Now we all know that when we add headers. catbacks and intakes, the computer adjusts the settings. My question is, where is the limit? Can you have a full bolt on car ( Full intake to full exhaust) and the stock computer still be able to make the necassary adjustments?

 

When you say "stock computer", I'm interpretting you as saying "stock computer & stock program".

The stock PCM and program can actually do a pretty amazing job of adapting to changes. I ran my 383 with a totally stock PCM for a while, and the car ran quite well. But when I got it programmed for the engine, it made a world of difference. I thought my car was running well with the stock tune; it was actually running like crap compared to the way it does now - I just lacked a frame of reference.

The key here is that the PCM is sophisticated enough that you can do a fair bit of modifying, and the car will still run OK. But you're not getting the full advantage of your modifications without a PCM tune by one of the experts like Bryan or Ion. Their prices are so reasonable that you're really wasting money with modifications if you don't get the PCM programmed for them, IMO. Once you're at the full bolt-on stage, I would suggest a program. If you do H/C, a program is a must.

Someone might chime in with info on how far a stock (but custom programmed) PCM can be taken before it becomes a hindrence.

 

Since you didn't bother to tell us the year of your car, engine, etc. its almost impossible to answer your question. But if its an LT1.......

Depends.... there is problem with high stall converters on the OBD-I PCM's. The timing tables only go to 7,000rpm. The stock MAP sensor is only a 1 bar unit - not good for forced induction. But there are ways around most of the limitations. People are running high boost and 2 bar MAP sensors with the right programming. There's even an external "black box" that allows you to run huge low impedance injectors. There are people who have taken cars into the 9's with the factory PCM - but obviously not "stock" programming.

Its sort of foolish to try and hold on to stock programming, even for a stock engine. There's 15 HP sitting there for free simply by leaning out the power enrichment mode target A/F ratio on a totally stock engine. Think of how much power you may be giving up trying to run an altered engine on stock programming.