Dave95Formula

Are there any advantages or disadvantages to using different years PCMs?

I am curious because I have noticed that several of the wiring harnesses out there are based on using a 98 and earlier PCM. Painless Wiring and the GM ASA harness for example. I had figured it was simply because of the fact that they were developed based on those particular years harnesses and PCMs and they didn't feel the need to develop additional years harnesses (Painless Wiring in particular).

Is there anything about the earlier PCMs that make them easier to develop swap harnesses? Is there any reason not to use a later PCM? Do earlier PCMs have the torque management, etc? Are earlier PCMs more easily adapted to using a return style fuel system?

Thanks,

Dave

Speartech

iTrader: (14)

Both styles (98 & 99-up) will work ok for a basic swap.

We build all of our harnesses based on the newer style, unless the customer already has a 98 PCM laying around.

The MAIN advantage of the newer PCM is the wide use over several years = many PCM's available in junkyards etc. Not being rare keeps the price reasonable.

If horsepower is an issue, the newer style has a longer and better defined MAF table (especially 2001 and newer PCM's) which helps when upgrading to bigger MAF sensors.

Also, we are starting to do a lot of Electronic Throttle Controlled setups for guys, and on these, the 99 and up PCM is much more flexible.

So unless you have a 98 PCM already, or prefer a "painless" style of harness, the newer PCM is the better choice.

Dave95Formula

Thanks for the information. I am probably going to use 99+ PCM as the motor I purchase will probably be a 01-02 preferably. I intend to use your harness or one similiar.

I intend to modify the motor substantially, so the larger tables with more resolution of the newer PCMs should provide a lot of benefit. I wasn't aware of the tables in the pcm being different..so I am glad I asked the question.

Another question..... What is the upper limit of the pcm tables for an LS1? I know an LT1s end at around 7000rpm...effectively causing that the be the most you can spin a LT1.

Thanks,

Dave

Speartech

iTrader: (14)

Most of the RPM related tables (spark advance, etc.) go to 8000 rpm, so you are well covered for almost any application.

If you are making the transition from an LT1 to an LS1, you are going to like the changes!

John