Tach slows after 5k

[kpc_0721]

Car is a 91 240sx with a 95 motor swapped in if that makes any difference.

Just recently noticed that when laying wood to the car the revs will climb like normal but once it hits around 5000 RPM's it tends to slow greatly and seems like it will never get to redline.

Could this be a wiring problem or even possibly something mechanical?

Let me know if you guys have any idea what the problem might be.

[91SuperS13]

lol.... well the problem is your "laying wood" to your car!

[fliprayzin240sx]

Stock KA? Stock KAs have no balls after 5k, if you have stock everything...

[kpc_0721]

Nah motor is built, bored .20 over, 8.8 arias pistons etc. Car came with dc header and gay intake when I picked it up back in the day.

Just waiting on manifold and downpipe from AMS then it goes to get tuned.

It never had this problem when the stock motor was in, started after I swapped the new motor in. Also when im on the highway or at higher speeds the needle's tend to bounce around when they are loose, dont have a clue why they started doing that. Again that started after the new motor was in.

Oh and I realize "laying wood" should only be used in a porno

Stock KA? Stock KAs have no balls after 5k, if you have stock everything...