Or at least some throttle response or a combo of the two but I firmly believe it picked up at least 5 hp which does not sound like a lot but I could for sure tell there was a rather big change in the way the car drives so here is what I did...

Remove the intake tube and cut the big muffler box off of it then patched it with a thin piece of ABS plastic attached by epoxy now I have no pics because I was just looking to see what it would sound like and was not expecting any gains but much to my surprise it seemed to pick up some low end power and I am sure there was a power gain because before I could barely get the tires to squeal from a dig and now it will spin them half way through first gear on demand now keep in mind these are 275-40-17's .

Now I need to figure out exactly why it picked up some hp but my best guess would be that the air flow entered the muffler box and created some turbulence thus disrupting the air flow from being smooth and in a n/a car smooth flow is everything so take it as you may but it's a free mod that made some hp and also I should mention that I have a 3" cone filter on the end of my maf that got rid of all the air box but that was like that before I did this little "mod".

 

Cant picture it. Post a pic when you can.

 

I will try to get a pic in the next couple of days but it is located right off the throttle body on the lower side of the tube and you can't miss it because its bulky and ugly Lol.

 

I think they make a piece for the is300 that sounds like what you did

 

Did it make it louder?

 

Yes I had one in my is300 but the gains if any were minimal but this made more of a diff than the joe z in my is300 but that could be because of the added displacement I suppose.

 

It made it more quiet which is the exact opposite of what I expected

It sounds good though but a bit less throaty and more "mechanical" sounding for lack of a better word.

 

basically, i'm guessing you removed the resonator box on the intake tubing. Personally, I wouldn't have removed it as the resonator acts as a capacitor of sort for the engine when giving it that omph. There was some research done on planetsoarer that showed the importance of that resonator for the intake.

http://planetsoarer.com/resonator/resonator.html

 

I disagree with what they are saying BUT their "testing" was on a Karmen vortex mass air meter and a stock air box and this was done with hotwire afm and an open element filter and karmen afm's can do funny things when you mess with the way air flows through them and I believe timing is affected by the readings of the karmen type afm on a pre obd 2 car so that could explain why the claim a loss but I will for sure stand by the fact that my 97 gained some hp as the car is soooo much more lively now and not such a slug around town.

I did run this by a buddy of mine who owns a well known head porting business and he agreed with my initial thoughts about the turbulence that it caused so we are on the same page as far as thoughts on this and he is a fluid dynamics geek so he knows a lot about flow to say the least.

 

+1 on pics

 

I tried to take a pic today but my batt was dead so I have to buy some more then try to remember to take a pic but if you need a visual look in the pic on the link posted and imagine the box being removed from the tube...

 

Ok here are the pics let me know if you have any more questions.

Before

after

 

Now I wish I would have done a write up

 

seems pretty straight forward.

cut off the box or whatever, get something to cover up the hole and seal it with epoxy or some sort

 

Yup that's about all and it only took about an hour or so which is with me taking my sweet time because I am a measure twice cut once type of guy.