2.2 Dimma Hdi

[zx_volcane]

For a vnt though, it should still spool really well

You wont need more psi with the GTB!!! More efficient, so you will need less and have more air, cooler too as a result.

Although, still, that VNT should spool quicker

Errrm, yeah cause I run my GTB at only 4si

You still need pressure, to increase air density and oxygen content yah?

Sounds good

I would have a look into being able to use a full electronic actuator...like on the gtb turbos

How? Unless you plan to rip apart the ecu and solder some more circuit in there - its designed to control a solenoid, which its doing a grand job of.

and for what gain? With the right maps, vac solenoid is just fine, ask about a million VW owners if their vnts run ok.



electronic actuators are useful for manufactures as you can be a bit more precise about your vane position, no more stop screws + actuator position feedback for error state detection, not having to rely on a vac system ..etc


I ran my gt2256v at 30psi - and don't think it was the underlying cause of any turbo failures, more to do with boost hoses pushing the comp housing. If you've got an emp gauge you'll soon see when it starts getting unhappy.

Not much you can do about spike issues, like you've already tried its a compromise becasue boost is building load dependant, and presumably you've only got quite simple mapping that can't account for this. Exactly the reason my vnt looked laggy on the dyno, as it was setup to react for the load you get in 3rd gear upwards on the road.


full boost by 2.8k is not to be sniffed at, it'll be moving a large amount of air before then - can't remember what mine was boosting at, but was about the same.

plus you'll be running far less emp on spool which your turbo will thankyou for, and as already mentioned saving a stupid burst of torque coming in and killing everything.

you can setup a gt2256v to spool so fast, the head will surge before you build target boost - and choke up -sounds like you've been there, can't reach target boost in 1st or 2nd

I'm not a fan of winding the stop screw in for epic spool - you get a fat ton of emp at the same time - im more of a mass airflow boy, than an all out psi kid.

my gtb2260vk isn't in full chat until about 2.7k either - but by god does it move

yeah a gt20** will spool up very early - have you seen the size of their toy turbines, then it'll choke up just as you really start to get going.