How and why is an rv275 injectors supposed to get better mileage than stock injectors?

It is my belief that bigger injectors allow you to utlize a different part of the ecm timing maps.

 

Here is the Static State Map, ( not changing rpm, tps, etc)   Y axis is rpm, X is how much fuel is being commanded.   Note how timing falls off as rpms come up in the 25 35 columns.    

 

 

So by using bigger injectors you need less duration to produce the same power to move down the road at a given speed.   Less duration means you are in a more advanced area of the map, and thus get more timing, which leads to better mpg.

18 minutes ago, Me78569 said:

It is my belief that bigger injectors allow you to utlize a different part of the ecm timing maps.

 

Here is the Static State Map, ( not changing rpm, tps, etc)   Y axis is rpm, X is how much fuel is being commanded.   Note how timing falls off as rpms come up in the 25 35 columns.    

 

 

So by using bigger injectors you need less duration to produce the same power to move down the road at a given speed.   Less duration means you are in a more advanced area of the map, and thus get more timing, which leads to better mpg.

Ok thank you ,that makes sense i get it.

I dont know about all of what @Me78569 has posted, but it works. Even the DAP 50's I have on now have maintained the mpg advantage.

simply put, the truck ecm calibration is made for stock injectors.  This means that at 55 mph you need ~ %30 throttle input, the above map is using that %30 input to see what timing to command.  

 

By adding 50 hp injectors you might only need %25 throttle to move down the road at the same 55 mph, thus putting you in a lower part of the above map, giving you more timing.  

11 hours ago, Me78569 said:

giving you more timing.  

I'm on board but still can't grasp the whole @Mopar1973Man reducing timing for better mpg

Has to do with the higher cetane values of winterized fuel.  Higher cetane numbers increases the fuel's ability to self-ignite, so for Mike's truck that seems to like slightly lower timing than mine, he reduces the timing to bring the combustion event back to his truck's liking.  If that makes any sense lol.

you gotta also remember,  Stock timing at 65 mph is ~12*, mike is running 17-18* so he is still well advanced vs the above map.

Don't know how true it is but someone once told me that they have a better spray pattern / atomization of the fuel too.. ?

Great, I don't even know how many holes are in the nozzles

7.

Thanks for your reply. 

Stock is 5?

Stock is 7.  12 valves have 5 hole injectors.

7.

 

I really doubt the atomize fuel better.  Bosch would use the same nozzle design on both.

Thank you for your knowledge I really appreciate your help...

Perry. 

They have a wider cone angle than stock. Why some complain about increased smoke with them. 

Update, tore into my Dodge today and changed out the stickers for the rv275 injectors today they installed Easley my first time , truck seems much peppier on the short drive i took im happy. 

 We will see how it does in the coming weeks hopefully I will get better mileage. 

Next I'll be installing a new vp44 and Fass titanium 95.

Oh I also adjusted the valves today.

On 2/13/2018 at 8:29 AM, Me78569 said:

you gotta also remember,  Stock timing at 65 mph is ~12*, mike is running 17-18* so he is still well advanced vs the above map.

 

As I flip-flop between stock (level 0) and Level 3 of the Quadzilla I see roughly about 2-3 degree advancement over stock fully warmed up. This could be upside down if the fuel temperature and the IAT colder. Then I'm about 2-3 degrees retard from the colder temperatures on the fuel and IAT. Temperature plays a role in tuning yet and have to be aware of your conditions, weather, etc. In the extreme cold I've seen stock as high as 21* just cruising at 55 MPH. But the fuel was barely 45*F and the intake was 48*F.

 

Being my overall engine load at 65 MPH is barely 18-20% it doesn't drop off like @Me78569 mentions. But you have to remember I'm a +75HP injector so it flowing more fuel for the stated engine load. I'm waiting for the summer fuel to kick back in. 

Edited February 19, 20187 yr by Mopar1973Man

My truck came with an old banks ottomind box. 

Kind of like myself going from Edge Comp to a Quadzilla it day and night difference in tuning. Technology has come a long ways for our truck since the release of the Banks Tuner. You might step over to the Quadzilla forum and take a peek.

 

https://mopar1973man.com/forum/174-quadzilla-power/

I definitely want to change this antique out it came on the truck when I bought it.