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...

http://webpages.charter.net/kumari1/Cars/DSCN0666.JPG

interesting info!!! i might try it

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 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...

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

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 :)

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:

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

good for you!

It's ok. I understand. It's like owning a BMW Yawn....

can you post a video??? or recorde the sound??

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?

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.......;)

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...

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!

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!

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...

Well, so much for not dicking with my car. :p

The great thing about this mod is the easy reversibility. I'm trying it this week! :)

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.

you can just pull out the plug like i did and no light on mine either

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!


Hey, about the drop in performance air filter, I made some measures calculations and I believe found one . Will post update soon as it gets here and test fitted. By the way there's no company making one for the F.

Hey - another ISF owner who also has a Mustang!! I'm not the only one!!! I suspect yours has been "breathed on" a bit. My "other ride" is a '97 Mustang Cobra; stock, except for Magnaflow Exhaust.

Hey, about the drop in performance air filter, I made some measures calculations and I believe found one . Will post update soon as it gets here and test fitted. By the way there's no company making one for the F.


Definately keep up updated!...Darshana S...

Definately keep up updated!...Darshana S...

Well guys finally is here I tested for a few miles around my house last night. I did not feel that much of a power but it sounds awesome, maybe the ecu needs time to know the new mod(more air). Later today will double check the airbox for proper fitment.

Well guys finally is here I tested for a few miles around my house last night. I did not feel that much of a power but it sounds awesome, maybe the ecu needs time to know the new mod(more air). Later today will double check the airbox for proper fitment.

What was the filter you got?

In other news, the vac plug is not necssary at all. You can simply unplug the solenoid. Since it is not a critical system, there is no current sense on it. Works great :p

After looking at the intake system it is my conclusion that the factory macroni pipe is not restrictive at all. Even the damping mechanism is very minimal. I think I did figure out what can be improved...and that is the airbox/ram air. I will keep you gys posted and start a thread once I get further along. Feels good to get into the engine bay again and tinker

Fig

In other news, the vac plug is not necssary at all. You can simply unplug the solenoid. Since it is not a critical system, there is no current sense on it. Works great :p

After looking at the intake system it is my conclusion that the factory macroni pipe is not restrictive at all. Even the damping mechanism is very minimal. I think I did figure out what can be improved...and that is the airbox/ram air. I will keep you gys posted and start a thread once I get further along. Feels good to get into the engine bay again and tinker

Fig

Fig,
I thought about doing that initally also, but I wasn't sure if it would trigger a check engine light so I decided to "fool" the system into thinking that nothing was disconnected. But I don't know too much the stock ECU (I don't think anyone does) to know whether that stock airbox plug does more than just control the secondarly intake flap...hopefully it doesn't also have some part to play in the air fuel ratios?? I doubt it, but I was just playing it safe by doing the vacuum cap mod rather than disconnecting the connector. But anyway, do you notice a difference in the throttle response also?...Darshana S...

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

you are not going to void a warrantee for a system that is not in the "metered" airflow path. This is all prefilter airbox modifications. I took the whole thing apart last night and this is nothing worse than what an open element filter will do.

The fact of the matter is that this is exactly the type of thing that Lexus puts in to preserve luxury. Its just a trap door that opens the filter to the engine bay (not even the fender.)

What is your technical argument?

Fig

Fig,
I thought about doing that initally also, but I wasn't sure if it would trigger a check engine light so I decided to "fool" the system into thinking that nothing was disconnected. But I don't know too much the stock ECU (I don't think anyone does) to know whether that stock airbox plug does more than just control the secondarly intake flap...hopefully it doesn't also have some part to play in the air fuel ratios?? I doubt it, but I was just playing it safe by doing the vacuum cap mod rather than disconnecting the connector. But anyway, do you notice a difference in the throttle response also?...Darshana S...

Throttle response, possibly. The only to way to know is to do a few runs on the Gtech and average the findings. The A/F ratios are purely calculated based on the hot wire sensor and MAF in the intake tube just after the filter. you could not base anything off of an inprecise flap opening and closing on the front side of the filter. I will post pics later.

