Ok, I bought this car and did not build it, 1st, 2nd, 3rd and even 4th gear seem fine. My 5th gear is an issue. When I'm on the freeway doing 75 mph, my rpms are at 4k. Seems just a tad high for 5th gear lol. Is it something that can be adjusted by the chipped p28 that I have or does the tranny need to be taken apart and done that way?
Engine is a b16a3 with a b series tranny.
F.Y.I. Who ever had it before my buddy sold it to me put a lot of work into this engine, forged pistons, rods, cam, intake manifold, injectors, hasport mounts, aem fuel rail. Lots of stuff I didn't do, and it did a turbo kit on it before I got it. Thanks ahead of time for suggestions.

 

That sounds exactly right for a B16/ITR tranny. You can swap in an LS 5th gear set to drop the RPM down a few hundred RPM to cut down on the noise, but it wont do much for the fuel situation.

 

Bummer, fuel is worse than I thought, but what concerns me is when I put the turbo kit in, if I reach full boost at say 4000rpm, then I'll be driving on the freeways that way. Hhmmm

 

You'll only be in boost if your foot is in it.

Even with the gearing you should be getting 35+ mpg cruising when tuned right.