Ok so i pulled out the he351ve turbo that i had in the shop and was looking at how to make it work on my 93 6.5td. I basically have everything i need fabbed up besides a way to control the VGT vanes. I am running a tial mv-s external wastegate that is set for around 17psi. My question is how much backpressure can a 6.5 handle? i was planning on controlling the VGT vanes with just a simple spring set up so that the more backpressure the engine has the more it will open the vanes(if that makes sense). The problem is that i am worried that when the wastegate opens the VGT vanes will be part way open and then i will lose all my backpressure so the vgt vanes will close quickly and act like an exhaust brake and cause some kind of damage to my engine or the turbo.

So really wat i need to know is how much backpressure a 6.5 will handle, or how heavy the exhaust valve springs are?
Any ideas will be greatly appreciated.

 

only reliable and safe way to install a vgt, or vnt is to manually control the vanes via direct throttle linkage, remove the computer control, and use a linkage to the trottle, this way the vanes open and close based on engine output/demand. no need for a wastegate.