why so much hate for K&n?? seems to stop dust pretty well according to this guy I think the trick is to clean and oil it correctly
The "Official" 1HZ/1HD-T/1HD-FT Airbox/Intake Mod Thread (4 Viewers)
- Thread starter ForealBoreal
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
mudgudgeon
Resident galah
I'd try a genuine filter element.
In my hzj105 aftermarket filters would sometimes trigger the filter restriction sensor on the air box even when almost brand new and clean
mudgudgeon
Resident galah
There was an Aussie 4x4 forum that disappeared 10 years back. One member who regularly contributed to tech was an R&D engineer in a major filtration manufacturer in australia.
He spent a chunk of time testing and analysing numerous OEM filters, and a whole range of aftermarket and performance filters. And put his results on display.
OEM stuff generally was at the top of results.
Aftermarket stuff made for mining industry was often equal to OEM.
General consumer aftermarket don't match OEM.
K&N performed very poorly, aka the worst, on every measure except airflow.
He tested filter surface area of filter media, particle size the filter media allows through, airflow . . . Can't remember what else.
OEM and Donaldson filters out dust to the smallest particle size, and had the greatest surface area in the filter media and also in the pleated design of filters overall.
Large surface area is important to achieve fine filtration without restriction of air flow.
K&N filter media is very coarse to allow max airflow for gains in performance. But it means it allows large damaging dust particles through into the engine.
Anything but pure tarmac use, a K&N is a recipe for disaster for your turbo and engine.
There's plenty of anecdotes of guys removing K&N filters and finding a film of dust in the airbox and intake downstream of the filter and finding their engine has been dusted.
mudgudgeon
Resident galah
K&N have been discussed and analysed many times.
There is no good reason to run one.
Some good info here from 2007
Thread '80 Series K&N vs. OEM Air Filter' 80 Series K&N vs. OEM Air Filter - https://forum.ih8mud.com/threads/80-series-k-n-vs-oem-air-filter.156529/
And some analysis here
K&N Air Filter Review - Debunking the Myths (and why OEM is better)
Before spending your money on an aftermarket intake, let's debunk the misleading incomplete info about filtering and horsepower in the sales literature.
ATL Cruiser
GOLD Star
Really dumb question here, and I apologize if it's been covered in this mega thread already.
My understanding was that every turbo whistles under boost. Every diesel I have owned, even those with a stock turbo, has whistled.
Is whistling actually a sign of restricted intake?
mudgudgeon
Resident galah
They all whistle at least some.
A boost leak can be a louder whistle, or can sound like a screaming cat sometimes
check out this baby new to me anyone got one?
look at all the configuration options kinda cool
I'm thinking of maybe making my own airbox with a better air filter. retro fit a L5P banks filter 1000CFM with almost no pressure drop...
is it true an air filter with almost no pressure drop???
look at all the configuration options kinda cool
I'm thinking of maybe making my own airbox with a better air filter. retro fit a L5P banks filter 1000CFM with almost no pressure drop...
is it true an air filter with almost no pressure drop???
Last edited:
AussieHJCruza
Supporting Vendor
- Joined
- Jul 8, 2013
- Threads
- 64
- Messages
- 2,984
- Location
- New South Wales, Australia
- Website
- www.completecruisers.com.au
Round filters in a square box are silly. Get an airbox that uses a panel filter.
please explain why they are silly.
turbulence? look and design too complicated to change out?
what I think is silly is people who put the largest cone filter on top of their snorkelers with a sock prefilter. it looks dumb but I'm sure it functions fine.
AussieHJCruza
Supporting Vendor
- Joined
- Jul 8, 2013
- Threads
- 64
- Messages
- 2,984
- Location
- New South Wales, Australia
- Website
- www.completecruisers.com.au
From a flow/turbulence perspective I just can't see how they work effectively.
PatrolDocta used to do a round airbox with a round filter which I thought was a good design but would go with a panel filter like Moonlight or PDI personally.
I've had various causes of whistle that seemed "grossly more than normally expected". I don't have an intuitive feel for that as this is the only diesel I've ever owned, but when it's consistently annoying at a wide range of boost that seems off.
First: Turbo inlet pipe had a giant hidden crack that wasn't obvious., turned out to go around about 75% of the entire pipe! Shocked I had any pressure at all! Replaced with a silicone pipe, MUCH less whistle, slight improvement in power/response.
Second: Intake gasket blew a chunk out and created a SUPER annoying whistle at basically all pressures--not the "screaming cat" analogy from mudgudgeon but I could see that being totally possible. In hindsight upgrading the intake gaskets should be a required part of a turbo upgrade.
It still whistles but at higher boost and not nearly as bad as the video I posted last year. I feel like it should be more of a powerful whine than a proper whistle--again, for no experienced reason--and I think it might be related to intake restriction. I have a restriction gauge but haven't installed it yet, I need to start with a new turbo controller because suddenly my old one seems to not work/have a max PSI which is scary....
The overboost explanation video posted by Veiloctane is good motivation to match the intake to the turbo capabilities!!! Just seems like it shouldn't cost $2k......
a turbo with a wine-like siren can be a broken bearing or the fins touching the housing worst case scenario a broken fin too
in my case a multi-combination of things hit.
