I’m wondering how noticeable the difference is between these two parts. Any thoughts?
One is green and the other isn’t.
Adi said:
One is green and the other isn’t.
Thanks for that groundbreaking observation! I’m sure this new knowledge will be critical as I reassemble my truck. You deserve an award 
. Many blessings to you!
You won’t actually see the difference, but that doesn’t mean it isn’t there. In fluid dynamics, a 90-degree elbow can reduce flow by about 13%.
Chao said:
You won’t actually see the difference, but that doesn’t mean it isn’t there. In fluid dynamics, a 90-degree elbow can reduce flow by about 13%.
[deleted]
Chao said:
You won’t actually see the difference, but that doesn’t mean it isn’t there. In fluid dynamics, a 90-degree elbow can reduce flow by about 13%.
[deleted]
We’re talking about a loss in fluid velocity here.
Chao said:
You won’t actually see the difference, but that doesn’t mean it isn’t there. In fluid dynamics, a 90-degree elbow can reduce flow by about 13%.
It’s all about that laminar flow.
Chao said:
You won’t actually see the difference, but that doesn’t mean it isn’t there. In fluid dynamics, a 90-degree elbow can reduce flow by about 13%.
That makes sense. I’ve been reading on Powerstroke forums that many people don’t notice much difference. But combined with my 3-inch ID charge pipe and new billet compressor wheel, I think it’ll help with EGTs and overall flow.
@Harper
A 13% difference is just that—13%. Whether it translates into noticeable torque gains is another matter. For a personal truck, I’d optimize. For a work truck, the 90-degree elbow is fine.
Chao said:
@Harper
A 13% difference is just that—13%. Whether it translates into noticeable torque gains is another matter. For a personal truck, I’d optimize. For a work truck, the 90-degree elbow is fine.
That 13% also depends on the fluid’s velocity.
@Blakely
And whether it’s a European or African elbow. Or if it’s carrying a load. 
@Harper
If the 90-degree elbow isn’t causing a bottleneck, replacing it won’t make much of a difference. It depends on where the restriction actually is.
A lot. The old 90-degree elbow restricts flow way more than the macaroni-shaped one.
Marley said:
A lot. The old 90-degree elbow restricts flow way more than the macaroni-shaped one.
Mmm… macaroni.
The green one is probably smoother inside, allowing for better airflow. The angle also reduces turbulence compared to a 90-degree stock pipe.
I’d go with the green one! Maybe in charcoal metallic gray, though.
Kim said:
I’d go with the green one! Maybe in charcoal metallic gray, though.
It matches my turbo perfectly!
I don’t think the elbow alone will make a huge difference. Restrictions like these are more critical for naturally aspirated engines than for turbocharged ones. Turbos can easily overcome small restrictions. You’ll see some improvement, but it’s probably negligible.
@Jesse
I agree. Turbo systems have inherent restrictions, and fixing one doesn’t change much. It’s the cumulative improvements that make a real difference. Don’t forget, airflow is also about density, not just volume. Good luck with your project!
The green one has slightly less restriction, but it’s not something you’ll feel while driving.