Experimenting with removing hemholz resonator from intake tube.

So I am super bored today and decided to further gut my airbox.. The first time I did it I left the grey resonator in however I cut the bottom off so it could draw in air though the bottom. Well today I took the piece out all together and also decided to "disable" the other small resonator on the intake tube, this is what I came up with:



I found a cap that was from a big jug of kitty litter that happened to fit snug over the opening of the resonator. I pressed it in and then used JB weld around the rim to secure it. Hopefully this will give me alittle more SC whine. I just hope there is no way of this breaking loose. Tell me what you think

The kitty litter cap over the resonator mod! Nice. Bet no one's done that one before!

It's probably safe, but I don't think it's doing a whole lot. Losses from the resonator are very small, imo. Finish gutting that air box and swap the panel for a higher flowing unit. Or, just toss the OEM intake altogether and fab up a FWI or CAI set-up!

(mod bug has bitten once again)

I already have a K&N panel filter.. I kinda like the "stock" look of the factory intake but I'll probably end up building a FWI soon enough. I mainly did this just to make the SC louder

If it works for you, that's all that matters. I like the stock look, too. Kept my OEM intake & airbox for a few years with a K&N panel. It's not a bad set-up really. Take a look at what some of our members have done to modify the stock airbox - I think someone even sneaked a cone filter in!

The next time you need to change your air filter I would just go with a FWI. Let's price this out;

Tubing: $10.xx from Lowe's. You get 10ft (make sure to get the ones without holes)

Clamps: $3.xx from Lowe's. I got 2 and ended up not needing either. The filter comes with 1 and you can reuse the stock one. I just used the ones I got for uniformity.

Filter: $30-$60 depending on what you get. I got a $40 9" K&N from Autozone with a 4" outlet.

Roof Flashing: This is optional, but it keeps everything clean and helps separate the warm air from the colder. $2.xx from Lowe's

Total: $45-$75 (I spent roughly $60).

Stock Panel Filter:$15-$40 depending on what you get.

Slicing fingers every time you replace it: 3 band aids, some cursing, and maybe a counselor.

It's worth doing a new intake.

Not hijacking, just showing. Under the hood, my intake looks stock (except for the Northstar TB and LQ4 MAF). I trimmed the intake tube to fit the new TB, and gutted and smoothed the entire airbox. I then cut holes in it behind the headlight, and underneath. I took this picture when I rebuilt my trans. I've been driving this car year-round, so I'm a bit scared at the thought of sucking water through an FWI. Notice you can see right through to the headlight. All the rest of the box is still intact....It's loud as hell

Did you cut/enlarge the hole under the airbox with and angle grinder? I have been wondering what the best technique is that folks have used to open that up.

al_roethlisberger wrote:

Did you cut/enlarge the hole under the airbox with and angle grinder?  I have been wondering what the best technique is that folks have used to open that up.

Yep. Just a cutting wheel on my 90* Die Grinder. I first measured and marked off where I wanted to cut. If you look, too much farther towards the engine and I would've been cutting frame.

Scott, do you have a cone or flat filter? is that how the end result looks or do you have a cone hanging out the hole?

What you see is what you get. Minus all the fender liners and such because I had it all apart. You can see the K&N panel through the hole....

Thought thats what it was. I wonder what performance differences are between what you've done with your Riv and any ol 4" intake.

Who knows? My IAT is located in the MAF sensor now because of the N* setup. Only downside to that is that if/when it goes bad, I have to replace the entire MAF. It's about a 3-1/4" intake (75mm). I don't see the point in a 4" intake. The stock throttle body can only take in so much air. At 4" you're almost 40mm larger than a stock TB opening. It's kind of a waste fabricating something that big IMO.
All I know is that it's loud as hell. The S/C whines like mad...it certainly has no shortage of air.

It almost looks like the bottom of the box is missing. did you pretty much just cut the bottom out leaving the mounting locations ?

SC_Sailboat wrote:

It almost looks like the bottom of the box is missing. did you pretty much just cut the bottom out leaving the mounting locations ?

Yep. I cut a big square out of the bottom. There's foam underneath it too to give it a little seal. I also cut a triangular square out on the front side behind the headlight, and on the fender side.
There's always air blowing around the headlight, so why not suck it up? lol



AA, feel free to move this. I fear this is totally off topic?

Yea slightly off topic... But since we are on the subject, I also further gutted my airbox today. Just slightly more conservative


I honestly believe the factory intake tube and airbox is one of the best options. The factory tube is huge, has little bends, the material is excellent at insulating, keeping the air cool, and box is still technically pulling air from the fender. not to mention the box itself acts as a heat shield. The big benefit to a custom fenderwell intake being the ability to run a filter with a larger surface area, which I think would make the biggest difference.

Yeah, I went nuts on the bottom thinking that I could make the hole in the chassis that big lol. NOPE   Oh well. No harm no foul. I'd just cut that entire front piece out man. May as well. The more the merrier  
As for the resonator, I just duct-taped over the hole, then clamped it back into place. I figured that of all sticky stuff, duct tape was going to stay put...As it's been said, there's no gain whatsoever to blocking off that resonator, but it sure sounds cool  

Did you do your lid too?



A Riv gutted box is fine by me. Just look at it. There aren't any restrictions at all. It's not like a Grand Prix setup where the Intake tube is way higher than the Intake on the box. If you've ever seen a dirty air filter on a GP, it gets nasty in one spot, right where the tube is. Ours is just open (when gutted). I've always wanted a FWI, but after the turbo car I had sucked up water, I was done with it. Didn't even want to try again. It sounded sweet though. A 3" mandrel bent piece of stainless with a giant cone. It sounded like a jet...

Quote :

I honestly believe the factory intake tube and airbox is one of the best options. The factory tube is huge, has little bends, the material is excellent at insulating, keeping the air cool, and box is still technically pulling air from the fender. not to mention the box itself acts as a heat shield. The big benefit to a custom fenderwell intake being the ability to run a filter with a larger surface area, which I think would make the biggest difference.

For an unmodified 3800 engine the OEM air box is more than enough, but compared to a 3.5" fender well intake (FWI) it will hold you back for making more power. When I dropped to a 3.4" supercharger pulley and 1.9:1 rocker arms, I kept the stock intake tube with gutted box and K&N panel filter. I recorded mass air flow (MAF) and boost readings, then replaced the intake with a smooth steel tube, larger cone filter, and heat shielding between the fender well and engine bay. I saw MAF increase significantly, boost gained +1 PSI, and intake air temp (IAT) dropped to near ambient temperature.

Here are my thoughts:

1) As you mentioned, a cone filter offers a lot more surface area than a flat panel. I think I calculated it as about double the area.

2) The OEM intake tube has several accordion-like ribs, similar to a flexible straw. These affect the air flow inside the tube - turbulence can affect how much air enters the throttle body.

3) Without heat shielding, the fender well actually sources part of its air from the hot engine bay. This is especially prevalent if using tube-style exhaust headers. I noticed a consistent 3ºF drop after installing the shield.

On the water issue, I've ran a FWI with open K&N cone for the last 8 years, all year round. I've driven through giant puddles, raging t-storms, and 10" snow drifts. The heat shield helps guard against splashes and spray, and not driving through lakes helps. There is definately more exposure to the elements, but it's not really hurting anything. Use a quality filter that doesn't rust, clean it once per year, and there should be no worries.

How much could you expect to spend for someone to fabricate a custom intake with mandrel bends?