Installing some new injectors and wanted to double check some timing values with you guys.

 

Setup is in the title, current timing values for the tune I’ll use are...

 

max load timing offset - 2*

low psi timing reduct - 5*

timing reduct scaling - 50%

light throttle timing adv - 2*

light throttle load limit - 30%

 

I would be fairly conservative with the light throttle advance, since you don't have studs.  I know you're not going to be going 100% duration with lots of timing under 2k rpm, but still better to be safe and deal with slightly lower timing.

Edited June 9, 20187 yr by trreed

5 hours ago, notlimah said:

light throttle load limit - 30%

High you go up with the main timing values the more this can go down because engine load will be reduced. Like I'm at 20% light throttle load limit and cruise at 65 MPH at about 15-17%. Holding this number too high will cause efficiency problems. 

 

5 hours ago, notlimah said:

light throttle timing adv - 2*

This is all based on the max timing. I've been as high as 7* here. Now which base timing being pulled up this has to go down. 

 

18, 21, 24, 27 so now add +3 to that. 21, 24, 27, 30 is my cruise timing. Since my max is 27 the cruise timing ends shortly after 2k on the tach and forced back to performance timing values. 27* is about all mine can do with bucking.

Edited June 9, 20187 yr by Mopar1973Man

So what would be a conservative number for light throttle adv?

Not the way to look at it. It more what do you want for a target timing value during cruise? This should be based more on engine load and EGTs. As you get closer to optimal timing the EGT and engine load will fall. The amount to give is more on the experiment and see side.

I don’t really care about cruise timing. More about what would be the best way to keep my timing numbers conservative.

 

Current timing is set at 16/19/23/27/29

Ok another way to look at it. Set the Quadzilla for Level 0 and monitor your timing. Now build a timing setup which is plus 1 or plus 2 over stock.

 

Not exactly a good way to look it being stock has a nasty retard hole in the middle of the map.

 

I'd rather base it off engine load and EGT then you know you got efficiency on you side.

I agree with mike.  Watch OEM then fill the hole

So you guys think the current timing curve I have it set too is no good? 

I think it's fine.  We have a lot of room to mess with before a curve gets "bad"

Ok, I’ll run it as is and see how it goes. Not trying to get it super fined tunes as studs and a new turbo are hopefully coming soon. Either way just looking for a conservative starting point being I’m studless with large injectors and stock turbo. 

Look at it this way. The Stock ECM tune can use the full range of the VP44 timing already. It's just when does it occur. All we are doing is dictating when and where the timing occurs. So the VP44 is capable of 30 degrees of timing and stock can touchh the 30 degrees but I'm going to assume its way up the RPM range. 

 

I'm more focused on the timing where I do the most driving, So the 1,500 and 2,000 RPM band is where I spend the most time. So those two ranges are the most important to me. Now as for the 2,500 and 3,000 I look at those for passing power but I might use those ranges only 1% of the time. 

 

Give you a feel. (7 x 0.0085) Injectors... No studs, HX35/40 hybrid 60/60/12...

 

18, 21, 24, 27, 27 (Timing max)

 

Max load offset 3*

Low PSI Timing reduct 5*

Timing  reduct Scaling 50%

Light Throttle Timing Adv 3*

Light Throttle Load 20%

 

Edited June 9, 20187 yr by Mopar1973Man

Ok got the injectors in and went for a test drive. 

 

Has a weird sound at idle when cold but it was the inital start up so we’ll see if it comes back. 

 

Dropping into reverse and then drive when cold almost kills the engine. 

 

Decent amount of white smoke for first 250ft when cold, never again.

 

Has a slight stumble when the pedal is first pushed. Almost like it hesitates then goes fine once more throttle input is there.

 

Otherwise she ran fine. Valve lash quieted things up a little I think and EGTs were fairly manageable, peaked at 1450 around 33-34lbs of boost on a pretty steep incline at 3/4 throttle.

 

Any advice on tuning out the early tps stumble?

More fuel.  Use valet mode to figure out how much fuel you need at 0 psi.

Then use level 2 to build your defuel range. 

2 hours ago, Me78569 said:

More fuel.  Use valet mode to figure out how much fuel you need at 0 psi.

 

So my fuel from 0-5 is 68/68/69/70/71/72.

 

Would it be ok if I tried a flat fuel curve from 0-5 like all 72?

use valet mode to figure out how much fuel you need. 

Ok, I can do that but I’m already on the verge of being really smokey throughout the rest of the tune. WOT I have a black haze of smoke constantly. Seems like my only issue is down low so I don’t want to mess up the upper end of the fuel curve when the bottom is what needs to attention. 

 

Am I approaching that wrong?? 

Basically what @Me78569 is getting at for building fuel curves. This is how you would break it down into smaller chunks and clean up each piece of the fuel map.

 

Start with level 1 set your valet mode power till you get the smoke tuned out. Now that is going to be your start power %.

 

Now step up to Level 2 and now build your curve till you make your starting point to 100% fuel clean. If you need to clean up more push your 100% point higher in the boost range.

 

Now Step up to level 3 and build from the 100% to the max you can handle without smoking heavy for the rest of the span.

 

Now step up to level 4 or higher and build your wiretap level. With as big as your injectors are I really wonder if wiretap will be even needed.

Well went on a tuning drive. Not sure the truck is going to run like I want with this big of injectors and stock turbo. Maybe having the stockers rebuilt and putting those back in until I can get a bigger turbo.

What did the tune end up as and what is the truck doing?