Power Commander V PROS!!!!!

[Readymedic]

Hey everyone. Two weeks ago we were at McBride BC for a week. Temps were above +1 Celcius. Awesome snow up between 6200 and 7500feet.
The big question I have is about mapping. I put the Jaws Big Shark pipe(14HCR 800) on, which is a totally amazing pipe by the way, totally dialed in to where I live here at 1400 ft. Sled ran good for the whole week. I just got done cleaning up the sled and getting it ready for summer when I pulled the plugs. They have a heavy layer of carbon on them and literally chunks of carbon on them. I can't believe it ran so good, like a top, but now obviously looking at the plugs, I left a lot on the table.
I talked to Greg at Jaws when I got the pipe because they only use Boondocker, but I knew that I had to go with a PCV. He told me that the mapping is good up to 7000ft. Obviously it is, the sled ran, but badly carboned plugs.
The question for the PCV gooroo's....I obviously have to lean the map at that elevation, but how much.
I had some one send me 2 maps which I purchased and they are totally out to lunch. My sled barely runs, loading up hard with it. It flooded and puked hard.
My plan is to talk to Greg again, but what do other people think..

Any help sure would be appreciated.

 

[Thunder101]

A/F gauge is must. The one Greg sells is good bc it has large digital numbers.
Mount it close to the gauge so you can see both at the same time and the its just up to you figure your throttle posisions. 40-60-80 . 100 is the easy one.
This is how I do it . Weld your bung into the fat part of the pipe pointing at the tank seems to be a good spot.

 

[Readymedic]

Originally, I did have an AutoTune on, but that just did not work. The maps were all over the map, sled wouldn't run, just couldn't control it.
So that sounds like the best solution...... BUT once you get your readings of A/F, what do you adjust too in terms of that ratio. What numbers do you want?? 13-1 to 14-1?? Lower numbers, leaner? etc...

 

[DynojetResearch]

Readymedic,

As you've witnessed, The PCV does not perform automatic alterations to the maps when you change elevation.....but lucky for us the sled's ECU will do all the work and it does not have to.
Since the change in elevation (air pressure) is delivered to the ECU via its barometric reference, the fueling of the machine is constantly changing to keep things in check based on that changing air pressure.
I'll provide you with an example to display the beauty of the percentage mapping tables found in the PCV.

Say your ECU would run your injectors at 50% Duty Cycle at WOT in stock form at your home of 1400'. Based on tuners recommendations or your own testing, your Jaws Big Shark modification requires 8% added fuel to that WOT area for your desired AFR. Thus, 50% + (.08*50%) = 54% output duty cycle.

Now you come up to that elevation of 7500'. Based on knowing that engines make less power at higher elevation (lower air pressure), tuning engineers at Arctic Cat would have the ECU begin trimming fuel back at the same ratio of the decreasing air pressure. We can explore the math of the air pressure (14PSIa at 1400' and 11.1PSIa at 7500') ratio changing how the ECU would fuel the machine as:
11.1PSIa / 14PSIa = 79.2857%

Thus, based purely on elevation change alone, the ECU would shift to a different table in the mapping to deliver 79.2857% of that prior 50% it requested in stock form.
79.2857% * 50% original DC = 39.6429% new stock DC.

Now, the addition of your Jaws Big Shark hard parts modifications still needed that +8% fueling compared to stock (this bolt on didn't change in its efficiency)
39.6429 + (.08*39.6429) = 42.8143% new Mod DC.

And just to double check the math:
42.8143 required high elevation DC / 54% required low elevation DC = 79.2857% === the same as how much the air pressure changed.

Since the added "modifications" to your machine may require 8% additional fuel at low elevation, you'll still need that 8% additional fuel at all times no matter the riding condition. The hard parts of your engine are never changing, but purely the environment is.
Bottom line - you'll never need to Re-tune your sled to ride in a different area once it's dialed in - usually..... I say usually because - sometimes the ECU gurus who create the compensation tables can miss the mark slightly, thus didn't exactly nail their fuel mapping for low/high elevation.....we see this in some cases (especially Snow Bikes) and does warrant some additional changes to the map.

