Which wastegate to use?

[ezspooling]

Hey guys,

So I'm debating which wg I should should. I will be running the FP GT30, mild everyday tune 20-25psi, and tune at the track 30psi. Also I will have to wg on the collector of my manifold. So my question is will the tial 38mm MV-S be enough?

Anyone?

 

[turboglenn]

Yea, it will be fine... Actually it takes more wastegate to run lower boost than to run higher boost because you need to bypass more exhaust to keep the pressure lower as compared to keeping boost higher where you need that exhaust going through the turbine instead of out of the gate.

There was a rule i saw posted somewhere before and it was somethign like
Big turbo - low boost = big wastegate
big turbo-high boost =small wastegate

i forget the conditions that flip flopped the WG needs but put it this way..I have the oldschool 38mm tial on the manifold and it works perfect at 25-30psi, but on the faster spooling turbos like the BB 57 trim and the holset, i have boost spike issues with lower boost settings

The only time i feel the gate is not enough is when runnin the nitrous shot (90HP curretnly but had issues even at 50hp, but the 30hp shot was just fine) when the gas is on for the entire gear Imust set the boost controller much lower so it starts to open earlier or i'll not be able to hold it at under 30psi and have to let out. I think because of the placement on my setup (#1 runner) that enough gas cannotesacpe to keep things in check with the extra exhaust created by the nitrous

 

[ezspooling]

Yea, it will be fine... Actually it takes more wastegate to run lower boost than to run higher boost because you need to bypass more exhaust to keep the pressure lower as compared to keeping boost higher where you need that exhaust going through the turbine instead of out of the gate.

There was a rule i saw posted somewhere before and it was somethign like
Big turbo - low boost = big wastegate
big turbo-high boost =small wastegate

i forget the conditions that flip flopped the WG needs but put it this way..I have the oldschool 38mm tial on the manifold and it works perfect at 25-30psi, but on the faster spooling turbos like the BB 57 trim and the holset, i have boost spike issues with lower boost settings

The only time i feel the gate is not enough is when runnin the nitrous shot (90HP curretnly but had issues even at 50hp, but the 30hp shot was just fine) when the gas is on for the entire gear Imust set the boost controller much lower so it starts to open earlier or i'll not be able to hold it at under 30psi and have to let out. I think because of the placement on my setup (#1 runner) that enough gas cannotesacpe to keep things in check with the extra exhaust created by the nitrous

Good post! This was very helpful thanks turboglenn!