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Old 09-14-2005, 12:32 PM   #1
saloonracer
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Default Theoretical intake idea

OK, So ive been scratching around for intakes a whole lot. Ive seen some that lose torque or some sort of power in a part of the rpm range.

So heres how my thinking went.
First thing I did with the stock system is to remove all the added piping from the Airbox - back. The airbox seems to help with mid and lower rpm power but loses some power in the top end range.

Then I thought about the KN filter replacement. But the more I look at it I wondered how the airflow would be without a filter stuck infront of the TB. So air flows nice into the box then gets swirled around because it has no unrestricted place to travel cept the filter which blocks off a big part of the airbox. (I know there is always air there but my concern is the flow characteristics.)

I have recently found the stage 2 mod from larry ganz. where he installs a complete 3" intake from the fender into the airbox. Exactly what I was thinking but my only difference would be that I want to get rid of the filter in the Box and stick a Conical filter on the other end of that intake pipe in the fender, much like Injen or Aem I think.
That way the air travels straight through the filter, through the 3" intake, into the Box where it fills the entire box with "fresh air" and nothing blocks it from entering the TB.

I would have to seal the Box because there is not filter in it but thats no problem as all id have to do is cut out the paper pleats in the stock paper filter and use the rubber surround to seal it off.
I dont even know if this would make a difference at all but I think it would increase air volume and velocity into the intake manifold. Also the box would now have more "free" air to increase throttle response and you retain the low end torque.
I thought this mod would be better than stock so why not give it a try, but I would appreciate some thoughts on this.

cheers
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Old 09-14-2005, 12:40 PM   #2
Boom05rs25
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Its backyard,But im biten'.....Beats dropping 260 for basiclly the same thing "witch im sure they thought less about then you have.... " I was gonna do somthing simalir till I install custom turbo,and even then im makin my own....
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Old 09-14-2005, 12:57 PM   #3
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sounds decent, pictures of the process and the product please
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Old 09-14-2005, 02:34 PM   #4
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I popped a HKS DD mushroom filter on to the end of my MAF and got +1 to +3hp and +1 to +4tq in the complete RPM range and even smoothed out some dips. I'll bet you can get them cheaper than KN filters via Ebay...
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Old 09-14-2005, 02:45 PM   #5
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Sounds interesting, I wanted to move the airbox (keeping the stock filter) to the fender side, run a j tube from the bumper to the airbox and another tube from the airbox to the TB.

Not that i put any real thought, but figured I might try it when i get bored and have some free time.

Dont know if i would expect any gains over whats already there (ganz)
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Old 09-14-2005, 02:47 PM   #6
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I was also thinking about this idea for a while, but I wasn't sure what kind of cone filter would fit perfectly. If you do go through this, let us know how it went.

The other idea I had was to somehow find a way to increase the size of the airbox. The thought behind this is that if I have a larger airbox, there would be more air readily available and maybe result in more low end torque (which is what I'm looking for).
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Old 09-15-2005, 01:03 AM   #7
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Default test run

I did a quick mod using a SRT-4 paper filter <conical> and the stock intake elbow coming from the airbox.
I am very pleased with the big difference this little mod made. Now mind you all i did was move the filter from the box to the end of the intake.

More responsive in all gears,
Feels like theres more torque all over the place,
The powerband feels perfectly smooth all the way to cut out.
Top end has improved a little. I think there will be a bigger difference here once the intake diameter has increased.
The sound of the car has changed dramatically. There seems to be hardly any machanical intake noise. I think this is because the fins inside the box are working alot better now since the filter isnt there. could be acting like resonators of some sort. My magnaflow street series muffler sounds the bollox. I was going to change it to something louder but now it sounds more BOXER all the time...not only when it heats up. Any ideas why?

Now I was still using the stock intake piece so next up is to get a 3" intake pipe running from the fender to the airbox using a higher flow filter.

I am honestly very impressed. What i want to do is run my RS against my brothers Spec v (its the 04 with updated software) in stock form then after the mod...run it again and see if theres any difference. This is the only form of comparison I have. recording it all ofcourse.
I will post pictures of this step tommorow asap.

cheers

I have a big smile on my face..
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Old 09-15-2005, 09:40 PM   #8
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Thanks for reporting back.. sounds like a winner!

I just thought of something. How about retrofitting the small filter box attachment from the MAF based cars? That way, it doesn't have to suck in the warm air from the engine or accummulate dirt as easily. Plus, when you need to change the filter, you could just get the OEM one for cheap insteading of paying for more $$ for the SRT-4 conical filter.
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Old 09-15-2005, 09:50 PM   #9
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...i spent 40 on an ebay intake and got 10hp and 11 lb/ft...

not trying to shoot you down, just sharing information
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Old 09-15-2005, 11:42 PM   #10
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No, Im sure you can get an Ebay intake and see some gains.