This is normally where Autotune can pop in and pick up the slack where the ECU missed. If you experienced difficulties when running the AT, 007 has done a great in field user report here for reference. The main things to remember with AT are:
- Use steady throttle applications on your tuning day w/ no braap braaping of the throttle. This jerks the DC around and induces accel pump pulses which the AT will try to follow. Depending on the location of your sensor, reversion could be an unwanted result skewing the readings.
- Establish a known good burn for your engine before relying on someone else's target AFR values. You are tuning your engine to obtain a light chocolate brown plug color and good piston wash. Your "sensor" might even need to see a 14.6:1 at WOT based on it's location, engine/pipe dynamic, etc., but the burn is optimal there - a reading on a gauge to shoot for is irrelevant, the condition inside the engine is important.
- Once you are getting close, either trim down the allowable AT window, only have AT active in the WOT area, or disable it entirely. You can set all the target AFR values to zero in the areas you don't want to tune, or set it to turn on with a switch, or remove it entirely. It's a very versatile tool allowing you to choose when/where it's active.

If you've recently idled your sled for extended periods, the black carbon on the plugs is quite normal. Lack of heat during idling, oil choice and high oil/fuel ratio adjustment are devious culprits.

Hopefully this can help you in your tuning quest!
~T.J.

 

[Readymedic]

Thanks Thunder101 and TJ at Dynojet. I have talked to you TJ once or twice before about the PCV before I purchased because I was a little unsure of how they worked.
The one part that I left out when I posted is that the fuel, 91 octane that we used was from a Husky gas station was called marine fuel but it was dyed pink actually.
When we went to McBride, there was myself,3 guys with Polaris 800s and a Skidoo Freeride. I asked the Polaris guys to pull their plugs and let me know what color their plugs were. I got the pictures back and they were nice brown. So who knows what that dye is? Is it an oil? Does it normally burn clean, I personally can't see it because it is an additive.
I understand the concept TJ, but my sled definately did not run in an idle state very long at all over those 4 days. So for carbon to be caked on and literally chunks on the plugs, I can honestly say that my map from Jaws is too rich at that elevation. DOES ANYONE ELSE AGREE??? I'm not looking for guys to send me maps NOT, just looking for insite into this problem. I need help on this one guys. Like I mentioned in my first post...the two maps which I purchased was for a low elevation and a high elevation. The numbers are ridiculous!!! Who adds 18% fuel at 8000 feet!!!!!!!!!! LESS AIR REQUIRES LESS FUEL or a RICH CONDITION EXISTS!!! YES OR NO!!!!!
I'm sure I understand air/fuels ratios and rich is rich and lean is lean..

 

[Insaneboltrounder/sjohns]

You have to remember , the jaws pipe flows more air and requires more fuel to make the added hp it makes. Hp isn't free. They are adding extra fuel over and above what the cat ecu is calling for at 8000 feet. Without it you would burn up.

 

[tchriste]

I run a PCV, autotune and POD-300. The autotune and POD-300 can be used as an AFR gauge when the autotune is not turned on. I found working with a PCV and autotune without the POD-300 was trying to tune blind. Thunder has a good point with having an AFR gauge connected and the nice thing about the POD-300 is that it will tell you AFR as well as Throttle position, RPM, duty cycle, etc. al the information one needs to tune so f you find a bad area you can clean it up by following TJ advise.

 

[Readymedic]

I definately get that when you add 8% at a low altitude, you need it at high altitude. Yes, this pipe flows like a dam!!
But why after a week of riding at 7400-7600, my plugs are layed carbon and carbon chunks..if the ECU is still compensating for barometric and temp differences above my map..why is it happening???
I have always been a carb guy and carbon is rich, why isen't the same for EFI..
So is a A/F gauge recommended??

