Gene's DIY CAI thread

[svxfiles]

Originally Posted by 92 SVX

I plugged them I am getting the ecutune stage 1 so it would appear I would not need the bypass presently.

It is still a clever way around the 250 hp threshold.

[Bonestock]

Quick pic with my cell phone. Thanks to Gene for an awesome and cost effective mod! Thanks mate!!!!



I used the small grey 3" MAF adapter from auto zone and redrilled the bolt pattern to fit the stock MAF and trimmed off the corners.

I also used a K&N E-0773 filter.

On Gene's parts pic I used the small L shaped bracket and re-drilled the hole about 3/4 closer to the bend. Stuck the small end under the hose clamp closest to the inner fender and bolted it to the rubber mount where the air inlet tube used to bolt on.

[Lookin4SVX]

So you have a cone filter is inside the passenger fender?
How do you clean it/install it?
Do you have to remove the fender or does the filter fit through the hole in the fender from under the hood?

Doesn't the stock air box take in air from the same hole your using to stick the cone filter through?
So why not just leave the stock box there and put in a high flow rectangular filter in it?

Are there any #'s for replacing just the accordion plastic to the MAF compared to a full intake into the fender, on the SVX?

I know on my 2001 Impreza, removing the box and going to a pipe with a cone filter on the end decreased low end torque.
That the air in the box at the ready helped the performance, that is why the "gonzflow" style makes use of the stock box and filter, instead of a pipe and cone on the end.
Then again, the air filter box on my impreza was at the motor, not the fender, and I didn't have this MAF stuff to deal with.

I am just wondering if its worth the trouble switch to a cone in the fender.

[92 SVX]

You need to remove the splash shield in front of the front tire to access the filter, not a big problem. It will all be accessible from under the car not in the engine bay.
The stock box has a resonator in that location inside the fender, that resonator decreases air flow to the stock box. Remove the resonator and keep the stock box is an option but the main benefit of this type of CAI is smooth air flow from the outside to the throttle bodies.

[oab_au]

Originally Posted by 92 SVX

You need to remove the splash shield in front of the front tire to access the filter, not a big problem. It will all be accessible from under the car not in the engine bay.
The stock box has a resonator in that location inside the fender, that resonator decreases air flow to the stock box. Remove the resonator and keep the stock box is an option but the main benefit of this type of CAI is smooth air flow from the outside to the throttle bodies.

No that is not right. The stock air box takes cold air in from under the front, and suppresses the sound. It does not restrict the air flow.
The only advantage of modifying it is to say" look at what I've got."

Harvey.

[Bonestock]

Originally Posted by oab_au

No that is not right. .
The only advantage of modifying it is to say" look at what I've got."

Harvey.

I haven't disagreed with something this much in the history of EVER! But, you have the right to your opinion.

[Bonestock]

See bold sections for my response.

Originally Posted by Lookin4SVX

So you have a cone filter is inside the passenger fender?
How do you clean it/install it?
Do you have to remove the fender or does the filter fit through the hole in the fender from under the hood?

Easiest way is to clean it when you rotate your tires... you do rotate them every other oil change... yeah? Take two minutes and a 10mm socket and ratchet to access the filter.

Doesn't the stock air box take in air from the same hole your using to stick the cone filter through?
So why not just leave the stock box there and put in a high flow rectangular filter in it?

Yes, but what you don't see is the fresh air inlet makes a U shape inside the inner fender plus the resonator chamber. The inlet sets about even with the back of the headlight.. pretty close to it too.


Are there any #'s for replacing just the accordion plastic to the MAF compared to a full intake into the fender, on the SVX?

The accordion bit is there to give the intake some flex since the engine isn't sold mounted to the chassis. If you just want to replace that bit, I believe SVX Motorsports Warehouse has a pipe.

I know on my 2001 Impreza, removing the box and going to a pipe with a cone filter on the end decreased low end torque.


How do you know that? Did you swap them out on a dyno between runs? I ask because in my entire life I cant say that I have ever seen a car not benefit from a "free flow" or CAI... unless the system was flow limited further down stream. Furthermore I assume you are speaking about "peaks". What about area under the curve? Sometimes you may trade a bit of HP for TQ or vise-versa but typically the gains far exceed the any losses.

