M TDI with M vnt turbo / MPG

[snakemaster]

going to put a M vnt 20 on the golf at some point M TDI  , just wondring about MPG what psi should a vnt run at 2000 rpm 5th 60mph 950kg , flat road not on load just croozing , and having higher air psi will this bring down  my MPG at 2000 rpm at 60 mph

[8v-of-fury]

What are you going to be running for Vane control??

If manual, it should have the vanes fully open for 2000 rpm cruising as you will have barely any pedal on at all.

Boost should be minimal if at all.

[snakemaster]

manual set up 2 psi ,i was thinking , but what if i was running 9 psi would that give me less MPG = 2 psi

[8v-of-fury]

I have no personal experience on the matter, but I have read accounts of higher cruising boost being more efficient. I run a k03 right now, and my trans causes me to cruise 100 km/h at 2550 so you know I am cruising with at least more than 5psi easily.

I do not have a boost gauge but I would like to get one very shortly lol.

[410]

I found that with the vnt's, the less boost the better for mpg as long as you're not seeing any smoke.  I think 2-4 psi cruising on level ground is perfect.  I tried a vnt with a direct connection to the vanes in the cab and it actually feels like the engine is being held back the more you close the vanes. 

[libbydiesel]

Definitely the best economy is from the least boost and vanes as open as possible for the demand for power.  Set up the injection pump so that there is just under the smoke threshold so that there is no smoke off or on boost at less than full pedal.  Then close the vanes proportional to pedal position.  The amount of boost is will then be determined by the load.  The boost/fuel will find it's own equilibrium. 

[R.O.R-2.0]

What are you going to be running for Vane control??

If manual, it should have the vanes fully open for 2000 rpm cruising as you will have barely any pedal on at all.

Boost should be minimal if at all.

a VNT 20 has almost NO restriction with the vanes closed, until closer to 3k rpms..

a VNT20 is NOTHING like a vnt15, in terms of restrictions, and how far open you need to run the vanes..
my vanes are limited, so they CANT open 100%.. if they open 100%, its just like not having a turbo..

a VNT20 with the vanes open, wil not make ANY boost till 5000 revs.. a VNT15 with the vanes open, will still make 20+psi, and will still spool before 2500..

i dont think that its nearly as important to have the vanes open while cruising on a VNT20, as it is a VNT15..

(i run one of these turbos, i know EXACTLY how they perform)

[libbydiesel]

He's installing on a 1.9 which has considerably more exhaust flow than your 1.6TD.  A VNT 20 should be decent.  FWIW, I will be installing an GT1852V onto an ALH before too long.  I think it will be perfect for what I want.  It is one of the two parallel turbos from a V10 Touareg. 

[snakemaster]

good info its nice to no that diffrant vnt turbos like to be run ,  i have a kkk vnt same as the vnt15 , and a vnt 1749v , and a vnt 20 ,

 i run a gt 15 ,on a flat road steady 6 to 7psi in my van t4 1.9 MTDI 1700kg  with 45mpg  would i see more MPG with a vnt 1749 mec control set up , rather than a gt15 normal wast gate  , i feel the gt15 not big enuff for my t4 van , but sound on my golf .