I am planning on getting an FPred BB turbo. Which option should I go with the internal or get a MVR Tial 44mm wastegate?

Also picking up gsc s2 cams with GSC Power-Division Beehive Valve Springs w/ Titanium Retainers, pretty excited.

 

The MHI housing works fine with an internal gate. That's the route you should go.

 

Regardless of turbo, I will always recommend internal wastegate . Yes, external dumps may give you more power but the noise is absolutely not worth it to me.

 

He's referring to the actual gate itself. Not whether it dyno's or is recirculated. You can have an external dump or have it recirculated with both an internal and an external wastegate.

 

I should be able to control boost fine with the internal one, right? I wanna make 500-550whp with the red bb. Thats the only argument I have heard for the external wastegate.

 

My car and Abacus's car both make 600+ on the internal gate. It's not the power number that matters. It's that sometimes the internal gate has a limit to how little boost it will run. Like mine won't make less than 25psi. I need to do some porting if I want to run less boost.

 

Here we use a general rule of when an internal wastegate is used or an external is necessary, depending of the application. For 25 or up to 30psi we try to use internal wastegates for many reasons. First of all, ease of use, space, costs etc. But eventually if you are going to run 35psi I think external wastegate would be more appropriate. If you hate the sound of dumping exhaust gasses, consider plumbing the gate back to the downpipe. Also I do not know yet about the external, but the internal wastegates tend to lose their holding power through time... I had a Forge internal and my friend a turbosmart and after around 1 year, the springs become too soft to hold the pressure as the rpm goes up. Last week we road tuned my friend's car and as it was boosting to 26psi, it could not hold more than 21psi at higher rpms and it was not responding to the solenoid valve

 

Wait for FP to offer their UHF turbine wheel on the MHI housing. It will give up a little spool (but not as much as their SS housing) and should gain you plenty up top that is closer to their SS version

 

Internal wastegate actuators use the same spring and diaphragm design as an external gate.

My car runs 38psi no problem with an internal gate

 

Does it holds pressure until limiter?

 

That depends on turbo size, not type of WG

 

No but it has nothing to with the internal gate. Turbo is just maxed out.