To tune or not to tune

I put a turbo on my TD42 at 412 000k's. I am running 8psi boost and the fuel has been wound in 3/4 of a turn. It seems to run pretty good and i am not boostin all hell out of it so would it be worth the cash to get a professional tune or not?:1056:

Yeah bud with that much extra fuel you could sit on 12 psi and be quite happy with the result

Personally i'd prefer to tune it myself on the road.
Depends what you mean by a tune If they are just going to stick it on a dyno and adjust your fuel screw i see no point .
I'd spend the money on an egt.

Yeah I do my own but feel comfortable doing it. If you are comfortable doing it yourself then go for it. The only real thing you can gain from a dyno is getting your afr's right.

I would defiantly invest in a EGT gauge. Then you can kinda tune it your self. However getting it dyno tuned by a professional will make a big difference. When I got mine tuned it reduced turbo lag and came on to boos heaps smoother.

What else did they do though.
He is talking about a td42 standard pump with a turbo fitted.
What is your setup ? does it have a boost compensator did they change pump timing or anything else because just messing with a fuel screw and boost it is quite easily done without a dyno.

Nah i just put the turbo on myself and wound the fuel in till i got up to 8 psi boost. I installed and EGT guage and boost gauge but i don't have a tacho so i dunno what its really doing. It doesn't get hot, i think the max i have had is 450 up a long steep hill. It is still no rocket ship, in fact i was a bit dissapointed which is why i thought maybe it needs a proper dyno tune so they can check pump timing and fuel and what ever else. To my knowlegde the pump is stock. I guess my main concearn is i don't wanna blow it up, its not a new engine and i don't wanna be 1000k's from home and have it fail. Everyone always wants more power and after hopping out of my ss ute into the gq maybe i am expecting too much, it does go well but sometimes its surges and i think its not getting enough fuel through to the pump, i will fit a lift pump and see if it works, did the same on my last td42 and it worked a treat.

I have one of those low pressure electric fuel pumps on the side of the battery tray their are threaded bolt holes that line up perfectly.
Sounds like you need to wind the fuel up some more.
I run 14-15 psi peak boost in mine but that all depends on the fuel you will get a feel for it .
Is your egt before or after the turbo ?

yeah i think its a bit lean too, maye the injetors and pump are a bit tired. EGT is post turbo, i welded the fitting ringht into the dump pipe pretty close to the turbo. I have been told buy a diesel mechanic at work to just advance the timing a fly sh*t and not worry about a tune. 10-12psi would be great.

Have you adjusted the waste gate on the turbo that's what controls your boost..
And just wind the fuel screw in some more .
Basically more fuel more power then more boost will help it burn and bring the exhaust temp down.
you'll get to feeling for a balance between the two .
don't worry about fuel mixtures you won't lean it out and melt anything like a petrol engine.
If you over fuel a diesel it creates excess heat wich does damage that's what your egt is for.

I have the same turbo as you 97_gq_lwb and the only way i could see to adjust the gate as on the external thread. Is there a spring or something inside? I am not too familiar with turbos hence doing this for experience. I have worked with pressure relief valves before but they don't work like the wastegates.
I will wind the fuel up a little more and see what it does.
Is it nessesary to adjust the injector timing when running boost or only for more extreme applications?
I have been told the rig blows a teeny tiny amount of black smoke but i need to see it for myself.

Hey mate just grab yourself a boost tee and some rubber hose. Plumb the boost tee in where there small rubber line runs from your compressor to your wastegate, place in an easy to get at place and all good.

Is that for an external waste gate? i just have a cheap chinese turbo off ebay with the internal type setup. I wish i was at home to have a play with it but i won't be back for another month.
Well if i blow the TD42 i have a brand new bombed 355 stroker in the shed waiting to be put into something and some hair driers attached.

Ok your turbo has a threaded rod coming off the actuator.
How it works is that arm pulls tight closing off the wastegate as boost rises it pushes the arm out opening it up.
So by making that arm on the actuator shorter you are increasing your boost.
Does that make sense ?

yeah i'm with ya, i have it adjusted up so i am thinking i need more fuel for more boost.

I would say you need a fair bit more fuel mine was wound in before i even fitted the turbo then i wound it in even more .


I had to turn the idle screw back out a fair bit as well once i wound the fuel up.
Then adjust your aircon idle up to suit otherwise it will rev high with the aircon on.

But when i fitted the 3 inch exhaust i had to wind the actuator back out a fair bit as it was maxing out my 15 psi gauge.

i am in need of a complete new exhaust, i might get one sooner rather than later.

o fcourse to tune