I'm about to install an external Tial MVS wastegate on my twins and I had a question about choosing the correct spring rate. I run about 21psi so I was looking into getting the 1.1bar (15.85psi) spring for the wastegate. After reading on some other forums it seems like people are getting higher base pressures then what the spring is supposed to allow. Question is, should I go down in spring pressure or should I be fine with the 1.1bar spring to run 21psi?

Also, before anyone interjects, I know this is the single turbo section but I figured you guys would have a better understanding of external wastegate's then the other forums. Another point is that I know most people say you can't install an external wastegate on the twins, but I found a way that doesn't involve an aftermarket manifold. I plan to post a write up when it's all done.

 

i have the mvr wastegate. i get about 2-3psi over what is listed on there site. if you want to run a lowest 16psi go with the 13psi setup. that is was i do, great wastegate other than that issue.

 

not sure if its creep on mine but im runnin off a combo 14psi spring but seeing a bit over 16..

 

Seems normal...there is going to be some tolerances when the gates opens up depending on certain set-ups. I can live with a tolerance of 3psi or so...

Did anyone attempted to route cooling lines to their Mv-R's?

 

im running dual mvs with a spring combo for 1.0 bar and i dont see it past 15 psi.

 

I'll be routing coolant lines to mine. I plan to tee into the coolant feed and return lines going to the twins and run -4 line's to the wastegate.

 

How you running an external gate on your twins?

Nevermind, I didnt read the last part of your post

 

It's by no means an easy task and requires heavy modification to the exhaust manifold and turbine housings. Custom pieces also need to be made. If my goal wasn't to push the twins to the absolute limit I wouldn't waste my time doing this. The goal of this is to reduce backpressure in the manifold and increase flow to the turbine housings.