MSD DIS-2, CBR coils, DSM ignitor... - Page 3

joeymia · Jun 7, 2006, 04:44 PM

Quote:

Some vehicles with electronic fuel injection systems may require an MSD Ignition Adapter to run
properly. This is because many of these systems use the same trigger source to operate the MSD,
the tachometer and the fuel injection. This results in a voltage signal that is too low to accurately
trigger the fuel injection. If your vehicle’s engine starts and then shuts off after a short period of time
or the check engine light turns on then your vehicle will require an Ignition Adapter. An MSD
Ignition Adapter, PN 8912, PN 89121 or PN 8917 will usually remedy the problem.

evo's with the dsm ignitor do not need tach adapter.

ExViTermini · Jun 7, 2006, 07:06 PM

The DSM ignitor is nothing but a power transistor. It bumps the 5 volt signal from the EMS to the 12v signal the MSD needs.

I used the bypass plug and anything over 3k rpm the ignition just completely cut out. So obviously it needs the power boost the msd offers.

The stock coils are working just fine for the 500whp. Anything beyone that...and I'm going to need more. I'll just get a DLI box and call it a day.

racegate · Jun 7, 2006, 07:31 PM

I think you are confused on what the igniter does, and why its needed.

Here is what the various parts to this puzzle do, and WHY you need them:

DSM Ignitor--

The problem with the MSD and the EMS is that the EMS output trigger is on the wrong edge from what the MSD is expecting. The DSM igniter is a power transitor, but all it serves to do in this app is reverse the phase because there is no edge selection on the MSD. The ignitor has two functions: 1-- to apply/remove current to the primary windings on the coil, 2-- to provide RPM output for the tacho.

The reason the C2Di works without a DSM ignitor is because you can flip the trigger edge with a dip switch.

Tach adapter--

This unit simply bumps the signal voltage to a full 12v if something is giving an output of 5v. Most CDI prefer a 12v square wave trigger, so if your ECU is outputting 5v, then you wire in the tach adapter to boost the voltage. Thats is all this thing does. The reason it is called a tach adapter is because originally it was designed exclusively for use on ECUs which outputted a 5v square wave, trying to drive a tach that needed a 12v signal (old autometer tachs, etc which did not have the selection).

The AEM does have edge selection (some boxes), but the problem is it doesn't pull-up far enough to trigger. So you need to install pull-up to condition the signal to trigger. This is where the 'EMS mods' come into play, and why you need them. Some boxes even need jumpers to change the edge as well...some have software configuration.

Now, what would be convenient is if you could trigger the coils direct with the EMS since it can do its own dwell control. You can do that, the problem is the inputs on the AEM cannot sink enough current to cover the primary winding discharge on the coils, so you will blow up ign drivers. This is (another reason) why the igniter (transistor) is needed-- to sink the current.

The AEM can be modified to include transistors on the ign drivers, if you are brave, you can take that leap, and then you need no ignitor at all and can drive the coils directly with no CDI/MSD/igniter what so ever.

evodave · Jun 7, 2006, 08:34 PM

so basically what i have 300m coil packs wired up with a mounting plate similar to buschurs COP setup with a 1g ignitor and a dis2 will not work without a tac adapter? The person i bought it from said it worked fine but i am trying to decide to

A: see if it works like it is
B: install the tach adapter and rely on the setup i will have with the dis2 which some people say is unreliable
C: use all the components i have and swap the DIS2 out with a different brand CDI box that i have available to me (but its pricey).

Thoughts?

TTP Engineering · Jun 7, 2006, 08:50 PM

Quote:

Originally Posted by evodave

so basically what i have 300m coil packs wired up with a mounting plate similar to buschurs COP setup with a 1g ignitor and a dis2 will not work without a tac adapter? The person i bought it from said it worked fine but i am trying to decide to

A: see if it works like it is
B: install the tach adapter and rely on the setup i will have with the dis2 which some people say is unreliable
C: use all the components i have and swap the DIS2 out with a different brand CDI box that i have available to me (but its pricey).

Thoughts?

