Slow 2013 Apex se Help!

[rxwarrior]

I have a 2013 Apex SE that has the following mods, Ulmer clutch kit, air box mod, and PCV all from Ulmer. It really won't run with the stock 2013 in our group and I am looking for suggestions. Thinking about going back to stock!

 

[kviper]

Check the power valve setting. It don't need to be off much to make a big difference!

 

[rxwarrior]

Power valve has been checked and rechecked and is spot on.

 

[superb]

I went through the same thing on my 2013 Apex. I put it all back to stock, except I geared it down one tooth and ground 2 grams off each stock weight and now it runs strong.

 

[rxwarrior]

Where did you remove the weight from?

 

[Winderallday!]

I have to agree, not a drastic improvement on my 2011 either. PCV with Ulmer map, stealth air box mod, Ulmer clutching. Little to no top end improvement, but low-mid range pull did improve significantly imo.
Dialing in the rpm with weights (washers) is key, based on what Allen Ulmer advised, the 2011+ sleds need to be in the 10,500-10,700 range for optimal power performance, due to the air box horn design and exup system.
Something to keep in mind with this vintage Apex, the non exup sleds were spec'd out at slightly higher rpm.

 

[kviper]

I had the same issue with my 12 after I did the same mods except I dropped gearing one tooth also. I have never been able to make a short track Apex quicker or faster on (snow!)by gearing down regardless of clutch setup. The short track just don't have enough track on the ground and most people won't run enough studs on the trail to get it hooked up. My 129" Apex bone stock was ski to ski with my friends 11 XTX, we both did the same mods except he did not change gearing and he could then pull me. I suspected the gearing as I have seen it before! I didn't verify it because I Turboed it before I had a chance to prove it.

 

[rxwarrior]

Sounds like I need to consider taking the ex up valve out and tune from there!

 

[kviper]

Do as you like but as long as it's good and it works I would keep it tuned and leave it in! The reason the newer Apex's don't respond to mods as well is because they are in a better state of tune to begin with.

 

[thor452]

what rpm are you running at? do you need to adjust the weight in the clutch kit to maximize things? What did Allen say about it? Most people say there is not much to be gained on the 11 and up machines.

 

[rxwarrior]

Allen has had me change secondary springs and different setups in the weights, all to no avail. Have decided to put it back to stock clutching and take the PCV off. Then I will see how it runs and work with my stock components.

 

[kviper]

Do you have a stock air box to put back on? Reason I ask is they were on the lean side to begin with so moded air box with no extra fuel would make it leaner yet!

 

[kviper]

Just a suggestion for you. Just put stock clutching back in, tune RPM and give it a try. Some times aggressive clutching on anything but extrem hard pac can be slower! A good example is a 500+ hp snow outlaw sled, the race is won and lost largely in the first 60' by bringing just the right power delivery for the condition's! Being to aggressive on a condition that don't hook up digs a hole to climb out of. On my friends XTX we had the air box/pc-v and if I remember correctly we added 2 grams to the stock clutching with a better driven spring. The spring with Allen's kit would be fine!

 

[rxwarrior]

I will order a stock air box lid to have in stock for testing. Viper, I was thinking about doing as you suggested with stock helix, arms, drive spring, rollers, and Allens secondary spring. Then we will see what happens. Been down many roads clutching customers n/a and turbo sleds along with mine and feel like I learned from one of the best in Arctic's Larry Coltom. He was one sharp individual as far as I am concerned.

 

[kviper]

Sounds like you're on the right track. Keep us posted it will be interesting to see your results! We have seen as much as 4 track hp from a good driven spring alone!