1hdt Kinugawa TD05-18G, can't reach 20psi
thanks for this info i guess i have to lean out the fuel or even tighten up spring tension on the boost compensator to aim for 18:1 Negative. Increase the fuel. 18 parts air : 1 part fuel A leaner mix of 22:1 is 22 parts air :1 part fuel
forum.ih8mud.com
- I suspect an air intake restriction
- crack in the turbo-developed housing possibly causing turbo Overspeed was boost leak tested at 30psi with no leaks before going on a test run.
- thrust bearing gave way causing the fins to touch the housing and break off.
I’ve seen some here mention Donaldson filters.
I had a look in their catalogue and looked for the biggest one that I can make fit.
The listed CFM is less then I calculated for our 4.2 diesel, but anyway the filter element of the unit i got is approx 68% more surface area then the OEM filter, and has a 3,75” inlet and 3,5” outlet. Wich is both a bit larger then OEM aswell. So theoretically it should do better.
Unfortunatly this I think will only fit LHD 80’s due to the large filter design.
And another downfall is the complete box will need to come out to change the filter element.
It also comes with a 2nd safety filter for extreme dust conditions that can be left out if wanted.
Still waiting on all the hoses to make it fit, but I’ll report back once it’s in.
I had a look in their catalogue and looked for the biggest one that I can make fit.
The listed CFM is less then I calculated for our 4.2 diesel, but anyway the filter element of the unit i got is approx 68% more surface area then the OEM filter, and has a 3,75” inlet and 3,5” outlet. Wich is both a bit larger then OEM aswell. So theoretically it should do better.
Unfortunatly this I think will only fit LHD 80’s due to the large filter design.
And another downfall is the complete box will need to come out to change the filter element.
It also comes with a 2nd safety filter for extreme dust conditions that can be left out if wanted.
Still waiting on all the hoses to make it fit, but I’ll report back once it’s in.
Finally got to fitting the Donaldson filter in.
I had to order different connectors and hose a couple of times to make it fit.
I’m not 100% happy yet because the tubing between the filter and turbo is a bit longer then OEM and I maybe should’ve made it bigger diameter.
I’ll see if I can make this shorter, and possibly bigger.
Airbox outlet is the blue 3,5” to 2,75” (turbo intake diameter) elbow reducer.
Would it be better to go 3.5” all the way to the turbo and put a 3,5”-2,75” reducer elbow there?
I hoped to go in a straight line from airbox to turbo with just 2 elbows but it wasn’t possible, so had to do 2x 45 degree bends, therefor making the tubing longer.
Driving it, I can’t say I feel lots of difference wich I also didn’t expect.
The only thing noticable is it looks like boost comes in faster/harder, so thats a good thing.
Can make boost spike at 20 psi at 1900RPM easily with this turbo.
Note my HDJ80 is an auto gearbox so these things are always harder to notice due to the converter slipping.
I had to order different connectors and hose a couple of times to make it fit.
I’m not 100% happy yet because the tubing between the filter and turbo is a bit longer then OEM and I maybe should’ve made it bigger diameter.
I’ll see if I can make this shorter, and possibly bigger.
Airbox outlet is the blue 3,5” to 2,75” (turbo intake diameter) elbow reducer.
Would it be better to go 3.5” all the way to the turbo and put a 3,5”-2,75” reducer elbow there?
I hoped to go in a straight line from airbox to turbo with just 2 elbows but it wasn’t possible, so had to do 2x 45 degree bends, therefor making the tubing longer.
Driving it, I can’t say I feel lots of difference wich I also didn’t expect.
The only thing noticable is it looks like boost comes in faster/harder, so thats a good thing.
Can make boost spike at 20 psi at 1900RPM easily with this turbo.
Note my HDJ80 is an auto gearbox so these things are always harder to notice due to the converter slipping.
Last edited:
- Joined
- Sep 9, 2004
- Threads
- 200
- Messages
- 12,509
- Location
- Boise - Idaho
- Website
- www.snlandcruisers.com
Last one we built for an FTE, these are working well for us so sticking with them.
Cheers
Cheers
ATL Cruiser
GOLD Star
Update on the Donaldson airbox.
I’ve made the piping from airbox to turbo bigger. 89mm all the way to the turbo intake with a flexible hose and a reducer elbow on the turbo intake.
Since fitting this airbox I noticed a raise in boost pressure of 2 psi so I turned boost back down a bit.
I noticed there is a restriction in this airbox intake. I think it’s a pre-cleaber supposed to make the sucked air swirl around the filter element and trow dust and dirt particles outwards?
I cleaned the filter element today and I found most dust in the filter was all the way in the back of the filter, opposite of where the intake is, so I think it makes sense.
What do you guys think? Leave the restriction in or cut it out?
I’ve made the piping from airbox to turbo bigger. 89mm all the way to the turbo intake with a flexible hose and a reducer elbow on the turbo intake.
Since fitting this airbox I noticed a raise in boost pressure of 2 psi so I turned boost back down a bit.
I noticed there is a restriction in this airbox intake. I think it’s a pre-cleaber supposed to make the sucked air swirl around the filter element and trow dust and dirt particles outwards?
I cleaned the filter element today and I found most dust in the filter was all the way in the back of the filter, opposite of where the intake is, so I think it makes sense.
What do you guys think? Leave the restriction in or cut it out?
Last edited:
Indestructible 47
SILVER Star
I say leave the filter housing as it is. I'd rather be sure the intake air is as clean as possible rather than trying to gain the very small percentage in performance by removing it.
mudgudgeon
Resident galah
I'd leave it as is.
If you saw a gain in boost, you've already improved airflow.
If you saw a gain in boost, you've already improved airflow.
