djhammy

I was searching around for a cold air filter kits, and got no where, all I found were specifically for newer sleds, so im working on fabricating my own, I had to cut out a portion of the air box to make room, so the ecu and tools stay where they are...and I can use two 90 degree rubber boots at 2.75" ( slightly cut shorter on throttle body side) with two 60 degree aluminum pipes with a few inches of straight length on each side ( cut down to fit properly ) and either im going to use two mushroom filters or a shorter cone type. one of the tubes somewhere i'll have to drill out and attach the air sensor. should give my cat a nice growl noise as well as a bit of throttle response, plus a bonus of not worrying of mice getting in and nesting up in the factory airbox. they way I figure it is the filters will be over the the top end of motor, cone type would prob be just clearing over the spark plug boots and should get some nice abundant fresh and cold air from top side vents. I have yet to purchase pieces needed but im guessing under $80, aluminum tubes being the most expensive, but anybody else get creative on this subject?

smokingcrater

One thing to keep in mind, if you don't adjust the fuel pressure or ecu programming, you will most likely burn the engine down. EFI snowmobile engines are open loop, they don't monitor if the engine is running rich or lean with an 02 sensor. They just know that with the stock intake and exhaust, they have to add X amount of fuel at X rpm's. If you allow the engine to breathe better, either intake or exhaust, then you have to add fuel. The ECU won't do it for you.

__________________
1) 2000 Arctic cat ZR 700, which now thinks it is a 2001 ZR 600 EFI APV w/136" ripsaw. (for sale!)
2) 1995 Yamaha VMAX 600, which now thinks it is a Polaris! (Polaris x10 suspension, Polaris P85 clutch) (for sale!)
3) 2004 Yamaha Warrior
4) 2006 Yamaha Nytro

f7hustler

i will almost guarentee you wont show any power gains... About the only thing going to change is the noise level of your intake adding pipes to the intake tubes will also change your low and mid range throttle response mostly for the worst air boxs are designed the way they are for a reason not to mention arctic cat runs "case reed" engines which means changing the intake wont do anything unless your going to spend the money and have your cases seperated an tunnel ported you have to look at intakes like sucking through a straw the more holes in a straw the harder it is to bring air through it at a steady pace im all about making more power but it just wont be beneficial man but in the long run its your machine and youll do what you want with it good luck hope it works out for you

djhammy

there cant be just one reading the ecu allows, really? theres a sensor that reads either the air temp and or flow of air. and were not talking about supercharging it, just allowing a bit more fresh cool air, maybe my heads stuck in automotive but an ecu is an ecu and should adjust within its factory ranges.

kccats

It is a great idea! I built one for my 95 ZRT! And have a SLP air breather on my 02 ZR!
If you duct the cold air in threw the hood and insulate it from the engine heat!

smokingcrater

in a car, you generally have a mass air flow sensor (MAF) and also an 02 sensor. The sensor is the key part, it allows the ecu to see how rich/lean the engine is an adjust for it.

In your sled, there is no maf. Its essentially running speed/density tuning with no feedback from an 02. The ECU has no way of knowing you allowed the engine to breathe easier, and it has no way of seeing rich/lean conditions. (the sensor you are seeing is just a simple temperature sensor, which really isn't going to help one way or another in this situation)

Think of it this way, if you DO make any improvements, you are going to have zero additional fuel going in to compensate. Not exactly something I'd personally be comfortable with, I'd be watching the plugs REALLY closely for the first couple runs.

__________________
1) 2000 Arctic cat ZR 700, which now thinks it is a 2001 ZR 600 EFI APV w/136" ripsaw. (for sale!)
2) 1995 Yamaha VMAX 600, which now thinks it is a Polaris! (Polaris x10 suspension, Polaris P85 clutch) (for sale!)
3) 2004 Yamaha Warrior
4) 2006 Yamaha Nytro

djhammy

Kccats...you have any pics of your set up? Ill post one as soon as I get done with it...

kccats

I would if I could! The Cat EFI has an air temp sensor!

djhammy

yup and the ecu should read cooler air, and adjust, maybe not by much, but enough for a reason for arctic cat to have the air temp sensor over not having it for no purpose.

djhammy

and im not sayin i'd se these hp gains, but these do. and id have mine getting cooler air though the top vents, but check this out.....