 

[Readymedic]

Just purchased the POD-300, but too bad winter is done here.
But everything is still kinda a mystery to me.
So dealing with AFRs then, to clarify,,,what numbers are lean and which ones are rich...??

 

[Anylizer]

We ride at 10,000ft. The best initial map to date was a map from Jim At Dynotech Research. This map was developed on his dyno at 700ft. It is far closer to the correct map at 10,000 ft. than ANY other map i paid for.

There is no need for 2 maps (high/low elevation) with the PC-V just another gimmick sold by some guys.

 

[Thunder101]

Pretty sure that marine fuel is higher octane which you did not need and will hurt performance unless your mods require higher octane.
Tchriste that pod-300 sounds interesting. The only problem with tuning the way I do it is my eyes are looking at the gauges and my thumb is recording throttle posision . Lol. I do this in a safe area .

As for a/f ratios 11.75/12:00 wot
Mid can be 13.5/14.5
Idle 13
THIS IS WITH THE SENSOR IN THE FAT MID PIPE

 

[tchriste]

the POD-300 will allow one to record a run and later play it back so one can see what happened during the run. One can record a number of different perimeters such as RPM,TP, duty cycle etc. and compare with existing AFR table. I find the POD-300 a much better unit than the old LCD-100 for many reasons, most importantly one can actually read the screen while riding. I spend a lot of time changing my machine, consequently I spend a lot of time tuning and the POD-300 is a great tool.

 

[Readymedic]

Thanks guys for the info. Ya, definately can't wait to get that POD-300 hooked up.
GOOD INFO!!!Thanks for the info on the A/F numbers, something to shoot for now. When I did have my auto tune hooked on, I guess I should of took a picture of the factory #s.
Hey tchriste,,,do you need to have the Auto tune running to see the AFR numers or no..hope not.

 

[tchriste]

One does not need to have the autotune turned on to see AFR numbers on the POD, I run the autotune as an AFR all the time when I'm not tuning. It would be interesting to see what the factory numbers were, I did hook up my EGT on my sled before mods just to see what the numbers were, however EGT numbers change as mods change. TJ made mention of something that is very important to be aware of in that one mans AFR table my not work on your set-up. For example the AFR table I used on my slightly modified 800 was leaner on WOT than my fully modified 800 (12.8:1 on slightly and 12.2:1 on Fully) both these AFR gave 1225-1250 *F EGT and good plug colour and piston wash. When I started tuning the 925 it required an AFR of 11.6:1 to see 1225*F EGT with good plug colour and piston wash. The tune for the 800 below 6,000 RPM ran a bit richer than what the 925 liked, the 925 does not do well in a rich condition where as the 800 could run and clean up better and quicker so my AFR below 6,000 RPM for the 925 in leaner than the 800.

If one changes their clutching, ones fuel requirements will change and one will have to retune. I installed a P-85, as the P-85 pulls much harder in the lower RPM range I needed to increase fuel in this area.

Then one throws different fuel into the mix and changes have to be made again, it's a never ending science, it's a lot of fun and it can be frustrating.

 

[unboltedkitten]

I am running a big shark setup on a 14 m8 too and was dead set against a boondocker fc at first. But after riding a couple with it I was impressed and the selling point for me over the pcv was that if u have any mapping issues at a different elevations u don't need to pack a laptop with u to make changes.

 

[Readymedic]

Really...no computer..hmmm.

 

[tchriste]

with the PCV I use an 8" tablet for field tuning.

 

[Readymedic]

Which tablet do u have? My Samsung Tab 3 won't open the files.
Nor my phone either. Downloaded Adobe but won't open..

 

[tchriste]

Acer Iconia Tab 8 W with Windows 8.1. The screen is a bit small for working on, however it does work and I don't have to pack a laptop....the laptop is more versatile however.

 

[jbusch]

I use the hp stream it works great for changes. I changed out my windshield for a dan adams bag and keep the stream and the USB cable in the windshield bag.