TurboB15sentra
07-25-2004, 01:56 PM
Just thought I'd share this info.. I recently installed a stock SR20DET into a customer's '91 coupe. The engine came without a harness and ECU.. So I did some improvising. I retained the stock KA24DE wiring harness and 5spd ECU, as well as the MAF and ignition coil. I bought a SR20DE N/A Silvia distributor off of Ebay for 50.00. This makes the swap SO much easier.. Everything plugs in.. you don't have to repin any of the body harness, or the two plugs on the passenger side fender well. Also, you don't have to extend any of the MAF wires or anything. The only thing that had to be spliced.. was the IACV/AAC plugs and the knock sensor plug. They are compatible with the KA ECU.. but the plugs are different.. so you just solder on new plugs to the KA harness so it plugs in. If you don't have spare junk harnesses laying around to nab the plugs from.. just cut the sensor's plugs off and nab the ones from the sensors on your old KA. Very easy.. It took me about 15 minutes to solder those 8 wires and shrink wrap. Then, swap over your coolant temp sensors.. and you're done.
Most people at this point, would get JWT to tune thier KA ECU to make it work... but, we've learned that you don't have to do this. Believe it or not, the KA ECU will run the SR engine just fine.. The only thing we did, was use an AFC to lean out the mixture a little because of the 370's. The car runs like a champ.. we put a wideband on it, and did some street tuning. At 11.5:1, the car is sideways in second gear, even at the stock T25's boost level. The only mods, are a FMIC and Walbro pump. The engine was gone through and new bearings, hone job, and new rings installed.. The head was freshened up as well with new guides and seals. This works well.. but I wouldn't recommend going over 250-260whp.. because of the timing curve in the stock ECU's map. But, since you have a lower compression engine, and the timing is pretty conservative from the factory anyway.. this allows the SR to run pretty damn good with a stock KA ECU and AFC. It was just SO much easier than trying to use the JDM ECU and harness.. If anyone wants a write up with wire colors/etc.. on how to do this.. I'll gladly make one up.
Travis
Most people at this point, would get JWT to tune thier KA ECU to make it work... but, we've learned that you don't have to do this. Believe it or not, the KA ECU will run the SR engine just fine.. The only thing we did, was use an AFC to lean out the mixture a little because of the 370's. The car runs like a champ.. we put a wideband on it, and did some street tuning. At 11.5:1, the car is sideways in second gear, even at the stock T25's boost level. The only mods, are a FMIC and Walbro pump. The engine was gone through and new bearings, hone job, and new rings installed.. The head was freshened up as well with new guides and seals. This works well.. but I wouldn't recommend going over 250-260whp.. because of the timing curve in the stock ECU's map. But, since you have a lower compression engine, and the timing is pretty conservative from the factory anyway.. this allows the SR to run pretty damn good with a stock KA ECU and AFC. It was just SO much easier than trying to use the JDM ECU and harness.. If anyone wants a write up with wire colors/etc.. on how to do this.. I'll gladly make one up.
Travis