Anyone tried this mod to the stock airbox?

[Sierra Advocate]

I've read that high performance air filters, while offering better airflow, don't do a great job of actually filtering the air and can cause problems as a result. In light of this, I'm reconsidering my plans to replace my stock airbox with a K & N FIPK. I found a website that shows you how to modify the stock airbox to increase airflow while retaining the stock filter. My question is has anyone here tried this or something similar and what was the result? The site is here. I don't want ruin my airbox if this turns out to be a bad idea. Besides this mod, the site has alot of other tips for increasing the performance of your GM.

[CheckEngine]

This mod will definetly allow more air to be drawn into you airbox, but keep in mind that it will be hot air from the engine bay, not cold air. It is claimed that colder air is better for making horsepower (has something to do with the fuel atomization). But it is a cheap alternative to an aftermarket air intake. If you do any offroading or any driving that may allow water into the air box, I personally wouldn't recommend cutting up your air box... Again this is just my personal opinion....
CheckEngine

[Sierra Advocate]

Originally Posted by CheckEngine

I personally wouldn't recommend cutting up your air box.

Thanks, CheckEngine, for your input. If I do this mod I'm gonna try it on a used airbox that I'd buy cheap off ebay. Don't take this personal but you did mention something that I've always believed was more hype than reality and I'm bringing it up for the sake of argument:

Originally Posted by CheckEngine

This mod will definetly allow more air to be drawn into you airbox, but keep in mind that it will be hot air from the engine bay, not cold air. It is claimed that colder air is better for making horsepower (has something to do with the fuel atomization).

Since you mentioned this often-stated fact, if a FIPK, Volant, etc. isn't sucking air from inside the engine compartment, where exactly are these cold-air intakes getting their supposedly cold air from? Food for thought...

[sector95]

Originally Posted by Sierra Advocate

Thanks, CheckEngine, for your input. If I do this mod I'm gonna try it on a used airbox that I'd buy cheap off ebay. Don't take this personal but you did mention something that I've always believed was more hype than reality and I'm bringing it up for the sake of argument: Since you mentioned this often-stated fact, if a FIPK, Volant, etc. isn't sucking air from inside the engine compartment, where exactly are these cold-air intakes getting their supposedly cold air from? Food for thought...

"Cold air" is a relative term meaning the source of air is not the hot air of the engine compartment. Sources for "cold air" are typically the fenderwell area of full-size trucks and, through a snorkle, the core support area for the S-series pickups. I believe the aftermarket intake builders locate the filter in as cool an area of the engine compartment as possible, usually well ahead of the engine and away from the hot blast coming off the radiator. When the truck is moving, air the filter picks up will not be heated as it enters the engine bay (from the radiator) and will not be affected by the heat of the engine or exhaust manifolds.

IMHO, I think there is a trade off when dealing with the stock intake plumbing: do you gut the plumbing and allow a greater flow of (hot)intake air from under the hood or do you try and keep the cooler outside air but maybe get less of it. The ideal of course is to get the most and coolest air possible. The cooler the intake air, the cooler the fuel charge and the more power you'll get (provided the computer will advance the timing to take advantage of it). One of the best places to get a lot of cool air is through the cowl (the area just below the wipers).... the old SS Chevelles had "Cowl Induction" for that very reason.....

Colder air is better than hot air because there is more of it; colder air is denser than warmer air so for a given volume (the cylinder, the intake track, carb venturi, etc) you'll get more air into it, past it or through it the cooler it is. Ever notice your engine runs stronger on cooler days or in the morning? It's the air or rather the cooler air.

A good part of the problem with stock intake plumbing is that it is first designed to be quiet and second to provide "adequate" airflow to the engine. Before I would cut up my airbox, I would look and see if there are any restrictions to the airflow in the stock setup that I could easily remove. I have seen "silencers" that are installed in the intake plumbing that once removed free up some power (at the cost of an increase in intake roar). Are there any baffles or "mufflers" that can easily be removed? That's a good idea to have a second airbox you can modify and make comparisons with.

Good luck....

Mike