I've heard that running w/o the stock airbox costs a few horsepower due to heatsoak. I changed out my airfilter last night, and left the box top off. I like the sound (I can tell what the engine is doing now), but i'm concerned about losing power. I've got some things I want to try, but figured I'd post and see if i'm chasing a red herring here.

Goals:
More induction noise.
No loss of power.

Question I have:
1: The divider in the airbox. What's it's purpose? Is it an NVH thing, or to prevent stagnating air in a large box?

Here's what I plan to try, please fill me in if I'm wasting my time.

1: Hook up temp sensor at driver's back corner of airbox (back edge of filter)
2: Run with and without box top. See if there's a temp difference.
3: Use reflective ducting tape on bottom of box to try and act as heat shielding. Check temp differences.
4: Remove top 50 percent of back half of box divider, check for temp differences.

In the end, I think steps 1-3 are going to show a good difference, and I don't think the lack of a top is going to add more heatsoak to the box... if anything it might give air a chance to get out. I think at the end, my config will be a no-top, shielded box, but being that someone's probably already tried this, i'd love to not waste my time if possible.

Thoughts?

 

Most people agree that you lose some torque and that heatsoak can be an issue. That divider in the airbox can be taped or completley sawed off (I sawed mine off and duct taped the opening) for a better sound. I personally think it sounds better. You may also want to consider adding a tube that goes behind the passenger side headlight hole and adds cold air to the box. Oh and I cut most of the divider out of my box. No problems yet with water and I doubt I'll ever have any.

 

My end goal is to not lose torque (though I don't plan on gaining anything), and have some extra induction sound. I notice a slight power drop, but that could be the buttdyno fooling me... I'm just wondering how the box can heatsoak MORE w/o a top. I understand that happening with no box, but with the same bottom, the same heat-soak should be present, but now with an escape route.

If it loses power, I'll go back to stock. Sounds like some reflective wrap might be for the best either way though.

 

It heatsoaks more because now that the top is off it can suck in all the hot air from the engine bay. With the top on it can only suck through the little opening facing forward.

When I took my top off, I felt a lot of powerloss especially at like 7k plus. Don't do it

 

does sawing off the divider make it sound like the airbox top is off?

 

nothing you do will make it sound like the top is off with the stock unit. The only way to make it louder (aside from taking the top off) is plugging up the resonator hole that is underneath the filter cone.

Otherwise you eithor A) deal with the powerloss but great sound or B) buy a new intake and get a great sound with no powerloss

 

moving to S2ktalk.

 

...but that's all just ambient heat that would soak into the plastic anyhow... plus all the heat sources are located aft of the box itself... in motion, i'd think that it'd not have the issues.

Guess I'll find out when I hook up a temp sensor.

 

I gutted my airbox and then dyno'd and it doesnt do shit.

 

how about increasing the size of the front opening...? cut the airbox along the front side, a slit roughly the size of the original horn in height and width? anyone have any experience with that?