It seems when I search for parts. Some parts are suggnificently for the 88-92 model as appose to the 86 and 87 model. What is the difference. Why? ANd is there a problem with pre 88, post 85 rx7s?? I have an 87 and a bit on the worried side that I might have a car that I should have waited on to get a little bit newer of a model. Its a t25 speed

 

The new one has a different engine+dash ect.

 

Different engine???????? ARent they BOTH 13bs, or 13b-rew or whatever.. PLease EXPLAIN the difference. And is there an upgrade kit for my 87.

 

its 86-88 which is Series 4 (S4)

89-92 (we didnt get 92's so its really 88-91 for us the U.S.) these are Series 5's (S5)

Series 5's had 10% more power (S4 NA to S5 NA, S4 T2 to S5 T2) but they weighed more, which actually gave the Series 4 a better ratio in lbs/hp

There are some exterior changes, like new wheels, new body kits, the mirrors and side mouldings where all body color now (unlike S4 which had black side mouldings and whatnot)
Uhm, S5 had a different turbo (twin scroll) which supposedly helped it spool up faster. S5 also had a faster computer, updated dash, more black interiors, more sunroofs (well actually less cars w/o sunroofs), different compression, different taillights

The S5's are somewhat rare compared to S4's. So don't try to settle on a Series 5 no matter what, try to be reasonable (duhhh like we could do that )

http://2ndgenrx7.freeservers.com/page1.html heres a good site that you can read about 2nd gens on.

*edit*
And oh yeah, they both had same engine type, just S5 was updated. The S5 was more like the 3rd gens engine than it was like the S4 engine. Well in some ways but I won't try to confuse you any more.
And there are other differences like mechanical and electrical OMP, and fixed bugs, better alternator, bigger gas tank blah blah blah

 

I have had both. The only reason I swapped the 87 was I found the 91 with lower miles and leather interior. The mechanical differences are the minor tweaks that happen as a design evolves.