NNBS Tahoe wastegate sizing
 

Hey guys, I'm trying to figure out what would be the best wastegate size for my set up. It's an fully built ( forged pistons and rods) all aluminum 5.3 Bored .20 over accompanied by a MP T76 Q trim with a .96 AR. I'm running a 3" down pipe that enlarges to 4" and its going through a Corsa 4" diesel muffler. I would will be pushing 16-20 lbs daily driven with the option of turning it down to 12lbs at minimum. I have already ordered a JGS 50mm BOV and I inquired about their wastegates and the gentleman pretty much told me that the 50mm would be to much for the 5.3 and I should go with the 40mm so what are you guys running and what do you recommend? Other post I've search are mainly for people on stock bottom ends and only want 10-12 psi max. Thank you

The more boost you run, the less wg you need. I would agree with him, a JGS 40mm will get the job done on your setup, but at the same time, a 50 won't hurt anything either

I'm running a Tial 44mm MVR. I have no problem keeping the boost between 5-10psi. Like KB mentioned earlier, the more boost you run the less WG you need, so I would think even a 38-40mm would be more than fine.

Thank you, is there a such thing as too much wastegate?

Yeah, this should help.

Big turbo/low boost = bigger wastegate
Big turbo/high Boost = smaller wastegate
Small turbo/high boost = smaller wastegate
Small turbo/low boost = bigger wastegate

I would do the 50mm. Better to have too much than not enough.

Agree with Atomic.
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Just do the 50. easy to add boost then take away.

Ok thanks guys, I'm pointing towards the 50mm. What is considered a large turbo? I've seen that scale once before on this forum.

I would say the 80mm and up sizes would be considered the larger range.