Edit: Retract and delete statement after I realised I mis read your post.

Lengthening the tube will help reduce turbulence to the turbo's compressor wheel if you can keep it straight. This will up the efficiency of the compressor. To test turbos I think they use a straight pipe 8 diameters length before the inlet. This is not realistic for most cars. Some of the car companies are actually putting guide vanes in their tubes just be fore the turbo to reduce turbulence.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

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