Not sure if I'm in the right section for this but anyways heres the deal. I have a 94 camaro z28. About two years ago I had a STS turbocharger put on my car. I had the car dyno-tuned for my stock engine. Recently my stock opti-spark (lt1 distributor) went out on me. I replaced it with a new MSD opti-spark. But the new MSD opti-spark features a built in timing **** to adjust the timing. It's supposed to already be set for factory specs. My question is will this throw my tune off?? Many told me it could and others told me it will not. I really dont see it affecting the tune myself because it's all stored in the computer already. I was told as long as I dont mess with that timing screw I would be okay. Basically it would kinda be like a stock opti-spark from the factory since it's set for factory specs right??? That should not affect my tune at all then if thats the case. That timing **** is Basically like a option feature from msd. Any information will help.

 

Changing the Opti will not affect the tune. That assumes the MSD unit was set correctly when it left the factory. Since there appears to be no "index" on the MSD adjustment, I guess you just have to take it on faith that they set it correctly.

If the MSD adjustment is "off", it will alter your ignition and injector timing.