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Discussion Starter · #1 ·
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 since 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...

 

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I would highly advise against this modification. The problem with the IS-F is not down low (where I have reached sixty in 4.2 seconds numerous times) and where there is an abundance of power on tap early but rather after 5,000 rpm's where we have seen torque curves drop off significantly, and where both intakes are fully open. Voiding your warranty to hear the often talked about "whoop" 1,000 rpm's sooner is simply idiotic, and something I would expect from Chevy iroc or Ford mustang owners!

IROC- Itailian Retards Out Cruising
 

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Discussion Starter · #4 ·
I would highly advise against this modification. The problem with the IS-F is not down low (where I have reached sixty in 4.2 seconds numerous times) and where there is an abundance of power on tap early but rather after 5,000 rpm's where we have seen torque curves drop off significantly, and where both intakes are fully open. Voiding your warranty to hear the often talked about "whoop" 1,000 rpm's sooner is simply idiotic, and something I would expect from Chevy iroc or Ford mustang owners!

IROC- Itailian Retards Out Cruising
I didn't do this so I can hear the "whoop" 1000 rpm sooner. When I was driving around my IS-F in non-sport mode, it felt so much more sluggish than being in sport mode. It literally felt like it was still trying to breath and there was something in the way. Well, that feeling is definately gone now. 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 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. Your right, the main problem is after 5000rpm when the torque drops off significantly. I believe that at this point the stock intake is very restrictive and the car just can't get enough air...you need a aftermarket intake to fully solve this. In regards to voiding the warrentee...this mod can be so easily reversed that no one will know that it was even done! ...Darshana S...
 

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Hey hey, carful what you say about Ford Mustang Owners, as I own one. Matter of fact, it's my 3rd !! And in the quarter mile I make the IS-F look stupid.

As far as this mod, it's not going to void your warranty by simply puling the vacuum hose off. Now if it causes damage, which i don't think it would, you might have an issue.


I would highly advise against this modification. The problem with the IS-F is not down low (where I have reached sixty in 4.2 seconds numerous times) and where there is an abundance of power on tap early but rather after 5,000 rpm's where we have seen torque curves drop off significantly, and where both intakes are fully open. Voiding your warranty to hear the often talked about "whoop" 1,000 rpm's sooner is simply idiotic, and something I would expect from Chevy iroc or Ford mustang owners!

IROC- Itailian Retards Out Cruising
 

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This could be interesting...any vids of what it can do down low? I'm not sure I'd want to do this personally, but it's definitely very interesting :)
 

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Hey hey, carful what you say about Ford Mustang Owners, as I own one. Matter of fact, it's my 3rd !! And in the quarter mile I make the IS-F look stupid.

As far as this mod, it's not going to void your warranty by simply puling the vacuum hose off. Now if it causes damage, which i don't think it would, you might have an issue.
I'm sure you do own three mustangs, and when you pull up to a stop light and look around you can see a mustang to your back, to your left and to your right because you're driving a "me too" car.....as in what car do you drive? A mustang...oh, me too!!!:cool:
 

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Actually, mine is a Fox Body, and is pretty diffrent. As far as pulling up next to one, only happens on the track...
 

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good for you!
 

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Please excuse my ignorence, but isn't it the function >

of the vaccum to OPEN the fender vent above 3500 RPMs? If the vaccums disconnected, how will the fender vent open and stay open all by it's self? Wouldn't it just remain closed all the time, in it's normal resting state?
 

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Actually, mine is a Fox Body, and is pretty diffrent. As far as pulling up next to one, only happens on the track...
My 17 year old cousin is selling her pink V6 mustang with 120,000 miles if you're interested bro....let me know!

Yawn.......;)
 

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Discussion Starter · #14 ·
of the vaccum to OPEN the fender vent above 3500 RPMs? If the vaccums disconnected, how will the fender vent open and stay open all by it's self? Wouldn't it just remain closed all the time, in it's normal resting state?
The resting state is the fender intake flap in open position. You can check this yourself by just taking off the passenger side engine cover and you can easily see the intake flap. If you have the vacuum line connected, as soon as you start the engine the flap closes. Disconnecting the vacuum line, like I did, results in the flap being permenantly open...Darshana S...
 

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Supraman, thanks for the quick and informative reply. >

I knew it had to either hold it closed or hold it open, just wasn't sure which. I've made the Mod and will try it out tomorrow on the street and up on the freeway to see what I can feel and report back.

Always fun and interesting to see what things things bring!
 

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Post mod test drive. Took the IS-F out this morning after >

having performed the described mod last night. The air temp this morning was about 65 with about 20% humidity. I ran the car both through the twisty's in the hills where I live and then up on the freeway :) and back home again.

I have to say I really like the result. The car perfoms much better in both the auto and manual modes, without using the Sport setting. Yes there is more power and low end torque, but more importantly for me is that there is a faster throttle response thoughout the RPM band. Just like most things, allow it to breathe easier and it will perform better.

If there was a drop-in high flow after market air filter out there we'd all jump to buy it IMHO. Isn't this really the same thing but for free? I will keep an eye on my air fliter and will expect to have to change it out sooner then reccommended with this mod. Not sure there is any possible downside to this mod? Would enjoy hearing others experience with this!
 

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Discussion Starter · #17 ·
having performed the described mod last night. The air temp this morning was about 65 with about 20% humidity. I ran the car both through the twisty's in the hills where I live and then up on the freeway :) and back home again.

I have to say I really like the result. The car perfoms much better in both the auto and manual modes, without using the Sport setting. Yes there is more power and low end torque, but more importantly for me is that there is a faster throttle response thoughout the RPM band. Just like most things, allow it to breathe easier and it will perform better.

If there was a drop-in high flow after market air filter out there we'd all jump to buy it IMHO. Isn't this really the same thing but for free? I will keep an eye on my air fliter and will expect to have to change it out sooner then reccommended with this mod. Not sure there is any possible downside to this mod? Would enjoy hearing others experience with this!
The much improved throttle response was also the thing that I felt the most. I'm glad you like the mod. Hopefully others will try it and give feedback...Darshana S...
 

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Someone must have communication contacts with Lexus to obtain information on the specific function of the intake flap. What the ramifications might be and how it effects the performance of the car good or bad...Lets hear more about this from the people in the know.
 
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