Clean Air Intake Systems | Hi-Performance Engineering

kccats

I have the airbox lid Air Breather, and it gets it's air threw the hood behind the windshield!

smokingcrater

Yes, it will adjust for cooler temps. No, it will not adjust to air flow differences if you allow it to breathe easier... Again, you are adding air without adding additional fuel. You might get away with it, or you might make it 10 minutes before the engine pops from being lean. Air temp isn't really a problem, as snowmobile sleds give off very little ambient heat. Your intake charge temp is essentially air temp, without modding the airbox even.

I know it isn't what you want to hear, but the ECU's on sleds are as brain dead as they come. They do NOT account for mods in any way, it is up to the end user.

If you are going to do it anyway, I'd suggest running the ethanol wire at least. That really has nothing to do with ethanol, it kicks the ECU in a different fuel map which dumps more fuel in, which just happens to correspond to burning e10 gasoline.

__________________
1) 2000 Arctic cat ZR 700, which now thinks it is a 2001 ZR 600 EFI APV w/136" ripsaw. (for sale!)
2) 1995 Yamaha VMAX 600, which now thinks it is a Polaris! (Polaris x10 suspension, Polaris P85 clutch) (for sale!)
3) 2004 Yamaha Warrior
4) 2006 Yamaha Nytro

kccats

No not at all! Even a Ram air intake would NOT add enough air to lean it down!
Cold air intake is just that COLD! The air temp change WILL add hp!
BC Dan put a great section in on just this!
BC Dan can you repost it here?
Great read!

djhammy

I respect everyones input, regaurdless of knowledge but yea im waitin on somebody with some expertise and proven results, to back up the idea....

kccats

Do the search of BC Dans findings!

djhammy

I read what bc dan had to say, sounds like I do know what im talkin about regaurdless of it being a cat efi, not just a car.... same principles apply, if used correctly (away from engine heat, getting fresh cool air) I guess those with carb however might run into some problems and need adjustments. all in all I just wanted to hear that atleast it wont be worse than the factory cheap air box.

kccats

My ZRT is carbed and I have NO issues!

djhammy

so I got some photos for you guys to check out my custom cold air im tinkin with, so this is basicall y what I came up with, the air sensor is being used, I mounted it in center of one of the tubes. next step is I got some aluminum sheets coming in two dif thickness's .032 and .063 (like a dime to a nickel thick) and build a box/ housing of some sort to route the fresh air from hood vent or vents by speedo/windshield, I got a couple of ideas, but not set yet. ill show where I cut out/trimed out the factory air box and what it looks like done.

Attached Thumbnails

       

93Wildcat700

It wont burn down because 99% of those cat EFI's are already running rich as hell.

And even if you ran open intakes (no filters) dirt scoring your pistons would be more of a issue than leaning it out. Wont happen.

But if you just made 90's to those uni's you may not have enough air volume.

I cant tell from the Pics what exactly you have going on. If those are just 90’s facing up into the uni filters you may not have enough air volume and you are taking in hot air. You want the feed for the airbox to be totally outside the hood.

What I did was leave the stock lower portion of the airbox alone and I feed the two horns in the airbox with OUTSIDE of the hood air. That will help
Those unis will be sucking massive amounts of hot air. They will work fine when its cold out but you want the airbox totally sealed from under the hood air.

Maybe you can use the lower portion of the airbox and than put the filters outside of your hood. You will have to figure out a seal and how to open close hood but it would be much more beneficial.

__________________
1993 Wildcat 700 EFI- river runner

2000 ZRT chassis/Wildcat 700 EFI motor swap. Stock lol

93Wildcat700

What i plan on doing is having 2 aluminum ducts that feed the upper air horns i am going to ditch my speedo and RPM gauge and run those 2 holes as intakes..

Im sure you can picture it. So imagine your unis outside the hood feeding the box. Much more efficient.

I have other secret plans for Speedo\RPM.... Trail tech Vapor Shhhhh

__________________
1993 Wildcat 700 EFI- river runner

2000 ZRT chassis/Wildcat 700 EFI motor swap. Stock lol