Soo... I just switched out my turbo for an aftermarket holset (looks about 1.5x the size of stock holset) the truck I took it off of was boosting 40+ psi nice and quick. Has some side to side shaft play but not excessive. I was getting around 20 psi on my old turbo. I guess my question is: is it possible that the truck can't spool the turbo because it's so big? Tried shortening waste gate, crimping off boost line and checked for boost leaks (it was working fine before the swap so I don't understand why I don't have any boost). My fuel pressure is steady at 16psi wot and egt seem about 200 degrees hotter then normal. about 2x the amount of black smoke as normal, using edge ez chip for now.

 

put your stock turbo back on. you don't have near enough mods to spool a larger turbo than stock.

if you want to spool an HX40 turbo which i'm assuming is what you got, that edge ez isn't going to do it. you need at least 125hp injectors and a real fueling box like an edge comp, tst comp, or quadzilla adrenaline.


btw with a boost elbow and a fueling box, you can spool your stock turbo to 35psi safely...

 

K, so fuel regualts boost somehow? Sorry I'm kinda new to diesels. Sounds good, I'll just throw my stock turbo back on.

 

A larger turbo requires more exhaust energy to spin it. More exhaust energy is the result of more fueling, either injectors or a box or both.

 

If i just leave this trubo on and put on a edge juiced with attatude, with bigger injectors the turbo will spool properly? I've got the chip and larger injectors sitting In a parts truck. With this set up is my truck going to get decent fuel economy (I realize it won't be stock but I just wanna make sure im not going through 100l in 200kms lol) and is the truck going to be a reliable daily driver/ okay for towing?

 

correct. it takes heat and pressure to cause a turbine to spin. more heat and more pressure = more spin = more boost.

you need engine load and lots of fuel to spin a big turbo.

take my setup for example...I have no problems getting my small turbo to spool up with just my injectors. my large turbo on injectors only will only push about 10-15psi. soon as I turn my fueling box up to push another 160hp worth of fuel, it quickly pushes 35-36psi which is quite a bit of air coming from a S475. compounded with the S357 it makes 65psi total boost.


but you can see from my mods I'm pushing quite a bit of fuel.

my adrenaline by itself does ~160hp over stock (I dyno proved this myself)
my 7x.010 injectors do ~150-160hp gain over stock.

for the turbo you have, 7x.009 injectors oughta spool it up good. just make sure you have gauges, good lift pump, and probably will still want a good fueling box like i mentioned above. head studs would also be a good idea. I popped a head gasket with a stock turbo running 35psi (I was running 10* over stock timing though)

head studs will help prevent losing a head gasket with higher boost levels..

also do you have a manual or auto trans? if auto you better build it first before you start adding power to the truck..if manual, upgrade the clutch and you should be fine.

 

I get 15mpg with my setup. my injectors need to be pop tested as they haze at idle and smoke like a coal train, so I'm definitely losing fuel economy there.

yours might lag a bit with a HX40..they arent the quickest spooling turbo's. you can run it with the extra fuel, but it will be a bit of a pig till it spools. economy all depends on turbo lag, injectors, timing, and driving habits..

light throttle with good injectors and a turbo that can spool quick and easy will get great fuel economy.

lead food + laggy pig turbo + crap injectors (like mine) = bad fuel economy.

best bang for the buck turbo for you would probably be a HE351VE with a fleece controller. its a variable geometry turbo that will spool quick and change pitch at higher speeds to keep pushing higher boost without overheating. amazing technology in those turbos. wish I had one for a secondary...

as for towing, depends on how fast that turbo will spool with the setup.

 

Wow thanks so much for the info! What would you guys recommend for 'good' injectors? Are they pretty easy to do? Do you need any special tools? If I'm staying under 35 psi would I be better off installing stock turbo again and then just getting injectors and installing the chip?

I have a 'built' auto trans. The guy that had it before me put about 4000 bucks into it last year upgrading everything but, he just put in a new oem torque converter *face palm* so I'll be putting in a tripple disk ASAP.

I have a fass 150gph lift pump installed and am steady at 16 psi wot and 18idle

 

soooo.... edge juice with attatude (lvl 5) and 125hp injectors later, stuck at 23psi with this turbo. Still seems to spool slow, but 0 black smoke at full boost and only 1000 degrees on the pre turbo pyro. boost leak? i've checked multiple times... help?

for those that dont wanna re read a form: 98.5 cummins, fass 150, gauges, clutch, 4" exhaust and intake.

 

what turbo are you running?! find out the size of the compressor, the turbine, and the housing....