I wanted to share a recent project on my X5D.
Disclaimer: This isn't a step by step guide however for those inclined DIYers all the critical information is covered and the process is outlined, there should be adequate information to build your own replica if you fancy. Follow at your own risk, do your own research, and take responsibility for your work. No that this is done....
The goals:
- Improve turbo response by shortening intake length and increasing air flow potential
- Retain "cold" air source
- Simplify system to make engine access easier
- Clean OEM+ aesthetics
I have yet to confirm the performance gains of the system but once I get my X5 tuned I plan to get some back to back dyno runs comparing the custom inlet vs stock airbox. I would love to find a race shop that can bench dyno the CFM too. This system was "engineered with common sense" so it would be nice too see some data to confirm the increase in performance
....or show that I wasted my time
Hopefully #CommonSenseEngineering prevails.
Here is the parts list, if they were modded those details are below:
- K&N RC-5000 Filter
- K&N RC-70031DK Dry-Charger
- 3.5" 45 Elbow
- 3.5" 90 Elbow (4" legs recommended)
- 3.5"-3" Reducer (3" length)
- 3.5" Aluminum Joiner
- HPS SSWC-59-83 x1
- HPS SSWC-84-108 x4
- Pro Fabrication 3.5" Oval 90 Pipe
https://www.profabrication.com/3-5-x-14-ga-x-4-90-deg-vertical-oval-bend-ms.html
Parts ran me ~$300
Here was when the idea was conceived. Happy to say this state-of-the-art scribble turned out to be fairly accurate.
The star or this inlet system is the 3.5" 90 degree oval piping as retains the 3.5" diameter while clearing the hood once it's shut. Originally I was looking at a 3.5" oval pipe from CX Racing that was aluminum but I went this Pro Fab pipe because it has a tighter 4" radius, I called CX Racing and asked them for the specs but they didn't know (must be lost in China somewhere, lol). If I had to guess the CX piping is 4.5-5" radius, either way the 4" of the Pro Fab is extremely helpful.
*This Pro Fab pipe is mild steel and starts to rust if you look at it wrong so plan to seal/protect it somehow.
Here is the original pipe being test fit
In an ideal world I would maximize the amount of metal and minimize the amount of silicone used to construct the inlet but the direct routing to the turbo meant form will follow function. Here is what I was eyeing up.
The oval pipe fit snugly into the oem hole in the shroud but the pipe needed to sit lower for hood clearance. This is without trimming, notice the height relative to OEM.
If you look closely at the edge of the green tape you can see there was a circular cutout in the radiator shroud so I trimmed the plastic on top and did my best to make a clean cut.
I did an initial trim of the oval pipe.
With the oval pipe and the radiator shroud trimmed fitment was much better, notice how low the pipe sits now, very similar to the stock snorkel.
I had to take some more length off the oval pipe to help straighten the routing. Here is after final trimming. I don't have the exact measurements but there is about 1" of leg (past radius bend) that goes towards the filter, the other end which runs to the turbo is slightly longer with ~2" of leg.
Here is the OEM turbo inlet removed from the X5
We won't be needed the top part and thankfully the PCV connection is built into the lower pipe. With the upper portion removed I noticed there was a large flange, this isn't ideal.
Using a sanding wheel I removed the outer lip and bored out the inside to make a nice smooth transition.
For good measure I bored out the MAF as well.
Disclaimer: This isn't a step by step guide however for those inclined DIYers all the critical information is covered and the process is outlined, there should be adequate information to build your own replica if you fancy. Follow at your own risk, do your own research, and take responsibility for your work. No that this is done....
The goals:
- Improve turbo response by shortening intake length and increasing air flow potential
- Retain "cold" air source
- Simplify system to make engine access easier
- Clean OEM+ aesthetics
I have yet to confirm the performance gains of the system but once I get my X5 tuned I plan to get some back to back dyno runs comparing the custom inlet vs stock airbox. I would love to find a race shop that can bench dyno the CFM too. This system was "engineered with common sense" so it would be nice too see some data to confirm the increase in performance
....or show that I wasted my time
Hopefully #CommonSenseEngineering prevails.Here is the parts list, if they were modded those details are below:
- K&N RC-5000 Filter
- K&N RC-70031DK Dry-Charger
- 3.5" 45 Elbow
- 3.5" 90 Elbow (4" legs recommended)
- 3.5"-3" Reducer (3" length)
- 3.5" Aluminum Joiner
- HPS SSWC-59-83 x1
- HPS SSWC-84-108 x4
- Pro Fabrication 3.5" Oval 90 Pipe
https://www.profabrication.com/3-5-x-14-ga-x-4-90-deg-vertical-oval-bend-ms.html
Parts ran me ~$300
Here was when the idea was conceived. Happy to say this state-of-the-art scribble turned out to be fairly accurate.
The star or this inlet system is the 3.5" 90 degree oval piping as retains the 3.5" diameter while clearing the hood once it's shut. Originally I was looking at a 3.5" oval pipe from CX Racing that was aluminum but I went this Pro Fab pipe because it has a tighter 4" radius, I called CX Racing and asked them for the specs but they didn't know (must be lost in China somewhere, lol). If I had to guess the CX piping is 4.5-5" radius, either way the 4" of the Pro Fab is extremely helpful.
*This Pro Fab pipe is mild steel and starts to rust if you look at it wrong so plan to seal/protect it somehow.
Here is the original pipe being test fit
In an ideal world I would maximize the amount of metal and minimize the amount of silicone used to construct the inlet but the direct routing to the turbo meant form will follow function. Here is what I was eyeing up.
The oval pipe fit snugly into the oem hole in the shroud but the pipe needed to sit lower for hood clearance. This is without trimming, notice the height relative to OEM.
If you look closely at the edge of the green tape you can see there was a circular cutout in the radiator shroud so I trimmed the plastic on top and did my best to make a clean cut.
I did an initial trim of the oval pipe.
With the oval pipe and the radiator shroud trimmed fitment was much better, notice how low the pipe sits now, very similar to the stock snorkel.
I had to take some more length off the oval pipe to help straighten the routing. Here is after final trimming. I don't have the exact measurements but there is about 1" of leg (past radius bend) that goes towards the filter, the other end which runs to the turbo is slightly longer with ~2" of leg.
Here is the OEM turbo inlet removed from the X5
We won't be needed the top part and thankfully the PCV connection is built into the lower pipe. With the upper portion removed I noticed there was a large flange, this isn't ideal.
Using a sanding wheel I removed the outer lip and bored out the inside to make a nice smooth transition.
For good measure I bored out the MAF as well.
