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Gelbster · 01-12-2017, 07:58 PM

I completed my hack CAI project as mentioned above. A complete description would be too lengthy and anyway it has not proved itself in service yet.
There are a couple of aspects that seem critical.
1. Use the 'tunnel' as a casing for the new CAI filter. I managed to get around 50+sq.in of surface area for the UNI filter.It fits tightly in the tunnel. The filter foam is supported by a ramp shaped cage of 1/2" wire mesh.
A trapezoid shaped filter is attached to the back of the external louvers. I attached the custom cut foam with after-market radiator fan ties.
2. I did not use Lexan for the plate at the end of the tunnel like others did. Imho it is too heat sensitive. I used steel sheet instead. The hole was sized for a cut down4 " MAF adapter. I bolted this to the plate.SAndwiched between the aluminum Maf adapter and the steel plate is fine wire s/s mesh. I used a mesh size slightly smaller than stock.
3. Attached to the MAF adapter is a cut down, 4" to 3" 90 degree silicone adapter that .Space is tight so even a 3" MAF would need cutting down. I used the big 4" size because of flow disturbance around the 90 degree bend.
4. Connecting this 90 degree adapter to the OEM MAF tube is a challenge. The short version is that I made a 15 degree "S" bend from aluminum tube and it fits perfectly.I used a straight 3" silicone coupler to connect withe the OEM Maf+tube. I 'buried' a 3/4" air straightener in the coupler.
This complication could have been avoided by using thin-wall, spiral-wound ,wire-reinforced,flexible silicone hose. This is available on EBay from China cheaply. I hate buying technical things from such a source so struggled with aluminum instead. The big failure was trying to use the claimed 10+ degree bend capacity of hump hose. That 4 ply hose is far too stiff to bend in this situation.The thin wall silicone hose would be vulnerable to puncture/abrasion damage so I was leery of using it. Maybe with a heat shield ?
Porsche could have easily designed something like this and had a huge airbox between the inner/outer fender wall.Or just sacrifice the trunk for mechanicals!
But if you examine this aspect of the Audi R8 ,you see how they still have issues
Standard R8 Airbox breathes HOT Air!!
http://gallery.audiworld.com/albums/album234/R8070057_medium.jpg
The other item that would greatly improve this CAI is a 90 degree aluminum fitting like the T6 adapter flange.It is too small.I could not find a bigger alternative.It needs to be around 4"x6" - Cummins ?
http://new2.cxracing.com/image/cache/catalog/product/Cast-Pipe/EB-T6-300V-CAST/01-650x650.jpg

01-12-2017, 07:58 PM	#29
Gelbster Registered User Join Date: May 2014 Location: S.California Posts: 2,029	CAI that is actually cold,inexpensive,makes a cool sound and may work I completed my hack CAI project as mentioned above. A complete description would be too lengthy and anyway it has not proved itself in service yet. There are a couple of aspects that seem critical. 1. Use the 'tunnel' as a casing for the new CAI filter. I managed to get around 50+sq.in of surface area for the UNI filter.It fits tightly in the tunnel. The filter foam is supported by a ramp shaped cage of 1/2" wire mesh. A trapezoid shaped filter is attached to the back of the external louvers. I attached the custom cut foam with after-market radiator fan ties. 2. I did not use Lexan for the plate at the end of the tunnel like others did. Imho it is too heat sensitive. I used steel sheet instead. The hole was sized for a cut down4 " MAF adapter. I bolted this to the plate.SAndwiched between the aluminum Maf adapter and the steel plate is fine wire s/s mesh. I used a mesh size slightly smaller than stock. 3. Attached to the MAF adapter is a cut down, 4" to 3" 90 degree silicone adapter that .Space is tight so even a 3" MAF would need cutting down. I used the big 4" size because of flow disturbance around the 90 degree bend. 4. Connecting this 90 degree adapter to the OEM MAF tube is a challenge. The short version is that I made a 15 degree "S" bend from aluminum tube and it fits perfectly.I used a straight 3" silicone coupler to connect withe the OEM Maf+tube. I 'buried' a 3/4" air straightener in the coupler. This complication could have been avoided by using thin-wall, spiral-wound ,wire-reinforced,flexible silicone hose. This is available on EBay from China cheaply. I hate buying technical things from such a source so struggled with aluminum instead. The big failure was trying to use the claimed 10+ degree bend capacity of hump hose. That 4 ply hose is far too stiff to bend in this situation.The thin wall silicone hose would be vulnerable to puncture/abrasion damage so I was leery of using it. Maybe with a heat shield ? Porsche could have easily designed something like this and had a huge airbox between the inner/outer fender wall.Or just sacrifice the trunk for mechanicals! But if you examine this aspect of the Audi R8 ,you see how they still have issues Standard R8 Airbox breathes HOT Air!! http://gallery.audiworld.com/albums/album234/R8070057_medium.jpg The other item that would greatly improve this CAI is a 90 degree aluminum fitting like the T6 adapter flange.It is too small.I could not find a bigger alternative.It needs to be around 4"x6" - Cummins ? http://new2.cxracing.com/image/cache/catalog/product/Cast-Pipe/EB-T6-300V-CAST/01-650x650.jpg Last edited by Gelbster; 01-13-2017 at 08:53 AM.