What was the filter you got?


http://www.clublexus.com/forums/showthread.php?t=386924

OK I should have a cross for the filter in a dry high flow drop in from Amsoil. I will confirm next week.
Fig

the IS-F though it was designed for the VW Cabio's and here is their reply:

"Dear Dean,

Thanks for contacting K&N. We have not released the air filter application for the IS-F. The problem with using an air filter which is not designed for the vehicle is the lack of complete seal. At K&N we designed the air filter from the air box to ensure a complete seal, so even if an existing filter with the correct length and width fits into the air box , it does not guarantee a complete seal and dust may get through the gaps. We are currently looking for an 2008 IS-F so if you would like to let us use your vehicle for R&D please contact K&N at 1800-858-3333. Thanks for writing.

George Hsieh
Tech Support
K&N Engineering
Georgeh@knfilters.com "

I'll contact them tomorrow about their requirements to use my IS-F so we can get an air filter from them... Will keep you posted....

great Dean, keep us posted, I will take pics of the stock airbox fitment when I get my amsoil dry filter.

Thanks Dean! I'm glad K&N got back to you now it's time to see what they come up with for the F :)

to talk about their filters and their possible use of my IS-F to make an air filter. I was told they have a mold of the inside of our air box already and are waiting for some prototypes to be finished. They will need another IS-F to check the pre-production fit in about 6 weeks or so. I left my contact information and said I'd be willing to help and or to call me so I can buy a filter. They assured me that they would be in touch... We'll see!

^Awesome news! Thanks for following up with them and offering your F! Keep in touch and let us know how it goes :)

Im guessing doing this mod + an aftermarket intake will noticeably increase power... when i say noticeably i mean relatively as opposed to intake itself, what do u guys think?

Awesome mood....seems pretty simple! Beat this would sound great with the new exhaust.

Any videos ....come on would love to hear

Guys I did it this morning and I'm never going back to normal, love what it did to the car, as far as I'm concerned they should have sold us the cars this way, and yes no engine light yet, hope never.
Thanks a million Supraman16.
Just out of curiosity, how did you come up with the idea.
People you have to try it, it took me 20 sec.

I want to try this out on my F.
What kind of vacuum cap does one get for this?

I used electrical tape for now

Guys I did it this morning and I'm never going back to normal, love what it did to the car, as far as I'm concerned they should have sold us the cars this way, and yes no engine light yet, hope never.
Thanks a million Supraman16.
Just out of curiosity, how did you come up with the idea.
People you have to try it, it took me 20 sec.

If you read my comments you can just disconnect the solenoid connector and it will achieve the same thing. :) No tape required

After spending the whole day with both of the intakes working the way they should have since day 1, I can tell you guys why Toyota never did it this way.
The car is actually way lauder, suits me just fine.

http://i88.photobucket.com/albums/k195/Figbline720/isf/intake/DSC07066-1.jpg
unplug the connector on this guy...done.

Thanks for the details Fig!

I did the mod tonight. First I took out the car (before doing the mod) and drove around slowly letting it warm up. I'm still not used to all the power, especially since I was also driving the is300 all day today.
Then I came back home and did the mod. At first I didn't really notice much.
I heard a bit of fluttering on the lower end. After driving the car on Sunset, from PCH to Hollywood I finally started to hear the difference. I put the car in sport mode and definitely noticed it feel a bit more pickup off the line. I also attributed this to the fact my fuel tank was on Empty. :)
I filled up the tank, kept it in sport mode, and yah, I do notice the difference.

I'll be keeping this mod on.
Are there any drawbacks to keeping this on? Higher fuel consumption? Additional wear on the engine? The former I'm not so concerned about, the latter a bit more.

Hi Guys,
I'm glad you like this mod. I've had it done now since I originally posted up this thread and I have yet to find a negative effect from it. Gas milage is the same, the sound is incredible...even more so in combination with the JoeZ exhaust I recently got, and more importantly, a bit more noticible power in the low end. However, the only thing I have found out and want to advise everyone one against is getting a drop in air filter, like a K&N filter...DON'T DO IT...with or without this mod! I had the K&N filter and it felt like it was making more power initially, but then it went away...likely when then ECU adjusted to it and the MAF got contaminated with the air filter oil. I started having really poor gas mileage and this promted me to put back the stock filter (along with the fact there was a thread on CL about how the K&N filter as causing problems to other members IS-F's). But yeah, I've had this mod for awhile and still nothing bad that I have experienced...Darshana S...
PS. I have mine done the original way...with the vacuum cap rather than disconnecting the solinoid. I didn't want any water or debris getting into the open connectors.

