Why an inner filter isn't enough

[PhilCod]

Back towards the end of summer I replaced the stock air filter and put the UNI on the inside of the Airbox and rode about 400 miles or so on 3 trips. Last week as you can see from my post, I did the mod to put the air intake up high like others have done. So this weekend I decided to take the Uni out from the inside thinking my air filter would be nice and clean. Wrong, dead wrong.
Now a few things.
1. I didn't oil the UNI enough. That is obvious.
2. Of the 3 trips I took, two were dust bowl trips.
But as you can see from the pictures, you could dip the filter in oil and it wouldn't help keep all that dirt from coming inside. So if you ride in dusty conditions think hard about doing the mod to put your air intake up behind the passenger seat. Or, take the air filter out and clean the UNI after every dusty ride. I'll say it again, the stock air intake location sucks. Sucks dirt to be exact!

 

[CID]

Damn, what a mess!!! I can't believe your stock filter got that dirty. How did all that dirt get through the Uni? (however lightly oiled) I didn't realize the internal Uni contacted the stock filter.

For the curious, Phil copied HondaBob's snorkel idea for the most part but stopped behind the passenger seat (Bob runs his up to the roof). Those details are linked in my sig, posts 18 & 19.

Very much like this but he used a K&N with a plastic bucket over it for waterproofing. I believe the K&N wasn't in place yet for the mess above.

This is my red Uni at 1066 miles, almost gooed shut but not quite. It's my opinion that a lot of guys clean their foam filters way too soon.

As bad as the Uni looks above, this is what my filter looked like at 1137 miles. The Uni was in place its entire life, zero miles without.

 

[PhilCod]

CID - correct, I had not done the Hondabob snorkel yet. Now that I have that on there it will be easy to see when the pre-filter is dirty and clean it. But, as you know, the new location of the pre-filter with the mod is the key. It's not down in that dirt box where the stock air intake is.

 

[Doogle]

Back towards the end of summer I replaced the stock air filter and put the UNI on the inside of the Airbox and rode about 400 miles or so on 3 trips. Last week as you can see from my post, I did the mod to put the air intake up high like others have done. So this weekend I decided to take the Uni out from the inside thinking my air filter would be nice and clean. Wrong, dead wrong.
Now a few things.
1. I didn't oil the UNI enough. That is obvious.
2. Of the 3 trips I took, two were dust bowl trips.
But as you can see from the pictures, you could dip the filter in oil and it wouldn't help keep all that dirt from coming inside. So if you ride in dusty conditions think hard about doing the mod to put your air intake up behind the passenger seat. Or, take the air filter out and clean the UNI after every dusty ride. I'll say it again, the stock air intake location sucks. Sucks dirt to be exact!

View attachment 242543 View attachment 242544 View attachment 242545

That Uni collected a lot of dirt, oiled or not. It's that much that didn't get to the Honda filter. I'm surprised it didn't get sucked off of the very flexible inlet tube. I think the biggest advantage to the external snorkel is the ease of inspection and cleaning. Hidden in the air box, it's a lot of work just to see if it needs cleaning.

 

[PhilCod]

Doogle,

I agree. Having the pre-filter out where you can see it and clean it is going to be nice. As for the UNI getting sucked off I put a piece of PVC tub inside the inlet tub to make it strong for the clamp. I milled the inside down to make it smooth and convex so air could go right though. I got that info from another member on this site.
Now the internal UNI is gone, I got a new Honda air filter this week so I'll put that in. I also bought a UNI UP6300 ST . I may run that one on weekends I know it's going to be dry, and run the K&N set up on wet weekends. As you pointed out, having it up top where it's easy to see is great and easy to put either filter on. Not to mention the fact that it will get a lot cleaner air then in the dust box by the rear wheel.

 

[Wigglysqiggly]

Went with set up and cost about $40. I call it a poor mans particle seperator

 

[PhilCod]

Went with set up and cost about $40. I call it a poor mans particle seperator

View attachment 248219

Nice set up! Please post the part number for the particle separator you have on top. Also, does it filter out dirt and dust with a filter you can clean? I've seen a few of those on line, but I'm not familiar with how they work.

 

[Wigglysqiggly]

I have a RC2 filter as you can vacuum/ air blow the filter but i definitely recommend it as last trip i was amazed on how much dirt it collected

 

[PhilCod]

Thanks, the more ideas we can come up with to make the Talon better is great for everyone.

 

[SLOWPOKE693]

I think you guys that are using those Uni Filters in your air boxes and/or on snorkel tube are restricting airflow. The surface area of those filters is nowhere near what the stock one is, so right off the bat you have a restriction. Now add dirt to the UNI and you have even less flow and more restriction.

Anybody know what the cfm rating on one of those UNI Filters is vs a stock Talon air filter?

