Has anyone tried this? I know that a SBC timing cover doesnt have provisions for putting the opti in, but has anyone tried to use the LT1 timing cover? Do the holes match up except the top 3, where as the SBC has 2? Has anyone tried to redrill the LT1 cover for the 2 holes and have that bolt up?

This is something I have recently thinking about doing, unless someone else has tried this and have failed. This would be a cheap ECU alternative to something other then some aftermarket DFI and would have an alternative to the stock unit. You could use the opti for spark, or just use the opti so the ECU can run and use a conventional dist or use the LTCC for a coil on plug setup.

Thanks
Jeremy

 

Why?.
What does the LT1 pcm give you over a oem ecm in a 3rd gen?.

The Tunercat R_T and Romulator make on the fly oem ecm tuning possible now.

 

It gives you another option from converting from MAF to SD bcuz you maxed out the MAF. Also the LT1 PCM allowes you to plug in a scanmaster type so you can read all your variables when driving around.

From my reading too, it seems that tuning for MAF and SD seams to be a hard thing, if you dont know what your doing. There are many programers out there for the LT1 PCM that are cheap, like PCMforless.

 

I will assume you currently have MAF. If you are maxing the MAF in WOT, just get yourself a WB and tune via the PE tables. It doesn't get any simpler.

For part-throttle, get the Romulator as Bruce suggests and tune your MAF tables if you are a stickler for 128/128 (but in all honesty, if you are within +/- 5 it really doesn't matter).

However, if you are hell bent on making the LT1's PCM work on your car - go for it. I am sure there are a lot of people that would be interested in a PCM conversion for 3rd Gen cars.

But there are plenty of ways to tune your MAF car even if the MAF get's maxed in WOT.

 

Well one of the other things I just thought about is you can use the 4l60E and have the ECU control the shift firmness and when it shifts. Just an added bonus to anyone who cares.

I still like the fact that I could go get a tune that will get me in the ballpark for $99 if you have an OBDI ECU. Besides I have everything except the opti and the wiring harness. I have Autotap for OBDI and got that for free. So I figured why not give it a try.

 

Max'ing out the MAF runs you out of resolution, not adjustiblity.

Yes, Scanmaster is nice, maybe there ought to be an effor to get Bailey Eng to do one for the 3rd gens.

It looks like that PCMforless is just an editing service, he'll change the bin for you.

There are memcal'd PCMs that offer all the same features.

Be sure to investigate what happens when a Flash PCM hangs during programming.

 

mastrdrver, check out the message archives on www.diy-efi.org.

I remember seeing some messages about using an LT1pcm with a gen 1 big block. One of the people who was in that conv was the creator/owner of www.lt1swap.com.

The main part of the conv involved welding the slotted disk & light emitter/reader from an optispark onto the shaft of a standard gen 1 distributer. It has been a long time since I was in the diy-efi archives so please check for yourself and correct me if I'm off. I didn't pay much attention to that conv in the first place so my details could be off. If this is correct then it should be easier than adapting an optispark dist to a gen 1.

 

I thought about putting the pickup and disk inside a gen1 distributor, but thought it might be easier to put on the lt1 cover and us the opti, not to mention that you might have mosture problems with the disk and pickup in a distributor bcuz of having to hack up the cap. Also I figured it would be the easiest straight forward job.