I am running around 12- 13#'s. This has been a long and expensive journey. The MCX kit was not available when I purchased my MPI stage 1 kit. I blew a motor and had to do new block and pistons, head work and valves. I put in low comp wiseco instead of shim and carillo rods. To push these up you have to upgrade the fuel pump and add 4th injector to get enough fuel at WOT to see sub 11 AFR #'s.
Late last season I was running 9#'s on the XTX and would pull the skis 12" on launch and then at 40 start to rise to almost 3'. I feared blow over several times and then I tore both limiter straps. Other than stupid stuff like revers actuator failure, hand warmer and dash pod failures no running gear problems. Over the summer I spoke to Matt at MPI and Allen Ulmer cause I was not happy with AFR #'s or clutching that Hauck put in it. I droppe the sled off to Allen and said I want the max.
We remachined the primary for true overdrive not Haucks 1 sheave system, machined the secondary for spring bind relief, added 4th injector. Found I did have a cracked header and replaced that. He went through the entire machine and then set the switch for 9 & 12#'s of boost. He then clutched it on the track dyno where at 12#'s it made a calculated from track HP 252 hp. It is almost perfect now just banging off the rev limiter 2 times on launch casue it hits so hard I have a bit of track spin in loose conditions. 9 is great on the trails and 12 is crazy on the lakes. I only have an afternoon of running 12#'s but have seen sub 7 seconds 0 to 100 mph on GPS. I also coupled the rear suspension to keep the front end down.
https://www.youtube.com/watch?v=pOztLtIkIYE&feature=youtu.be
Late last season I was running 9#'s on the XTX and would pull the skis 12" on launch and then at 40 start to rise to almost 3'. I feared blow over several times and then I tore both limiter straps. Other than stupid stuff like revers actuator failure, hand warmer and dash pod failures no running gear problems. Over the summer I spoke to Matt at MPI and Allen Ulmer cause I was not happy with AFR #'s or clutching that Hauck put in it. I droppe the sled off to Allen and said I want the max.
We remachined the primary for true overdrive not Haucks 1 sheave system, machined the secondary for spring bind relief, added 4th injector. Found I did have a cracked header and replaced that. He went through the entire machine and then set the switch for 9 & 12#'s of boost. He then clutched it on the track dyno where at 12#'s it made a calculated from track HP 252 hp. It is almost perfect now just banging off the rev limiter 2 times on launch casue it hits so hard I have a bit of track spin in loose conditions. 9 is great on the trails and 12 is crazy on the lakes. I only have an afternoon of running 12#'s but have seen sub 7 seconds 0 to 100 mph on GPS. I also coupled the rear suspension to keep the front end down.
https://www.youtube.com/watch?v=pOztLtIkIYE&feature=youtu.be
CustomApexMan
Extreme
Yes I was
CustomApexMan
Extreme
RIGIDONE could you hear the blow off valve lol. You had two nytros with pipes right?
RIGIDONE
TY 4 Stroke Master
Your sled is very impressive, I was off the trail talking to a buddy at a house on O'hara rd and you went by about 60 and wacked it..Skis in the air!!!holla!!! lol..I saw you stopped a mile or so down the trail, I was going to stop and chat with ya but I didn't want to drool all over your sled..lol
RIGIDONE
TY 4 Stroke Master
Oh hell yea I heard the BOV!!!!SICK!!! to say the least, I was with a big guy on the purple Nytro, (He was riding my wifes sled, his was in the shop) and I was on the blue one..
jpnytro240
Veteran
- Joined
- Jan 24, 2012
- Messages
- 42
Hey yamadog what coupling system did you use?