What I want needs to be different, It needs to really smooth out the powerband, I realy hate the dips in power when you get on it at around 1500rpms to 4000rpms. I also want a rather..:non-flashy look. Id like the car to have more power wihtout looking like I added alot of cheap boltons to get it.

After running the car a bit more over the past day or two....it seems the ECU has really caught on to the new change. It pulls alot harder in the upper RPMs now than it did a day ago. It really runs into the redline swiftly. This might just be me but the needle seems to pick up speed on the way there.

If anybody on here has the time to fiddle around with their car and set it up in this manner. I would really appreciate some other opinions. I think this is a really great mod and it has changed my car alot. But without someone else to verify all this I have no way to prove this.

One thing I have noticed though is that the car seems to be a little more thirsty now. The fuel needle has dropped a bit more than usual.
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Old 09-16-2005, 12:35 AM   #11
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haha. i have dyno charts
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Old 09-16-2005, 12:40 AM   #12
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actually, i have copys of the charts, Kevin Thomas actually did the work and put out the money for it to disprove the $=power idea.

http://forums.nasioc.com/forums/show...e+dyno+results
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Old 09-16-2005, 02:23 PM   #13
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nice numbers. Not at all what I want though.
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Old 09-16-2005, 08:48 PM   #14
Kevin Thomas
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Saloonracer,
It'll work! I did something similar to one of my Subaru XT6s. I took the stock airbox, cut the snorkus part out and routed duct tubing down and out through my passenger side foglight. Of course you may not want to go to that extreme BUT I did have a decent gain. It would be difficult to measure this on the dyno since the ram air affect wouldn't be taking place.

On the highway, my Subaru XT6 did not have to downshift as at certain points like it had to previous to the mod.
After the modification:
http://xt6.net/forum/viewtopic.php?t...ight=dragstrip

As noted in the thread, I gained 3mph in the 1/4 mile doing this mod so I know power gains are to be had. I'm not sure what you could expect on your ride.
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Old 09-19-2005, 11:19 AM   #15
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Thanx,
I was actually thinking about that route as well. Since most of my driving is on the highway your ram air type setup would be most beneficial.

I found some parts I can actually use to make this work. They have some interresting stuff. You can basically build your own Intake system from scratch.

www.spectreperformance.com

They have an application for Suby's but it is custom so anything can happen. EX. Dual intake.

I will be using these parts to run a pipe from the box to the fender and use their compact design filter.

I think they are available at AutoZone or such places.
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Old 10-03-2005, 12:43 AM   #16
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well....ok....its been a while but ive finally got something going.

I have now got to the part of running a 3" pipe from the factory box to the fender with a high flow filter on it. The box has no filter in it so there is no restriction to airflow into the TB.

The results...I think this is the best thing Ive done to my car since the JLM aluminum pitch stop. It pulls alot harder than any other setup ive tried. The low end torque is great. All gears have great pull....fifth gear is still a bit much but I didnt expect anything to happen there. The car now has great throttle response and it sounds great. Not a very high scream, imagine a V6 with intake on it. It only becomes noticable in some rpm ranges. But it is defenitely there.

Im still trying to post pics....sorry. Any advice here???

What i want to do next is get a pipe to run into the fender for the colder air available there. I mounted a sensor in both locations and the air is much better there. As soon as the car starts moving the temp drops at least 10F..the more/faster you drive the colder/better that air is going to get.


Ill try to finish this by the end of the week.

Cheers
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Old 10-03-2005, 12:48 AM   #17
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Quote:
Originally Posted by saloonracer
Im still trying to post pics....sorry. Any advice here???
Cheers
www.photobucket.com
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Old 10-03-2005, 01:18 PM   #18
saloonracer
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Picture of the short style intake I put on the stock elbow. Elbow is around 21/2" and intake pipe is 3".


After I did this mod the amount of oil inside the box was amazing. I assume its because there is more "pull" from the airbox that pulls more blow by through the tubes. The filters are not that clean anymore.


Heres whats inside the box now. I cut out the paper pleats..and used the rubber surround to seal the box when it is clamped closed.

This setup is great so far. I ran the filter to the inside of the fender and my throttle response went down by a huge amount. The car felt like it was actually working harder to pull air. I need to get the air from the front of the car to the filter.
I also have a temp sensor installed on the front of the filter so I can get some readings to see if there is actually air being pulled from the front of the car.

Ill have some updated pics soon.

Last edited by saloonracer; 10-03-2005 at 01:30 PM.
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Old 10-03-2005, 02:02 PM   #19
saloonracer
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Heres a pic of the ram air extension tube sticking out a tad. I will trim this away eventually but right now im testing some fitments.

another

The air temp sensor is mounted on the inside of this tube. You can see the sensor wire running into the tube. This thing is awsome. It seems to be very accurate.

