Its been a busy year with the GN, started with a dyno session last fall. The tuner I went to took a lot of time with the car making it very drivable when cold and hot, it drives perfect, no stumble, starts easy when cold and hot, tip-in is perfect, all good. He did find the turbos were too big, I suspected they were and this confirmed it. I wasn't sure if the big port S2 heads were causing it to lag or the turbos, it took too much rpm to get them to spool, 3 cylinders were not enough to spin S300s. It did make almost 700rwhp @ 6500rpm, a couple hundred off what it should make and not as fun to drive as I thought it should be.
So I sold the S300s and installed BW 7163 EFR turbos last winter:
These turbos solved the problem, these start to spool around 2500 and come in hard/fast, the engine has now come alive, the trans also bangs much harder even at light throttle. The EFR turbos have aluminum cores and weigh-in 12lbs lighter (each) than the S300s, they are water cooled so a bit more plumbing was required. The physical size is much smaller and the light weight made them pretty easy to install, just had to add about an inch to each downpipe which was easy.
Also installed a G4 knock detector which works great, sensor is screwed into the block:
When I received the engine from Chis the first thing I did was pull the pan and have a dipstick installed since this is not a drag race only car.
Also installed the new center console after I had a body shop paint it and I put in a much better street shifter. I built a new stereo system, I couldn't see the old stereo display very well and the tiny factory speakers just couldn't cut it. Had to sell the racing seat as it was too uncomfortable, the Braum seats I installed last fall get a 5 star rating from me, very nice seats.
Re-torqued the heads last winter as well while the headers were off, the Cometics spit oil on the floor when I park it, doesn't seem to leak when running only when I park it and it cools down. Still spits oil on the floor, I don't have it in me to pull the heads so it will just have to drip. Very happy with the whole car now other than than the oil drip, I love these turbos and the engine is very capable of 900-1k horsepower, its waay to much for the street which for me means its perfect. I have not had it back to the dyno as its too expensive but it really screams now, I have the boost at 20psi with dual nozzles spraying 100% methanol, no knock.
Mike