CAT Filter suction test Verses OEM and Baldwin

Suction tests results:

CAT 1R-0750:
RPM..Suction
Idle: 6.4"Hg
1500: 6.5"Hg
2000: 6.6"Hg
2500: 6.7"Hg
3000: 6.7"Hg
5000: 7.0"Hg
Suction change from idle to redline= .6"Hg

Baldwin:
Idle: 5.5"Hg
1500: 5.7"Hg
2000: 5.8"Hg
2500: 5.9"Hg
3000: 6.0"Hg
5000: 6.1"Hg
Suction change from idle to redline= .6"Hg

Bosch (OEM) filter with 20,000 miles
Idle: 3.8"Hg
1500: 4.0"Hg
2000: 4.1"Hg
2500: 4.2"Hg
3000: 4.5"Hg
5000: 4.8"Hg
Suction change from idle to redline= .9"Hg

Bosch (OEM) Filter BRAND NEW
Idle: 3.8"Hg
1500: 4.2"Hg
2000: 4.2"Hg
2500: 4.2"Hg
3000: 4.3"Hg
5000: 4.7"Hg
Suction change from Idle to redline= 1.1"Hg

DB

DBW, a brief explanation of the test setup please. Where is the pressure measurement being taken?

Yes, what is a suction test and what should we be looking for?

This is about the fuel filters methinks...

So, Pete, what is 'the rest of the story'.... Did this much increased restrction pose performance issues with the engine or, hopefully, was there no noticeable difference in actual engine operation with the new CAT/Baldwin setup.????
Anxiously awaiting.....
George

cool. That cat has almost twice the restriction of OEM.. I would guess it filters alot better!

If a 2 Micron Absolute filter has 6.4"Hg of restriction with the engine at idle and the OEM only has 4.2 how much is that filter catching?

The suction test is measured by placing a vacuum gauge between the filter outlet and the injection pump. The internal vane pump of the injection pump is what creates the suction and fuel flow to and from the pump.

The pump is designed as a "Suction" system the one thing we wanted to find out is does the pump have sufficient suction to pull the fuel and circulate it. The answer is yes. We tested the filter on a 1997 Passat with 160,000 miles. We drove the car around and allowed the system to operate at every rpm range and load.

The fuel pump at idle is probably flowing at least 1 gallon maybe more per minute. This fuel is obviously not being used and is simply returned back to the filter where it can be refiltered, some of that fuel is routed back to the tank. The best part of this system is fuel is never routed back to the pump unless it has been filtered. This assures that if the pump makes any metal and it does due to normal wear, that metal is caught by the filter before being routed back to the pump inlet.

The Baldwin is rated at 6 Microns Absolute with a 1 micron nominal. What this tells us is that the CAT filter based on the suction differences is very likely a true 2 Micron absolute filter.

What is interesting is the difference in suction values from idle to redline engine rpms. The CAT and Baldwin have smaller increases in suction and our best guess is that it's due to the huge capacity of the filters total surface area. The OEM filters become more restrictive as the fuels flow rates increase beyond a certain rpm. If you enter the values into Excel the chart will show what I am getting at.

We have the Fuel samples taken and will ship them out on Monday. We only took a sample of the CAT and the station pump so we have a beginning quality and "polished" fuel quality. We were going to do a sample on the Baldwin but I felt the data would not show an accurate reading since the CAT filter had already been run in the fuel system thus reducing the contaminant levels. The Baldwin will be tested later next week once more fuel has been added to "contaminate" the fuel system.

Perhaps George can chime in on how fluids flow and respond at various flow rates in these types of filter media.

DB

Damn, Pete beat me to a post already!

The Cat and Baldwin fuel filters were tested on my Passat. My Passat was chosen as there is more room to install the filters. We did a lot of messing around with fittings and such. The filters were installed dry and filled with a vacuum pump attached to the filter outlet line.

A Tee was installed inline between the fuel filter outlet and the supply line to the fuel pump. The vacuum gauge was hooked up to the Tee. All measurements were taken with the engine and fuel at normal operating temperatures. Fuel temp was measured at about 100F before, during, and after the tests.

