I am currently using the GTY-R stepped stainless steel, carbon fiber exhasust. I pulls harder off of the bottom, a little stronger through the mid and about the same up top. It is louder than stock, spark arrested, and needs to be repacked often, but I really like it. I have heard the DSP is very good too but very loud.
i've got the dsp stainless unit on my '00 426. love it. i believe i have the motocross header, and it runs a lot like my '99 400 with the fmf silencer and power bomb. the 426 hits harder and makes more power to be sure, but the style of delivery is very similar. it "breathes" easily, if that makes any sense. to compare, my buddy has the same bike, and for a while he was using the white brothers e-series. the bottom end was monstrous, but the bike felt stuffed up - maybe it was a difference in compression braking.
anyhow, my elevation is around 1000' and i'm jetted with a 168/45 pilot/main combo.
I have another question..I experienced severe amounts of plug fouling w/ my' 01 426 when the temp was 50 degrees or less.My friends who have 426's say they leaned the pilot one step from stock and relieved the problem. Anybody have any similar probs?
i do ride tccra - either look for a yellow yz wearing number v2, or a skinny feller in a bright orange helmet. the yellow yz is actually a 400 - i only use the 426 for motocross - and it has an 8 oz. flywheel weight. i'm not even sure if terrycable is making that one for the 426, though. if i heard correctly, they are only offering 10oz. and larger. either way, it's a good move for a tree machine.