Forum » Practical Diesel Tuning » bigger injector base tune

bigger injector base tune

Practical Diesel Tuning

Forum Posts

Courses

Blog

Tech Articles

Discussion and questions related to the course Practical Diesel Tuning

= Resolved threads

Page 1
Author
379 Views

hi,

a friend of mine is upgrading his injector to 70% oversize and i wanted to know do i just divide the whole table by 70% and change the injector coding in the ecu, as a start and 0 the timing tables including pilot injection? or can i use the stock timing table , and how does injector size effect fuel pressure?

thanks

What car/engine? What injectors? You can sometimed get the data you need from the injector manufacturer.

Fuel pressure should be targetted and controlled independently.

its toyota land cruiser 200series,

the injector is resized oem injector, we asked for the data but we didnt get any thing yet

I would start with the Factory timing and fuel pressure tables. You'll probably end up with more timing and fuel pressure on the low end to counteract the laziness of the larger injector. Starting from zero on the timing tables will make your job harder than it needs to be.

Do not change the entire pulse-width map just yet. Usually larger injectors only deliver their advertised outputs at medium-high load. Idle and light cruise output may be surprising close to stock. A data sheet is the only way to know for sure (or back into it with a wideband O2).

-Nick

i kept injector data stock, and timing, i just raised rail pressure based on egt, car runs and drive great relatively, the only issue is smoke when cruising or boost is lower than 16psi even when afr is leaner than 30 to 1 , not sure if i should remove some pilot injection or adjust timing/rail pressure.

the spool is really slow it hit full boost at 3200rpm instead of 2400rpm as stock, it has 2.75'' downpipe and 4'' muffler back maybe its too big?

I'm curious to know why the turbo spool has changed so drastically? Any info from Nick on this? Does the timing need to be retarded to put more heat in the manifold and get the turbo spinning?

Reading this topic regarding smoke @ low load. Maybe went a bit over the top with your injectors??? Get them tested see what return fuel dos on them and test the injector response time as well. Slow opening due to pressure imbalance on the nozzle and chance is even slower closing of the injector needle dos not give great performance.

On lo load how dos the engine sound? Flat Smooth or nocking?

the turbo we are using is "upgraded" its basically rebuilt turbo that handles more boost, but it's slower to spool.

right now, we have the VGT duty cycle at 88% during spool and 65% at wot.

The injector probably has not been properly tuned as I haven't found the best way to do it. I feel like I need to adjust the injection limit based on boost rather than maf, and we still haven't change the injectors ID in techstream.

another question is how can we do pop and bang tune and 2 steps on a diesel? is it the same concept as a gas engine? basically, retard the timing if so how far can we go

Like this https://www.youtube.com/watch?v=rnZDfK42S9k

Yes, is it just timing retard?

and also, on upshift, I remember that there was one time I did it accidentally when I was messing with the rev limiter hysteresis and injector pulse-width table

Here is a other one but more refined [url=https://www.youtube.com/watch?v=FjDSxSjrMxU]https://www.youtube.com/watch?v=FjDSxSjrMxU

We do 4 things. Cylinder cut to maintain very precise engine RPM. Retard injection and torque control on fuel and boost control that controls retard as well.

We have something that you could call a turbo kicker or ALS that keeps the turbo spinning on transient throttle action but we only use it on our rental ECU systems for motor sport only. These only pop and bang on a cold engine and do not work well under cold conditions.