Injector questions

[Jeepmedic]

Quick question for you injector experts.

If I have read it correctly the “stock” 2002 Dodge truck 24v engine is rated at 235hp and the injectors are 7 x .0079?

I have a “stock” industrial 2002 24v engine rated at 260hp and I pulled out 6 x .008 injectors.

Can somebody explain to me how the “stock” Dodge truck engine makes less horsepower with larger injectors than the industrial engine does?

Edited April 25, 2020 by Jeepmedic

[Me78569]

Tuning.

[Jeepmedic]

The industrial engine is as it left from the factory. No tuners have been added, unless you are saying the factory computer has been tweaked.

Edited April 26, 2020 by Jeepmedic

[dripley]

Just tuned differently for the application. The truck engines have to meet diffrrent standards for the highway.

[Me78569]

Factory tuning is just more aggressive.

[Haggar]

Jeep,

 

Automobiles (on road vehicles) had to meet different EPA standards than off road vehicles or Tier 1 compliance.  So you could tune completely differently.  I don't remember how cam profile effects these numbers but I am sure that was used to make output changes also.

 

Here are the numbers for Tier 1  "Light heavy duty onroad vehicles"

 

Here is the table for off road engine tier 1

[Mopar1973Man]

On 4/25/2020 at 3:54 PM, Me78569 said:

Tuning.

 

Then there is timing and fuel maps. The stock ECM tuning is designed around stock 235 HP (245 HP HO) injectors and its duration. Now with larger injectors the duration is shorten and then depending on pop pressure it can be late, like myself I'm running 320 bar pop pressure so I'm tad late in timing. Then looking at the Quad stock timing drop out really quick and could be rather low with engine loads over 20%. Then there is a another factor is tuning to your current fuel. Up here it can be above 50 cetane most of the winter and need to retard timing a bit. Now summer fuel is hear I been increasing timing and gaining back MPG.

[Jeepmedic]

The engine is in a medium duty truck so I am note sure where the epa standards would fall between the light truck and offroad rigs. The OBDII system does not communicate with the Medium duty truck ECM protocols.

[Mopar1973Man]

Still in all the fuel and timing maps are going to be EPA regulated even for medium duty for that model year. Even less ability to run a tuner or anything that will customize those fuel and timing maps. Like the Dodge/Cummins ECMs at least you can buy a tuner (Quadzilla, Smarty, Edge, etc.) and make the timing and fuel maps better fit for what you have for parts.

 

[Jeepmedic]

Yes, I found that out when trying to find a programmer for it. The only thing that I have found that the salesman claims will work is the quadzilla xzt.

[dieselautopower]

Injectors for that ESN are 

0432193649  nozzle is a VCO 7 hole .00767  DSLA153P797   0433 175 197 

 

Its really close to stock nozzles size.  FYI RV275 nozle is 7x .00807 and flow about 1.6LPM

 

 

 

[Jeepmedic]

On 4/30/2020 at 7:17 AM, dieselautopower said:

Injectors for that ESN are 

0432193649  nozzle is a VCO 7 hole .00767  DSLA153P797   0433 175 197 

 

Its really close to stock nozzles size.  FYI RV275 nozle is 7x .00807 and flow about 1.6LPM

 

 

Well, that's really interesting. You have the correct part number on the injectors but the guy I took them to at the injector shop told me the injectors were rated at 250hp and were 6 x .008 injectors.

Before I knew what they were I got a set of VCO 7 x .008 to replace them. Figuring out they weren't much of an upgrade from what I had,  I opted for a set of 7 x .0085 and hoping I won't have too much smoke or heat issues with it as a tow rig.

Edited May 3, 2020 by Jeepmedic

[dieselautopower]

I'd bet a nickel that he just missed a hole when he counted.  Many shops dont have equipment in smaller than .0005 increments for hole size.  Metric gauges can offer greater sizing accuracy.