[fl335i]

Guys, I like the filtering capability of the factory paper filters, but was just thinking if I do an intake system of some kind.... why on earth couldn't I run it the way I did on my Supra? These 335i's are MAP systems. Not MAF. Some points:


1- Stock the air box/filter is on the driver side. the Turbos are on the passenger side. I think the filter needs to be on the passenger side. Why have more piping crossing the engine bay and reducing flow to the turbos.

2- BOV/Recirc valves. I'd run a aftermarket BOV on the passenger side as well. To address the open during cruising run a foam filter on it. just like the intake, why not.

Ideally, the turbos are on the passenger side, Throttle Body is on the driver. so the turbos should discharge into the passenger side of the intercooler. the driver side of the cooler should pipe up to the throttle body. Intake & BOV on the passenger side, above the turbo discharge pipe. Am I missing something here? B/c I actually looked at the piping closely for the first time last night and it's a criss cross mess.

[Dave W.]

The IC pipes are already routed like you describe- they go from the turbo to the right side of the IC, then the IC outlet goes straight to the TB.
The pipe from the filter to the turbo inlet is long and restrictive. It's not easy to work around it since there's not much space.

[jwalker87]

You have a good point. The fact is there's room on the driver's side, and not the passenger side. If you got a couple of cone filter to fit over there, you could see some gains, but you'd be sucking hot air as well. In my mind, probably not worth it in a real world scenario.

[fl335i]

I looked around the engine bay tonight with a nice LED light. I clearly see where the front turbo is getting air from. But the rear turbo I could not see the air inlet pipe to it??? I have a bad feeling it's the air pipe going rear-ward from the air box.... around the back of the engine. am I right?

I need some advil just from looking around for 10 minutes. Who the hell came up with the routing? It's like they tried to make it complicated.

[E90Company]

Originally Posted by fl335i

I looked around the engine bay tonight with a nice LED light. I clearly see where the front turbo is getting air from. But the rear turbo I could not see the air inlet pipe to it??? I have a bad feeling it's the air pipe going rear-ward from the air box.... around the back of the engine. am I right?

I need some advil just from looking around for 10 minutes. Who the hell came up with the routing? It's like they tried to make it complicated.

Your bad feeling is right

[fl335i]

RealOEM's diagrams helped me confirm too... uh. Even opening the weird can of CHF 11S power steering fluid is retarded. WTF is wrong with these people? That's the stupidest container lid I've ever seen. You literally have to try and F'k that up. I want to know which country/car maker in europe pushes simplicity. Maybe it was Volvo.. woops.


Back to zee issue at hand. the inlet piping to the turbos is like 1, or 1.25" pipe. very small. You could easily run that up to behind the passenger headlight in a OEM air box, put the coolant overflow by the P/S resv.... and eliminate a shizi load of "stuff". The Stett CAI actually eliminates the OEM box, and duct work which is nice. Seems to be my favorite. I can't believe Dinan just make a lid and pipe for 1,300 and they didn't even eliminate the OEM box. I need a 98 TT 6spd Supra....

Take this mentality one step further. Microfilter (aka cabin filter). Big SOB that takes up the whole damn cowl. Lexus, Toyota ETC put a small 8" x 8" panel filter behind the glove box that takes literally 1 minute and no tools to change. Our was designed by a bafoon.

[BoostedE90]

Originally Posted by fl335i

I looked around the engine bay tonight with a nice LED light. I clearly see where the front turbo is getting air from. But the rear turbo I could not see the air inlet pipe to it??? I have a bad feeling it's the air pipe going rear-ward from the air box.... around the back of the engine. am I right?

I need some advil just from looking around for 10 minutes. Who the hell came up with the routing? It's like they tried to make it complicated.

There was a thread months ago on someone fabbing a set upgraded inlet pipes and I remember him saying what a pain it was to get to the rear inlet pipe. Not sure if anything ever came of it but there were some good pics of what the inlet piping looked like.

EDIT: found it... http://www.e90post.com/forums/showthread.php?t=665931

[fl335i]

^thread is closed, links and photos don't work. no luck.

Edit: I really like the Stett intake. Seems to be top on my list.

