Has anyone ever converted the Thirdgen HEI or Forthgen OPTI-SPARK to a distributorless ignition? I have always wanted to use a Coil pack instead of the distributor. The reason I mention the Forthgen computer is because the only thing stopping me from putting a Forthgen computer in my car is the OPTI-SPARK distributor the LT1’s have.

 

Yes, the 4gen LT1 cars can use CNP from the LS1. So basically you have to convert your distributor to accept an opti and use the LT1 ecm (8051) with a convertion box from Bailey engineering and get a set of LS coils. Problem is money. Getting an opti and 8051 pcm and the Bailey box and LS coils will run you about $1K if you don't get some serious hook-ups. Then you have to make the opti fit the dist which is up to a machine shop. BTW, the opti sensor itself is very small. The large size of the housing is because of the need to run a cap and rotor but that won't be necessary with the CNP.

 

Instead of using the opti spark to trigger the ECM why not just us a crank trigger?

Kat

 

I know of a guy that is running a EDist with his SD setup (7730) & CNP coils (this is an old Oldsmobile). The trick was putting a "cam Sensor" in his Dissy, to trigger the EDist.

BW

 

Yep, forgot to mention you could use the eDIST for this. The Cadi 4.9L PFI engine that isn't a Northstar has a dist. with a cam sync signal and MSD sells one too. I like the LT1 idea for the use of the ecm with its SFI and ALDL tuning capability. However, if using an 8051 LT1 PCM you must use the opti as the ecm won't recognize any other signal than an opti. Unless of course you're really good with code and maybe some hardware changes and make it see whatever cam/crank sync you want.

 

I have always wanted to use the 95 LT1 computer because you can flash it, so I could pull over flash the chip start it up and tune it some more. Would there be a way to add a crank sensor and covert the output to make it so the ECM wouldn’t know the opti is not there. You would have to rig up a coil pack some how too. Also what is eDIST?