Yesterday i spent a few hours trying to tune this VGT turbo and spool-up got worse and worse.
Finally I noticed that half of the engine compartment was sooted up along with the intake hose and inside the turbo... and came to the quick realization that it had a major exhaust leak on my home-build turbo adapter.
Today i finished mending the cracked welds and got it all bolted back up.
HOLY SPOOL-UP!!!!
Spools a touch faster than the stock HX35 and hits much, much, much harder.
The best explanation that I can come up with is it drives like a well tuned gasser V-8. TONS of throttle response! I pulled out of a gas station at idle and just as I was completing a right hand turn and almost straight I nailed it and whoosh instant spool and instantly sideways! Truck is a BLAST to drive right now. The only complaint is that it makes a pretty annoying whine/whistle because it's closed down so tight. I loosened up the housing and now there is no whine till about 1200 rpm. As soon as you get on it, the whine goes away because it only takes a little drive pressure to get the turbo into a higher flow less whistle flow.
This truck with an open 4.5" exhaust sounds like it has a supercharger mounted under the hood when I close down the housing pretty tight. When you nail it, the whoosh of air is unique to say the least.
For a daily driver, you could run the housing a little looser to get rid of the whistle at idle. I'm not running a filter or airbox and the passenger window is down full-time because it's hot here in the desert so it's as loud as can be on the Junker.
Tomorrow night is street legal midnight mayhem racing and I plan to make a few more passes in the Junker. My used 215 injectors came in the mail today but I won't have time to install them before the drags tomorrow night.
Truck feels like it picked up another 20-30 HP with this turbo even though the fueling is identical to my last time at the track. In fact, the weather is going to be about 20* warmer than last time so any improvement in MPH will reflect a significant increase in HP.