Why prefilter if stock filters down to 2 microns

[upsguy]

If the stock filter filters down to two microns, what good is it going to do to add a prefilter. If the prefilter is two microns and doesn't catch it, the stock filter won't either?

[Idle_Chatter]

The stock filter is FAR from 2 microns. Filters are rated at "nominal" and "absolute" ratings. The OEM style racor is about 5 microns nominal and actually about 15 to 20 microns absolute. Absolute is "real world" filtration efficiency based upon temperature, flow, vibration, etc. (REMEMBER, the stock filter head is ENGINE MOUNTED and gets shaken continuously). Aftermarket filters like CAT, Baldwin, etc. have 2 micron absolute ratings. Compare the sizes - IF the OEM style filter ACTUALLY filtered to 2 microns, how long do you think that small filter element would last? (LESS than a week - I guarantee!) The larger filters with better filtration have to have a much larger filtering media - both to accomplish the actual filtering and to allow much more filter media surface area to reduce flow restriction and allow a resonable filter life.

[upsguy]

I thought I read that when they improved the stock filter that it had 2 micron tolerances. I've been thinking about getting an auxilliary filter and I guess I've been reading so much about them that I've confused myself.

I was actually looking at the Racor filter that Lube Specialist sales becuse of the ease of installation.

[Idle_Chatter]

I haven't seen any "hard" numbers published on the latest generation of OEM fuel filters, but they wouldn't publish any on the previous ones, either. The dual-pleat filter in the latest OEM is an improvement, but the actual physical size is still a limiting factor and filter life has gone down (GM recommendation on the previous filter was 15,000 miles - now reduced to 10,000 miles and many users are reporting filter restriction at 7500 to 5000 miles) which shows that it's filtering better. One advantage to an aftermarket secondary is more available statistics on the filters, in addition to the obvious benefits of much larger and more efficient media.

[O&A party rock]

read my tale of woe (previous post-'help.. please'). I'll be ordering 3 prefilter kits for the 3 new LBZ's next week.

Kennedy- I like the larger filter you use over the lube specialists' model, but do you have a mounting location picked out for the '07 LBZ's I have?

thanks
Jesse

[Kennedy]

All filters are rated using multi-pass tests, so just because it says it's 98% efficient at "x" microns doesn't mean it's going to stop that percentage of particles on a single pass. Having 2 filters goes a long way to helpuing with clean fuel.

I now have my 1um synthetic media filter on my 550 gallon storage tank (installed new) and filter before delivering to tank (except when I'm on the road) then it hits the OE filter, and then my Super Mega on 2002 and Mega on 2005.

Overkill, maybe but IMHO, running without is like going to certain "establishments" w/o protection. It's going to catch up with you sooner or later...

[Kennedy]

read my tale of woe (previous post-'help.. please'). I'll be ordering 3 prefilter kits for the 3 new LBZ's next week.

Kennedy- I like the larger filter you use over the lube specialists' model, but do you have a mounting location picked out for the '07 LBZ's I have?

thanks
Jesse

Ours is a 5 micron absolute as rated by Baldwin vs. 9 micron absolute rating for the smaller engine mounted unit. You won't find a better media in Baldwin's lineup.

I have a couple of options:

1) Modify the OE air box as others have done. It's not that hard to do, but not reversible.

2) I have a Universal unit that mounts near the tank on the frame rail. It also accepts lift pump(s) for improved supply flow and elimination of accumulated air.

[cowboywildbill]

John, can it be mounted on the frame on an 06 with a 56 gal transferflow tank? And/or can it be mounted under the new style airbox on the 06?
Thanks

[WILLYD-MAX]

I have installed 2 of Kennedy's Mega systems under the air box on 2 06 trucks. It requires some minor modification. I took pics of my installs so if you need some let me know. The filter head goes in the same place as the 01 thru 05's for the front 2 screws and then I added a little steel strap for the 3rd mounting hole. The biggest outlet on the bottem of the airbox with the rubber deal on the end I cut it off almost even with the airbox. Hope this helps.

[cowboywildbill]

Thanks, I still have a filter kit that I bought from John a couple of years ago for our 02 but I never got around to installing it. We were in the middle of moving and I just found the stuff a couple of months ago. I would like to see the pics.
Thanks again.

[Kennedy]

I have the pics that William took and can fwd them with a simple email request.

[DmaxMaverick]

I have the pics that William took and can fwd them with a simple email request.

Post them in the Photo Album.