I remember reading something long time that everytime you mod 93s f-bodies that you have to burn a new computer chip to get the full benefit of the mod even if its just few bolt ons.

What`s the difference between modding 93s and 94+ f-bodies, I want to get headers done next year so I just wondering if I would need to mess with my computer to get full benefit of the headers.

 

The 94+ cars use different computers that have FLASH memory instead of removable burnable chips that the 93 has.

With the different computers came MAF and heated O2 sensors so a fair number of 93 owners have actually swapped over to the 94-95 pcm.

The 93 system definitely can work but the 94-5 system is usually considered a bit cheaper and easier to work with and is a more advanced system.

Are you looking to get into your own tuning or just going to have someone else do it all??

 

93's are batch fired injectors. All the rest are sequential. 93s are 22# injectors. After that were 24#'s.

A good change to make is switching to 4 wire heated O2's.

93's are speed density. While all the rest are MAF type. Thus the missing MAF sensor on the 93.

One interesting point is most of the aftermarket fuel/ignition systems are speed density. All most all of them support both batch and sequential injection.

 

A tune was my first mod from Alvin at pcmforless. I sent it back once to correct the a/f ratio for a small nominal charge. I also ran the tune 4 years before installing headers and still have the same tune. You do not need to burn a chip for every mod.

 

The key difference, requiring more frequent tunes, is the speed-density control, in the absence of the MAF sensor.

Most performance improvements involve "breathing" improvements - more air in, more exhaust out. The MAF sensor directly measures the mass air flow.... it knows when breathing has been improved. Speed-density has to calculate the mass air flow, and it does that using the pre-programmed volumetric efficiency (VE) tables - a measure of the engine's breathing efficiency, arrived at through engine testing by the manufacturer. As you improve breathing, the volumetric efficiency tables have to be adjusted to reflect the imrpoved breathing, or the ECM will have problems accurately fueling the engine.

Everything else - unheated O2 sensors, batch fire injection, etc. - are relatively unimportant with regard to the need for frequent "tunes".

 

Yeah, I remember reading how '93s were weird as heck. That's why I turned down a couple of '93 Camaros and T/A and got my '94 instead. I believe they have the speed density instead of MAF. Which is the main reason for the modding headaches.

Here's a good thread on the differences: http://www.ls1tech.com/forums/lt1-lt...fferences.html

Also, this says some differences: http://en.wikipedia.org/wiki/Chevrol...ration%29#1994

 

I would like to do my own tuning for sure, but right now I don't know much about it, so I don't know how hard would be and what I need to get started. I dont hear many guys doing their own tuning on 93s they all seem to get somone else to do it for them.

 

Moates has what you need. http://www.moates.net/

Rich