[Zebra99]

Space is too restrictive for all the work you're talking about. Increasing the piping from 1.25" to lets say 2.5"-3" would obviously see gains, but good luck fitting it.

The costs would outweigh the gain. The other thread that's being mentioned tried that, but it looked absolutely ridiculous IMO and cost well over $700 for just piping.

These motors already make decent gains on stock turbo, so the extra 10whp isn't worth all that trouble. If you went with a different set-up than it may definitely be doable.

[roadkillrob]

The reason it works on a supra is that it sits straight up and down with lots of room on both sides, BMW has the engine leaned way over to the passenger side, so there just isn't any room on that side and all the room on the other side.

It historically worked good when the exhaust w just a pipe and the intake was rather large, but now leaning the block the other way would make more sense and simplify things greatly!

[Dave W.]

I just feel sorry for the upgraded RB turbo's trying to pull air through the stock intakes. I'd love to put a vacuum gauge in front of the turbos and see how bad it is.

[fl335i]

^ I can only imagine. In theory if we could just fix the turbo intake pipes .... Man.

So that's what's not quite right about my I-6 LOL. they leaned it. It's a slant 6. So after running through the mill, the only real options I see on the table w/out taking over a design team is:

A- Stock
B- Stock w/drop in foam filter; Ie KN etc. I think this is the best option. It already sucks air from the front of the car, so as long as you are moving over 20mph you are getting cold air.
C- Stett CAI. I have no idea what the air filter looks like on the end of their pipe. ?? Anyone know?

[BoostedE90]

Here are the pics from the thread I posted earlier. As you can see there was no easy to route the rear piping.

[fl335i]

OMG. That must of been a lot of work. So it can be done.... that's a good starting point. A good aftermarket company with plastic making ability could make a nice kit that relocates the coolant bottle and run the intake behind the RF headlight. would be costly though....

Guess the answer is buy a Kia Optima with the 4cyl Turbo. lol

[Jeff@TopGearSolutions]

Getting to the rear turbo is a LOT of work. That is why you dont see many over the counter intake upgrades directly to the turbo's. Can it be done, sure.

The above kit does have some functionality but it is not easy on the eyes. If one were to move the coolant reservoir and Wastegate boost tanks that may be a more ideal place for the filters.

And OP, Stett CAI is one filter. The reality is if you want big power, go single turbo. If you want every last drop out of stock turbo's or upgraded stock frame turbo's then an upgrade like(posted by boostede90) this may grab a few more ponies.

[Zasquatch]

Just do a Mr. 5 style intake.

[fl335i]

^HUH?


I've come to the conclusion I'll pick up a K&N or some other brand of foam performance filter for when dyno'n and at the track. OEM filter for daily driving. done.

[BQTuning]

Not worth it unless your doing a literal sizing turbo upgrading

[Zebra99]

Stupid question, but isn't there a way to get that piping run straight down near the ground, but still safely under the plastic undercover?

There has to be a shorter/easier route than that monster piping all around and wrapped to the front!

[Dave W.]

Originally Posted by Zebra99

Stupid question, but isn't there a way to get that piping run straight down near the ground, but still safely under the plastic undercover?

There has to be a shorter/easier route than that monster piping all around and wrapped to the front!

If you go straight down from the rear turbo, the filter would be right on top of the downpipes. Probably not the best for cold air intake.

[Zebra99]

Originally Posted by Dave W.

If you go straight down from the rear turbo, the filter would be right on top of the downpipes. Probably not the best for cold air intake.

So? Heat shield it and wrap the DP's.... Any of the vendors can get this done with their resources.

I can see this making big numbers considering the increased airflow, less tube, less restrictions and much more user friendly than the above wrapping job.

Probably could be done for approx. $300 - I'd say that's worth the extra 20whp/trq no?

[Zasquatch]

Originally Posted by fl335i

^HUH?


I've come to the conclusion I'll pick up a K&N or some other brand of foam performance filter for when dyno'n and at the track. OEM filter for daily driving. done.

http://www.e90post.com/forums/showth...squatch+intake

pics scattered throughout the thread. IMO the best intake option unless taking the time an money to redo the turbo inlet piping.