Hi Guys,
I'm glad you like this mod. I've had it done now since I originally posted up this thread and I have yet to find a negative effect from it. Gas milage is the same, the sound is incredible...even more so in combination with the JoeZ exhaust I recently got, and more importantly, a bit more noticible power in the low end. However, the only thing I have found out and want to advise everyone one against is getting a drop in air filter, like a K&N filter...DON'T DO IT...with or without this mod! I had the K&N filter and it felt like it was making more power initially, but then it went away...likely when then ECU adjusted to it and the MAF got contaminated with the air filter oil. I started having really poor gas mileage and this promted me to put back the stock filter (along with the fact there was a thread on CL about how the K&N filter as causing problems to other members IS-F's). But yeah, I've had this mod for awhile and still nothing bad that I have experienced...Darshana S...
PS. I have mine done the original way...with the vacuum cap rather than disconnecting the solinoid. I didn't want any water or debris getting into the open connectors.

Yeah teh K&N and MAF do not get along. That is why the amsoil filter was my choice. Completely dry and easy to clean. So far just turn 8K on the clock and no looking back.

Fig

I've had my K&N now for 2K miles. I also have the JoeZ intake tube. So far no issues with my K&N.

BTW, I've used K&N for years. My last car, a G35 coupe had a MAF, and worked fine for 6 years with a K&N. It was cleaned and reoiled countless times.

Lou

go get the nissan gtr. forget isf and mustangs. bye bye!!!!!!!!!!!1

I've had my K&N now for 2K miles. I also have the JoeZ intake tube. So far no issues with my K&N.

BTW, I've used K&N for years. My last car, a G35 coupe had a MAF, and worked fine for 6 years with a K&N. It was cleaned and reoiled countless times.

Lou

Hi Lou,
May I ask what your gas milage is? The reason I asked is because poor gas milage was how I found out that the K&N Filter was not a good idea. With the K&N Filter I was consistantly getting no where better than 16mpg. After cleaning the MAF and reinstalling the stock filter I started getting 19-21mpg. I didn't actually notice or feel any oil on my MAF when I removed the K&N filter, but obviously, my IS-F was not happy with the K&N filter. I still got a K&N cone filter on my Supra TT and it has served me well for years, so I'm going to stick with it in the Supra, just not with the IS-F....Darshana S...

Yeah teh K&N and MAF do not get along. That is why the amsoil filter was my choice. Completely dry and easy to clean. So far just turn 8K on the clock and no looking back.

Fig

Fig, can you tell me where i can get the amsoil filter?

Hi Lou,
May I ask what your gas milage is? The reason I asked is because poor gas milage was how I found out that the K&N Filter was not a good idea. With the K&N Filter I was consistantly getting no where better than 16mpg. After cleaning the MAF and reinstalling the stock filter I started getting 19-21mpg. I didn't actually notice or feel any oil on my MAF when I removed the K&N filter, but obviously, my IS-F was not happy with the K&N filter. I still got a K&N cone filter on my Supra TT and it has served me well for years, so I'm going to stick with it in the Supra, just not with the IS-F....Darshana S...

Yep, I'm getting between 20 and 22 depending upon how I drive. This, IMHO, is great mileage for a car with this potential.

Lou

Hello Superman16 this is BJG403 I have a 09 isf i tried it also .I do think there is a little more power on the low end.Did you cap off the other end.

Hello Superman16 this is BJG403 I have a 09 isf i tried it also .I do think there is a little more power on the low end.Did you cap off the other end.

Hello,
Yeah, I capped off the other end so no junk goes in the actuator. Glad you like the mod...Darshana S..

Are there any problems so far with this mod? There must be a reason why the car has this part to begin with. If we take it off, what purpose are we defeating?

Are there any problems so far with this mod? There must be a reason why the car has this part to begin with. If we take it off, what purpose are we defeating?

I've had it for several months now and still no issues whatsoever. I believe that the reason that Lexus did this was due to keeping the car quiet in the lower RPM's. I don't think that there is any performance reason from keeping the secondary intake closed in the lower RPM's...Darshana S...

