[fl335i]

I pulled the air box lid off this weekend for some more pondering... Came up with this:

1- The underside of the lid has tons of fins. What about grinding the fins out and opening upthe area between the filter side and inlet side?

2- What about a "taller" larger more domed air lid. I think the air filter is huge, the restriction may be coming from the area the air travels from the filter into the inlet side. I think it would be more benefienial if someone came up with a modified "lid".


Thoughts on this?

[Zebra99]

In glad your pushing this discussion because there are some very important factors to consider here.

1. Some of us want a complete sleeper look and that applies even under the hood. I for one work in the insurance industry and can appreciate performance that replicates the stock look. Avoids problems if there is ever an accident.

2. There are gains to be had here. It's just a matter of someone figuring this out. We all know any of the stock piping is restrictive so it's a win for the community of anything.

3. I would spend $300-400 if I knew it would yield me 15-20whp/trq. I bet most other members would to.

I'll be looking into this more the next time I have the car at the shop. I want to assess the space under the vehicle to see if I can run a straight inlet from turbo to floor as I suggested earlier.

This ^ coupled with a nice sealed CAI would be a dream come true.
- keep advocating dude, I certainly appreciate it!

[fl335i]

oh, i'm a persistant for sure.

[Torgus]

I run my air intakes into my cabin so they can suck in cool air conditioned air.

In all seriousness I don't think the gains are worth the trouble. But as said above if it was $400-$600 for 15-20whp across the entire power band many would pick it up...

[Dave W.]

I had a chance to check out the space behind the rear turbo today. I'm sorry to say that it's tighter than I remember! Like I said earlier, the downpipes sit right below the rear compressor inlet and the motor mount is between the DP and comp inlet. It looks like approx 2.5" of space, not even enough room to put a filter directly on the turbo. It's really tight in there! The best I could see is to use a 2.25" tight radius U bend on the turbo and route the piping someplace where there's room for a filter. To be honest, it looks like it was already done this way in the link someone posted earlier in this thread.

[fl335i]

Total PITA. I'm running the stock system. Like I said before, I think maybe the lid itself may yield some gains??? maybe.

[BoostedE90]

Originally Posted by fl335i

Total PITA. I'm running the stock system. Like I said before, I think maybe the lid itself may yield some gains??? maybe.

I don't think you'll be able squeeze much more from the stock system. Maybe a little with a mod like the Mr. 5 intake, but as you can see in the pic the inlet pipes to the turbos get pretty restrivtive. You'll only be able to push more air with larger piping.


I had an idea (and I wish I was good at photoshop or CAD to draw it) for an intake similar to the STETT CAI design that could fit on the passenger side that would eliminate pipes 8 and 13 in the above pic. From the pics I posted earlier the rear turbo can be gotten to from the top down on the passanger side. The front one is prob going to be an issue to route piping to starting from the passenger side. And then finding enough room to pipe the filter to an area by the bumper. Things are just so tight on the passenger side I don't see how it could be possible.

[fl335i]

nice pic! Man I wish we could make this happen... Is there company that has the CAD and abilities to do this if we do a group buy? I think you can use a U of some sorts to get the back turbo and route the pipe through the turbo discharge Y. Is there a reason we have two Recirc valves? Why can't we get rid of one of them? I'd love to have a simple engine compartment.

[Torgus]

Originally Posted by fl335i

nice pic! Man I wish we could make this happen... Is there company that has the CAD and abilities to do this if we do a group buy? I think you can use a U of some sorts to get the back turbo and route the pipe through the turbo discharge Y. Is there a reason we have two Recirc valves? Why can't we get rid of one of them? I'd love to have a simple engine compartment.

Hard to get a group buy for a product with no proven results. I like your idea but I think a group buy is unlikely.

Any shop that builds it's own turbo piping can make the type of intake we are talking about in this thread. It should cost less that 1k. Do a before and after dyno to prove the results. I would suggest this on a FBO with and without meth to see the gains. Then start a for sale thread. Basically once it is all fabbed up it should be easy for the shop to build more from 1/4 of the price. All the price for the 1st one is from the amount of labor they have to put into the 1st piece.

If you could enlarge all of the piping(Including #10!) to the maximum amount allowed given the space and not going over 3'' I think you would see some decent gains, especially FBO on RBs.

But then again I don't know much.

[fl335i]

^ That's b/c you're from Boston. LOL. J/k. I would also like to see some dyno #'s before and after. Making the system out of plastic, like the OEM would work.

[Zebra99]

Originally Posted by fl335i

^ That's b/c you're from Boston. LOL. J/k. I would also like to see some dyno #'s before and after. Making the system out of plastic, like the OEM would work.

This would be preferable. I think the plastic would dissipate heat better than aluminum / steel. And, not to mention that plastic costs less

When I go to the shop to get my DP's on I'll snoop around under the car and discuss this with him. I also know a shop locally that does fab jobs, but charges $130/hr lol. If there were enough interest I'd say he'd be done to reduce his costs significantly.

[Dave W.]

Just for the sake of finding dyno results, why not remove the stock intake and do a before/ after pull? The dyno should have clean air so you don't have to worry about running the car without filters for one or two pulls.

