ALL black top sr20det's come with 54c pistons and updated piston oil squirters (to take advantage of the newer piston design). Blacktop sr20det's also come with a better oil pickup although they still come with a crappy little pan. All black tops also come with the larger O2 sensor..."fat-type".
97-98 kouki blacktops do come with the J4 and a harness to work with the updated design but the mafs are the same. If you really wanted to eliminate the J4, there's no need to waste your money on a new harness. Instead, you can repin the old harness to work with pre-J4 ecus. Also, if you got a redtop ECU to replace the J4, you'd have to change the O2 sensor to the older, "skinny-type".
I wouldn't bother with swapping out the J4/harness/o2...I had the same "problem" when I was trying to figure out how I was going to run an ecu tune with all my upgraded parts. I was planning on running an Enthalpy tuned pre-J4 ecu and repinning the harness. Now that Enthalpy is MIA and rarely responds to emails anymore, I'd ditch any retune ideas since he was the only one doing them with half a brain. Today there are more options.
You can get a bikirom for around $300 wich will allow you to hookup a latop to your stock ecu and anyone can tune it (yourself included). I would have gone this route but bikiroms are currently backordered for a little while.
I ended up getting a used power FC for a kouki blacktop. I got the PFC for next to nothing since i got it used and without a controller. The controller sucks though anyway so I bought a FC-datalogit which adds inputs/outputs to the power FC (for datalogging or a wideband o2, fan control, ect). I basically got a full, plug and play standalone for around $500...can't beat that IMO.
Anyway...there's more than one way to skin a cat.
S13 Slide said:
I also heard that the oil Squirter patterns on the Black Top are different then the Red top???
You are correct sir.
95se5384 said:
They are the same save the money and buy a redtop the only minor diffrence is a larger o2 in the blk top and a grid pattern on the front of the blk top head that serves no point..
Note to self, don't take advice from 95se5384.