Question about gutted exhaust (please help)

[87gtNOS]

I installed an Excell and now have a low end stumble. I tried the Pod CO adjustment up to + 20 with no success.

This was tested last winter, or in your garage just recently on concrete?!

Last winter. Rode about 600 miles with the Excell and pod adjusted to +20. I know not to evaluate the sled unless i'm out riding.

LOL!! Just checking! Too many people driving their sleds in the their garages!

 

[SledFreak]

From FixPowerSports says, for intake mod, that it may bog for a bit until the computer learns it and it will soon compensate for the more air flow. Wait about 60 miles or so, then if it still bogs, add soe fuel throught the pod. Go up to +10.

You need a MAS = Mass Airflow Sensor (which the Apex doesn't have) for the ECU to compensate for changes in airflow. I had a White Knuckle Exhaust and didn't have a stumble but it resonated badly in the midrange. I installed an Excell and now have a low end stumble. I tried the Pod CO adjustment up to + 20 with no success. I have since purchased a Power Commander III. I have a modded air box and have yet to ride it with the Power Commander and air box mod. Most of the time when opening up the intake or exhaust you will need to make fuel map adjustments unless you are already running rich. The Apex midrange is already lean from the factory so quite a bit of fuel was add in the Power Commander fuel mapping to compensate for the increased airflow.

Mirance, did you buy the PC III from Excel or did you buy it from Ulmer? I thought the same as you about the computer learning it, because my Grizzly 700 is the same and it has no mass air flow sensor. But I'm no expert and FIX seems to sell some good stuff.

 

[cat hunter]

My 06 Apex GT did the same when I gutted the muffler The sputter down low dissapeared after I drove it for awhile.I think the computor adjusted the problem.Works great for the last 2 years.I think you should put some miles on it before you adjust anything.

 

[Iceman57]

Mirance, did you buy the PC III from Excel or did you buy it from Ulmer? I thought the same as you about the computer learning it, because my Grizzly 700 is the same and it has no mass air flow sensor. But I'm no expert and FIX seems to sell some good stuff.

From Ulmer. The ECU needs some way of telling it that there has been a change in the airflow. There is no way the ECU can adjust for a increase or decrease in air flow without a MAS (there are two kinds used, the vane meter and the hot wire, the vane measures air volume and the MAS determines the mass of air flowing into the engine’s air intake system) or compensate for a lean or rich condition readings off of a o2 sensor also known as; Wideband zirconia sensor or lambda sensor, the Apex has neither. For the ECU to learn and compensate properly for changes it would really need to have both.

 

[apexgt4life]

to do the comuter reprogram were is this thing u have to add the paper clip too