Tuning for 90hp injectors ?

[icem237]

What is the rule/s of thumb when it comes to tuning for larger injectors? Less duration? Lower timing? I had to have all of my injectors replaced and went ahead with I.I. 90hp models.

Now i know with stock fueling and turbo i cant make full use of these but still would like some pointers if anyone would be so kind?

Thanks in advance!

[DoghouseDiesel]

Your biggest adjustments are going to be in the duration, but it will be mostly in the lower end of the table to control the smoke in daily driving.

Once you put them in, just do some data logging and see where you normal day to day driving habits put you on the duration map. The best thing to do is use the runway highlighting feature and have the map open while the ScanTool is doing the data logging. This will let you see the areas you'll be adjusting...trust me, it makes it a lot easier.

90hp injectors are approx 40 - 45% over. This doesn't mean you'll be cutting duration by that %, but start with 10% at a time until the smoke tapers off under normal driving and acceleration. Once it gets to a haze, then adjust your timing values a bit.

You can also lower the rail pressure slightly in those same areas. Same pressure going through larger holes = more fuel delivered. 90's aren't so big that a slight decrease in pressure will bother anything. With my 160's, I have the rail pressure lowered slightly in the daily driving range, so I can extend the duration slightly. This seems to help quiet the motor too with less of an abrupt cylinder pressure rise.

There are a few ways you can do it, but ultimately you bought 90's for more power on top. Leave your upper RPM settings as they are and you'll be fine. Just dial back your daily driving settings to get rid of the smoke.

[AdamRRT]

That's good info man. Thanks for this thread.

[icem237]

Your biggest adjustments are going to be in the duration, but it will be mostly in the lower end of the table to control the smoke in daily driving.

Once you put them in, just do some data logging and see where you normal day to day driving habits put you on the duration map. The best thing to do is use the runway highlighting feature and have the map open while the ScanTool is doing the data logging. This will let you see the areas you'll be adjusting...trust me, it makes it a lot easier.

90hp injectors are approx 40 - 45% over. This doesn't mean you'll be cutting duration by that %, but start with 10% at a time until the smoke tapers off under normal driving and acceleration. Once it gets to a haze, then adjust your timing values a bit.

You can also lower the rail pressure slightly in those same areas. Same pressure going through larger holes = more fuel delivered. 90's aren't so big that a slight decrease in pressure will bother anything. With my 160's, I have the rail pressure lowered slightly in the daily driving range, so I can extend the duration slightly. This seems to help quiet the motor too with less of an abrupt cylinder pressure rise.

There are a few ways you can do it, but ultimately you bought 90's for more power on top. Leave your upper RPM settings as they are and you'll be fine. Just dial back your daily driving settings to get rid of the smoke.

Really appreciate the help!!! Makes perfect sense.... I thought it would be more complicated than that but again I was wrong lol....

[DoghouseDiesel]

It's not necesarrilly complicated, it's just time consuming dialing out the smoke.

Adjusting duration for smoke control is what takes me the longest. I try to use the duration tables to control it vs the limiters.

Timing.....no big deal.

Rail pressure....no big deal.

Duration is what takes the most time to adjust when you've increased injector size and need smoke control in a daily driver.

For example, in my truck, most of my daily driving is in the 30 - 70mm3 range and up to 110MPa on the rail pressure, that's where I focus on for smoke control. 70mm3 - 110mm3 is mostly passing / harder acceleration and anything above that I consider WOT anyways.

[icem237]

It's not necesarrilly complicated, it's just time consuming dialing out the smoke.

Adjusting duration for smoke control is what takes me the longest. I try to use the duration tables to control it vs the limiters.

Timing.....no big deal.

Rail pressure....no big deal.

Duration is what takes the most time to adjust when you've increased injector size and need smoke control in a daily driver.

For example, in my truck, most of my daily driving is in the 30 - 70mm3 range and up to 110MPa on the rail pressure, that's where I focus on for smoke control. 70mm3 - 110mm3 is mostly passing / harder acceleration and anything above that I consider WOT anyways.

Perfect info. Exactly what i was looking for. I mainly went the 90hp tip route because it gave me some room to grow without getting too wild. I like components i can build on, makes me feel like i get more for my money without having to spend a ton at one time.

I have a cam and E.D. 63/68/14 to put on thats just been laying around and now i have the injector to really make it work i think. Efi should really make it sing when i get the fuel system built up some.

[DoghouseDiesel]

You've got plenty of fuel right now.

A stock CP3 will support 90's up into the low to mid 600 hp range without issue.

The intank lift pump does an "okay" job of keeping at that point also.

Git after it.

[mstordahl]

Just to clarify, reducing the timing is what will help to reduce the low rpm smoke, correct? Thanks.

[FUBAR]

A stock CP3 will support 90's up into the low to mid 600 hp range without issue.

The intank lift pump does an "okay" job of keeping at that point also.

I'm in the same exact boat as Icem. The only difference being is I'm installing a mechanical lift pump that idles at 8-10 psi and relieved at 17psi WOT. I have enlarged the inlet/outlet on the gear rotor pump on back of the CP3, but that is all. Still on stock turbo right now too. I wonder if the mech lift pump will help keep the rail pressure up at all vs an electric or stock one??

Thanks,
Andrew

[DoghouseDiesel]

Just to clarify, reducing the timing is what will help to reduce the low rpm smoke, correct? Thanks.

A little over simplified, but yes.