I have never been a fan of the Optiair air cleaner because the lid is about 75mm deep and so it sticks out that far or further and it was plastic but the only choice if one went for a Donaldson like the original and metal was at a cost of $800 odd.
I did install one in my Oka as many others did, I am installing a turbo in someone else's Oka but didnt want to use the Optiair so looked around for an alternative and couldn't find one so set about in getting one produced to suit the Oka.
I have now got a sample being made and sent over for testing and checking measurements.
It is all metal with a lid that fixes like the Donaldson with 100mm in and out and a primery and safety filter. the capacity is 900 m3 per hour
The inlet I hope ( if not we can make changes ) will be inline with the snorkel so no need for the S bend which will also cut down on resistance.
I know it is a bit late for the ones who have already done the upgrade but anyone who may be interested let me know.
The indicated cost is in the region of $ 200.00 which is way better than Donaldson and around $75 less than Optiair.
I am also looking at custom made intercooler but not down to final design yet.
There is some mods that I will talk to the factory about but all in all I am happy if they couldnt change anything.
The price is not an issue for me but transport even though it came down from where it started I think there is room to move.
I will let you know as things progress.
- Dean and Kaye Howells
- Posts: 524
On #413's 'maiden run' with the factory standard Cummins and original Oka air filter the fuel consumption was greater than with the Perkins, as cruising speed was increased so did fuel consumption. eg. with the Perkins highway cruising gave around 16.5 l/100Km at an average 90-95 Km/hr. With the Cummins this became 19-19.5 l/100Km. At lower speeds and using 4th instead of 5th better consumption was attained ie. loafing down the Strezleki Track at 75-80 k's got around 16.5 l/100Km.
Early in the trip and sitting on 105 k's and not really paying attention to the fuel gauge I actually ran out of fuel at exactly 450 k's from a full tank. A pretty poor result. Well, that's what shakedown runs are all about I suppose. So after nearly 10,000 K's of trying various cruising speeds and gear combinations I knew pretty well what the fuel consumption was under different circumstances. Unfortunately I couldn't do much about it even though I figured early on that taking the cover off the air cleaner would be a good thing to try but as we were mainly outback off road/dirt road I wasn't game.
The proof of the pudding was the 'home run' down the Calder/Sunraysia Hwy from Mildura to Home, a run of around 720 Km via Ballarat and the Queenscliff/Sorrento ferry.
I removed the air cleaner cover after re fuelling in Mildura and headed south, I changed tanks just south of Ballarat at 500 Km and the improvement in power/driveability was noticeable from the start. We got 16.5 l/100km sitting on 93 km/hr or 1950 rpm on 325/85 R16 Michelin XML's. On the more congested run from here to home (220 Km) we got 16.8 l/100Km. IMO on the more direct Calder Hwy the consumption would have been even better. Even more so with less 'aggressive' tyres.
The point of this 'long winded' story is to point out that the restriction was obviously poor air flow especially the small snorkel diameter standard in the Oka.
I've been waiting for an Acco air cleaner to try but hopefully your solution will be a success so I watch with interest.
- Dean and Kaye Howells
- Posts: 524
The point here is that the restriction in the factory snorkel setup makes a significant difference when air consumption requirements are increased and IMO the air cleaner Martyn is working with could go long way to resolving this issue.
I read somewhere that you were in Tassie, You will get better fuel consumption for a number of reasons being. you installed the turbo without changing fuel settings so this will give you a leaner mix which unlike a petrol engine a diesel engine can run lean without any detrimental effect but too lean I am not sure. Being in Tassie the air is denser and more humid also colder so in simple terms more power or the same with less pressure on the accelerator all in all better economy.
The opposite is true for the hot dry climates.
- Posts: 763
mort wrote: Hi Tony,
I read somewhere that you were in Tassie, You will get better fuel consumption for a number of reasons being. you installed the turbo without changing fuel settings so this will give you a leaner mix which unlike a petrol engine a diesel engine can run lean without any detrimental effect but too lean I am not sure.
1) a petrol can be leaned out, and the last few years in F1 that have been fuel limited, so to get a better "Brake Specific Fuel Comsumption" (BFSC) one then needs more air.
(When air restricted and not fuel restricted then adding fuel gets more power at the expense of BSFC.)
The other example is in aircraft... both require running lean of peak (LOP), and most engines are tuned to run rich of peak (ROP). Does does not want to go through the peak to get lean at wide open throttle (WOT) as that is where detonation is most common.
2) However I am not sure how the turbo alone will give a leaner mixture? How is the mixture determined? I assume mechanically, and there is more boost at lower RPM and also that the engine is running boost at cruise?
- Peter and Sandra OKA 374
- Posts: 1247
More air means more fuel can be burnt and getting the exhaust away quicker with less restriction gets rid of heat quicker.
The turbo can be changed to a different flow rate and also changed to give boost lower or higher in the rev range.
Fitting an intercooler drops intake air temps which are increased considerably when the turbo compresses the incoming air never mind the heat picked up from the turbo itself and the intake trunking.
OKA 374 LT Van, converted to camper/motorhome,
400ah Lithiums, 1100w solar, diesel cooking heating and HWS,
Cummins 6BT, Allison 6 speed auto, Nissan transfer.
Yes you are correct sort of ... an F1 I cannot comment on as I have no knowledge off except that they go fast and rev at that is ridicules and at the end of each race the engine is stripped down and rebuilt.
