just had my nismo single coppermix put into my s15.
first impression was DAMN is it noisy!! Is this thing installed properly?haha
I get vibration noise all round until i get over 4000rpm. 1st and 2nd are ok actually, but worst would be 50kmh in 4th, 80kmh in 5th and 100kmh in 6th. funny enough they are my cruising speeds. makes whole cabin vibrate. chatters a bit when slowing down also.
but seems very grippy, i have only put 80km on it so far, so been taking it very easy.
it's just a little stiffer than stock on clutch in. pretty good i reckon.
I just have to put up with it, spent a lot on it.... didn't quite expect all that noise though.