Fig, please post the p/n for the amsoil filter if you kindly would, thanks

do we have to disconnect both wires/tubes or only one and if so which one? plug it back in and we're back to normal????

after a week of having done the solenoid disconnect, and driving around my impressions are as follows:
1) off the line low rpms - seems more responsive
2) mid range - might have lost a little bit of torque in the normal driving band, just seems a little less responsive to me. Although, given the better volumetric efficiency this should not be the case unless the ECU/O2 sensor are playing a role, but this should be a simple closed loop feedback, no?
3) high end - well, no change because its the same as before
4) sound is definitely more smile provoking now

A very small side note, I seem to percieve an eerie rythym between the intake and exhaust frequency. Its almost like one cylinder is more distinct, and the lag between the intake "pop" and the exhaust "pop" amongst those in the background are....well, subtly more noticeable. Just an odd observation I had.

Anyways, its worth the 2 secs. to disconnect and try it out for two days.

I can't believe you guys missed this thread over CL, this is what I found about this mod last year...

Originally Posted by Juanca:
OK guys, I have hard data about this mod. I did it last Sunday and you can feel the difference right away. First of all you can hear the intake way earlier, from around 2K RPM. Just the sound makes you believe that your car is faster, maybe more HP I thought? So I went to the track today and tried my ISF. I did about 7 runs and I knew there was something wrong, my times were a little bit slower than 2 months ago, I was runing 8.7 at best in the 1/8th mile. Even though I could swear that the car was faster, the slips were saying otherwise. For my 8th run I decided to take this mod back to the way it was stock and I immediately picked up 2 tenths! I couldn't believe it so I did 6 more runs and I ran consistently 8.5 (all runs). My trap speed also jumped from 84MPH to 86MPH. So I'm taking the intake back to the way it was, and I'll enjoy that lovely sound from 3600RPM, not before.


Originally Posted by Supraman16:
This is some great real world data. However, I do have a couple of questions:
1. Was the flap mod done RIGHT BEFORE doing the runs, then put back to stock after finding out the slower times, or was the flap mod done for awhile before doing the runs? The reason I as is to see if the ECU had properly compensated, for what I would assume increased air from the opened flap.
2. Are you still running the stock air filter, or an aftermarket one (K&N or Amsoil)?
3. Have you done the vaccuum cap mod as I showed in the intial post, or just disconnected the plug for the flap accuator? The reason I went with a vacuum cap mod rather than disconnecting the plug was because of my concern that disconnecting the plug may alter what the ECU was reading and change something around in terms of the A/F ratios or something else. By just doing a vacuum cap to plug it off, it doesnt change anything electrical, I would assume just fools the ECU to thinking that it's still stock. Once again, this is all hypothetical.

I returned my airbox to stock after reading your post last night and driving the car this morning, to me at least, seems sluggish compared to with when the flap was open. Fig also showed a 5hp gain and to me, I agree with this that there is a increase in HP and torque with the flap open. However, I know that Fig also has a Amsoil filter in place.

Inregards to why the factory that this intake flap was put into place, I believe it to be mainly for the purposes of perserving the luxury and quietness of the car in the lower RPMS. I don't believe it to be due to performace reasons...once again, hypothetical. I don't see how having the flap closed in lower RPMS can increase the HP or torque, or for that matter increase it in the higher RPMS when it opens.

Originally Posted by Juanca:
Here are my answers:

1. I did the mod last Sunday and drove that way for about 250 miles before I went to the track.
2. My car is completely stock except for tints.
3. I did the mod just as you showed it on the first post, so it's confirmed, I used a vacuum cap.

As I said I thought my car was faster. When I went to the track 2 months ago the air temp was about 86F, so this last Wednesday I was expecting better times because of this mod, and also because air temp was 66F. Two months ago I was runing 8.65@85MPH in the 1/8 mile, and you can imagine my surprise when this week my best run out of the first 6 passes was 8.75@84MPH. I wondered if the mod had something to do with being slower when I should be faster (at least because of the cooler night), so I removed the cap and connected the hose back. I had another pass right away and bam! 8.57@85.5MPH. The following 5 passes were similar. This experience showed me that the mod doesn't help performance-wise.

Originally Posted by anajri:
what were youre 60 foot times.. maybe you had more wheel spin during the launch ? or maybe que amsoil filter was ofsetting any negative drop need more testing......

Originally Posted by Juanca:
My 60 foot times were always around 2.1, with and without the mod. Wheelspin is there, I can't avoid it, these stock Bridgestone don't help launching the car and the track isn't the best either.

I don't have any aftermarket part on my car, not even the air filter, I'm stock.


