ability to drive any coil you want (up to 8cyl sequential, 16cyl in wasted spark)go to this website www.vems-group.org. The only downside is you need to do alot of work. I have one of these installed in my Unimog running the ls1 coils. It works excellent but took me a few months to put together and understand. If anyone wants to try it, I would be glad to pass on my knowledge, but do me a favour and give me a mention if you order one (there is perks for recomending people).
BE AWARE, it is not a project for the faint of heart but if you buy a completely assembled unit, the worst of it is over, the setup and programming has a lot of support.

 

[Sandy]

Eric -

Very familiar with the VEMS controller, it's based on a low cost 8 bit AVR cpu, (around $500 or so as I recall for the assembled one less all other needed parts...) some crazy good software folks have done a lot of work on it. They are some very creative folks to be sure, they have crammed lots of interfaces and is very flexible. I was actually waiting for the ARM based CPU proto's they are working on. I have worked on other DIY EFI systems in the olden days (EFI332 based on the motorola 68332) and did a couple of early prototypes. Just decided that time is too short not to spend a couple of extra $$ and get one that is working so I can balance my electronic projects with automotive /ubbthreads/images/graemlins/smile.gif

The Megasquirt is another that is from Bruce Bowling and his partner. They are alway working on some related projects as well (wideband o2 I think, and some other automotive gadgets)

Only so much time to have fun with the projects! Thanks for the info on the LS1 coils.

Sandy

 

[David Briggs]

There are any number of ways to fire your plugs and almost any after market ignition is over kill for the average street motor. The 7600 gives you very precise timing, it has been trouble free and the engine(w/webers) runs like it is fuel injected. It looks pretty complicated but is easy to install and program. I seem to remember the total cost was about $1,800.

 

[Sandy]

Syd -

The CPC is like a bunch of MSD's crammed into a box (well 2 boxes), and as I understood it to be similar in electrical output per coil. And as such it should never have to compromise having a fully charged state to fire any cylinder, where the conventional MSD's may.

Also to note is that MSD's are not electrically like conventional ignitions who saturate a coil (coil stores energy) like the LT1 COPS,etc. The MSD's dump a charged up capacitor (400-500vdc) into the primary of the coil were most of the COP's are more conventional ignitions (saturate and fire). CDI's generally suck for ignitions as they tend to have very short spark duration, but MSD fixes that with multi spark, and cramming lots of energy into the components to keep the spark hot and longer burning.

I'm not sure if you can directly use the watts to determine how powerful the spark really is in the MSD case, I'm sure it gets tricky since the MSD's are multi-firing and other such stuff. The 'xxx MilliJoules Per Spark' I would guess is better. But who knows.

From MSD's CPC Description -
[ QUOTE ]

When triggered, the capacitive discharge ignition will deliver a powerful spark with 170 mJ of energy and 475 primary volts to each coil at any rpm! Below 3,300 each spark plug will be fired multiple times, for 20° of crankshaft rotation...


[/ QUOTE ]

From the MSD Digital 6+ (Similar for most msd's)
[ QUOTE ]

Every spark of the Digital-6 Plus ignition is packed with 135 ((Digital 7 is 190mj)) millijoules of spark energy and up to 535 volts. When used with the MSD Blaster HVC Coil, PN 8252, a spark with over 300 milliamps burns across the plug gap for 400 microseconds. Below 3,300 rpm the Digital-6 Plus produces a series of sparks that glows in the cylinder for up to 20° of crankshaft rotation...

[/ QUOTE ]

The note of the CPC is 'AT ANY RPM' and that is where it should shine vs. the regular MSD's

Again, I love the COP concept, just the MSD version is mighty expensive when all said and done. The more power question would just depend on where a conventional MSD runs out of time to charge it internal capacitor fully, and where that is I don't have a clue, but I know I'm runing 7500rpm with a simple (non-ecore) coil with ~12.8:1 compression and it does not miss a beat until the rev limiter hits /ubbthreads/images/graemlins/smile.gif

Good chat about ignitons, and it's amazing how well a bad igniton will work, and how much better a good one really does.

It was a multi-donut and cup-o-coffee day if you can't tell from the post /ubbthreads/images/graemlins/smile.gif

Sandy