Simply put, the higher the vacuum number (in inches/Hg), the harder the fuel pump was working to pull fuel through the filter media. Obviously the Cat filter beat the Baldwin and both beat the snot out of the stock VW/bosch unit.

The VW/Bosch fuel filters were tested on Pete's car in the same manner as the Cat and Baldwin filters were on my car.

Pete has the Cat filter and we left the Baldwin unit installed on my car as it was tested last.

So far I have about 350 miles on the Baldwin filter. The car runs as it always has. It appears to me the Bosch fuel pumps have more than enough suction to pull fuel through these filters. As Pete stated, these fuel pumps recirculate a very large volume of fuel quickly.

Guys, thank you so much for excellent work and superb write ups! Regarding the comments about the restriction and pumps. A pump drawing "clean" fuel through it is going to last much longer than a pump drawing contaminated fuel, even at a lower restriction level. The fuel analysis results next week will give us quantitative filter efficiencies for the CAT and from that we can then get a good target on the CAT (Baldwin close to follow) fuel filter affect on pump and injector life extension. We will be running just particle count and water (Karl Fischer) before and after as we already know the rest of the numbers for Pete's fuel. I would anticipate some super fuel cleanliness numbers coming up which will result in exponential fuel system life extension.
Again, fantastic work... Thank you...
George Morrison, STLE CLS

[ September 28, 2002, 19:15: Message edited by: Georgeseq ]

Excellent! I'd like to add this filter to my car, what P/N's are you using for filter and plate?

I would assume that the filter itself would be widely available and probably cheaper than a VW filter at a stealer. However, I'm sure the change interval would have to be what 5 or 10,000 miles? Also, is the CAT filter avilable in different sizes (bigger is better)? Would also like a large one for my fuel tote.

[ September 29, 2002, 08:08: Message edited by: Hollywood ]

Hollywood, actual production of the customized plate is set to take place after the improved filtration is verified by George's lab. The filters are indeed cheaper, and other details can be found in these threads:

Fuel quality

BP Diesel Supreme Analysis: Not Supreme!!

Fuel quality results from the Fuel station and Post filter on the car

So far DBW hasn't said what the price will be for the plates.

Hey, I see you're from Florence. I was just there Thursday!

Dave, down in B'ham

Hollywood, you have come in at the end of a long succession of posts. DBW has designed an adapter plate for the CAT/Baldwin fuel filter and it is in prototype evaluation at this time; the prototype came off the CNC machine Wednesday, on a vehicle Friday! This whole fuel filtration issue began just 3 weeks ago and has moved from discussion to prototype reality with incredible speed!
There are many 2 micron CAT filter models; however, some may not be adaptable to the new DBW baseplate, some may be too large, etc.; the filter fitment informaiton will evolve as it is developed . The first drive of the new combo began Friday, 9/27/02, so this whole program is happening, developing "right now"..
And yes, some of the larger versions of the CAT 2 micron fuel filter would serve as excellent fuel/bio transfer filters if a suitable baseplate existed for them. However, next week will give us the true story on the CAT's filtration performance.. Again, this is still an on going development story.. Stay tuned..
George Morrison, STLE CLS

[ September 29, 2002, 08:51: Message edited by: Georgeseq ]

The Cat & Baldwin filters will be a VERY tight fit on everything but the Passats. If you decide to use a different filter it will have to be smaller in length and diameter, and then the mounting plate might be different. The plate is being custom made by a local machine shop. Pete doesn't have the final numbers on cost from the machine shop yet.

The Cat filter number is 1R-0750, the Baldwin number is BF-7633. The Cat filter is slightly larger than the stock VW/Bosch filter, and the Baldwin filter is larger than the Cat filter. The Baldwin is 7 1/8" long and 3 11/16" in diameter. I don't have the specs for the Cat filter handy. The mouting plate will add at least an inch the the total length.

In the stock VW/Bosch unit, the filter element only occupies the top half of the filter. The bottom half is an open space for water collection. In both the Cat and Baldwin units, the filter media fills the entire length of the filter housing or twice the filter area of the VW/Bosch unit. So these filters should easily go 20,000 miles or more between changes.

