Hi! I'm a rotary newbie, having just bought an 83 RX-7 Limited Edition that had been sitting for 2 years for $500. After cleaning up the carb, rebuilding the starter, and cutting off the cat, I've finally gotten to enjoy driving the thing (albeit gently while I get everything worked in). I have the 12A engine in it, and wondered how much of a performance difference there is between that and the 13B. I'm thinking about dumping some money into the car and would like to know if the 12A is still viable or if I really have to get the 13. It's the first car I've ever had 'for fun' and am still learning alot about car repair in general, and have no prior experience with the rotary. I'm not looking for ***** out...just fun.

Thanks Much

 

You'll have fun with the 12A. Hell, you dont even have to port it to have fun with it... just get some decent headers and you'll be ahead of the game. If that isnt enough, get a different carb, or get your Nikki modified. Once you've got all that stuff done and you want more speed... port the motor!

 

Too many people just want to yank their 12As and shove a 13B in. Be a man, make that 12A scream (hahaha).

Seriously though, the 12A is a great engine and it can produce a very nice amount of power for that 2400 lbs chassis with a few minor mods - carb, pump, headers, cats and intake.

 

I agee with RXcertra, keep to the 12a as the advantages of going tu the 13b are limited.

Too many people throw out there 12a based on incorrect advice dropping in a 13b will give you up to 40hp. The real difference between the two motors with everything else being the same is about 12-15hp.
Most of the misleading comparisons are based on having a good EFI on the 13b.

There is little demand for 12a motors so the change over could cost you $500 plus labor, the price you paid for the car in the first place!

In reality you will get some 12hp increase for say $500 [local prices vary considerably]. Go for a good header on the 12a and you could get twice the increase for half the money. Use the saving to have a modified carb and you will be up by some 40-50 hp overall. at that level you will have a great fun car with plenty of opportunity to pick up speeding tickets

When your exhaust and muffler needs relacing upgrade according to what is best locally.

When the time comes for a rebuild then going for a street port is a relative cheap way of getting more power up, to 80 hp total increase
To give you an idea of how much you will need check out some of the prices in the net, say at pineapple racing, but remember the need to take the motor out to get a comparison with your local tune shop,

If you want to end up with a 200+ motor, then it is worthwhile going the 13b route. After that it is how fast you want to spend your money.

However whatever you add, the power has to come out somewhere.
Brakes, clutch, and diff could be worn while internals may not take the increasd load. Don't end up with a hot motor in a dead car!