Originally Posted by stick:
20 degree difference in air temp.......good for intake air, bad for tire grip. The warmer day will have a hotter track and give better grip. Too many variables. I don't know if the mod works, but a more controlled environment is needed for testing.

Originally Posted by Juanca:
This is why I posted times before and after the mod. I basically picked up 0.2s in the 1/8 mile after pluging the vacuum hose back. These runs where done one after the other, during the same night, so conditions were identical.

Originally Posted by lobuxracer:
Sorry, but MPH trumps all. Better MPH means the engine is making more power. End of story.

i took mine off over the weekend and you can really hear the difference in the exhaust. hard for me to believe the car can me slower with this mod. anytime an engine gets more intake air it will produce more power.

one we remove the hose, should we cap of both sides of the solenoid?

i took mine off over the weekend and you can really hear the difference in the exhaust. hard for me to believe the car can me slower with this mod. anytime an engine gets more intake air it will produce more power.

one we remove the hose, should we cap of both sides of the solenoid?

You should cap both ends of the solonid to prevent any gunk from getting into it.

In regards to Juanca's data...I feel there is one major flaw in regards to the track conditions. The day that he did these runs were approximately 20 degrees cooler...thus worse for grip. Now you do this mod with I still believe results in more torque and power down low (this is what I feel, I don't have a dyno to prove it), you have a bit more wheel spin and thus lower ETA's and MPH, especially on the 1/8th mile. The 1/4 mile would be more accurate for both ETA and MPH and using the MPH for estimating the HP. With the flap closed/in stock mode, you have less torque and power down low and therefore less wheel spin (especially on a cooler day) and thus better times.

I have had this mod since I first came up with it and I have reversed it several times to see if it was only a part of my imagination that my car felt stronger down low with this mod. Sure enough, every time I chaged it back to stock it felt like my car was suffocated down low (kind of makes sense...it's not allowed to breathe as well with the flap closed). The throttle response was definately not as crisp with the flap closed/stock mode.

I currently have the JoeZ exhaust (which by the way is INCREDIBLE) and it seems that this mod makes even more power because now you have the car less restricted in the exhaust side and when you let it breath easier on the other end (intake side), you have a better performing car.

Juanca has some great objective data, but it is not completely equal given the track temps. I however like how my car feels with this mod and it's easy enough to return back to stock. I encourage people to give it a shot and also consider what Juanca has posted and make the decision for themselves.

Have fun modding...Darshana S...

finally did this mod last friday. lovin' it so far! the growl occurs around 2k now with around half-throttle or more. it sounds like what happens when you add a CAI on other cars. it "feels" faster, but not sure if it really is. the growl at 3.6k "seems" less noticeable since the 2nd intake is now always open. one thing for sure though is that my foot has gotten heavier from flooring it more often. :D

does anyone have the joz intake + this mod?

I tried it for a day and somehow the car idled at 500 rpms as opposed to its usual 8 or 900... dunno y that was the case, i plugged it back in and the car went back to normal... does this happen with all of u?

I still experience some low rpm bogging after gear changes in normal driving. I have not yet bothered to plug it back in yet though.

I tried it for a day and somehow the car idled at 500 rpms as opposed to its usual 8 or 900... dunno y that was the case, i plugged it back in and the car went back to normal... does this happen with all of u?

If it's not causing you too much hassle, how bout leaving it like that for a couple of days to see if the ECU will "learn" or adapt to the new conditions, and retun to normal idle speed. hmmm...

I tried it for a day and somehow the car idled at 500 rpms as opposed to its usual 8 or 900... dunno y that was the case, i plugged it back in and the car went back to normal... does this happen with all of u?

Sounds like you have a vacuum leak when you unplugged the solinoid. Make sure the vacuum cap that you used isn't cracked or has a leak...I personally have had rubber vacuum caps that have a very slight crack in them that you can't see without looking at them very carefully...Darshana S...

interesting... i'll try it when i get back from my trip to dubai which might be a bit long... im gonna go in our sts-v

I have just gotten around to trying this mod. I'm a bit mixed on it so far. I haven't noticed much of a change in performance, but I'm not 100% sold on the sound yet.

Have the original posters kept the mod, or gone back to stock? Has anyone noticed any problems? Just curious.

