Pipes too large for the application or too long will cause turbo lag. More space to fill = turbo lag. Now, if you're at a power level that you need the added size then the power up top makes up for the increased lag down low but intentionally creating a system with pipes either too large to long isn't helping the situation. Get a good efficient intercooler, run alky injection or both and be done with it.
Also, most OEM intercoolers aren't as efficient as aftermarket intercoolers and welding two together will double the pressure drop across them. You can get quality intercoolers on eBay these days inexpensively and save all the effort of putting two together too. Just my two cents for what it's worth.
Also, most OEM intercoolers aren't as efficient as aftermarket intercoolers and welding two together will double the pressure drop across them. You can get quality intercoolers on eBay these days inexpensively and save all the effort of putting two together too. Just my two cents for what it's worth.