Stock Air Box Mod..

[02Tahoe2Quick]

So I determined that the incessant rattling from the front right of my Tahoe was the Stock Air box not being seated fully into its grommets (thanks to the member who had this idea!)...

 

Why chevy didnt bolt the air box down is beyond me, and I will never profess to understand why car makers do what they do... so.....

 

While fooling around with the idea of bolting this box down to the vehicle.. I pulled the steel plate the sits below the air box. The only apparent purpose of this plate was to hold the rubber mounting sleeves that the airbox sits in. Also, below this plate is a world of fresh cold air straight from the ground. Protected from engine heat on one side and road debris by the fender well... (insert lightbulb over head here!).

 

I cut a approx 5x7" piece from the bottom of the air box and siliconed a screen over the hole to keep large debris out, though I dont see it picking up too much road debris this high, you never know.

 

I then used the stock water drain hole (which conveniently lined up the a stock mounting hole for the plate... drilled another hole on the opposite side of the box and bolted her down...

 

Now no more rattle and more air flow..

 

The butt dyno says we have success. Noticeably more pull and upper rpm band power. I will have to get her on the dyno to see if it all is for real...

 

We did this on the MKIV Audi/VW's in my last car club and the modified stock box actually outperformed ALL cold air intakes when coupled with a high flow air filter..

 

We will see if the same is true for GM I guess...

 

Any opinions? Negative/Positive??

 

Thanks,

Rodric

[LogixRat]

I think this is a great idea. I have a buddy that runs alot of quads, and they frequently modify their airbox in a similar method. But instead of using a screen material, they actually use pantyhose so it will collect more fines, along with the larger debris. I have often considered doing this to my truck but didn't want to be the guinea pig. But based on your comments I think I'm gonna have to try it.

 

Let us know the results after you dyno the thing. Of course, we all know the buttdyno is the best!

[Shaners]

I have read where some people "swiss cheese" their airbox... I don't really know what gains they have achieved, but they claim they feel the difference!!!

[JayMan]

Keep us informed how this works out long term. I'd worry about more turbulent airflow confusing the MAF and setting the Check Engine. Granatelli Motorsports makes a high-flow MAF specially designed to work with extra/turbulent airflow.

 

Jerry

 

2000 GMC Sierra Extended Cab 4WD, Z80, 4.10 gearing, G80 Gov-Lok, Z82 towing

[02Tahoe2Quick]

After having to be sucked through the dense paper filter, I would assume that any turbulence experienced pre-filter would be eliminated, am I missing something??

 

She's still pulling strong...! Cant wait to get it on a dyno and see what kind of numbers we are looking at.

[JayMan]

I did check out the Granatelli Motorsports URL - they claim the PCM will "tune out" the extra airflow after about 400 miles. At this point, the Check Engine may come on.

 

Keep us informed if the PCM lets you "keep" the extra airflow long term. I would like to try it without having to get into a different MAF and wideband O2 - costs too much $$$.

 

A friend of mine bought - brand new - a 1995 Chevy Impala SS and had a similar problem. Went with recalibrated MAF and wideband O2 sensors to keep the improvements working. Impala SS rulz!