Andreas may disagree with me so I won't answer for him, but I do believe the same goes for larger IC pipes (that's what that BMW thread is about after all). From that thread:
It is about the restriction. Don't go bigger just for the sake of it. Even with my 3" thick intercooler I decided on 2.5" pipes and I think that was perfect for me and my goals. Even if 3" pipes would fit, I don't think it would have been a good idea. Not because of turbo lag or anything, but just because of the expense and trouble with fitting larger pipes.
As a general rule, I like to see and recommend charge pipes that are as large as the opening to the throttle body. That's a good rule of thumb I think. That means if your TB opening (not the plate inside) is 2.75" or what ever like ours are then around 2.5" - 3" charge pipes are appropriate. This applies to both "hot" and "cold" sides.
If the intercooler in/out is 2.25" then that is your major restriction right there. Assuming you are going to keep that intercooler, then it would be best if you kept 2.25" piping and make a good transition to the larger TB. You won't see any real gains going to 3" pipes if your intercooler has smaller in/outs. More than likely you will mess up the laminar flow with all the size changes.
2.5" piping tends to become a big restriction around 600HP. So 500-700HP people should consider the [3"] option. Less than 500HP and it's not worth it generally.
It is about the restriction. Don't go bigger just for the sake of it. Even with my 3" thick intercooler I decided on 2.5" pipes and I think that was perfect for me and my goals. Even if 3" pipes would fit, I don't think it would have been a good idea. Not because of turbo lag or anything, but just because of the expense and trouble with fitting larger pipes.
As a general rule, I like to see and recommend charge pipes that are as large as the opening to the throttle body. That's a good rule of thumb I think. That means if your TB opening (not the plate inside) is 2.75" or what ever like ours are then around 2.5" - 3" charge pipes are appropriate. This applies to both "hot" and "cold" sides.
Originally Posted by gtswrx
So the same goes for enlarging the intercooler pipes? No ill effects and better flow in the end?
Yes I do believe so.So the same goes for enlarging the intercooler pipes? No ill effects and better flow in the end?
If the intercooler in/out is 2.25" then that is your major restriction right there. Assuming you are going to keep that intercooler, then it would be best if you kept 2.25" piping and make a good transition to the larger TB. You won't see any real gains going to 3" pipes if your intercooler has smaller in/outs. More than likely you will mess up the laminar flow with all the size changes.