The Yamaha Road Star Warrior Forum

I added PR Hi-Flo BAK and wanted to try to make a cold air intake.  I took some measurements and have found as much as 125 degree F air temps, under the tank, while riding around in 85-90 degree air.

Here is what I came up with.  I fashioned the air intake from plastic and the air box from foamcore which was fiberglassed.  I am using a rubber gasket to seal around the velocity stacks.  Air is drawn in through the front 'scoops'. 

I had to relocate my LCV under my seat as well as remove everything that was inside the frame rails above the TB's.  I mounted cylinder vacuum sensors on the inside plate of the left side air scoop.

Bike: 2005 Warrior (stock pistons) 13k miles, Dyna Coil, PCIII, V&H Bigshots, PR Velocity Stacks, Desert Warrior Map

The bike pulls incredibly compared to the stock snorkles and air filters I was using as my own DIY BAK (I was definitely leaving power on the table).  The 3rd gear roll on is amazing.  It now rushes to redline like never before.  It feels like a new bike.

I will want to get it dyno'd to see what the numbers look like, but it is breathing cooler air (Ambient) now and that was the goal.

The entire air box and intake 'scoop' has heat shield material on the bottom as well as a thermostatically controlled set of fans in the left side air scoop.  The fans will blow air up and under the box to help evacuate the hotter air, if it gets over 110 degrees F.  The heat shield seems to work very well at keeping the heat from getting into the air box.  I think the foamcore is acting like an insulator too.  I will locate a thermocouple in the airbox and see what the temps look like. 

Air Inlet (right)

 Air Inlet (left)

Box build:

 Atmospheric and temperature sensor

 air box fiberglassed: (I had to stack the air filters until I can get one that fits the bill.  The flangs were removed on the air filter to make the opening as wide as it could be.

Air Inlet (looking from the top of box)

Velocity stacks up close.  I am cutting my own bellmouths (lathe) to go on these

Box covered (it just fits under the tank, I wanted the box to be as big as possible)

Thermostat located behind the box to control fans (small pink lugs with the black plastic disc):

Fans in the left side scoop

Air Filter for the LCV

 This was a fun mod to create but it took a bit of time.  While I was in there, I re-routed my rectifier harness (left side) to move it from the left downtube to straight down behind the motor and then let it run under the motor to the rectifier.  

Once it gets to a dyno, I will see if the cold air offered any significant increase in power.  It is supposed to and since they sell a sh*tload of cold air intakes for motors, I figured it was worth a try.

 All feedback, good or bad, is always welcome.  Often helps to perfect an idea.....

Sorry, that was a long post......lol

why did you modify the 2 cone style filters instead of use a nice k&n panel filter in the same location it would have made more air passage ,right now you have 2 tbs breathing thru on filter size hole if im looking at the pics corrcetly, but if it works go for it will like to see the numbers on it ,but remember the dyno wont have the ram air effect ,your bike is just sitting still on the dyno, good luck , cya ,btk572

btk572:

why did you modify the 2 cone style filters instead of use a nice k&n panel filter in the same location it would have made more air passage ,right now you have 2 tbs breathing thru on filter size hole if im looking at the pics corrcetly, but if it works go for it will like to see the numbers on it ,but remember the dyno wont have the ram air effect ,your bike is just sitting still on the dyno, good luck , cya ,btk572

A flat panel filter would not have given me the same total area (filter media) that the cone ones do.

The filters are opened to their fullest (no flanges)  The total square inch area opening is more than the combined opening of the two TB's so the air flow is sufficient.  I had the filters and for testing, I did not want to waste them.

It does not rely on any ram air effect since that would be minimal anyway.  I just angled them out a bit so they would have some flow directly into them.  The TB's still have to 'suck' the air they want but are now getting that air from outside.

I also tried to make the inlets as subtle as I could so they did not take too much away from the lines.  Not sure if I won there.....

 wow Scootman - that's pretty innovative!

a few q's...

the fan looks really trick!  Does it direct air into the intake or is it currently just used for cooling/moving the hot air from around the outside of the intake box?

the modified intake scoops look like they are somewhat flush to the frame.  Are you depending upon intake vacuum to draw the cold are or looking for a ram air effect on top of that?  Perhaps some scoops attached to those intakes may help (maybe not show up on dyno but real world)?

