SUPERTUNER said:
Yea I have twice had my filter pack right off and it is totally stock. The engine ran terrible and now I noticed that my tail pipes are black with soot. This could be why some people are carboning up their rings and using oil.
Trxster
TY 4 Stroke Junkie
I just bought some home HVAC vent filters...you place them under the vent/registers and they allow air but filter some stuff. I got a pack for $3.50 at the local hardware store and I cut them to fit all of my hood vents. I then used a glue gun to glue them in. I also glued one under the lip of the front hood to keep the snow out of the front compartment. I think this will reduce the amount of moisture in the compartment dramatically on the deep snow days. I also reinstalled the rubber flap to keep some heat in the carbs. I also found last time that turning the carb coolant switch to full open helped keep things running good. If I still see excessive freezing moisture on the pre-filters I will try to bypass the Evac system.
Trx, neat idea.
Question: Is there a fine line between to much vent for purposes of snow passage and too little for proper cooling of the brake, clutches and/or other stuff and/or to properly feed the beast with enough air to roar right, not to mention the potential heat saturation perfomance loss ST mentioned?
If I found some minimal filtering material, I'd probably try filtering all vents. The tighter the filter (I'm using duct tape on the inside right now - cant get much tighter than that), I was only comfortable going with the two smaller v shaped vents at the nose not knowing jack about the possible bad things that could come of not enough air under the hood.
Anyone know of a source for getting sheets or rolls of the pre-filter material like the stuff used in Fredie's kit, preferably in different color options?
Question: Is there a fine line between to much vent for purposes of snow passage and too little for proper cooling of the brake, clutches and/or other stuff and/or to properly feed the beast with enough air to roar right, not to mention the potential heat saturation perfomance loss ST mentioned?
If I found some minimal filtering material, I'd probably try filtering all vents. The tighter the filter (I'm using duct tape on the inside right now - cant get much tighter than that), I was only comfortable going with the two smaller v shaped vents at the nose not knowing jack about the possible bad things that could come of not enough air under the hood.
Anyone know of a source for getting sheets or rolls of the pre-filter material like the stuff used in Fredie's kit, preferably in different color options?
SUPERTUNER
TY 4 Stroke Master
Sodbuster said:
Yep...I have in stock or can get...
Color white, red, blue, black, 11"X12"X3/4" coarse filter media $8.00.
Color Green, 12"X16"X5/8" tight media $13.00. Black 12"X24"X3/8" coarse media $13.00.
8"x10"X2" Red, blue, black $13.00 each.
8"X10"X2" Red very coarse media $13.00. <--probably not good for the application but who knows until someone tries it.
Freddie, I was thinking more along the lines of the nylon-type stuff of the pre-filters that come with your kit, the thought being that it would allow good air flow, prevent snow from entering the chasis but any snow lopped up onto the hood and vents would probably blow off again rather than get deposited/trapped into a foam-type media. Have any sheets/rolls of that stuff laying around or know where it can be got?
Trxster
TY 4 Stroke Junkie
Sodbuster,
The filter media I referred to I think is ideal for what you are talking about. It allows super airflow (think about how much air gets pushed out a HVAC register) but will not let snow in. I think it it what you are looking for and is only $3.50.
I will get a pix if I can and will be trying it out tomorrow and this weekend but I am very sure that this is a good way to go.
The filter media I referred to I think is ideal for what you are talking about. It allows super airflow (think about how much air gets pushed out a HVAC register) but will not let snow in. I think it it what you are looking for and is only $3.50.
I will get a pix if I can and will be trying it out tomorrow and this weekend but I am very sure that this is a good way to go.
trx, I'm interested to see how it works for you. That stuff is pretty pourous, though, isn't it? My only concern would be that it would plug up pretty easlily if you had a bunch of powder up and onto the hood - not shed the powder like nylon would. But, hey, the price sure is right. Please post up results.
nhrxrider
TY 4 Stroke Junkie
Its really easy to test how restrictive the stock airbox is. The carbs are jetted for the restriction. Remove the airbox and try riding the sled, and see what happens...it won't run for crap and bogs down seriously in the midrange and won't rev very high. Goes to show how much restriction the stock airbox has...the carbs can't even cope with the improved airflow of removing the filter box! Not a very scientific test, but it proves a point.
Jim
Jim
SUPERTUNER
TY 4 Stroke Master
- Joined
- Apr 17, 2003
- Messages
- 5,333
- Location
- Menno, SD
- Website
- www.ulmerracing.com
- Country
- USA
- Snowmobile
- 2014 Yamaha SR Viper LTX, 2014 Yamaha SR Viper RTX SE, 2015 Yamaha SR Viper MTX SE 162 (turbo), 2015 Yamaha SR Viper MTX SE 153
- LOCATION
- Menno, SD
- WEBSITE
- www.ulmerracing.com
Bottom line is the ECP KIT ROCKS! Last summer we had been racing an F6 and struggling with it. For the last race we setup our old 2003 RX-1 (yes, we admit we are crazy to setup a sled for just 1 race). With limited test time (I'm talking 6 test passes down the track the night before we left for the race) we not only competed, we ran the fastest ET of any RX-1 that weekend! The added acceleration and throttle response from the ECP kit is un-freakin-real!
