[Edman951]

Hey guys,
I made a home made twin air filter ( K&N) induction set-up on my car last night.
It came out pretty good and simple.
The idea came to me when thinking of finding a simple way to get a K&N filter on my car. And not ad bends to the system since it already got the long pipes to the turbos.
I figure since I got twin turbo's, why not go twin air filter.
Many will say this will take in the hot air from the engine bay. Sure it will, but the intercooler is there to cool the charge after it gets heated by the compresssor.

On my first test drive i got some boost spike that i never got befoe.
This set up did increase boost buy a good 1 to 2 psi. from before and after reading on my boost gauge.
ps. I have a turbo tuner on my car from the M Shop, That I installed last week.
So if the boost went up just from the filters install that means it remove some restriction right.
And I could always box the filters and use the factory cold air inlet.

The factory box seems restrictive because of it design. and the gain in boost does show this fact.

I was lucky that this set-up went in easy, and that my idea and chossen parts worked. Because I designed this without re-moving any part for the car. Just took mesurements and figured what i needed.

Here what i did and used.
Ordered 2 K&N filters part # RX-3800, I wanted X-stream flow tops. And the 20deg angle help on the install.
http://www.knfilters.com/search/prod...x?Prod=RX-3800

Remover air box. To do this you will have to remove the A/C filter system and bulkhead by unbolting it. This is easly done, and will help you acces the rear intake tube clamp/

I used 2 aluminum 2" IPS ( 2.375" OD) pipes I had at my shop that i cut about 1-1/2" long to joint the filter to the factory pipes.

Then bolt on the filters using the pipe adaptors. angle the filter so the don't tuch each other. Re-intall the bulkhead and A/C filter assembly.

I can now hear the turbos spool up and the bypass valves work (not very load do for the valves) but its descrite.

Here are some pictures.

[imaznumkay]

wow! very interesting...

[RedGT3]

Not bad.

[O-cha]

Keep in mind with a turbo its not as simple as "The intake temps are higher but the intercooler cools the air anyway." Higher intake temps mean the turbos have to spool faster in order to make the same boost post intercooler. So while yes you removed restriction and probably gained some low end torque, you likely will lose HP especially with a tune.

[///AFRO]

lol, stupid question. But, can this work on the E92? Howmuch did everything cost?

[Edman951]

The E90 & E92 335I's have the same engine bay set-up, so i don't see why it would not work.
Cost me 100$ for both filter.
I had the aluminum pipes in stock.

[Neema]

pretty interesting, i doubt they will fit back in the factory intake box though.

[HyperM3]

Gotta love the DIY'ers. This is perfect. I dont care if it has gains, losses or whatever. Kudos to you for trying and achieving!

[1clean335i]

that would be a good set up for the first pass down the track then useless once the engine heats up

[Edman951]

O-cha,
Higher temp doesn't always mean less boost post intercooler.
I guess it depend on the cooler's efficiency.
If its max out already sure it will not help if the intake charge it hotter.
But having the compressor work less hard to pull in the air means faster spool up. It will also work less hard at top end since less restriction helps top end.

but who knows right!, I'm just some guys playing on his car.

Low end torque on the street is fun to have.

Also when the car is moving, i'm sure the engine bay temps goes down alot.
Plus the hot exhaust is on the other side.
Just look at a Porsche 944 turbo. The intake manifold is over the turbo.
And when the car is moving, the intake doesn't get hot.
I have one, and have seen and tested this myself.
See picture of my motor.

[HyperM3]

Originally Posted by 1clean335i

that would be a good set up for the first pass down the track then useless once the engine heats up

FWIW, that side of the engine doesnt get as hot as the opposite side which has the turbos and the exhaust headers. Plus, once the car is moving theres a lot of air circulating around and the direct air from the ram tunnel coming from the kidneys. People are making it out to be worse than it really is.

[Edman951]

I agree with you HyperM3, Clad you like my tryout

[Edman951]

Your intercooler will also get hot after the first pass.
And won't get very cool from the return road back to the pits.
Thats the biggest problem when drag racing with a air to air intercooler.
But this is not a dragster right, its a street car.

[itsbrokeagain]

its not bad. Pricing is pretty good as well.

To really see if it makes a difference, you should have waited for a cold day, drove the car stock cold and then drove the new setup cold to see if the boost still stays up.

If it still stays up 1-2 psi, then we know that regardless of the car being hot or cold driving, it will still make more boost because of less restriction, not the car getting hot in the engine bay and upping the boost on its own to keep the power the same.


I was idling my car outside before with the hood up. I could easily touch the airbox and intake manifold without being burned. Anything on the exhaust side was scorching...even when the hood was up and letting all the heat escape...so the filters should be relatively unharmed by it. Besides the second you start driving, cold air flows into the filter area, so any hot air there from idling will be gone.

