Lt1 => Ls1?

[Cougar281]

For you experts out there... How hard would it be to make a 96 LT1 Firebird work with a 97 or 98 LS1 PCM? I know someone that converted his to run with a Pre-OBD-II PCM for tuning, but EFI would be a good way to go if he could make it run with the LS1 PCM.

[dfe1]

It should be relatively easy. All you really need are LS1-compatible cam position and crank position sensor pulses, eight coils and a wiring harness. But, you'll have to do a little rewiring to accommodate the difference in firing order, (unless you change the camshaft) and you have to change some of the sensors or connectors, unless you have a custom wiring harness built.

[N0DIH]

Been wondering the same thing. I do a lot of PCM tuning on the LT1 now with TunerCat OBD1, but have thought of it. But being the Optispark has a lot of good capabilities, you would lose all of that.

From what I have read the LT1 PCM/Opti treats the engine like 8 1 cyl engines, not 1 8 cyl. The grainularity in cyl to cyl timing tuning is excellent. You might lose some of that with the LS1 PCM. BUT, you would gain coil on plug....

[joecar]

If you are going to do a harness, and if your LT1 is worn out, you may well want to drop in an LS1/2/6, it would fit wouldn't it...?

[Cougar281]

If you are going to do a harness, and if your LT1 is worn out, you may well want to drop in an LS1/2/6, it would fit wouldn't it...?

I suspect it would since it's more or less the same engine... Kinda like with my Cougar. I put a 2002 4.6L in it with PI (Performance Improved) heads, which was a direct drop in, with just some wiring changes due to the different intake.

[dfe1]

I suspect it would since it's more or less the same engine... Kinda like with my Cougar. I put a 2002 4.6L in it with PI (Performance Improved) heads, which was a direct drop in, with just some wiring changes due to the different intake.

Negative-- the LT1 is a traditional small block, the LS-series has completely different architecture. In Fordspeak, the differences are like those between a 5.0 and a 4.6. Unlike the Fords, both of the GM engines are of the pushrod persuasion, but the blocks are totally different. Swapping an LSx in place of a conventional small block isn't terribly difficult, but does require some adaptation. Corvette Fever magazine is doing a project that includes installing a 5.3 LSx engine in an '87 Corvette, so that should shed some light on what it takes to do a quality conversion.

I think it would be a kick to run an old-style small block, or any other engine for that matter, with an LSx PCM. I think that will really show off the capabilities of EFILive. I've been talking with a few people about doing a project like that. If it happens, I'll post the results.

[Cougar281]

I see said the blind man . Thanks for the correction! Learn something every day!

[ChipsByAl]

If your main interest is using EFI Live to tune, you can use your current crank sensor with the Express van program. You would need a high voltage switch (ie. distributor) to handle the single coil. Setting up a cam sensor to trigger the sync signal if desired would be the only fabrication necessary.
AL

[joecar]

For the cam sensor, could he fab up something off the optispark distributor...?

[dfe1]

For the cam sensor, could he fab up something off the optispark distributor...?

I don't see why not, but I think some electronics are required. The Opti-Spark distributor has high and low resolution pulses. The pulses are generated by a shutter wheel inside the distributor and if I remember correctly, the high res section of the wheel has 360 slots. Somehow you have to boil all this down to two pulses-- one for crank position, the other for cam. Someone with a solid electronics background should be able to figure this out pretty easily. There are a few systems that have done that and they use the OptiSpark distributor to generate the triggering pulses, feed them into a control module and then route them to four or eight individual coils. These systems are designed to work with the original LT1 PCM, but they wouldn't be necessary if you switched to an LSx PCM since you only need cam and crank position pulses. Any electronic wizards care to comment?