Tuning for nitrous

SPEEDSHIFT

SPEEDSHIFT

New member
I am going to spray my 03 and plan to start with a .032 Jet and possibly work up from there depending on drive pressure. I am looking for tuning info for what timing I should be running with nitrous. I know some say timing isn't as important on a diesel like it is on a gas engine with nitrous.

Specs:
S467.7/83/90 T4
125hp injectors
Dual CP3s
stock long block
425 head studs
Hamilton Valve Train

60psi boost
?? Drive pressure
2700us
36* max timing @ 4000rpm
26k rail pressure
1900* EGTs
Smokes fairly heavy all the way down the track.
11.44 ET @ 119mph 1.70 60ft

I want to spray this truck into the 10s with nitrous and possibly a larger exhaust housing. Is there anything I can adjust in my tuning that will make the nitrous safer/more efficient/more power than what I am currently running?
:nos:


https://www.youtube.com/watch?v=oXdhSPBAeNw
 
Last edited:
Might pull a little timing in the lower rpm, but if you're not spraying till 3k+ I wouldn't do anything. Depending on how much that shot cleans things up, try a jump in pulse width.
 
Bodie, on some of the bigger power trucks that I've been tuning I run about 65% or more timing split above 34-3500rpm. At 4500rpm+ I've been up as high as 80% split. Have also been running a 6.7 rail sensor and bringing rail up to 29k psi. Now I must mention that this is only for dedicated race/pull trucks and that much rail is really hard on injector bodies, but I've seen pretty big jumps in power with going up to a 29k Rail.
This is also usually accompanied by a bigger injector, 200% and larger so I'm not running over 2200Us pulse. I would not run that high of a split with a 2700Us Pulse. 60-65% no problem, but above that and you're asking for trouble.
Bit of a Ramble to read all that but what I'm trying to get at is I think you can get a little more out of your tune.
 
Dom_c13b said:
Bodie, on some of the bigger power trucks that I've been tuning I run about 65% or more timing split above 34-3500rpm. At 4500rpm+ I've been up as high as 80% split. Have also been running a 6.7 rail sensor and bringing rail up to 29k psi. Now I must mention that this is only for dedicated race/pull trucks and that much rail is really hard on injector bodies, but I've seen pretty big jumps in power with going up to a 29k Rail.
This is also usually accompanied by a bigger injector, 200% and larger so I'm not running over 2200Us pulse. I would not run that high of a split with a 2700Us Pulse. 60-65% no problem, but above that and you're asking for trouble.
Bit of a Ramble to read all that but what I'm trying to get at is I think you can get a little more out of your tune.
Click to expand...

I appreciate the info! I drive this truck to the track most of the time, thats about all it ever sees of the street. I may try going up to 27k and see how it does. I really need to get my timing dialed in, since I added the dual pumps the truck has/had a few concerning issues.

I had a popping noise at about 2800-3200rpm which I assumed was way too much timing, like so bad the boost gauge would jump around as it popped. At first I thought I had blown and exhaust manifold gasket. I pulled 1-3* of timing in that area and it quit. I am not as hip with timing calculators as I need to be, so I need to get better with them.
 
That popping is coming from the pilot timing tables. At least in my experience with the 03 and early 04 trucks. I had a couple tunes for early trucks that I posted in the HPtuners forum, mostly in threads but you could look at the pilot timing that I've run in those tunes.
For the timing calculator I recommend just downloading efilive and using their calculator. You can than paste transpose the tables into hptuners.
I think that pretty much all of the tables I have in hptuners I built in efilive. I would say that most people that are tuning these trucks would say the same. The HPtuners tune tools just aren't up to the same caliber that efilive is at.
 
Dom_c13b said:
That popping is coming from the pilot timing tables. At least in my experience with the 03 and early 04 trucks. I had a couple tunes for early trucks that I posted in the HPtuners forum, mostly in threads but you could look at the pilot timing that I've run in those tunes.
For the timing calculator I recommend just downloading efilive and using their calculator. You can than paste transpose the tables into hptuners.
I think that pretty much all of the tables I have in hptuners I built in efilive. I would say that most people that are tuning these trucks would say the same. The HPtuners tune tools just aren't up to the same caliber that efilive is at.
Click to expand...

I have all my pilot fuel QTY tables zeroed out, wouldn't that shut it off?

I tried all that with EFI Live, and couldn't figure it out. I think I needed a tune to open to be able to get to the calculator. I couldn't find where to download a tune to use.

Heres a video of the popping I had from a while back. https://www.youtube.com/watch?v=_F7ol5K5Hf8
 
Last edited:
Only timing calc I've used is in Excel. Duramax though...

How much timing did you have in the problem areas? At 3krpm I'd say stay around the 25-28* range under full fuel.
 
JWhite said:
Only timing calc I've used is in Excel. Duramax though...

How much timing did you have in the problem areas? At 3krpm I'd say stay around the 25-28* range under full fuel.
Click to expand...

It had almost 33* at 3k. Now I believe it is around 30 at 3k.
 
What's your shift rpm again? If you wanted to clean it up on fuel only, start pulling a tad of mm3 above 3k but bump up the fuel pressure.
 
JWhite said:
What's your shift rpm again? If you wanted to clean it up on fuel only, start pulling a tad of mm3 above 3k but bump up the fuel pressure.
Click to expand...

I usually try to shift at 3700. I really dont care about smoke, just want more power. I have a 1.1 exhaust housing coming next week, hopefully that will help a couple things.
 
Last edited:
You must log in or register to reply here.
Back
Top