Recommended Wastegate Size for Stage 2 274 ci

[eop002]

Curious on what is the recommended wastegate size for a 274 ci Stage 2, GN1R heads, Precision 70 turbo, etc.

I have the Precision 39mm yet to be installed and am concerned it may not have enough flow to provide proper
boost control. Considering potential upgrades on the turbo in the future, so want some room to grow on the
wastegate.

Thanks for your inputs.

 

[turbobitt]

I'm not familiar with that gate by I suspect you would be OK. I had an old ATR gate controling boost on my T-76 with no issues but was also running low boost levels and probably not running into back pressure problems. I would think that you would need to consider how much boost and backpressure you may run into with your turbo or future upgrades. For myself, I upgraded to the Turbonetics HP new Gen gate. I was able to control boost from 20 PSI base pressure to 35 PSI without CO2 but by backpressure was very low.

Allan G.

 

[Dusty Bradford]

The 39mm Precision should be able to do everything you need as long as it's properly positioned. I'm sure it flows as well as the Tial 44's.

It will control the 70mm. How big you need in the future depends on what size turbo you plan to upgrade to. If your looking at something 80mm or larger you may want to go ahead and swap it for the larger precision.

You don't look at a wastegate as how much power you plan to make. You have to look at how low you want to run the boost. If you need to control an 88mm down to 10psi you will need a pretty large gate. If a waste gate is to small you won't be able to control the boost down as far as you may like. For example I had a single 60mm on a 106mm turbo. Lowest boost I could get is 17psi. So as soon as I launch the boost would go to 17psi. I had to add a second wastegate to get it under 10psi.

 

[norbs]

A guru on the other board pointed me toward this calculator. Looks like mine 45MM on average for 850 BHP
BorgWarner MatchBot

 

[eop002]

I appreciate the inputs. Good information to consider. I am going to stay with the 39mm and how far it takes me.