It's nice to see some different things being tried out!

mdfdwarrior:

 wow Scootman - that's pretty innovative!

a few q's...

the fan looks really trick!  Does it direct air into the intake or is it currently just used for cooling/moving the hot air from around the outside of the intake box?

the modified intake scoops look like they are somewhat flush to the frame.  Are you depending upon intake vacuum to draw the cold are or looking for a ram air effect on top of that?  Perhaps some scoops attached to those intakes may help (maybe not show up on dyno but real world)?

It's nice to see some different things being tried out!

Thanks for the comments.  No ram air, it's too hard to achieve any real value from that.  Vacuum is in charge.......Thats's why the opening had to be a certain size.  Took a bit of creativity to make it all fit while staying inside the rules of airflow.....I have a flow bench at work to play with, so that helped.

When looking at the bike standing at it, you really cannot see the fans.  They just blow air into the area between the bottom of the airbox and the TB's.  Just wanted a way to pull some hot air out....

Nice work, very creative.

Here's the info on intake temp tests I conducted in '03.

http://rswarrior.com/forums/p/18852/278744.aspx#278744

Nice idea, please keep us updated on temps and performance.

Looks good

 Thanks for the comments.  I might have to give the power increase solely to the PR stacks and the new map, either way, it runs great.

When I connected a digital temperature probe to mine, I was finding some significant increases in temperature under there, but I will run the numbers again to confirm your numbers, your test sounded more empirical than mine.

If nothing else, it does guarantee cool air to the TB's....

Nice job,  I've been mulling over the concept and reaaly like your location of the inlets.

Question:  Why not just remount the filters to the stacks?  Maybe a high-flow prefilter for the large bits that get sucked in?

Donncada:

Nice job,  I've been mulling over the concept and reaaly like your location of the inlets.

Question:  Why not just remount the filters to the stacks?  Maybe a high-flow prefilter for the large bits that get sucked in?

The filters stood a little proud and would have made the box harder to fabricate.  I went for the largest I could make it while keeping the top flat.  I also am making my own bellmouths for the stacks since I thought I could create a better one than the filter afforded (if you can call that a bellmouth)

 Always nice to see some thinking going on , keep us posted on the results.

 Please don't take this as stiffling your creativity. I think anything custom people do to thier bikes themselves is cool. But, aren't you just kindof reinventing the wheel here. I mean your airbox looks pretty much like a stock airbox you are just sucking air from under the neck instead of out of a side scoop. I guess I just dont see the difference. Without ram air effect and smooth passages going to the throttle bodies it seems like it would be restrictive. I am seriously asking, not criticising.

Good work, would seem youll loose some of the benefits of the opes stacks but may pick it back up with the introduction of the cooler air. Will the foam core hold up to the undertank temps even with the glass? Any first riding impressions yet? I'll be watching this one keep up the good work!

baclay9:

 Please don't take this as stiffling your creativity. I think anything custom people do to thier bikes themselves is cool. But, aren't you just kindof reinventing the wheel here. I mean your airbox looks pretty much like a stock airbox you are just sucking air from under the neck instead of out of a side scoop. I guess I just dont see the difference. Without ram air effect and smooth passages going to the throttle bodies it seems like it would be restrictive. I am seriously asking, not criticising.

+1 - Now bolt on the PR BAK and see if there is any difference (loss of power) with that custom map.

baclay9:

 Please don't take this as stiffling your creativity. I think anything custom people do to thier bikes themselves is cool. But, aren't you just kindof reinventing the wheel here. I mean your airbox looks pretty much like a stock airbox you are just sucking air from under the neck instead of out of a side scoop. I guess I just dont see the difference. Without ram air effect and smooth passages going to the throttle bodies it seems like it would be restrictive. I am seriously asking, not criticising.

No, stifling here, keep em coming.

The stock air box was too small to be effective for power.  This airbox is larger overall (considerably) than the stock one.  The goal was to provide enough fresh air to help it out.  It may very well show no difference between this setup and the filters mounted directly on the PR stacks.

From all the reading I have done (which I admit, could be more), it seems the final result of any of these types of changes are really only beared out in the real world.  People design intakes and then have to tweak them (longer, shorter) even though the math indicated x.  Same thing with exhaust.  Trial and error and you see what you get. I like that it now has a sure path for cooler air, even if that is the only benefit.

I do think this arrangement will be better once I get the bellmouths installed.  The velocity stacks will work better (how much is ???) with bellmouths (all flow ports work better with bellmouths).

Trial and error and I get to play.....lot's of learning in playing.....

Thanks for the feedback