 

[CID]

Thanks, the more ideas we can come up with to make the Talon better is great for everyone.

Exactly, options are a good thing; pick the one you like. 👍 We all agree the stock Talon's air intake needs attention or a bottomless supply of stock filters.

 

[PhilCod]

I think you guys that are using those Uni Filters in your air boxes and/or on snorkel tube are restricting airflow. The surface area of those filters is nowhere near what the stock one is, so right off the bat you have a restriction. Now add dirt to the UNI and you have even less flow and more restriction.

Anybody know what the cfm rating on one of those UNI Filters is vs a stock Talon air filter?

That's probably a very good question. I have the K&N like yours, and a UNI. Once I run both I'll post my findings. But as quickly as the stock filter gets dirty, I wouldn't count on a cfm rating to be accurate after a day ride in mildly dusty conditions. I think we all know HondaBob is at 10,000 miles or more with the set up, and it seems to be working fine for him.

 

[SLOWPOKE693]

That's probably a very good question. I have the K&N like yours, and a UNI. Once I run both I'll post my findings. But as quickly as the stock filter gets dirty, I wouldn't count on a cfm rating to be accurate after a day ride in mildly dusty conditions. I think we all know HondaBob is at 10,000 miles or more with the set up, and it seems to be working fine for him.

Thats not what im getting at here.......

Let's say a brand new Honda filter is capable of flowing 200 cfm in a stock air box with the stock intake piping. Now throw on a UNI Filter that has less surface area than the stock filter and only flows 175 cfm. You just created a 25 cfm restriction before the UNI Filter ever gets dirty and its only going to get worse from there. That's why I chose the K&N filter. It has alot more surface area than the Talon filter and will take alot more dirt before it becomes a restriction, unlike those UNI filters.

 

[CID]

HondaBob has done literally dozens of these snorkel prefilter conversions starting with his Razors and continuing on the Talons. I'm good with his decades of off road involvement, much of it with Honda.

 

[SLOWPOKE693]

You guys are thick....... Just because it "works" doesn't mean its the correct application and not restricting flow. 🙄

Did Hondabob dyno the machines before and after the mod to make sure he wasn't restricting flow and limiting available horsepower, or did he just run with it because it "worked"?



*No disrespect to Hondabob intended.

 

[CID]

You guys are thick....... Just because it "works" doesn't mean its the correct application and not restricting flow. 🙄

Did Hondabob dyno the machines before and after the mod to make sure he wasn't restricting flow and limiting available horsepower, or did he just run with it because it "worked"?



*No disrespect to Hondabob intended.

Your first priority is airflow, you race, most of us don't. I'm not arguing that the stock Talon filter doesn't have a LOT more surface area than the Uni. If you're running a pod type K&N, it has less surface area than the stock Talon filter too. And K&N has an unenviable reputation for ruining engines, it tests in the bottom third when tested against other filters, numerous internet comparison tests show that. This probably doesn't matter when used ahead of the stock filter, it will catch what the K&N misses.

 

[SLOWPOKE693]

I'm running a very large cone style K&N filter that has more square inches of filter area than the stocker. I took a few measurements before I just went to the store and grabbed whatever was on the shelf. K&N filters are great if you know how to properly maintain and oil one. Most don't so they get a bad rap for being s***ty filters....

Raceco ran a prototype K&N filter on their Baja winning Talon with nothing more than a KWT particle separator in place. Go to their FB page and watch the KWT video where they open up the airbox and show you the inside..... No dirt in it and the K&N is filthy. How do you expect that happened, miricle?

 

[PhilCod]

Thats not what im getting at here.......

Let's say a brand new Honda filter is capable of flowing 200 cfm in a stock air box with the stock intake piping. Now throw on a UNI Filter that has less surface area than the stock filter and only flows 175 cfm. You just created a 25 cfm restriction before the UNI Filter ever gets dirty and its only going to get worse from there. That's why I chose the K&N filter. It has alot more surface area than the Talon filter and will take alot more dirt before it becomes a restriction, unlike those UNI filters.

I agree with your point. The K&N does have a lot more surface area and only has one filter layer verses the UNI. I have a filterwares outer cover on my K&N to add an extra layer of protection. I can also clean that a lot easier at the end of a days ride than the K&N fins or a UNI. I know you race, and having less flow rate will certainly cause a HP restriction. But it appears the UNI works for the trail riders. I think the most important thing, and the whole point of this post, is to show how the stock air intake is in a extremely dirty spot and needs to be routed up to the top. Once you do that you can experiment with filters, intakes, particle separators and the likes. Thanks again for the post and the part numbers on the K&N. I have a post about "Phils intake mod" under accessories and mods, and I have pictures of what I did using the K&N.
Its always great to have many options to mod our machines.