A new pic of the engine bay with a new 6" straight pipe attached to the filter. The previous one had a 22 degree bend in it.

Still collecting some temp readings....ill try to post some readings with day traffic and night driving temps.
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Old 10-03-2005, 09:26 PM   #20
Kevin Thomas
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This is EXCELLENT info. Thanks for the picture information. That air filter is EXACTLY what I'm looking for. Can you tell us where you got it, the name of it, and the part number of it? I want to get THAT filter for my OBS and one of my XT6s. I have a K&N stile that is similar to that but it costs $65.00. I want to attach the ram-air tubing to one like you have. I can understand why it would be effective. If you don't want post this info, please send me a PM. Thanks!

BTW: I've been looking for an air filter like that for quit some time. One with open sides and pretty much flat for space savings but with an opening for a 'ram-air' tubing to be attached like the PRM (Cobb) air filters. Your filter fits the bill EXACTLY. Actually, your filter would be the perfect replacement for my Cobb air filter. The Cobb is excellent for isolating hot air from the air filter, however I believe it comes at a price....in performance. I think the very same container that houses the PRM (Cobb) air filter restricts the flow by only allowing air to come from one direction.


Last edited by Kevin Thomas; 10-03-2005 at 09:34 PM.
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Old 10-03-2005, 11:58 PM   #21
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Video of my Ebay intake, I have to snap a new picture, I'm still using the stock tubing just took the airbox off.

and yes it's loud.

I don't know if you can hear it in the video but at 14-17 seconds you can hear the air being sucked in, seems to happen around 2500 to 3500 rpms then it goes away and the CAI becomes loud.

I have no clue if you can hear it outside the car but it's pretty audible inside with the radio off.

http://s38.yousendit.com/d.aspx?id=2...S3LQL6FKE8XPAN
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Old 10-04-2005, 11:10 AM   #22
saloonracer
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The filter is great and i think I was lucky to find it. Go to Autozone or PepBoys and they will have a huge selection of filters there....different colors too. In my opinion Pepboys has a much better inventory and they carry better quality parts.

The filter is about $27 and its a SpectrePerformance P/N: 8168.
The adapter for the tubing into the filter is about $6 and the P/N: 8147.

I think you can also find these parts online but because Pepboys are about everywhere there is no reason to buy online and pay shipping costs.

As far as the air temps go. With the engine properly warmed up.

I took readings as follows
Day, Traffic, outside tube.
Stopped at light: 118F increasing
Driving 30mph:96F decreasing
Driving 50mph:91F decreasing

Day, Traffic, Inside tube.
Stopped at light: 89F slow increase (about .2F every 2 or 3 seconds)
Driving 30mph: 82F slow decrease
Driving 50mph: 80 Slow decrease

I only tested night with the sensor inside the tube so far:
Stopped: 85F increasing
Driving 30mph: 79F decreasing
Driving 50mph: 73F decreasing

Becuase of the filters relatively flat shape, the air coming in from the tube doesnt have to travel nearly as far as the longer intake filters and can enter the intake tube alot faster with little gain in temperature. These readings can be more accurate but I was only trying to prove that the air was being "rammed" into the filter while the car was moving at any speed. The tube that flows the air is ribbed so it could be possible to get a better flow by using something more smooth.
Interresting enough.....The sensor in my car(windows down) showed a consistant reading of about 10-12 degrees warmer than the air hitting the filter. Also driving faster will give better numbers I.O.W...temperature will depend on speed, which will yield better performance. I think everybody already know this..this is just my train of thinking....i apologise.

Florida is pretty damn hot and humid so anything that helps......well helps.
All in all the cost so far is about 50 bucks.

Last edited by saloonracer; 10-04-2005 at 11:34 AM.
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Old 10-04-2005, 02:28 PM   #23
Tim Sanderson
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Looks good. Nice job.
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Old 10-04-2005, 02:50 PM   #24
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You're quite the thinker man, excellent info and pics.
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Old 10-04-2005, 08:49 PM   #25
Kevin Thomas
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Quote:
Originally Posted by saloonracer
The filter is about $27 and its a SpectrePerformance P/N: 8168.
The adapter for the tubing into the filter is about $6 and the P/N: 8147.
Thanks for all the info you provided. Do you know the part# for the tubing? If not, where can this tubing be gotten? I have a tendency to look for this stuff in Home Depot and can never seem to find it except when I don't want or need it. Is the P/N 8147 for the adapter as well as the tubing or just the adapter?

I'm not asking this stuff just so you can put it out here. I'd like to pick this stuff up sometime this week possibly, test it at the track this weekend and share my findings.
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