Msd dis4
 

i'm trying to get this going on my mach, obviously it seems the 89121 are impossible to get. i've read some articles that say 8912 can be used on COP but i've also have been told i must only use 89121. has anyone used the 8912? or should i just give up on the msd ignition set up? thanks

Re: Msd dis4
 

im not familiar with these at all, what is it you're trying to achieve with these things?

Re: Msd dis4
 

i'm sure its crazy but its the only way i can find to be able to retard timing when activating nitrous. i have a tune for my procharged set up, i cannot have multiple tunes so i figured this is the only way to achieve spraying nitrous. the more im into it, the more it seems like its just not worth it. i originally purchased the msd 8921 and didnt realize that wont work and need the 89121, which are just not available at all.

Re: Msd dis4
 

i dont plan on spraying much 50-75 hp so i didnt want to change my tune based off the nitrous

Re: Msd dis4
 

ah ok.

Why cant you have multiple tunes - what device are you using? I know swapping between them is kind of a pain in the rear

Re: Msd dis4
 

i'm not sure what software he used. i know its not HP and i know that when i had sct i was able to have multiple tunes but not with this. i think he plugs right into the ecm.

Re: Msd dis4
 

ah ok, makes sense

if you can still get them the J&S vampire/knock detection/prevention system would be an issue if you cant get the MSD to work. You can wire in a switch to the system and retard 2-4 degrees without changing the tune itself

7) If you are using nitrous oxide, connect the J&S “Aux” wire to the nitrous switch. When you hit the nitrous switch, the unit will retard either 2° (S5 down) or 4° (S5 up). You could also wire pin 2 to a toggle switch, and use it to retard 2° or 4° when you fill up with low octane fuel.


http://www.jandssafeguard.com/VampirePage/Vampire.html

this system listens to the factory knock sensors, I did the MSD 2 step harness install so as not to splice into anything. It's basically running the coil signal through this unit so it can delay the signal. If it detects knock/detonation it will pull timing before that cylinder fires again. I also run the better gauge that will tell you which cylinder(s) detected knock

Re: Msd dis4
 

thats absolutely perfect, i appreciate the information. i found one and bought it yesterday. i have the msd 2 step as well. how did you wire it in without splicing?

Re: Msd dis4
 

http://www.jandssafeguard.com/Instru...PNRVampire.pdf

starts at page 5 using the MSD 2 step harness. Using this AND an actual 2 step - not sure how that would work tbh. It seems like you could probably still tie it in but I dont have any experience with setting up the 2 step box

Re: Msd dis4
 

i got in touch with the owner. he still makes these units and the new one has a 2 step built in. the original will work with the msd 2 step as well. this will work perfectly for my application and i appreciate your input on this topic. you helped big time, thanks again

Re: Msd dis4
 

sweet, glad I could help and now the motor will have some true protection as well.