Need help designing an airbox

[siren676]

factory intakes are shit, you can prove it on a turbocharged engine by noting the 2 - 4 psi maximum boost increase by using a pod filter, would be closer to 6psi increase with a cold air pod filter.

On another note you can spend around $500 doing a cold air intake, which doesn't really sound like good gains per dollar spent..

Sound ridiculous? Well add up the cost of 2 gauge wire, battery box, terminals, pipes, bends, couplers and clamps before you get to the actual air box construction and you're already $300 into it and haven't made a single gain yet.

Don't let that deter you though, you can buy things bit by bit until you've finally achieved your goal and its one of the easiest and most satisfying modifications you can do yourself without major tools or jacking up the car.

I agree that factory airboxes are shit. They are designed to make the induction noise quieter by using resonance chambers which must disturb the airflow a bit.

I like buying things bit by bit as it it way easier (and less depressing) than paying in a large lump sum.

I may consider getting a small sealed battery to help in saving space for an airbox.

[siren676]

Be very careful with that type of setup, wouldn't be ther first time a low mounted filter has hit a puddle and hydrauliced a motor.

Callum

That is 1 thing im wanting to be careful of. I really dont want to put in a new engine and the first time it rains have it take a lungful of water and blow apart.

[Bling]

With the amount of guess work going on in here I can't wait to see the results

Factory airboxes are shit and just to reduce induction noise? I've heard it all now, you guys are pros...

[sergei]

factory intakes are shit, you can prove it on a turbocharged engine by noting the 2 - 4 psi maximum boost increase by using a pod filter, would be closer to 6psi increase with a cold air pod filter.

On another note you can spend around $500 doing a cold air intake, which doesn't really sound like good gains per dollar spent..

Sound ridiculous? Well add up the cost of 2 gauge wire, battery box, terminals, pipes, bends, couplers and clamps before you get to the actual air box construction and you're already $300 into it and haven't made a single gain yet.

Don't let that deter you though, you can buy things bit by bit until you've finally achieved your goal and its one of the easiest and most satisfying modifications you can do yourself without major tools or jacking up the car.

I agree that factory airboxes are shit. They are designed to make the induction noise quieter by using resonance chambers which must disturb the airflow a bit.

I like buying things bit by bit as it it way easier (and less depressing) than paying in a large lump sum.

I may consider getting a small sealed battery to help in saving space for an airbox.

The factory air box is not as shit as people think.
In modern vehicle air box is well designed equipment which is very difficult to surpass in performance. Normally you would find that the resonance chambers are for fixing holes in the torque curve and not silencing it. When people play with air boxes, they change the whole flow and acoustic characteristics of the inlet system and modifying torque curve (and ultimately power curve). Yes of course you can gain power from a different air box, but generally whatever you gain, you loose in the bottom to mid range, which is more important.
Of course some manufacturers would make air boxes to be as cheap as possible, but lets not talk about Lada here.

Same thing applies to exhaust.

People approach modification from wrong end. First you should look into what actually increases power of the engine - increase how much air it can pump through. One way of doing it is increase RPM, another way of doing it is forcing more air through via secondary pump (supercharger or turbo).
If you increase RPM, your engine becomes restricted by cam timing, so you install bigger cams (which shifts the power band higher, but you get loses on the bottom end due to acoustic and flow dynamics).

Otherwise you will be spending thousands of dollars on mods that only return 1% at best on an average car.

[Bling]

+1

I tried with varying success: Open trumpets, Pod filter, Factory setup.

Open trumpets felt faster, as I lost most of my torque range and compacted it into the 7-8k rpm range. Up until that point it was so slow that when you hit 7k it torque steered

If you want to fiddle around with things, by all means do. But to claim your ideas (unproven) are better than the shit factory design before even trying it is just silly talk. I always thought that restriction in the intake actually helped create torque. This could be completely wrong, but with all three setups above, the more restriction I had in the intake the better it drove.

Out of all three options, I preferred the sound of factory the least, both other options sounded much better. But I wasn't after only sound, I wanted the car to give the best driveability it could. Only option three could offer that.

I drove all three options for long periods of time too, no dyno proof, just experience.

[gt4dude]

Sergei you obviously have seen what I'm talking about, pathetic wastegate aside though, you cant deny 1.2bar is more powerful than 0.9bar whatever way you look at it.

If factory intakes were so great why does TOM's a factory tuner supply a cold air kit for certain cars, like your levin bzg guy

It's obviously hard to prove on a dyno since the car is not moving air at high speeds and the bonnet is open so the air temp and density is relatively the same nomatter where you take the feed from, but im pretty sure in my case a 0.3 bar increase is big enough to be felt.

also restriction - doesn't that equal pumping losses? and those extra resonance chambers don't they just make more things for the air to do? how is an obstacle course the fastest way to supply air? and those ribs on the piping they're not there for extra pleasure

[iOnic]

With the amount of guess work going on in here I can't wait to see the results

[TRD Man]

... why does TOM's a factory tuner supply a cold air kit for certain cars, like your levin bzg ...

They do? For a BZG?

They did, for a very short time some years ago, produce a product they called a "Super Intake" which had a pod internally mounted.
It was cosmetic value only, didn't sell well and wasn't available for long.

The product that they made which actually did work was the TOM'S intake system for silvertop. This utilized a larger chamber together with a set of tapered trumpets which narrowed the diameter of the throttle body all the way to the butterfly increasing the venturi effect. You needed both bits for it to be effective and, ironically, it hooked up to the standard airbox.

[sergei]

Sergei you obviously have seen what I'm talking about, pathetic wastegate aside though, you cant deny 1.2bar is more powerful than 0.9bar whatever way you look at it.

If factory intakes were so great why does TOM's a factory tuner supply a cold air kit for certain cars, like your levin bzg guy

It's obviously hard to prove on a dyno since the car is not moving air at high speeds and the bonnet is open so the air temp and density is relatively the same nomatter where you take the feed from, but im pretty sure in my case a 0.3 bar increase is big enough to be felt.

also restriction - doesn't that equal pumping losses? and those extra resonance chambers don't they just make more things for the air to do? how is an obstacle course the fastest way to supply air? and those ribs on the piping they're not there for extra pleasure

Well your boost creep is problem and not gain. Of course you might get power from extra boost but not because intake flows better. Uncontrollable boost is a very bad thing.

I would say the car would perform better with boost controller on standard intake running standard air box than with the boost creep you are getting on aftermarket/home made intake.

The reason why they make aftermarket airboxes is 1) they tune airboxes (if tuners are genuine) for their other performance parts (ECU, cams, headers, exhaust) or 2) because ultimately people will pay money for bling.

My bottom line is of the following: if you don't change turbo/install cams or run enormous boost, then you don't need to muck around with modern airboxes.

In other words there are far better places to spend $300-$500 than on an airbox on a stock standard motor. Especially something like 5EF(H)E or whatever the OP got.

[Mr Revhead]

Oh chuckle.

Yeah the factory intake can be improved on.
But think of the time and money the factory spend on making it work with the stock engine.
Unless you go nuts on the rest of the engine the stock intake will be hard to improve on, and easy to screw up.
As mentioned by several, the best you can do is improve air flow to the box.
there may be the odd thing out there with a rubbish stock air box, but not any Toyotas I know of.

Yes some companys make intakes, some are good and have been properly done with dyno testing etc. Others are merely $$ bling with fancy stickers.