Author Topic: Foam filter mod  (Read 35099 times)

thumperdh

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Foam filter mod
« on: February 18, 2014, 09:51:16 pm »
I ran across this on the Yahoo group a little while ago and I'm curious if anybody has actually tried it.





I just got a new HiFlow filter and i'll be working on this mod tomorrow. I'll report back with a report on what happens.
1982 FT500
Conti Classic Attack tires
Foam filter mod
Round headlight
Rejetted carb
Progressive springs
Supertrapp muffler
Thumperstuff header

J6G1Z

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Re: Foam filter mod
« Reply #1 on: February 19, 2014, 10:33:31 am »
Yes. One of the previous owners of my first FT500 had done that filter mod. I think it's also explained in the "FT500 Essentials". It is a good modification. It allows the bike to breathe a bit better & it's easy to service the filter. The hardest part is just unrolling the filter media inside the cage so its straight & there is no gap between the two ends where they come together.

I much prefer the oiled foam type of filters over the pleated screen & gauze (K&N Type) of filters. I used to run K&N's in all my vehicles at one time until I noticed that fine dust was getting past the filter & on into the intake tract. I replaced almost all of my pleated gauze filters with oiled foam. I still run two pleated gauze type of filters, but they are made by AFE. The AFE Pro-Guard 7 has seven different layers of gauze type of filtering media sandwiched between the screens. They have tested much higher than the K&N in filtering efficiency. They probably don't flow as many CFM's of air as the K&N, but they still outflow the pleated paper filters & I have found no dust downstream of the filter on the clean side of the intake tract.

Good luck
J.

Lefty

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Re: Foam filter mod
« Reply #2 on: April 27, 2014, 08:04:59 pm »
I am being pessimistic, but it seems like if the foam is on the inside of the can, isn't it prone to being  "sucked" out of shape by intake vacuum?
 I have read about this mod & this is the 1st I've seen it- I have heard nothing but positive feedback about this, but it seems like vacuum would suck it in?

thumperdh

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Re: Foam filter mod
« Reply #3 on: April 28, 2014, 12:59:24 am »
I preformed this mod a while back using my leftover old air filter and I have to say....

Meh. It didn't really seem to do anything for me.

3/10 if you have a sheet of foam filter element laying around and some filter spray then go for it. If not, a brand new hiflow filter from Dennis kirk costs around the same as buying the filter and oil and takes less time to install.
1982 FT500
Conti Classic Attack tires
Foam filter mod
Round headlight
Rejetted carb
Progressive springs
Supertrapp muffler
Thumperstuff header

J6G1Z

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Re: Foam filter mod
« Reply #4 on: April 28, 2014, 10:05:01 am »
I don't think the vacuum signal or strength is that high around the filter area of the airbox. It gets stronger as you approach the carb inlet. Plus the foam is being placed inside the cage where it is supported very well. The air flow path is from the center of the filter to the outside, instead of the more common other way around.

My first FT had already had this modification done, along with the jetting & the petcock was converted to full manual. This leads me to believe that one of the P/O's was a member of the Yahoo FT Ascot Owners Group. Modifying the filter to an oiled foam media just lets it breathe a bit easier & allows you to wash & re-use the foam filter vs. buying a new filter every time you service the filter.

Good luck
J.

Lefty

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Re: Foam filter mod
« Reply #5 on: April 28, 2014, 05:07:23 pm »
Thanks for the info, guys, I'm going to order up some foam & jets. I'm wonderinf if I change the jets to #145 & #58 without opening up the exhaust if I'm going to have performance problems. Should I wait to re-jet until I get my exhaust?

thumperdh

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Re: Foam filter mod
« Reply #6 on: April 29, 2014, 11:05:25 am »
Rejet as soon as possible. They really make all the difference in the world. When I ran my stock exhaust I had no issues with the increase in jet sizes.
1982 FT500
Conti Classic Attack tires
Foam filter mod
Round headlight
Rejetted carb
Progressive springs
Supertrapp muffler
Thumperstuff header

Lefty

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Re: Foam filter mod
« Reply #7 on: April 29, 2014, 06:17:52 pm »
Thanks Thumperdh, going to order 'em up!

J6G1Z

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Re: Foam filter mod
« Reply #8 on: April 30, 2014, 11:34:03 am »
When you order the two new jets, you might as well order a new 16 or 17 tooth countershaft sprocket at the same time.

The new jets will allow your engine to make more power. The taller countershaft sprocket will allow you to put that new power to better use. I took the conservative approach & ordered the 16 tooth sprocket. If I rode on the freeway & open road more, I would've bought the 17 tooth.

Good luck
J.

PS. Please tell Mark from ThumperStuff that John said "Hello".

Lefty

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Re: Foam filter mod
« Reply #9 on: May 04, 2014, 06:41:03 pm »
Will do, limited time so it might be next week before I get to the jets &  foam- Christ I've been working 12 hrs/6 days & HAD to go in a 7th day this week, we're short handed & my boss is very picky who he hires.......

J6G1Z

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Re: Foam filter mod
« Reply #10 on: May 05, 2014, 11:05:36 am »
Will do, limited time so it might be next week before I get to the jets &  foam- Christ I've been working 12 hrs/6 days & HAD to go in a 7th day this week, we're short handed & my boss is very picky who he hires.......

Those are long work weeks. Look on the bright side... Keeps you out of trouble, should have some nice looking checks & be greatful that you are not one of the many that are looking for work. Trying to find a new job is the worst kind of work out there.

J.