Thanks,

Jeff
08 Smoky Granite Mica IS-F

I have just gotten around to trying this mod. I'm a bit mixed on it so far. I haven't noticed much of a change in performance, but I'm not 100% sold on the sound yet.

Have the original posters kept the mod, or gone back to stock? Has anyone noticed any problems? Just curious.

Thanks,

Jeff
08 Smoky Granite Mica IS-F

Went back to stock a long time ago

Went back to stock a long time ago

What made you decide to go back? The sound or warranty/performance concerns?

Thanks,

Jeff
08 Smoky Granite Mica IS-F

What made you decide to go back? The sound or warranty/performance concerns?

Thanks,

Jeff
08 Smoky Granite Mica IS-F


the sound was nice but it was a step back in performance, albeit slight

You don't need to remove the vacuum hoses to keep the second intake open. Disconnect the wire harness plug that powers the solenoid valve when the car is off. When the car is off the door is in the opened position. It does not close until the car is started and the engine pulls vaccum to pull it shut. When you unplug the harness the door stays in the open position and when you start the car it never closes the secondary intake. Its easier than messing with vacuum hoses. It works and the car was louder, but my shifting was harder, so I went back to stock.

You don't need to remove the vacuum hoses to keep the second intake open. Disconnect the wire harness plug that powers the solenoid valve when the car is off. When the car is off the door is in the opened position. It does not close until the car is started and the engine pulls vaccum to pull it shut. When you unplug the harness the door stays in the open position and when you start the car it never closes the secondary intake. Its easier than messing with vacuum hoses. It works and the car was louder, but my shifting was harder, so I went back to stock.

Yes that is what I did, thanks. I haven't noticed any weird shifting behavior or loss of power. Then again, I don't get much chance to drive the car hard so I can't swear that no performance was lost.

Jeff
08 Smoky Granite Mica IS-F

I remeber reading somewhere that the loss in power was pretty small, not much to worry about. I did this mod by disconnecting the plug too. I ended up reconnecting after about 2 weeks. I missed the 2nd opening at 3600! I don't need the roar all the time. Just when I want to get on it.

I ended up drilling a 2 inch hole on the side of the flap towards the wheelwell. I left the flap in working order thinking maybe it is the best of both worlds. It should give a hair more air with the hole as well as the flap open and with the flap closed, it gives the ability to breath just a little more. No clue as to before or after regarding power but I really like how the car runs as well as the sound. I cannot feel any reduction in performance in any rpm range.

Hey,
I'm new to this forum and could use some help :)

I'm owner of the MY09 Starfire Pearl ISF. Today I tried the DIY intake mod but I chose the easier option, and just unplugged the connector leading to the small metal box as per the photo instructions of the other member, instead of fiddling with vaccum hoses and caps.

After unplugging the connector, I started the engine and let it warm up by driving slowly around town. To my surprise, there was absolutely no change in the sound, and the "ISF roar" came at regular 3600rpm. Dynamic characteristics of the car also remained subjectivelly unchanged.

After parking the car in the supermarket lot and starting it up 10 minutes later, I got the engine light come up together with VDC Check. These fault indicators remain lit even after plugging of the connector back and driving around for about half an hour. Car still runs flawlessly though.

So my questions:
1. How do I get rid of the engine fault and VDC check indicators?
2. Why didn't the mod work for me? Did I unplug wrong connector (there seems to be just one)? Wasn't "the roar" supposed to arrive sooner, at around 2000rpm?

Not sure what you unplugged. It should have worked just fine. I could only guess that you unplugged the wrong thing. As for the VDC light I am not sure, you could try to disconnect the battery for 10+ mins and reattach and see if that does it. If not it looks like a trip to the dealer is needed.

Good luck. Let us know what happens

I unplugged the connector that Fig highlighted in his photo. There's just 1 connector so I doubt I unplugged the wrong one :-/

I'm new so can't post links, but the photo can be found on page 5 of this thread. I really don't understand what is wrong :-/

Hey,
I'm new to this forum and could use some help :)

I'm owner of the MY09 Starfire Pearl ISF. Today I tried the DIY intake mod but I chose the easier option, and just unplugged the connector leading to the small metal box as per the photo instructions of the other member, instead of fiddling with vaccum hoses and caps.

After unplugging the connector, I started the engine and let it warm up by driving slowly around town. To my surprise, there was absolutely no change in the sound, and the "ISF roar" came at regular 3600rpm. Dynamic characteristics of the car also remained subjectivelly unchanged.

