Intake - Balance of performance quietness, and economical?

[Cooshman]

No offense, but I highly doubt the R&D department at Injen, if they have one, does even 1% the amount of work car manufacturers do. The Injen intake I had on my '99 si looks exactly like what they sell now. A metal pipe with a filter on the end. So I wouldn't use their design as evidence of good intakes compared to OEM.

The argument though is a moot point, when comparing the modding of OEM to replacing it with aftermarket. You are basically doing the same thing, removing aspects of what the MFR. did to either increase flow or sound.

But I can agree that auto mfrs. do put in a lot of work to design their intakes for power, sounds and emissions. However, there are tons of vehicles out there that do see benefits from modding stock air intakes to some degree. I've personally done it on many of my past vehicles when a true aftermarket isn't needed, and do replace when it's beneficial.

 

[SteveCo]

OEM goals are largely driven by bean-counters, not engineers.

In that case I'm sure they would have been delighted to poke additional holes in their intake system, and save on the plastic used to manufacture it ...

 

[xot1]

l bet you the OEM filter costs less than one tenth of Injen. Cheap budget.

 

[SteveCo]

No offense, but I highly doubt the R&D department at Injen, if they have one, does even 1% the amount of work car manufacturers do. The Injen intake I had on my '99 si looks exactly like what they sell now. A metal pipe with a filter on the end. So I wouldn't use their design as evidence of good intakes compared to OEM.

No offense taken. An intake designed with minimal impediments to flow (e.g. mandrel bending with no acute angles), and optimized pipe lengths, diameter, and filter sizes, all within car-specific space constraints, is considerably more involved than supplying a 'pipe with a filter on the end'.

They do dyno test and document power gains with their final product, and while the numbers look impressive I'm sure they ran them with the hood open and auxiliary fan cooling- like all other aftermarket intake manufacturers. As I said, I'm happy with the looks and sound, and believe that they provide significantly better breathing at high RPM - but without controlled testing results to back that up it's only my opinion, nothing more.

 

[Hapa88]

The factory does a lot of testing with air flow and pressure gradients when they design the air intake system, the goal being maximum performance and fuel economy while meeting noise and engine protection targets.

Agreed to an extent. I wouldn’t say their top priority is ultimate performance since it has to be balanced with federal emissions and fuel economy standards. Secondly they look for reliability (which is where filtration is important). Then go for noise suppression.
The stock system is perfect for anyone who wants to leave the car stock. If you add a JB4 or other ECU modification that ups stock boost pressures, then the air flow requirements and constraints are no longer valid for the stock system.

Cutting new holes drastically changes flow and pressure. I'd like to think the engineers knew what they were doing, and homemade cut-outs have a good chance of going the other way.

The engineers knew what they were doing but they designed the system to meet a different set of requirements and constants than what a performance enthusiast is looking for. Someone who wants increase performance and noise at the expense of fuel economy, emissions and reliability would require something different than the current system was designed to perform.

My modifications, should, in theory, allow for increased flow (should I up the factory boost) and reduce the pressure gradient from before the filter vs after. The additional noise generation has already been confirmed.

 

[Manaz]

In that case I'm sure they would have been delighted to poke additional holes in their intake system, and save on the plastic used to manufacture it ...

Poking holes costs money, or adds complexity

Process and complexity almost always cost more than materials.

 

[CoconutRob]

Does anyone know how much more filter surface area tha AEM cone has compared to the K&N panels?

 

[CoconutRob]

I bought a set of OEM airboxes off a guy on eBay for $125 and modded them (Dremeled a few holes into them and removeled the mating piece in the front). Sound level increased marginally over the OEM setup so that now you can hear the turbos spool but you can't really make out any Diverter valve sounds.
I've done one round of IAT logs before and after and so far the data seems to show an improvement of about 2-3 degrees cooler, on average, over the stock unmodded airbox (which doesn't make much sense to me based on the design, but hey, I'll take it).
I may make the side hole a little larger, but we'll see.

Did you notice any throttle response difference. And do you still have stock filters?

 

[Hapa88]

Did you notice any throttle response difference. And do you still have stock filters?

When I did launch control before the change, I could never break the tires loose. Now I can. Not sure if it’s just different environmental conditions or added power.
“Throttle response” seems about the same. I’m running the factory Kia OEM filters.