S/C Apex Gems settings 10k

[SRXSRULE]

Looking for a good starting point on stage 1 S/C for 10,000 ft. Its set to full boost so should make right around 10psi.

Did several short test drives today at 1,000 ft just to check for leaks and all that stuff. One thing that I couldnt tune out of it was right around 6 to 7000 rpm with very little throttle movement it would surge or cut out for a second. I thought maybe it was the TORS so I bypassed that and it still did it. The second issue was at that same rpm range and with steady throttle the air/fuel would jump from 12.5 to 17.1

I have seen a few posts now about the throttle return spring needing adjusted. There was only one time today the sled felt like it stayed accellerating when i let off the throttle so i will likely do something with that.

Last thing, Spark plugs. stock plug or the 10ek's and what gap. Thanks for any help. Eric

 

[mtnxr]

I ride mine from 7-11k but spend most of my time at 9-10k. My settings are:

Mode 1: 2
Mode 2: 3
Mode 3: 3
Mode 4: 4
Mode 5: 2.5
Mode 6: 4 down low and 2.5 to 3 up high

When my sled surges bad it is usually mode 6 is set too high and needs to be lowered. Those numbers should get you close based on my experience over the last 3 years. Good Luck.

 

[SRXSRULE]

Thank you very much. Any other tips or sugestions you have gathered?

Are you running stock weights in the primary? Any idea how much weight you have in them?

Eric

 

[mtnxr]

Stock primary weights fully loaded with rivets, B-P-B spring 14.5 rollers and about 45 deg of helix on the shockwave with a white spring @ 70. It over revs some but overall it works pretty well

The clutch setup is actually from MPI so I did not come up with that on my own. I did try running the 8FA weights loaded and it pulled a little harder down low but suffered 1000 rpm swings on a deep snow hillclimb.

I think my main struggle was learning the GEMS controller and how it worked with changing altitude/air temp/air density all in combination. Some days when I went from the truck to 10k feet, the sled would surge so bad it would almost thow you over the bars like someone else was in control of the on/off switch. If you suffer from that, adjust the altitude, mode 6 down until it clears up. It was so dramatic that I was sure the GEMS got wet and carried a spare controller all the time until I figured out the adjustment. At first I tried adjusting too many settings at once...if the settings worked 1000 ft lower leave them alone except for mode 6.

I have come to the conclusion on these that if you get them running at 90-95% your gonna be pretty dang happy with the performance and learn to live with the 5% or so that's not quite right.

 

[stu]

gems mode

please explain mode setting on gems. when tou say mode 1 set at 2 what does that mean? And how do you get it there? i have a stage ii MPI nytro and idles at 13.7 AFR runs about 14.5 at wot. First ride and still learning grms settings

thanks

 

[mtnxr]

I think you might want to study the info from MPI to get a grasp of the basics. Here is a link:

http://mountainperformance.com/Files/Download/Nytro Supercharger GEMS Controller Setup.pdf

Then maybe talk to Matt or Mack at MPI to get the base settings for your elevation and setup. I am not familiar with the Nytro or stage 2 stuff. I carry a printout of the above linked info with a pen in my sled and make notes of my settings in a chart form...Get it close and make 1 adjustment at a time and you will get what you want.

Good luck.