[07bmw335iguy]

yeah I was poking around there today also, would really love to be like most turbo charged cars where the filters are on the same side as the turbos. Was looking at moving the coolant reservoir over to where the intake is now and running the turbos into one large cone filter in its place.

[Torgus]

Originally Posted by Dave W.

Just for the sake of finding dyno results, why not remove the stock intake and do a before/ after pull? The dyno should have clean air so you don't have to worry about running the car without filters for one or two pulls.

You could even put a super nonrestrictive filter on just encase it tries to suck a leaf in or something. like 5 micron or whatever. Will not effect HP.

The problem with plastic is you have to make a mold which is super expensive, takes a long time, not just any shop can do this, etc. The gains of larger piping will surpass heat soak imo(From Boston so I could be wrong acording to someone... You could always ceramic coat or wrap the pipes if you are concerned.

$130 and hour isn't horrible. If it takes 3-4 hours it is the cost of a CAI no? Especially if it has gains and you have the chance of selling a full kit to enlarge all piping. If you could gain 25whp for instance(over DCI) I bet you would have alot of people picking it up. Even a 15 or 20hp gain would be pretty huge.

I suggested going to a shop and tell them your goals and get a quote. It is just money, spend it. I would definitively explain your goals to a shop and get their input. Mention that if it makes good gains you will be back to have the kit taken off so they can fab up 10 more for you to sell. Best case scenario is you team up with the shop and they do it for cost and you both make some scratch selling the kits.


I just want to be the 1st one to say no one will go through with this.

[Zebra99]

Originally Posted by Torgus

You could even put a super nonrestrictive filter on just encase it tries to suck a leaf in or something. like 5 micron or whatever. Will not effect HP.

The problem with plastic is you have to make a mold which is super expensive, takes a long time, not just any shop can do this, etc. The gains of larger piping will surpass heat soak imo(From Boston so I could be wrong acording to someone... You could always ceramic coat or wrap the pipes if you are concerned.

$130 and hour isn't horrible. If it takes 3-4 hours it is the cost of a CAI no? Especially if it has gains and you have the chance of selling a full kit to enlarge all piping. If you could gain 25whp for instance(over DCI) I bet you would have alot of people picking it up. Even a 15 or 20hp gain would be pretty huge.

I suggested going to a shop and tell them your goals and get a quote. It is just money, spend it. I would definitively explain your goals to a shop and get their input. Mention that if it makes good gains you will be back to have the kit taken off so they can fab up 10 more for you to sell. Best case scenario is you team up with the shop and they do it for cost and you both make some scratch selling the kits.


I just want to be the 1st one to say no one will go through with this.

I love your positive attitude.......
Until the end lol.

I'm gonna call the fab guy right now and get his opinion. Maybe he can make mine free knowing that he will surely sell 50 units more!

[longliven54]

Originally Posted by Zebra99

I love your positive attitude.......
Until the end lol.

I'm gonna call the fab guy right now and get his opinion. Maybe he can make mine free knowing that he will surely sell 50 units more!

keep us posted. def intetested if it can be around other cai prices

[07bmw335iguy]

You can do it!!!!!!

[Torgus]

Originally Posted by 07bmw335iguy

You can do it!!!!!!

[NiVeDh]

Originally Posted by fl335i

I pulled the air box lid off this weekend for some more pondering... Came up with this:

1- The underside of the lid has tons of fins. What about grinding the fins out and opening upthe area between the filter side and inlet side?

2- What about a "taller" larger more domed air lid. I think the air filter is huge, the restriction may be coming from the area the air travels from the filter into the inlet side. I think it would be more benefienial if someone came up with a modified "lid".


Thoughts on this?

Regarding the fins, they are there to smooth out turbulent flow. I would not recommend grinding them off as you might end up causing more restriction.

[07bmw335iguy]

Been doing a lot of reading and online window shopping: www.Siliconeintakes.com has a lot of parts to piece together an intake. Also here http://www.racerpartswholesale.com/p..._Temp_Ducting2, this stuff has a lot of great reviews about it and the fact that it comes in 11ft sections and is cheap helps a lot to.

[packinDSS]

Interested. I think there is 20hp/tq hiding in the restrictive piping on a FBO car with stock turbos. Even more with RB turbos.

I haven't looked but there is no way to get the piping and filters into the fender well?

[Zebra99]

Originally Posted by packinDSS

Interested. I think there is 20hp/tq hiding in the restrictive piping on a FBO car with stock turbos. Even more with RB turbos.

I haven't looked but there is no way to get the piping and filters into the fender well?

I wouldn't suggest routing to the fender wells. To much dirt, water and other crap going that way to not mention on lowered cars you'd be hitting the system if you go over any bad bumps.

Pipe/Section 13 looks annoying because it seems to have a sensor near the top. Not sure what that is but I'm assuming it's important.

I honestly just want to be able to have a pipe literally do a 90degrees straight to the ground. We have plastic all throughout so that we would be the safest way. You'd also be eliminating a huge amount of piping under the hood.

Does the stock fuel system have enough capacity to match the amount of airflow we'd be freeing up?

Edit: just had a look at the intake/airflow system online for the N54 and there is a lot of recirculating and charging or air happening. Would eliminating pipes 8 & 13 have a negative affect on this process? They made this engine way too confusing for my liking lol....