PCM difference LSC vs base

[mark0101]

I had a tune for my base 97 Mark VIII but that car is dead know. I have a 98 LSC and was wondering if can swap the computers? I know people usually have to get re tuned after gears and since base and LSC is different, would it be the same?

 

[driller]

I'm not sure, it would probably run alright but it would not be the same since the different gearing would result in a different NV value. As a rule of thumb, all else being equal, you can step up 2 ratios in the gears before a tune would be considered 'required'.

 

[Jamesvinar]

Gears are a bit different, i ran a gps speedo on my vic before my tune. Otherwise i think the LSC was just a little bit more aggressive. I dont think you will have any issues with the anti theft

 

[Jd1978]

I am upgrading my ls c to 3.73 gears and have to retune the trans shift points. You are probably ok with the base computer but don't expect max performance. Base is 3.08 to lsc 3.27. Remember the computer controls suspension, braking and other things on the car.

 

[chris2523]

gearing change is minor.
it will be alright.

 

[billcu]

Let us know how it works.
I'm planning on putting my 97, 373 tuned PCM, in the 98 CE, which is a 327 stock PCM.

I'm hoping it's going to be an improvement, if not, I'll swap back

 

[mark0101]

Alright, so far so good I think. My base used to shift at 6250, the LSC now is 6050ish. Those sluggish shifts are gone, it was just awful on this LSC.

Here is before and after

Here is when my Base Mark VIII was working against this very same LSC. The LSC definitely was faster off line but you can see it slows down so much during the shifts.

 

[billcu]

Let us know how it works.
I'm planning on putting my 97, 373 tuned PCM, in the 98 CE, which is a 327 stock PCM.

I'm hoping it's going to be an improvement, if not, I'll swap back

Well, this didn't work out. The 373 tune caused the shift points to be too early and the car didn't run very good.

I did like the way it seemed to hold the gears better, especially the TC lock on the expressway.