96 to 97 PCM Upgrade

[FirebirdGT]

Well, I finally got around to having this done. Steve (ssms5411) came up from Phoenix with a 97 PCM, installed it and corrected the speedo due to my 3.73 with HP Tuners. Thanks Steve!

This is a "stock" tune except for a consistent idle speed (changes with engine temp normally) and a change to the advance at 4000 rpm ("stock" drops from 35 to 15 ONLY at this rpm).

I highly recommend that if you have a 96, get the 97 PCM even if you keep it stock. After driving this car for 8 years I can tell the slightest change. And it changed. Not only did GM change the PCM for 97, I really think they also changed the PCM algorithms for controlling the engine for the better.

Should have done this a long time ago. :rant:

[TheGr8Schlotzky]

Re: 96 to 97 PCM Upgrade

and a change to the advance a 4000 rpm ("stock" drops from 35 to 15 ONLY at this rpm).

what do you mean there?

I have a 97 pcm, but haven't had a chance to put it in, this is some motivation, i think i'm going to get it in this Saturday.

[FirebirdGT]

Re: 96 to 97 PCM Upgrade

what do you mean there?

Not sure what your question is.

[TheGr8Schlotzky]

Re: 96 to 97 PCM Upgrade

what are you referring to when you say

and a change to the advance a 4000 rpm ("stock" drops from 35 to 15 ONLY at this rpm).

?

ie, drops from 35 to 15 what?

[FirebirdGT]

Re: 96 to 97 PCM Upgrade

what are you referring to when you say ?

ie, drops from 35 to 15 what?

Values on the advance table using HP Tuners. I assume it is degrees, and not a "factor".

[TheGr8Schlotzky]

Re: 96 to 97 PCM Upgrade

So you said it drops timing at 4000rpm? So you just changed it from 15 to 35 at 4K?

[FirebirdGT]

Re: 96 to 97 PCM Upgrade

So you said it drops timing at 4000rpm? So you just changed it from 15 to 35 at 4K?

I think you need to talk to someone who has HPTuners. As I said, I had it done for me by Steve (ssms5411).

[97rs4life]

Re: 96 to 97 PCM Upgrade

just smooth out the timing table where that big dip is. for some reason they threw that in there and you can smooth it out to the same #s as the neighboring cells.

[ssms5411]

Re: 96 to 97 PCM Upgrade

I didn't get too much time to make some good scans on Roberts( I hate taking out virgin pcms that haven't been touch since 1996. PITA to take out), now that he has driven it for awhile, we can do some smoothing on his high/low octane tables and maybe reducing the KR sensors a bit. Also getting his LT trims in order. Then once he gets his wideband installed, we should really be able to tune it better. Probably get better gas mileage and such.

[crushedout]

Re: 96 to 97 PCM Upgrade

I didn't get too much time to make some good scans on Roberts( I hate taking out virgin pcms that haven't been touch since 1996. PITA to take out), now that he has driven it for awhile, we can do some smoothing on his high/low octane tables and maybe reducing the KR sensors a bit. Also getting his LT trims in order. Then once he gets his wideband installed, we should really be able to tune it better. Probably get better gas mileage and such.

When you refer to PITA to take out you mean physically remove? I have a stock 96 that I'm about to remove and install a 97 I have on hand.

I have a issue, the one I'm going to install is set for 160 thermostat and I have a stock one. What will happen if I drive car with computer thinking I have 160 but really have the 210 one. Best guess on my part is the fans will come on earlier per the sticky. Would it keep the engine so cool the thermostat would never open up and get flowing through my heater core to give me heat? When it warms up outside I'm going to install my headers and want to have someone tune the PCM for everything I have so I really dont want to send it off now just to get the thermostat tunes back to normal. Also I dont want to change thermostat. I would consider changing to a 180 but no lower than that.

[bigbrian442]

Re: 96 to 97 PCM Upgrade

Your fans should run all the time once the engine warms up. The stock T stat is 195*. If they change the fan on/off, What else did they change?


Brian

[ssms5411]

Re: 96 to 97 PCM Upgrade

You can't program the computer for a thermo, you only do the fans to come on earlier, so I don't think it would hurt anything having your stock thermo in there. You have a 195 is stock, so it won't hurt anything. Fans will just come on earlier. I mean it is a PITA because physically I took the whole case out with the computer(plastic piece it slides into to keep it in place). I tried to pop it out from the casing and after a few trys I didn't want to crack Roberts casing since it is not my car, so I pulled the whole thing out. On mine since I have swapped it out a few times I don't lock it all the way down into the plastic case. It is still in place where it doesn't move, but it lets me not go through the hassel of pulling the whole thing out each time. Good luck on yours. Steve