The only thing the Cat and Baldwin filters are giving up is the water collection space. I have never drianed a drop of water yet from my fuel filters and stopped checking years ago. If you get a bad tank of fuel, no filter is going to help you anyway.

Both the Cat and Baldwin filters sell for around $10, a hell of a deal when compared to the ~$35 or more the VW dealers charge for the junk Bosch filter.

Brian, 97 Passat TDI

what is the maximum flow rate for that small filter? These cars push alot of fuel...

Greg, that is the problem with most all fuel filters right now. Filter manufacturers talk about 95% efficiency, multi-pass efficiencies, etc but when it comes down to real world testing, they are not even close. As Pete et al are doing right now is going to be the best way to come up with an effective 5-10 micron filter; i.e. real world testing. If there was an easy way for you to do an after the Racor sample we could run a "before and after" on your Racor setup in your 6.5TD. That would be some great info to add to our work here..
George Morrison

[ September 29, 2002, 17:16: Message edited by: Georgeseq ]

Couple ideas came to mind on my way out west this morning. Any input you guys have is appreciated so please fire off your opinions. The goal here is a simple, cheap, BUT VERY effective fuel filter set up. Personally I like the idea in #2, but since a few people brought up the idea in #1 I'd entertain that as well and I can easily test that configuration and suction level.

Question #1
Would the A4 owners consider adding the CAT filter as a "Secondary" filter in addition to OEM VW filter? I would have to test the suction values to see if they would increase beyond the current values. If this were done you could simply and I shiver when I say this "Ricks" advice and change the OEM VW filter maybe every 40K? HOWEVER you would now rely on the CAT filter to do all the final filtration with possibly going to 20K changes on the CAT filter at $10.00 a piece, this would assure you that no particles are making it to the pump of any significant size. If this were the case then all you would have to do is check the OEM filter every 10K for water and rely on it as a "Primary" coarse filter. I would have to check the suction values but in this case I may suggest adding a small fuel pump to assist the Injection pump, this as you have realized adds slightly to the complexity but I would only do this if continued operation of the motor can be assured in the event of a secondary fuel pump failure. The Fuel pump would simply be a "Boost" pump providing low pressure and low volume simply to assist the Injection pump. This is an allowable consideration per Bosch for the VE series injection pumps.

Question #2
Would the A4 owners mind repositioning the fuel filter to the space forward of the Drivers side wheel well and eliminating the OEM filter all together? This would allow a wider assortment of various CAT High Efficiency filters, possibly larger allowing much longer change intervals possibly beyond the 50K mark. The good thing is even if you have an Amsoil Oil-Bypass filter the fuel filter could still fit in this area. This also frees up some of the space under the hood and can provide an easy place to mount an OilGuard By-Pass filter where the OEM filter used to go... This would also allow the possibility of adding a fuel cooler in the summer months or even in the winter for that matter. Gary M could possibly elaborate on the findings of fuel temp and smoke relationships...

At this point we have an adapter that works and retains the OEM fuel circuit design along with the thermostat. Now all we have to do is make sure that we have a workable adapter for all the TDI's out there. Personally I like the idea of having the fuel filter forward of the wheel well simply because it makes changing the filter so easy as well as providing a very easy place for mounting. The additional fuel line should not be a problem in terms of the pump being able to draw the fuel since it is not increasing the "lift" just the "head" and slightly at that.

DB

Since they have mentioned the filter size/location/fitment in the engine compartment, I'll add what I saw on Friday.

I was at Pete's and we test fit into an A3 Jetta and my A4 Golf. In the A3, the fitler was too large in diameter to allow for the stock filter mount screw to be used. It was tight in the mount anyway. The length was too long and caused the filter to be cocked at more of an angle.

In my Golf the same problem was encountered with the diameter. The screw and clamping pieces had to be removed from the filter holder, and the band part pulled apart more, in order to get the filter to fit. Length was a problem again as it appeared that a closed hood would hit the adapter plate. I suspect that the bottom of the filter rubbing on the inner fender panel could be a problem over a longer period of time due to normal vehicle vibrations.

I would recommend a search for a smaller filter. This would require retesting of fuel flow and filtration too.

