Outer Limits 4x4 Board

Hi, I did a search and found a thread or two, but they started to go off on tangents, so continueing them would seem futile to me.

Anyway, Looking at one of these airboxes for my fathers 4.1L 15B-F powered Hilux: https://dynamic.donaldson.com/webc/WebS ... tem=240603

I know that the air box is nearly as big as the engine, but no fear we have sorted that out, and know where its going. Behind the cab under the tray, essentially where a stock Hilux mufler is, but higher.

Questions:
- First of all who has used a filter in this series? If so have you been happy with it? Does it filter the air well, is it of sturdy construction? Robust? Any issues with it at all?

- Secondly, My calcs indicate that at absolute worst case the Toyota 15B-f engine should need about 297cfm of air (i'll stick with these horrible imperial units) whilst assuming no ineffciency in the air induction system (will be 3m of air intake ducting, with probably 2x 90deg bends, and sizing from 80mm to 120mm roughly[larger towards air box end]). This filter is given cfm ratings of:
Restriction LR (In H2O): 247
Restriction MR (In H2O): 282
Restriction HR (In H2O): 314
So would this filter be adequate? Or should I go up in size in the range?


Also for those not familiar with Toyota engine designations; the 15B-f is a 4.1L 4cylinder 4stroke diesel with 16 valves, and it is naturally aspirated. Red line is about 3600rpm, but actual users indicate pushing them yields up to 4000rpm (i.e. worst case). And I'm about 90% sure the engine will never get forced induction.

We found some suitable production car ones, but we can get one of these donaldson filters brand new for less coin, and they should filter out the dust better than the cas ones.

Thanks

I use one of these (or a very similar model). on my 3B with a turbo. does a great job. filters last for ages and i've never seen any dust on the outlet side of things. They do take up a fair bit of room though.

Cheers Swifty. Thats good to here, we really want something that will keep very clean air going to the motor, so I'm glad to hear that. The room isn't an issue, as we a filling in dead space anyway.

If you want very clean air, then you should get an "off-highway" spec dual element filter. As fitted to isuzu engined landies. I can give you a donaldson PN if you want (they are about the same size engine).

Also- make sure you get a pressure indicator, and only change the filter when it says to.

Go to the Donaldson website and download their air filter PDF and it tells you how to size up a air filter for a engine.

then simply look up the fliters for XCFM or larger CFM amount filter from what you end up with.

ISUZUROVER so is that filter a Rover or Donaldson product? i.e. is the part no for for whole filter box or just the element? Just I dont know where I would get a genuine Rover box, either brand new or second hand around where I am. I am interested, sadly the only Rover ones we were able to look at thus far were little diesel Discos, which are too small.

Could you explain this pressure indicator? Does it detect how much back pressure the filters are creating, and hence determine how blocked they are or something? Is it part of the box, or a seperate in line item?


Zagan, I have already used the Donaldson estimate calculations. I didn't like it though, as it uses engine power, not capacity or revs. The donaldson estimate gave about 265cfm, my own calculations gave about 297cfm. My question about adequacy was mainly to do if I needed to supply more air due to the air ducting being 3m long, with 2 90deg bends, there will also be 1 ~30deg bend.

Thanks guys

AFAIK, the air filters Isuzurover was talking about are made by Donaldson and fitted to Land Rovers that have the 3.9 litre Isuzu engine.

The filter telltale senses pressure difference across the filter element.

Donaldson list 2 methods to determine air flow. The approximation based on hp and another based on engine displacement, rpm etc.

i.e. CFM = displacement (cu in)/1728 x rpm/CF x VE

where CF is cycle factor 2 for 4 stroke, 1 for 2 stroke
VE is volumetric efficiency 0.85 for N.A. diesel, 1.4 for turbo diesel engine

Thanks.

Cannot find that second method you list in their catalogue...
Anyway using it as you posted gives about the same numbers as their estimate through HP.

I found the double element filters in the Donaldson catalogue, I imagine it would be one of these that the Isuzued Land Rovers run then.

I also found stand alone pressure gauge items in their catalogue, but cannot find a box with it incorporated; I'll keep looking anyway.

Thanks again.

Highway-Star wrote:ISUZUROVER so is that filter a Rover or Donaldson product? i.e. is the part no for for whole filter box or just the element? Just I dont know where I would get a genuine Rover box, either brand new or second hand around where I am. I am interested, sadly the only Rover ones we were able to look at thus far were little diesel Discos, which are too small.

Could you explain this pressure indicator? Does it detect how much back pressure the filters are creating, and hence determine how blocked they are or something? Is it part of the box, or a seperate in line item?