After parking the car in the supermarket lot and starting it up 10 minutes later, I got the engine light come up together with VDC Check. These fault indicators remain lit even after plugging of the connector back and driving around for about half an hour. Car still runs flawlessly though.

So my questions:
1. How do I get rid of the engine fault and VDC check indicators?
2. Why didn't the mod work for me? Did I unplug wrong connector (there seems to be just one)? Wasn't "the roar" supposed to arrive sooner, at around 2000rpm?

This is odd. I've been running this mod for now 2+ years without a problem. I've also coverted over to the "disconnecting the plug" method rather than the vacuum cap method because I've noticed after awhile the caps would start to crack and leak. Anyway, in regards to your problem...I would reset your ECU and try to get rid of the problem codes, or better yet, get a OBDII scanner and pull the trouble codes before you reset the ECU. Do you have any other mods on your car such as a Throttle Controller, etc?...Darshana S...

Nope, nothing else. The car is stock and this was my only mod so far. Considering I'm from Europe, is there any chance that US spec is different from EU spec? o.O As I can't imagine how would pulling the plug and leaving the intake system "powered off" still make it work. I'm going to try and disconnect the battery today and see what happens. If that doesn't solve it, I will ask someone to connect it to diagnostics. Hopefully it's only fooled ECU by too much air and not something serious.

Alright, got some update. The engine light and VSC Check went away this morning all by itself, with the connector plugged. So the only problem left is why doesn't this mod work for me :-/

It's hard to see in pictures, but look around where the vacuum lines come into that circular part (solenoid valve I assume). There should be a connector there as well that is different than the one you previously disconnected.

I very nearly disconnected the one you did until I figured out that it looked like the air flow sensor.

Good luck.

Jeff

There we go, I think Jeff hit the nail. Fig's photo has a small metal box on the passenger side next to the round thingie circled. When I looked at it, I saw just one black connector with 2 wires leading to it, so I instinctively unplugged that one. And I fear it was indeed an air flow sensor and I need to search for another plug :-/ Oh well, I will look into it tomorrow, but it would explain everything.

Lesson learned - leave the technical stuff to qualified people :D

Glad to hear it reset itself. Hope you don't have that problem again. I did the mod for a few weeks and went back to stock with it. I guess give it another shot and see what happens.

So this morning I tried to unplug the vacuum hose. I wrapped irs open end with an insulation tape so no stuff gets inside. The car seems to ve slightly more responsive down low, but the sound isn't exactly that much improved. I expected more. Will test it for a few more days and will decide meanwhile.

So this morning I tried to unplug the vacuum hose. I wrapped irs open end with an insulation tape so no stuff gets inside. The car seems to ve slightly more responsive down low, but the sound isn't exactly that much improved. I expected more. Will test it for a few more days and will decide meanwhile.

I agree, I'm not 100% sold on the sound. The sound from 2k to 3k RPMs sounds a little odd. From 3k on it sounds pretty sweet though.

Jeff
08 Smoky Granite Mica IS-F

Well I'm "working from home" today...

I decided to just plug the diaphragm side of the solenoid and leave everything connected. No air leaks, no disconnected trigger wires, looks stock, etc.

Here is the DIY:

Small fine thread machine screw for plug. I used an M2 x .5, 3.5mm length:

http://i113.photobucket.com/albums/n239/naterry/IMAG0443.jpg

Thread screw into diaphragm end of solenoid. I chamfered the port on the solenoid to help the threads start, align, and center. :

http://i113.photobucket.com/albums/n239/naterry/IMAG0447Large.jpg

Again:

http://i113.photobucket.com/albums/n239/naterry/IMAG0449.jpg

Replace vacuum hose over plugged port on solenoid:

http://i113.photobucket.com/albums/n239/naterry/IMAG0450.jpg

Cheers!

N8

Hello, I have seen a lot of pictures capping of the actuator and hoses, are there any pics of disconnecting the plug to the harnesss? I dont want to pull the wrong plug.. Thanks

Can someone upload some vidz how it sound and some pictures how to do it perfectly?
Is it any problem if I have JoeZ intake tube?

Hello, I have seen a lot of pictures capping of the actuator and hoses, are there any pics of disconnecting the plug to the harnesss? I dont want to pull the wrong plug.. Thanks

see the plug in the picture right above your post... pull it