CDI Ignition Modules, Whats the deal?

[RT40Corona4AGTE]

I have started looking into CDI's and seeing what is available. I have found several comments regarding these both negative and positive.

The only experience I have had is with MSD gear. They have been reliable to me, but others consider them as "My Spark Disappears" devices.

There are a few to name, M&W, Autronic, Motec, AEM, MSD, etc.

From what I am led to believe M&W is the leader along with Motec and Autronic. But compare the prices of those units to AEM, MSD, HKS, etc and they are quite expensive for a bunch of ignition electronics.

I couldn't find any negative comments regarding the Autronic, Motec or the M&W devices.

But several people flame the hell out of AEM and MSD types and several people applaud them.

I know I will probably consider an M&W device at the end of this, as they appear to be the most reliable, but what do you guys think?

Is anyone familiar with the AEM, MSD or any other cheaper ignition units? The MSD's I have fitted are still going to this day, they include the 6AL series and the DIS series units.

Upon reading the AEM forum regarding their twin-fire ignition modules, the people that are having issues seem to stick with them as AEM warrants them for 12 months and when they do fail (ie. blow the inline fuse on the constant +12V supply) they get them repaired. They all swear by how good they work, its just when they work thats the problem.

I have emailed AEM to try to get some clarification of the issues they have been having with their units. But before I do any more chasing I want to find out what you guys use and compare your reports on reliability, etc?

I also didnt want to hi-jack andrew_mx83's thread on CDI stuff too, hence why this thread exists.

[Radar]

Depends on the ECU your running, I'm running sequential twin spark on a 3tgte with an SMC AUTRONIC.. Pretty simple; 4x bosch 008 modules / 4x Hyundi wastespark coilpacks / 4x Ign outputs. (cheaap as chips if you goto u-pull-it) I get close to 35mm worth of spark. PLUS no need for CDI.
If your going down the road of CDI just seriously spend the same money on a decent ECU.
Quicker & Cheaper than CDI.
My2c.

[RT40Corona4AGTE]

I am looking at Adaptronic, Autronic and Motec ECU's so the ECU side of things shouldn't be an issue.

I am more interested in CDI's to be honest and want to know what experience people have had with them with regards to my first post.

Thanks for the advice though Radar! +rep

[mr1jz]

If your going down the road of CDI just seriously spend the same money on a decent ECU.
Quicker & Cheaper than CDI.
My2c.

Regardless of ECU, the ECU will only trigger the ignitor or ignitor coil combo. The ECU has nothing to do with the power of the spark.

If you are looking at a decent ECU, look no further then the Vipec range of ECU's. They are super user friendly, come with every option that you will need and are very precise. I have tuned all of the above and would choose a Vipec over all of them every time.

[RT40Corona4AGTE]

Thanks Mr1JZ +rep

Have you had experience with any CDI's though? as thats mainly what I am looking for info on.

[mr1jz]

I have. I have tuned a EVO3 with a M&W setup and it was fantastic. It ran a M&W CDI unit and M&W coils. The spark could probably jump 2in and it was a serious spark. This allowed the gap on the plug to opened further and increased the low rpm torque curve.
I have also heard excellent things about the HKS DLI modules.
What engine is this for and why are yyou going to CDI. Is a COP setup possible?
I have also found that Vipec are selling CDI units and if they are anything like their ECU's, they will be nothing short of brilliant.

Cheers, Brendan.

[RT40Corona4AGTE]

Yeah from what I have read the M&W ones seem to be the Beez Neez!

It is for my 4A engine that I am building in my RT40. I am mainly worried about blowing spark out at high boost levels and not having enough spark support for the use of nitrous oxide.

I have experienced these problems before on a mates drag car and a fitment of an MSD DIS unit rectified it. That and only a couple of MSD 6AL installs is as far as my experience in this field goes.

I do however think a COP setup is more than possible, I just wanted to see if I was heading down the right path with what brand to use, etc.

Thankyou very much for your feedback on the M&W units mate

[NME308]

Hi there,
I definatly agree that you are on the right path looking into CDI ignition modules when planning high boost!
My personal experience is with the MSD units. The very first one I owned was a 2nd hand 6AL and was in service for another 10 years before it was sold still working. The HQ runs a 7AL2 with so far no issues and my celica has a 6AL which has been flawless although only 5 years old so far.

There was a bit of bad press about the digital MSD's for a while although it seems they have picked their act up lately. I have only personally seen a couple of the old school style MSD's (analogue 6 and 7AL's) blown up through bad wiring or faulty operation - you can screw them up by running too long with a non sparking plug or lead hanging in the breeze...

Anything which has great feedback and genuinly provides 400+ volts to the coil (unlike certain SSS PC crap...) is going to be a good investment in my book.

Cheers,
Jason

[RT40Corona4AGTE]

Thanks Jason! +rep for the feedback!

[RT40Corona4AGTE]

Just got a reply from AEM regarding their Twin Fire CDI. I originally asked them if they had corrected the issue of the units reliability as they are prone to blowing their inline constant 12V supply fuse at regular intervals.

Hi,

We haven't had any issues with the latest revisions. Anything purchased
now will be the new revision.

I can't confirm exactly the issue with the previous revision but there was
a hardware update and they've been solid since. Unfortunately I don't have
anything more specific data than that.

Let me know if you have any other questions.

Thank you.

AEM Performance Electronics
Technical Support
www.aemelectronics.com

I am thinking I might give the AEM unit a try if the above is correct, it puts out the same if not more mJ of energy than leading CDI's and is a fraction of the cost and as I have said, a lot of people using AEM's love them, and their only gripe was that they dont last very long until their inline fuse blows.

Interestingly enough, most people I have read about only have the "fuse blowing" issue when running 4-channel sequential (direct-fire) setups with their Twin Fire CDI's, with none of them seeing the issue when only running 2-channel wasted spark through the unit.

Maybe there was a design flaw that was current related and it has been corrected now?

[andrew_mx83]

subscribed for learning

[jeffro ra28]

A handy feature of the Autronic CDI is you can swtich to ground 1 wire to obtain high power mode - 550 volts, whilst not grounded its just the normal 250odd volts (or there abouts). I guess this saves your spark plugs and coils a bit if your on the highway etc. But the motec and M&W might have this feature also, not sure.

MSD's are O.K. Have returned a few for repair and thats a pita. Namely, MSD10 dual coils and 7al's. You could say slightly hit and miss, these were not even in road going vehicles and didnt really fire that many shots at all, but i guess a slightly harsh environment.

[RT40Corona4AGTE]

thanks for the feedback jeffro! +reppage

I am familiar with the high power mode ability's of some of these CDI's. Could be useful to switch an aux output from an aftermarket ECU when above a certain boost level to put the CDI into high power mode.

I think other brands have that ability as well, as I remember reading about it. But cant remember off hand which ones they were.

I try will post up a comparison of cost, spark energy and features for some of the common CDI's sometime today.

[RT40Corona4AGTE]

[RT40Corona4AGTE]

Bang for buck appears to be AEM from the specs of the units I have looked at so far. But I am still weary of their reliability issues, even though they have replied to my email and said that they have resolved the issues they were having.