Zagan, I have already used the Donaldson estimate calculations. I didn't like it though, as it uses engine power, not capacity or revs. The donaldson estimate gave about 265cfm, my own calculations gave about 297cfm. My question about adequacy was mainly to do if I needed to supply more air due to the air ducting being 3m long, with 2 90deg bends, there will also be 1 ~30deg bend.

Thanks guys

As Bush65 said.

The filter fitted to the ISUZU 3.9(T)D engines in landies is a:
Donaldson FH003-0429 (numbers a bit illegible, so this may not be dead accurate).
Outer Element is a P90-0433
Inner Element is a P90-0434

I am not sure if the pressure indicator is separate or included in the above housing. I have seen them listed as a seperate item on the donaldson website.

i have the next size down on a 4.2 turbo diesel running 20 psi boost and it copes quite well

its aford not a nissan wrote:i have the next size down on a 4.2 turbo diesel running 20 psi boost and it copes quite well

Awesome. I really thought you would need a higher flowing unit for a boosted 4.2 though...


Anyway, my father has got in touch with a Donaldson sales rep for SEQ, and he has said that the donaldson website is a bit outdated, apparantly the one we were looking at has been superceded, although is still available (no price difference either way). So he is going to organise for my father to see some of the current products in this size range.

The sales rep also 100% agrees that the pressure gauge should be utilised, its seems that they are all seperate, no incorporated ones. He also said that new filter elements do not work 100% untill they get some dust caught in them, that is why you only change the element when the gauge indicates to; very interesting.

So after this bloke gives us some actual samples to check out, we should be able to make a decision. I'll let you all know what one we end up using.

Thanks everyone

Highway-Star wrote: He also said that new filter elements do not work 100% untill they get some dust caught in them, that is why you only change the element when the gauge indicates to; very interesting.

Nothing to do with "new filter elements", all (air) filters increase in efficiency as they load with dust. This is because filters aren't sieves, the "pore" size of the filter is much larger than the size of the particles they can collect.

I have posted it several times before... (usually most people don't believe it...) changing your air filter too often is BAD for your engine.

ISUZUROVER wrote:

Highway-Star wrote: He also said that new filter elements do not work 100% untill they get some dust caught in them, that is why you only change the element when the gauge indicates to; very interesting.

Nothing to do with "new filter elements", all (air) filters increase in efficiency as they load with dust. This is because filters aren't sieves, the "pore" size of the filter is much larger than the size of the particles they can collect.

I have posted it several times before... (usually most people don't believe it...) changing your air filter too often is BAD for your engine.

Ben, are these pressure sensors available separately to be fitted to other air boxes do you know?

+dj_hansen+ wrote:

ISUZUROVER wrote:

Highway-Star wrote: He also said that new filter elements do not work 100% untill they get some dust caught in them, that is why you only change the element when the gauge indicates to; very interesting.

Nothing to do with "new filter elements", all (air) filters increase in efficiency as they load with dust. This is because filters aren't sieves, the "pore" size of the filter is much larger than the size of the particles they can collect.

I have posted it several times before... (usually most people don't believe it...) changing your air filter too often is BAD for your engine.

Ben, are these pressure sensors available separately to be fitted to other air boxes do you know?

Yep, Donaldson list them in their catalogue somewhere

Highway-Star wrote:

its aford not a nissan wrote:i have the next size down on a 4.2 turbo diesel running 20 psi boost and it copes quite well

Awesome. I really thought you would need a higher flowing unit for a boosted 4.2 though...


Anyway, my father has got in touch with a Donaldson sales rep for SEQ, and he has said that the donaldson website is a bit outdated, apparantly the one we were looking at has been superceded, although is still available (no price difference either way). So he is going to organise for my father to see some of the current products in this size range.

The sales rep also 100% agrees that the pressure gauge should be utilised, its seems that they are all seperate, no incorporated ones. He also said that new filter elements do not work 100% untill they get some dust caught in them, that is why you only change the element when the gauge indicates to; very interesting.

So after this bloke gives us some actual samples to check out, we should be able to make a decision. I'll let you all know what one we end up using.

Thanks everyone

i thought i would need a bigger one also , going by the calculations they give to work out air flow etc i needed one at least twice the size of what i got , but space was an issue . seeing as i was using the original precleaner with a K&N i figured this is 2 1/2 times the size with a proper filter , it couldnt be any worse than what i had , so i took a gamble and it seems to have paid off , it does breath alot easier now and i had dig around my garage to find the original vacume sensor (it displays a light on the dash when the air filter is in need of replacement )that was fitted before i added the turbo , i found it and it screwed strait into the thread at the base of the filter (where the white bung is ), i did test it before hand by wiring it up and sucking on the end of it ( that dont sound right ) and with very little suction it lit up the light on the dash so it does work
and at 22 psi boost and 4500 rpm the light still doesnt light up so the filter couldnt be that restrictive but i will wait an see till it clogs up a bit