Sorry that answer sounded smartassed but I've heard so many versions of that question. There is no chip. There is an ECU modification available from Jim Wolf Technology for around 600 bux but it doesn't do much unless it's used in conjuction with a larger turbo, injectors, etc. http://www.jimwolftechnology.com
As mentioned no chip avaliable but you can get a reprogrammed ECU from JWT for 600. On a turbo 300zx it only gives 3hp over stock. So you are probably thinking whats the point, well as you start raising boost it starts to help a lot so it's worth it but only once you have some mods. If you are talking about a non turbo 300zx the same thing applies that you have to get the ECU reprogrammed from JWT. Hp gains have never been tested to my knolwedge. I have have one on my Z and another guy with a non turbo Z I know also has one. It felt only slightly faster and wasn't anything to write home about but when track tested it should to drop 1/4 mile times by about .3 seconds. However in order to get the full benefit from the JWT ECU you should have at least intake and exhuast but headers and a cam are recomended for a good set up.
You drive a car from 1985. Back in 1985 you didn't have an option of an aftermarket ECU. Now you do. Either you go with Jim Wolfe and upgrage parts on your car to benifite from the ECU or you tune the car without an aftermarket ECU. EXP: Boost controller, Turbo back exhaust, intake, port n' polish the heads, and maybe get a larger turbo.
The only problem is the Jim Wolfe ECU has issues that Jim Wolfe has yet to fix and you may have to run your Z with the o2 sensor unplugged.
OR you can do what many people are going to do and wait till around christmas time (It's not out yet.) and get the ZEMULATOR which is a tunable ECU that plugs into a lap top. It uses your existing ECU. Don't go with Jim Wolfe. Research and use the Zem when it is released.
Use the search function over at <http://www.Z31.com>
Ps. 3inch turbo back exhaust, a boost controller, and an aftermarket air filter will get your Z into the 13's.
280z/300zx: You are aware that you can't just install the ECU on a turbo Z and have it work, right? You need the new ECU, 420cc fuel injectors, Cobra MAF, and possibly rewireing the fuel injectors with lower resistors...
domdogg: there are two JWT turbo ECU's available. There is the standard JWT ECU that is just a plug in by itself and then there is the JWT 420 package. The JWT 420 package is the one you mentioned where you need larger injectors, cobra MAF, etc. The standard turbo ECU from JWT is like the non turbo one that you just plug in. For those who don't want to go all out with mods on their turbo the standard ECU is for them but if you are looking to make lots of power you want the 420 package. So yes I know, I was just a newbie back when the 420 package came out and remember hearing all the excitement about it
Perhaps they discontinued it or dont' have it listed for what ever reason. I'm pretty sure but I have been known to be wrong in the past. The main reason I'm pretty sure is becuase AZ ZBum did a dyno test on the JWT ECU and it was the non 420 package. Check Zbums website to see if you can find the dyno results for specifics.