S/C Apex Timing suggestions?

Zuki1216

Extreme
Joined
Dec 9, 2015
Messages
93
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Location
Indiana
Country
USA
Snowmobile
08' Apex LTX
07' Attak MPI S/C
After 2 years, I've finally been able to get this out in the snow and try to tune it. I'm still working on getting the fuel tables correct, but they are close. I've been unable to find much info on what to use in my ignithion tables though. The map I got from Allen was a great starting point, but it wasn't using anything in the ignition tables. So is it common to just run stock timing? I'm only running 5-6lbs, but I don't know how advanced/retarded stock is. Should I pull timing uptop? Rule of thumb I always heard was 1 degree per lb. How about idle, and mid?
 
After 2 years, I've finally been able to get this out in the snow and try to tune it. I'm still working on getting the fuel tables correct, but they are close. I've been unable to find much info on what to use in my ignithion tables though. The map I got from Allen was a great starting point, but it wasn't using anything in the ignition tables. So is it common to just run stock timing? I'm only running 5-6lbs, but I don't know how advanced/retarded stock is. Should I pull timing uptop? Rule of thumb I always heard was 1 degree per lb. How about idle, and mid?

5 to 6 lbs.. I would leave it stock.. Your not running enough boost to worry about it. Whats the AFR WOT at 6 lbs?
 
Running fat mid to low 11s from the few logs I've compiled.
 
Running fat mid to low 11s from the few logs I've compiled.
It harder to get the low end right.. SC in the Apex is a pig. I have had my SC Apex with Thick Head Gaskets at 12lbs of boost and its getting better but still a pig to drive on the trail.
 
looking more at my logs ,it looks like I'm only make 4lbs of boost? wtf? Am I looking at something wrong, or do I have issues somewhere? It's setup with 22/26 pulleys now. It was 26/22 when I bought it but didnt want to rely to race fuel where we ride. It had the GEMS on it. I switched pulleys, added MPIs BOV and went with the PCV PTI w/ autotune. Riding is mostly Michigan. Don't think elevation goes much past 1500ft. And I'm pretty damn sure I have no leaks.

18.57
18.46
18.59
18.2
18.98
18.79
18.79
18.75
18.74
18.82
18.68
 
looking more at my logs ,it looks like I'm only make 4lbs of boost? wtf? Am I looking at something wrong, or do I have issues somewhere? It's setup with 22/26 pulleys now. It was 26/22 when I bought it but didnt want to rely to race fuel where we ride. It had the GEMS on it. I switched pulleys, added MPIs BOV and went with the PCV PTI w/ autotune. Riding is mostly Michigan. Don't think elevation goes much past 1500ft. And I'm pretty damn sure I have no leaks.

18.57
18.46
18.59
18.2
18.98
18.79
18.79
18.75
18.74
18.82
18.68

If its not loaded hard it will make less boost too. Id you clutch weight really light, hows the RPMS?
 


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