Detroit 12.7 Injector Choice??

The 5915s are really good at keeping the egts down when you're working I hard.

 

Pm sent

 

Thread resurrection.
About to order a set. Shop is telling me there is no difference in the 7650 and 5915. Says they use same tip and flow same when they leave his bench.
Guess I'll go different from the crowd and get 7650s. Unless someone tells me different.
I'm running a 430/470 ddec 4 set to a hot 500. 171701 or tmf55 garret comparable can't remember p/n.
Appreciate any feedback.

 

There definitely is a difference between the two.

 

So I found a chart , "that I can't figure out how to post"
It says the 7650 Is a 9 hola D1 nozzle
5915 Is 8 hole b6 nozzle
7650 is a good step up then huh.

My 6977 are a b3 nozzle. Big step up

 

7650 is not a step up from 5915. 5915's flow 15% more. They're the standard injector to go with a 171702 turbo. With that setup you should get around 580 hp or so.

7650 (which I have) will produce the same or a bit less horsepower, but EGTs will climb faster in long pulls.

As far as MPG, I don't know which one is better.

 

All the reading I have done leads me to believe the 5915 injectors seem to yield the best mileage. That is the general consensus anyway.

 

The reason the 5915 seem to have better egts is because of the bigger nozzle. Fuel gets injected faster.

Smaller tip injector to get same power you need longer pulse width to get all the fuel in but that has negative effects with egts.

Piston is down further down the bore and injector is still spraying fuel.

Bigger tip gets same amount of fuel in but does it faster. Kinda like same effect as advanced timing.