That the air in the box at the ready helped the performance, that is why the "gonzflow" style makes use of the stock box and filter, instead of a pipe and cone on the end.
Then again, the air filter box on my impreza was at the motor, not the fender, and I didn't have this MAF stuff to deal with.

I am just wondering if its worth the trouble switch to a cone in the fender.

I think so but YMMV

[Lookin4SVX]

Ok, so to clean the filter you go at it from the wheel well, by removing the wheel and the wheel well liner?
This is a problem for me. The previous owner had the bumper repaired. When they repaired it they did a really half ass job on it. They made some new supports out of metal bits, and then riveted the fender liner to it and to the car. So my passenger wheel liner is no longer removable.

My oil is changed by a shop, and my tires are rotated by the tire place.
I don't even own a jack.

The plastic silencer crap in the fender has already been removed.

Ok, accordion pipe is there so I don't break it with my shot motor mounts.
Yes, I was thinking like that polished B pipe. Guess I will wait till after I get new mounts.

There is many, many, many, a thread on NASIOC about impreza intakes.
It stated over and over again, removing the air box on an impreza, hurts performance.
The Cobb intake, the one that deletes the air box, has a large sweeping curve to keep the low end torque up.

I know very little about my svx, that is why I am asking. I was driving the impreza for 9 years.

[Bonestock]

Originally Posted by Lookin4SVX

Ok, so to clean the filter you go at it from the wheel well, by removing the wheel and the wheel well liner?
This is a problem for me. The previous owner had the bumper repaired. When they repaired it they did a really half ass job on it. They made some new supports out of metal bits, and then riveted the fender liner to it and to the car. So my passenger wheel liner is no longer removable.

My oil is changed by a shop, and my tires are rotated by the tire place.
I don't even own a jack.

The plastic silencer crap in the fender has already been removed.

Ok, accordion pipe is there so I don't break it with my shot motor mounts.
Yes, I was thinking like that polished B pipe. Guess I will wait till after I get new mounts.

There is many, many, many, a thread on NASIOC about impreza intakes.
It stated over and over again, removing the air box on an impreza, hurts performance.
The Cobb intake, the one that deletes the air box, has a large sweeping curve to keep the low end torque up.

I know very little about my svx, that is why I am asking. I was driving the impreza for 9 years.

LOL Don't believe everything you read on NASIOC. But typically they are talking about short rams. Those are terrible because they suck up under-hood heat. I have tested this stuff over and over using ECUTEK Delta Dash on my old JDM V8 STi/V7 6MT swapped, 20g WRX. And have more dyno pulls testing various parts back to back than you can imagine.

Now there are a few caveats but I really don't feel like getting into it. Besides until you get your car fixed properly, you can not benefit from this thread.

[oab_au]

Originally Posted by Bonestock

I haven't disagreed with something this much in the history of EVER! But, you have the right to your opinion.

No not just my opinion.Some time ago, a member ran a test of the pressure in the plenum at full throttle and high rpms, with the standard air box and filter. He found that it was virtually atmospheric, no restriction at all.

Harvey.

[Jake@FAPFab]

i'd have to say this is the best bang for buck intake. although buying a few mandrels and straight from the columbia river mandrel b-list pipes might be cheaper. but then you'd need to weld

[Bonestock]

Originally Posted by oab_au

No not just my opinion.Some time ago, a member ran a test of the pressure in the plenum at full throttle and high rpms, with the standard air box and filter. He found that it was virtually atmospheric, no restriction at all.

Harvey.

Get it on a dyno and then we will see. IF there was no restriction or benefit from cleaning up the air flow to the T/B those split intakes wouldn't of made any additional power.... but they did. Posted on this very forum.

[Jake@FAPFab]

pressure=/=airflow

[svxfiles]

Originally Posted by Jake@FAPFab

pressure=/=airflow

Jake, are you saying that pressure does not equal airflow?


Just asking about your equation.

[SVXRide]

Harvey,

That would be me. Point to note is that I was running a full ram air system from the front bumper to the stock airbox, with a "Green" filter in the airbox when I took the measurements. New "Scorpion" system is replacing the stock TB to stock airbox system as soon as I can get some welding done (oh, and fingers crossed that the hood still closes without modification )

-Bill

Bumper to airbox:


Scorpion: