MLiebal

Guys,
I just got back from towing the popup from the coast with a loaded vehicle. I love the mod!!
I did the ISR first, I had the elbow already out. Hugh improvment. Just before leaving last week I went ahead and pulled the air box and cut my hole.
Man, was the truck loud then! Too loud. I covered the hole part way and now its is a great trade off. Actually I could not tell much improvement with the full hole in the box, but I did not loose any (that I could tell) by covering, yet the noise was cut dramatically.

Suggestion: buy a couple of extra deck plate covers and bore smaller holes in them. The 1-2" dia ought to be enough with the elbow out.

Just a suggestion for those who are not satisfied with the noise.

Mike
'96 4Runner Ltd

JaRuEL

I've been reading about this "noise" on the ISR mod.....what does the noise sound like? Is it like the sound of an air leak? Is the sound there all the time when the engine is running or only when you step on the gas?

midiwall

It's a roar, much louder than an air or vacuum leak. It's loud in the cab, and it's loud outside as well.

It's generally silent when you're driving around (unless you drive at WOT all the time!) and is there when you jump on it.


Remember what you're actually doing in the ISR mod - you're removing the intake silencers. They're there to quiet the air intake, so if you remove them...

The mod is quick and cheap to do. If you don't like the results, then it's very easy to put it back together and you're out about $5 in plumbing end caps.

If you're curious, you should give it a shot.