The adapter itself gets a thumbs up. Well made and clean design. Hose connections, when installed for the first time, would have to be watched. If you aligned a filter with the adapter and swapped hoses from one to the other based on positions, you'd get some lines crossed from what they should be. A minor thing and something worth noting in case a VW mechanic tries installing one (right Irishchicky?).

I'd like to see an adapter fit in the exact same location as stock in A4 chassis. Even if only 1 Cat Part number were to fit. I like the idea of retaining the stock plumbing.

What are the limitations with this approach? I can live with 20,000 mile fuel filter changes.

The filter that I have is the smallest that they have rated as a 2 micron element. I think the reason is because of the fuel flow rates with the extremely fine filtering, you need a lot of surface area...

I found another filter but the problem is that it was designed for a "Pressure" system not a "suction" system. The other issue is that the bracket was too large.

I'll keep working on this, I know there is a way to fit this in the car.

DB

For those fortunate to have a tank at home, how about an adapter for the spin on units typically found on the pump?

Originally posted by BKmetz:
Both the Cat and Baldwin filters sell for around $10, a hell of a deal when compared to the ~$35 or more the VW dealers charge for the junk Bosch filter.

Click to expand...

<font size="2" face="Verdana, Helvetica, sans-serif">MSRP for the OEM VW filter is $45, www.vwparts.com sells them for $34.

If you can have a bracket made for my MK4 that will house the CAT filter in the same place as the OEM filter, I'd go for it.

George
I will call you tomorrow and order up 2 kits. I want to see what the fuel quality is at the pump anyway, mostly to see if it is 50 cetane as they have told me. I will need to get the 2 micron Racor but that's OK because its time to change out the one I have in there now. I have to go to my supplier tomorrow for a laod of fuel filters anyway, so I'll just pick one up while I am there. Tried to see how the Racor is rated but the sight does not give that type of info.
Greg

I love the idea of cleaner fuel and less wear generated by the pump, but the extra 2-3" of resistance on the pump doesn't worry anyone? Do we know if the pump has some sort of rating on it?

George
Racor makes a small 2 micron spin on filter don't they? If the do then you could use one of their mounts and possibly evan have it heated. I have a heated Racor on my GM 6.5TD, it also has a drain in the bowel.

Greg

Just looked up my filter and it is available in a 2 micron, but it does not say if that is absolute or nominal. It's small as well only 4" dia and about 5" long.
Greg

This may be the next "killer" mod! Any photos?

I have a few pictures but the issue is that the design is already going to get some changes. Once I have the design finalized I'll get some pictures posted.

I don't think filtering the fuel prior to topping off is the answer. The reason is the fuel system has been contaminated from day one with high levels (realatively) of particulates.

Greg I'm curious to see how your Racor stacks up as well. One thing is for sure the CAT filter is nothing like any filter I have ever seen. No doubt about it it was designed from the ground up for fuel filtration at the highest level. Instead of stamped parts that resemble an oil filter they use cast aluminum, a poured resin at the base to assure a perfect seal, a sophisticated seal design and not some generic rubber seal as found on oil filters.

The good thing is we will have tests from CAT, Baldwin and now Racor... This is getting to be pretty interesting

DB

Just got done talking to George and the fuel sample kits are on its way.
Greg

might as well publish it here . . . lrpavlo and I are getting the Amoco PDF station that we use tested - lets see if we are getting better stuff

Looking forward to production, although the fit issue has me somewhat concerned . . . as in where do we put it if it doesn't quite fit in the existing space?

Question - is a slight redesign possible? Maybe to make the filter head/adapter lower profile? (thinkin about MOgolf's assesment of the Golf's fitment

Lets keep in mind Pete that I've got only 1 Passat to fix but 3 of those tiny compartment Golf's!

Don't know if it would be a concern....but I did have a fuel gelling problem one time going from 45degrees here to -15 F. in upper Wisconsin All the gelling happened in the lines from filter to pump. (Simply heating just those lines got the car started) Sooo, we'd have to consider would running a fuel line around the engine compartment allow the fuel to cool maybe too much when the car sits?