It's not MSA's computer, it's from Jim Wolf Technology or JWT. MSA just sells them. As for gains it's not much. In my 7 years with the Z31 I've never seen a dyno test done on the JWT ecu for the 300zx n/a so I'm not going to even try to guess at what it is. I have however track tested mine as did stevezcar who is on this board. We both saw about .3 secs decreased from our 1/4 mile times. It does feel noticably faster but nothing huge. I honestly didn't really notice any improvement until I got on the throttle. During regular driving it doesn't feel any faster and at WOT throttle it gives a low amount of power increase. While the hp and torque gain are low the reason you see the .3 sec difference is becuase it really helps out at the high rpms where in stock form the Z starts running out of steam. Honestly if I had to do it over again I wouldn't. There have been several times I've thought about selling my JWT ECU to get most of my money back. If you are looking to get the most from your non turbo go ahead and do it. If having a fast car is what you are looking for save your money and buy a turbo 300zx. The fastest the n/a 300zx will be with a streetable motor is high 14's. It's been shown a couple times that a 300zx n/a with all the bolt on mods, port and polish work, cams, etc only put out about 170-180hp to the rear wheels and run about 14.7 in the 1/4 mile. For the money spent you could have a 300zx turbo running 12's.
Last thing about the ECU, JWT strongly recomends having at least intake, exhuast, and headers BEFORE doing the JWT ECU upgrade. A cam is also suggested but can be done later. That being said look at the cost. For intake, exhuast, headers, and JWT ECU you are looking at 1200-1600 bucks which could easily buy you a turbo 300zx or enough to do a turbo swap. Honestly modding the non turbo is just not worth it unless you are just doing it becuase you really love the car and care less about having something fast. Also I hear some guy has cracked the ECU codes and will be coming out with his own performance ECU for less money and will have tunability options, which the JWT doesn't have. I think it's called the Zemmulator. Do a search for it over at z31.com, it's not supposed to be out until October or november I think. Probably won't be any better at giving hp gains than the JWT is but at least it will be cheaper.
280/300, Very nice post. Thank you very much. I've had this car for about 8 years and its in very nice shape - much nicer than any other 300 I've seen. As you said, I love the car and I know what I have. I don't have to go searching for another car thats in great shape with no hidden problems.
My only gripe is the lack of power. I can live with it, but if I could drop a couple of grand and up the horsepower 20 or 30 percent its worth it to me. Any thoughts on porting and polishing?