Hi Guys,

Well, I got to thinking about the stock dual stage intake and figuring out a way to keep fender side intake opening open all the time. In case you didn't know, the fender side intake opening is closed until around 3600rpm, which is when it opens up, thus resulting in the now infamous and much beloved "IS-F Roar". As you can see from the picture below, all I did was just pull off the vacuum hose from the actuator and plug off the other end with a vacuum cap. Now the "IS-F Roar" comes on around the 2300rpm, and to me atleast, there seems to be a bit more power down low...which makes sence because now the engine can breathe a bit better down low with both intake opening being open all the time. The only downside would be if this throws off the air/fuel ratio's from stock. I don't think it will drastically, but I'm not sure. Anyway, try it out and let me know what you guys think. Oh yeah, no check engine light either! Have fun...Darshana S...

 

a "vacuum cap", where did you take this from ?

 

Any autoparts store...costs about $2 for a pack of 5...Darshana S...

 

Not to threadjack, but has anyone figured out how to remove the actual intake completely? I need to install my parking lights and cannot get the passenger dust cover off...

 

Cool, gonna try that...

 

Wow! That's a very interesting mod indeed. But I wonder why they didn't just do this in stock form? And I wonder what kind of gains we'll see from the low end? Someone should dyno this!

I also hope that it doesn't screw up the ECU. But I don't see the harm, since it should accommodate both intakes anyways, and it should adjust the mixture automatically based on the amount of air going in. If anything, we might lose some gas mileage during cruising?

 

My only assumption that Lexus designed the dual stage intake was to keep the low RPM intake and engine noise down. I mean, you figure most who would be buying a Lexus wants it quiet and subdued. The dual stage intake achieves this by keeping the intake noise down under 3600RPM until the secondary intake opening (the opening that is disabled with this mod) opens up. I doubt very much it will do very much to screw with the air/fuel ratios. And it's more likely that you'll gain some MPG with this mod because the engine is breathing better down low. Time will tell...Darshana S...

 

I done it, and after a quick testing, it does seem to open earlier, around 2500 rpm, it is not as throaty at that rpm, but it is there and it is getting nicely louder as the rpm increase.
So far so good, I'll drive like this for a few days and report back again.

 

interesting.. might wanna try it myself.. let us know if you have any problems over the next week or so...

 

does it feel more responsive around 2500rpm vs before?

 

It's significatly much smoother now down low in non-sport mode with this mod. I drove around both in the street and the highway day before yesterday and I also had a friend drive the car, both with this mod and without this mod, without telling him what I did, and he also felt the same difference...that it's much smoother down low. What's great about this mod is that it's so easy to do and so easy to undo if you don't like it. Give it a shot and drive around and let us know how you like it...Darshana S...

 

i did it to mine today.. but i donno if i can tell anything lol.. my cutouts are over powering the noise coming from the 2nd intake.. you think it worked though?.. plus.. why is that blower there anyways?

 

Well after one week of driving around with this mod I can definately say that it's worth it! Not only is it more responsive down low, kind of like being in Sport Mode, without actually being in Sport mode...if that makes sense! Also it seems that my MPG has gone up by 2 mpg...not too shabby! Now if I just find a drop in high flow airfilter...anywone know what the dimensions are of the stock airfilter?

 

stock filter is roughly 10 1/8th x 9.5. I already looked at a local checker to see if I could find the stock number of one with the same dimensions so I could cross it to an AMsoil syn nanofiber filter. If you find one, let me know.

Fig

 

I am hesitant to think this mod will really make any noticeable gains in power, but my curiosity wants some hard numbers. Since I have a baseline dyno scheduled for 11/1/08 I'll give this a try and let you all know what I come up with.