the main part of stock plumbing is gone, all it is is an airbox holding the filter and the smoother pipe to the manifold. There is a resonator on the stock piece as well, with the removal of that its going to be making more noise. There is going to be more airflow into th engine but how much more who knows, its obvious the smoother pipe is going to flow more air than the ribbed stock piece which the incoming air will get caught in and cause turbulence.

https://www.clublexus.com/forums/sho...ght=joe+intake

imagine a large volume of air flowing in this, flow rates are definately affected:

 

The only benefit I can see the tube adding, and it's a small one, is the fact that it's smooth. Airflow will be more uniform in the metal tube vs. the factory rubber tube because of the flexible ridges. Those ridges will create turbulence.

 

since its more uniform probably gain some throttle response as well, might gain some top end power when the engine is sucking in a very large amount of air the flow will be more consistant

Now this needs to be combined with a K&N drop in which I believe is not out yet

Yea the engine looks nasty without the cover, during design knowing they will have a cover they can make the engine whatever way they want since it will be covered up anyways. Couldnt do that before, used a lot of time and reseources laying out the engine bay to make it look nicer

 

Yeah the photo of the inside of the stock tubing that 4TehNguyen posted is the one I took. I also took this photo of the inside of the JOEZ piping.

It basically takes the stock design with regards to utilizing the stock cold air induction method and gets rid of the sound resonator and smoothes out the airflow for more air, which equals more power. Gains are around 4 peak hp and 4 peak ft/lbs, but should be making anywhere from 6-8 rwhp in the mid ranges.. based on the JOEZ dyno that he provided, but I'm doing my own independent dyno test this Saturday (tomorrow) and I'll see what kind of gains I got with just the intake pipe or as JOEZ calls it, the "Direct AirFlow Intake (D-AFI)" I'll post my results tomorrow.

 

would like to see high rpm gains, its obviously gaining more in the mid ranges, the ribbed design is going to hinder high rpm flow rates. Now if a K&N drop in came out, would be even more gains over an OEM paper element

 

I'm speaking on my GS knowledge, but I believe oem filters are cotton, not paper. that's why K&N filters don't really do squat except risk the chance of getting oil on your MAF.

 

If you keep it properly lubricated that shouldn't be an issue.

 

The factory airbox is not restrictive, at least not at the current hp levels. Maybe once FI is available the airbox may need to be opened up a bit with a filter that has more surface area, but right now gains are only going to come from an upgraded intake pipe, a future drop in filter. I'm hoping for something from Blitz. As long as you aren't ingesting hot engine bay air, there will be small gains achieved with slight modifications to the factory air intake system on the IS.

 

Doesn't look like there is the best amount of space to fab up a heat shield, unless it gets wrapped. Radiant heat would pretty much negate some of the cold air effect after a while. Looks good though.

 

Aha! I was wondering what that was in the OEM tubing... it's the resonator. Usually it's buried down in the fender well, after routing the intake charge through all kinds of extra tubing to keep the noise down.

I take back what I said about the noise. If the resonator is in the stock tube, then yes, it should definitely be a bit noisier with this intake.

 

I would say the JOEZ intake is not noisy at all but a decibal or 2 higher than stock. Sounds very tasteful IMHO.

 

Same here, I like how it sounds. It has a deeper growl above 5K rpm. Below that, it is hard to tell the difference.
Sounds really sweet. I'll try to get some sound bites tomorrow.

Powerwise...hard to tell 5hp difference...what it is very noticeably is the throttle response, instantatneous.

 

the dyno graphs seem to show hp loss for anything under 5k rpm....

correct me if im wrong

 

Ok, i'll correct you. Basically since ALL IS350's are automatic and you can't view the chart at anypoint below aprox 4850rpms because that seems to be the downshift point when floor it in 4th gear. So anything below aprox 4850 is just a semi throttle and means nothing on a dyno graph.

 

ahh.. i see i see .. thank you for the update!