SUPERTUNER
TY 4 Stroke Master
Thanks for the props Allen! I am grateful to have a fine gentleman like you tuning these sleds for "our" customers and making all of us look good.
Freddie Klies
Freddie Klies
SuperStroker!
Pro
Things aren't always as they seem...
Well...this is not entirely true!
The stock air box may be a restriction to air flow vs filters and certainly no filter or air box at all, I agree.
But don't conclude that because you need to install a higher volume fixed orifice main jet (go from 135 to 150 for example) is entirely caused by more air entering the engine from the removal of the air box.Main jets never flow at total liquid capacity, because the pressure drop required to pull them to total liquid capacity is much greater than a running engine will create at any throttle position. Believe it or not, an engine requires more fuel upon acceleration (torque) than from high RPM (HP) pulls on the top end. You wouldn't expect this, since an engine is essentially an air pump and the faster you turn (RPMs) the more air volume it pumps, right?
The fact is, the stock air boxes are being developed these days to include things like sound or acoustical frequency tuning to inprove air flow.
The pressure around the needle jet can also be significantly affected by the shape of the intake tract. The idle air and pressure drop around air and fuel correction circuits that are positioned around the mouth of the carb, may be altered to actually increase or decrease pressure drop by removing a tuned air box and replacing it with a filter.
Simply put..."things ain't always what they seem to be, or what you might expect" and there is a lot of science, acoustical engineering and gas/fluid engineering that goes into the modern intake designs on our high performance recreational vehicles.
There are many examples of engines that make less power, even after proper jetting, when the air box is eliminated and filters are put in place of it.
nhrxrider said:
Well...this is not entirely true!
The stock air box may be a restriction to air flow vs filters and certainly no filter or air box at all, I agree.
But don't conclude that because you need to install a higher volume fixed orifice main jet (go from 135 to 150 for example) is entirely caused by more air entering the engine from the removal of the air box.Main jets never flow at total liquid capacity, because the pressure drop required to pull them to total liquid capacity is much greater than a running engine will create at any throttle position. Believe it or not, an engine requires more fuel upon acceleration (torque) than from high RPM (HP) pulls on the top end. You wouldn't expect this, since an engine is essentially an air pump and the faster you turn (RPMs) the more air volume it pumps, right?
The fact is, the stock air boxes are being developed these days to include things like sound or acoustical frequency tuning to inprove air flow.
The pressure around the needle jet can also be significantly affected by the shape of the intake tract. The idle air and pressure drop around air and fuel correction circuits that are positioned around the mouth of the carb, may be altered to actually increase or decrease pressure drop by removing a tuned air box and replacing it with a filter.
Simply put..."things ain't always what they seem to be, or what you might expect" and there is a lot of science, acoustical engineering and gas/fluid engineering that goes into the modern intake designs on our high performance recreational vehicles.
There are many examples of engines that make less power, even after proper jetting, when the air box is eliminated and filters are put in place of it.
Trxster
TY 4 Stroke Junkie
Superstroke,
That may be true, however, I did a mod on my airbox and cut a 3"x8" hole where the baffle goes and removed the inner divider. Then, when I went to put in 170 jets, I accidently swapped out the starter jets and left the 137.5 stock jets. The sled started fine but could not hit even half throttle without having full choke on. I think that tells you how much airflow difference it made.
T
That may be true, however, I did a mod on my airbox and cut a 3"x8" hole where the baffle goes and removed the inner divider. Then, when I went to put in 170 jets, I accidently swapped out the starter jets and left the 137.5 stock jets. The sled started fine but could not hit even half throttle without having full choke on. I think that tells you how much airflow difference it made.
T
Trxster
TY 4 Stroke Junkie
By the way, visit the RX/RS mountain section for more info on the vent filters that Yamaha and I have been testing. Looks very good so far. Filters are very pourous but do not let any snow in engine compartment. I have tested 1 time (today) in 12-18" of fresh in cold temps and I didn't get any moisture at all. I will keep testing though.
T
Ps. I don't care, I absolutely love the sound of my sled with gutted muff and ECP's.....mmmm mmmm mmmm!!!
T
Ps. I don't care, I absolutely love the sound of my sled with gutted muff and ECP's.....mmmm mmmm mmmm!!!
SuperStroker!
Pro
Trxster said:
It may be air flow or it may be the fact you modified your air box and upset a vacuum signal or changed the acoustical tuning of the box by doing so (see my previous note). The only thing you know is you needed a bigger main jet...again, thats all you know! You are concluding by assumption and assumption is speculation and speculation is a guess.
The only way to know for sure is to mount a mass air flow meter on the box after you modified it and measure the volume of air flow based on the measured and recorded air flow of a stock box.
I bet you're right and did improve the air flow to your engine. But I also bet the increase in the main jet isn't linear to the mass volume improvment in air flow.
"Things are not always what they seem"
Similar threads