Do not waste $50 on a 8912 tach adapter. It will do nothing for your setup.

joeymia · Jun 7, 2006, 08:59 PM

Quote:

Originally Posted by evodave

so basically what i have 300m coil packs wired up with a mounting plate similar to buschurs COP setup with a 1g ignitor and a dis2 will not work without a tac adapter? The person i bought it from said it worked fine but i am trying to decide to

A: see if it works like it is
B: install the tach adapter and rely on the setup i will have with the dis2 which some people say is unreliable
C: use all the components i have and swap the DIS2 out with a different brand CDI box that i have available to me (but its pricey).

Thoughts?

it will work fine without the tach adapter. I bought one and it did nothing.

here is my post on how i wired up the MSD

MSD DIS-2 installation question/problems

kcevo · Jun 8, 2006, 09:59 AM

Quote:

Originally Posted by evodave

so basically what i have 300m coil packs wired up with a mounting plate similar to buschurs COP setup with a 1g ignitor and a dis2 will not work without a tac adapter? The person i bought it from said it worked fine but i am trying to decide to

A: see if it works like it is
B: install the tach adapter and rely on the setup i will have with the dis2 which some people say is unreliable
C: use all the components i have and swap the DIS2 out with a different brand CDI box that i have available to me (but its pricey).

Thoughts?

Which CDI do you have available to you other than the AEM or MSD? I personally use an M&W Pro 14, after using both of the other units in various other applications other than an Evo.

GTVEVO · Jun 8, 2006, 01:44 PM

M&W

rraulston · Jun 12, 2006, 09:44 PM

I just fired my car up with my new COP. I did exactly what KCEVO said to do. 300m coils and a twin fire. I have dip switch set to multi spark, sw2 on falling edge and sw3 on. Car seems to run rough. Now i need someone to help with the configuring of the AEM like dwell settings ect. Ime also running stock irridiums. KCEVO......thanks for everything..... Ray

ExViTermini · Jun 13, 2006, 07:06 AM

Quote:

Originally Posted by rraulston

I just fired my car up with my new COP. I did exactly what KCEVO said to do. 300m coils and a twin fire. I have dip switch set to multi spark, sw2 on falling edge and sw3 on. Car seems to run rough. Now i need someone to help with the configuring of the AEM like dwell settings ect. Ime also running stock irridiums. KCEVO......thanks for everything..... Ray

open up both your cal file and a cal file for the viper. Copy over the dwell tables from the viper file to yours, and the dwell settings.

rraulston · Jun 13, 2006, 09:08 AM

o.k., ill go do that right now........

kcevo · Jun 13, 2006, 10:15 AM

Quote:

Originally Posted by ExViTermini

open up both your cal file and a cal file for the viper. Copy over the dwell tables from the viper file to yours, and the dwell settings.

No, you are running a CDI. The CDI sets the dwell time. Open up the coil dwell wizard and select all cdi except ford TFI.

rraulston · Jun 13, 2006, 10:47 AM

KCEVO, now i know YOU are the man. I just got off the phone to verify the viper settings and AEM said EXACTLY what you said. The cdi sets the dwell and to run CDI except ford in the wizzard. Thanks man. If anyone else needs help, the diagram KCEVO has is money...... I can make you a plate for $100. (sorry but i have to do it by hand and its 109 degrees outside here in AZ so it requires a little incentive) I paid like 43 for each coil and about 50 for all the harness wires. I paid about $350 for the twinfire. That gives you an idea of your cost. Ray

ExViTermini · Jun 13, 2006, 11:51 AM

interesting....I'm sure both methods work just fine...just wierd as a guy on the aemforums uses the viper settings...

BUT now that I think about it...I think he just uses and ignitor and the coils...doesen't use the cdi box...I'll have to go back and look.

kcevo · Jun 13, 2006, 11:54 AM

Quote:

Originally Posted by ExViTermini

interesting....I'm sure both methods work just fine...just wierd as a guy on the aemforums uses the viper settings...

BUT now that I think about it...I think he just uses and ignitor and the coils...doesen't use the cdi box...I'll have to go back and look.

Your thinking of Erich Moraga who uses the dsm ignitor and the chrysler coils. Yes he had better results using the Viper coil dwells with this setup.