Heatsoak? Rattling? Non-laminar disrupted turbulent flow? Who knows. He ditched it, went back to the gutted airbox, and found that solved the problem. Sold the JMB on eBay.

I had a Thrasher W-body CAI in my 1998 SSE and swapped it into my 95 Bonneville SLE SC later. I will not make the same mistake again. I only ran with the Thrasher box complete late in the ownership of the 95, but that plastic is worthless as far as heat soak goes.
I have an Intense FWI on my car now and I can say nothing but good things about it.
Never tried the JMB.

So, the INTENSE FWI tubing is corrugated on the outside, but smooth on the inside?

Correct.

The intese tubing is NOT perfectly smooth on the inside. When stretched or bent, the outside edge will be smooth, but the inside of the bend will still be ribbed.

The fact that intense tubing is smooth is a MYTH

Toasty, I have a generous length of it right here, and mine doesn't 'rib' on the inside when bent.

Not at all.

yours must be different than all the tubing i have seen.

can confirm that your tubing IS PERFECTLY smooth?

There are VERY minor 'waves' that are less than 0.5mm peak-to-peak, spaced the same as the outer reinforcing coil. These will largely not affect the flow. This is the smoothest inner wall tubing you'll see. It doesn't 'rib' when bent in a normal installation. I suppose if you WANTED to make it 'kink' or 'rib' by bending it as sharp as you could, you might make it deform, but it would be very difficult.

If you'd like, I can take some very accurate measurements and shoot some pics.

that is unnecessary for me. I know what it looks like,m i just have a problem with people saying that it is smooth, when in fact it is NOT smooth.

When i first saw it i was very surprised, i just want the general public to be aware that the tubing itself is NOT perfectly smooth, as many people tend to believe

Generally speaking, it IS smooth. It'* as smooth as you can make flexible tubing like this, and still have it be strong and hold it'* shape. 99% of the reinforced tubing out there is not smooth in any regard.

I don't think it'* inappropriate to call the INTENSE tubing inner wall 'smooth' at all. It'* a very accurate description.