pull on it. It will pop right off..

 

You were told not to buy the filter.... You have a 95 which has different systems than these. You run off a distributor and these run off coil packs. Keep that in mind. When people talk about fixes and upgrades, yours will be slightly different on most things...

On ours, There is a trumpet on the airbox. That is the trumpet we are talking about. We are also pulling the whole box and putting the new filter directly on the MAF. The filter we bought has 3 different sizes for the adapter. If you bought the cheap dinky one, it is 3" and no, it will not fit on the MAF (3.5")

 

I also have the trumpet.. if you pull it comes right off. I noticed I bought the other filter..they were the same price (red, blue, and white) and i chose the red which is my favorite color..so i went back and exchanged it for the blue one and it had the multiple size slips. Put it on and tightened it.

 

So the MAF on a 97 would be 3.5"? I have a cone filter with a 3.5" connector, so I'd like to try this mod if it means better gas milleage.

 

Running straight 0W oil year round and keeping your tires inflated to 60psi will increase your mpg too.

 

I did the air filter mod, but added a piece of 3" pvc pipe bent slightly to put the filter closer to the headlight and fender. a 8$ rubber sewer pipe connector holds it to the maf. The pipe is attached to the truck to keep everything in place. It stays mostly clean, but i plan on boxing it in on the engine side.

 

Ok, I don't know much about Land Rovers, but plenty about wannabe air-intake mods.

Filter media, paper versus oiled gauze doesn't matter as long as the surface area of the filter is sufficient for the flow rate of the engine. It's super easy to make a paper filter with enough surface area to flow. This is why K&N type filters almost never provide any additional flow that is useful. The bottom line is the paper ones flow more than the engine can suck. I have spent a lot of time in dynometer equipped shops for production class race vehicles and it was well agreed that there was no HP or torque in any filter. The OEM filters (like Honda) were the best. K&N was just something that shops sell to support their racing habit.

Airboxes, on the other hand, can be a big deal. On high speed vehicles over 120-130mph, ram-air is important. At 180mph we could make very big gains with a good ram air setup. At 80mph, you will see nothing. For Land Rovers, you will see nothing from ram air.

I worked mostly on open loop race systems. We used 3d maps for injector durations, not a closed loop type with MAF and O2 sensors. We also never had high intake temperatures. Therefore I cannot say much about cold air intakes, how much they might benefit. Personally I would not go to any great effort to get any colder air than what my stock setup gets.

At low speeds, the key features of an airbox are acoustic not flow. OEM's build a box to a spec that complies with regulatory requirements for noise. I would say that the huge majority of airboxes are designed for noise suppression while not affecting fuel efficiency. If there was a fuel efficiency gain in an airbox, the manufacturer would never miss that. They'd be total idiots to miss that. The benefit for cost to them would be huge!

On high performance vehicles, we are using acoustics to boost torque and the area under the hp curve. We use acoustic resonance via a helmholtz resonator. 2-stroke guys understand this easily from their exhaust pipes but it works the same way on 4 stroke intakes. We want a resonator to reflect a wave back at the intake valve at just the right time to pop some more charge in there before it closes. We can tune for a particular engine speed and get a nice bump in the middle-bottom of the power curve.

Looking at the Land Rover intake box, I'd say there are no useful resonances going on in there. If you look at a Ferrari box from the last 10 years, you can bet there are. Designing and fitting a helmholtz resonator box is not practical for the Land Rover, especially since it's end of life. I mean, if there was some kind of Baja outlaw circle track team running Discos this year with a $5 million budget, it would get done, but we all know Discos run snorkels not helmholtz resonators and power curves don't really mean anything to us.

Can you usefully increase flow by using a non-paper element? I doubt it. This would only be the case if the stock element dimensions were designed too small for the engine and this is unlikely. The difference in pressure would not result in any significant power gain. If you doubt it, put a manometer on the intake tube and compare at a given engine speed. Or put them back to back on a dyno and see that you gain nothing and in some cases you will actually lose power.

Can you usefully increase flow by eliminating or modifying the airbox? I doubt it. You can ruin the acoustics of the stock airbox design by cutting it off or open. Because it is not a sophisticated design you will not lose power but you will only gain noise.

Now with all that said I still want to pull off my trumpet because I want to put a 2nd battery in there. I believe the trumpet supresses noise without restricting flow because it is effectively shaped like a venturi. With a venturi, you get more pressure at the inlet (so less sucking sound), but the restriction in the narrow diameter of the venturi doesn't affect flow much because while the pressure drops the velocity increases and then once inside the airbox the pressure goes up again. The venturi allows a small airbox opening without restricting flow. Remove the venturi and you will need a larger airbox opening to compensate and the whole thing will make noise.

If you don't believe me, just look at the whole history of restrictor plates in racing. We can make tons flow and tons of power with restrictor plates, as long as you leave everything else to us.

 

Ok I don't have time to read all that but my theory's have changed..

I know for a fact the vehicle runs different with no air filter vs with. But I'm not sure how or why.

Fact is. It did work,

But I wouldn't believe it myself because the biggest restriction of air flow is the throttle plate. And that's it's purpose to restrict flow. The vehicle should run at the correct ratio if it's injected and isnt being choked by something before the throttle plate

But I still think
It worked... !?!?.

 

how about the ecm? i would think the ecm is calibrated for the stock air box & filter. it is programmed with different values for different situations read from sensors like the MAF. example, if the MAF is disconnected the ecm would try to correct itself and run on default settings or the last correct settings, right? the ecm has efficient preset values set by the engineers for almost every environment an average disco driver would encounter, did they program for the airbox to be removed also?

 

I doubt it. It's a closed loop system. I'm betting my dog has more memory than the ECM. It's probably 8-bit, total old school. But the advantage is all you really need is a MAF and O2 sensors and it will run, input and output. There's no maps or presets, or environmentals or anything like that as on an open loop system. Remember the only reason it's there is to pass emmissions regulations and not cost more than a carburettor. The marketing department is the only reason a customer ever thought any other wise. I suppose for extreme crawling it's good not to have a float bowl but, there's always propane.