Planes on the other hand I have some knowledge off, the idea of running rich or lean is similar to any other engine so on takeoff, climbing or landing so when power is required the pilot will manually set to rich for power but once reaching cruising altitude he will then set to a lean mix, it is based on the cylinder head temp which is the same for the Oka and the reason to install a pyro gauge. On aircraft if you run too lean you will stall and too rich you will seize either way you fall.
Using Tony's as an example we would assume it was tuned to an ideal air/fuel mix so he then installed a new turbo and did nothing else that turbo is now pushing more air in without changing the fuel hence the leaner mix, if he wanted to get max power he would need to reset injector pump.
Fuel consumption can't be measured accurately in any road test simply because the several variables can't be controlled. Terrain, altitude and direction profile, road surface, wind direction and speed, window open of closed, aircon or heater on or off, electrical load, ambient temperature, tyres, interference from other road users, driver skill and attitude and probably the main one which is how to measure fuel used.
Fuel consuption can be measured to several decimal places using a dynamometer, but of course then the complaint is that it bears little resemblance to real-world situations (the "s" being because everyone's situation will be different)
Gauge shows near to empty ==>>> Switch to the other tank ====>>>> fill the first tank and hand over the credit card. Dollar amount, litres pumped and Odometer reading all irrelevant.
Yes, might even get around to doing it one day - or just screw the adjustment in half a turn as someone suggested.
if he wanted to get max power he would need to reset injector pump.
- Posts: 763
One needs a fuel flow to fit he consumption part of fuel consumption.
For the "brake specific" part of BSFC, one needs a power measurement.
Speed and force do it but as mentioned there is tyre pressure wind load etc...
A strain gauge of a shaft or motor mount torque or some "load cell"" can give the force part.
But I agree with your posted 'tautological' conclusion of "it iis what it is", so while it would be technologically interesting who cares.
Diesels are a different beast, and the turbos run on engines with 15-20:1 compression ratios.
The thing I hear with petrol engines are that turbos get better mileage because they recover the energy in the heat.
A high compression engine running at WOT at max torque is where the lowest BSFC usually happens.
Any lowering of compresssion, or opening the exhaust value early to get more exhaust heat to spool e turbo, or retarding of the spark to avoid detonation all lower efficiency. Diesels do not work Thi sway, unless there is some gas LPG which iburns more like petrol.
I suppose people must use lambda gauges, but have no clue... I need to GTS it.
What that has to do with airfilters I do not know...
Are the new air filters better?
New air filter installed and all working as expected.
I have given the elements to a supplier to see if he has or can get the replacement elements if not they are an off the shelf item for the manufacturer so readily available ( in Europe and U.S. ) if not an off shelf item here then maybe if wanted could order say 2 elements as spares for future....wait and see.
Ok the element is/can be replaced with a Donaldson P130884, P789077, WA1028 or there is other brands that will replace the factory std so no issues.
I am now waiting for a reply to the changes and the final price which will include silicone bends from filter to turbo.
Should not be long now.
I have received from the factory confirmation of the changes which they can do except one that being the inlet at the front in line with the snorkel, the reason is the air flow inside the housing will change and affect performance so still at the back like normal but for ease of installation it is rotated to the left where there is more room.
The final price is $361.00
This is made up of Filter $181.00
Silicone fittings from filter to turbo $35.00
The filter all metal is a good price, the silicone bends x 5, I had to purchase for the filter that I just put in and 1 bend cost $40.00 in Perth. The shipping started at US$230.00 to which I told them it was a deal breaker and quoted what I was paying for turbos which are heavier but smaller so went to a number of shipping agents to get it down and its not the weight but size.
I have got a number of pre orders and although there is a minimum I dont believe that the price will change for larger orders.
If you want silicone bends for intercooler let me know and it can be added into the box.
Over the last week I have had a number of Phone calls or emails regarding ordering the filters and with a few questions as they are similar questions I thought I would put up some with my answers/comments.
Do I need to change my filter.
Short answer no but if you want to get the best performance and economy from your engine then yes.Its like when you go for a walk breathing is normal and steady but pick up the pace and you not only burn up your energy reserves but you need more air, restrict the air and you dont do too well.
Will the filter be big enough for a 6BT or similar.
Yes it was sized to suit any upgrades that has or may happen.
Is it an easy fit and install.
Yes I dont like complicated or hard, basic tools ie tape measure and pencil, tin-snips left and right hand, angle grinder, drill spanners and screw driver is about all.
If I had an old one from a truck is it ok.
Yes if it can fit in the space and is bigger than std why not.
I did go looking at the truck wreckers when I did this last turbo install and only found 1 that would have worked, it was from an ACCO and was a Donaldson so mounting brackets were similar it was a little bigger than std oka and sized for a 160 HP. They wanted $220.00 for it the biggest problem was that it only had a single filter which would be ok if staying on bitumen but the owner wanted 2 filters add the cost of cleaning and painting and new filters why bother.
There is a lot more truck wreckers in the eastern states so maybe you will have better luck finding a duel filtered one at a reasonable price that wont be too difficult to fit.
The other thing to consider is that old also means it may miss out on features and certainly one is if you look at one of the photos above you will just see some vanes/fins inside at the back this is to allow the air to spiral around and cover the entire filter but also any dust or water can be thrown to the edge away from the filter.
Is there any other advantage in having a larger filter.
Other than allowing the engine to have as much air as it needs without struggling a bigger filter means if you are in a dusty environment it will take a lot longer to clog up.
Any other questions just ask.