i have a modifitd suzuki sierra with a 13bb motor in it that i use for enduro off road racing and would like to find some information on upgraded comp chips or other performance mods that are proven not too radical as reliability is the number one priority

I have not seen any performance chips offered for the G13 series engine.

In case I am wrong (it has happend before ), Check out the samurai forum at Zuwharrie.com:

http://bbs.zuwharrie.com/content/board,12.0.html

There is at least one guy there that repairs ECMs and would have an idea on the availability  of aftermarket ECM mods.

Other than the bogus resistor mod and "electric turbines" seen on eBay, most folks use cams, carbs and other mechanical mods to improve power output.

There seem to be a few options for the DOHC engine. I know at least some of them have an external EEPROM that can be swapped out although I believe that the original EEPROM requires desoldering and a socket inserted. There are also piggy back computers available. I would suggest asking on a Swift forum.

i have a modifitd suzuki sierra with a 13bb motor in it that i use for enduro off road racing and would like to find some information on upgraded comp chips or other performance mods that are proven not too radical as reliability is the number one priority

do you mean the g13 zuk engine, or a 13b mazda rotary? if its the rotary, i kneed to know if its n/a, turbo, or twin turbo. for the turbos, get a greddy e-manage ultimate piggyback ecu or a apex'i power fc standalone ecu. if n/a, maybe a haltech standalone ecu.
if its a sukuki motor, i dont really know whats available, but a new ecu (standalone or piggyback) is always better than a chip.

The G13BB came out in the early Jimny befoe they switched to the M13A.

If you had swapped in the G13B you would have had a range of cams and chips to choose from and a forged bottom end as well.