Ok, my truck has an internal wastegate. For better overboost protection, i’d like to install an external wastegate. I figure i can weld a T and flange onto the downpipe, and put one on. My only concern is i dont want to buy too small of a wastegate, or too large. how do i determine what size WG i should buy?
I would not mess with it at all… I would just get a boost controller. For an external wastegate you are going to need to weld a fitting on the exhaust manifold and not the downpipe. Plus you are going to have to take apart the exhaust housing from the stock turbo and weld up the hole for the internal gate. I would say leave your setup alone and if you want to get an external gate, just order a bigger turbo thats setup for an external gate. I run a 60mm HKS Pro Gate on my turbo setup and it controlls boost rock solid. A good external boost controller can protect you from overboost now, and can still be used later if you really modify the truck, just my opnion.