[doba_s]

Originally Posted by Edman951

Hey guys,
I made a home made twin air filter ( K&N) induction set-up on my car last night.
It came out pretty good and simple.
The idea came to me when thinking of finding a simple way to get a K&N filter on my car. And not ad bends to the system since it already got the long pipes to the turbos.
I figure since I got twin turbo's, why not go twin air filter.
Many will say this will take in the hot air from the engine bay. Sure it will, but the intercooler is there to cool the charge after it gets heated by the compresssor.

On my first test drive i got some boost spike that i never got befoe.
This set up did increase boost buy a good 1 to 2 psi. from before and after reading on my boost gauge.
ps. I have a turbo tuner on my car from the M Shop, That I installed last week.
So if the boost went up just from the filters install that means it remove some restriction right.
And I could always box the filters and use the factory cold air inlet.

The factory box seems restrictive because of it design. and the gain in boost does show this fact.

I was lucky that this set-up went in easy, and that my idea and chossen parts worked. Because I designed this without re-moving any part for the car. Just took mesurements and figured what i needed.

Here what i did and used.
Ordered 2 K&N filters part # RX-3800, I wanted X-stream flow tops. And the 20deg angle help on the install.
http://www.knfilters.com/search/prod...x?Prod=RX-3800

Remover air box. To do this you will have to remove the A/C filter system and bulkhead by unbolting it. This is easly done, and will help you acces the rear intake tube clamp/

I used 2 aluminum 2" IPS ( 2.375" OD) pipes I had at my shop that i cut about 1-1/2" long to joint the filter to the factory pipes.

Then bolt on the filters using the pipe adaptors. angle the filter so the don't tuch each other. Re-intall the bulkhead and A/C filter assembly.

I can now hear the turbos spool up and the bypass valves work (not very load do for the valves) but its descrite.

Here are some pictures.

It almost looks like the car on the other picture below ... i wouldn't do it to my car ...

[schneid4323]

thats not a great idea, you are gonna screw with air going to the turbos, the front one will get more, and youll have turbulance heaven under your hood.

[Edman951]

Originally Posted by schneid4323

thats not a great idea, you are gonna screw with air going to the turbos, the front one will get more, and youll have turbulance heaven under your hood.

The turbo's are pulling in the air thru the filter, so they both get what they need.
And once they got into the intercooler it become one. So if one would draw a bit hotter air then the other. No difference once in the intercooler.

Sure this set-up is not the best ever built.
But for 100$ I'm happy with it.

But i will put it back to stock for the winter. To much road salt up here.

[1clean335i]

the engine bay's of bmw's are pretty enclosed so most of the heat created by the engine stays in there. which means it will get distributed to the intake side as well. if there was a vented hood on the car or something i can see some benefits but otherwise i see no improvements. do a few dyno's back to back to see the results

[ulises 335i]

Originally Posted by Edman951

The turbo's are pulling in the air thru the filter, so they both get what they need.
And once they got into the intercooler it become one. So if one would draw a bit hotter air then the other. No difference once in the intercooler.

Sure this set-up is not the best ever built.
But for 100$ I'm happy with it.

But i will put it back to stock for the winter. To much road salt up here.

Edman951,
did you notice any gains performance wise?

Are you planing on dynoing this setup? If I recall correctly a member here by the name of mr.5 had something similar and when he dynoed it he lost alot of power. Mabe your setup is better .

[Edman951]

Yes the engine bay is enclosed but I belive it's designed the evacuate the hot air under the car.
But i'm not here to prove anything. I guess not many people like to see thing done simply and not have to pay 1000$ for an intake pipe that may only ad 5hp.

I don't ever plan to go on the dyno... but if i get a chance for fun I will datalog engine bay temp with my inovative LM1 from my mustang. I will post the info if i ever do it.
This is my daily driver, I don't need to see if it made more power for now.
I just like the fact that this worked out simply and cheaply.
I just like to hear the turbos spool when i drive. I don't race this car.

I have a 550hp 94 mustang with complete 03 cobra drivetrain for drag racing (best run 11.06), and a 425hp 944 turbo for other times.

[ulises 335i]

Originally Posted by Edman951

Yes the engine bay is enclosed but I belive it's designed the evacuate the hot air under the car.
But i'm not here to prove anything. I guess not many people like to see thing done simply and not have to pay 1000$ for an intake pipe that may only ad 5hp.

I don't ever plan to go on the dyno... but if i get a chance for fun I will datalog engine bay temp with my inovative LM1 from my mustang. I will post the info if i ever do it.
This is my daily driver, I don't need to see if it made more power for now.
I just like the fact that this worked out simply and cheaply.
I just like to hear the turbos spool when i drive. I don't race this car.

I have a 550hp 94 mustang with complete 03 cobra drivetrain for drag racing (best run 11.06), and a 425hp 944 turbo for other times.

is it possible for you to post up some videos or something so we can hear the intake?

[Edman951]

did you notice any gains performance wise?

yes i did, the tracktion control did work alot harded after the install then 1 hour prior to the install.