Fuel Injector location, Duratec

[Drakman]

A quick call out to the brains trust here,

Is there any measurable improvement (HP, Torque or drivability) obtainable by moving the fuel injector location from the cylinder head to the ITB's with Jenvey ITB's in a Duratec 2 liter? 

 As an aside is there any difference in using extended injector tip injectors.  I currently have Bosch green giant injectors located in the cylinder head, i have been thinking about going to ITB located injectors so i have to change the injectors to a shorter version to clear the air filter and the Bosch 380 cc high impedance, 12 Ohm extended tip version has been recommended.

Is there any information/data, dyno results either way on this?

 

Cheers

Dave

[Colin_T]

Rule of thumb:

injectors positioned further back in the inlet tract produce more top end power with a loss of low end performance and drivability.

 

however, this is a rule of thumb. Personally I’ve back to back tested on some engines with an inner fuel rail and outer fuel rail on staged injection, overlaid the two graphs, one run on the inner bank, one on the outer bank and seen no difference. Other engines I have seen some differences. 

I think a lot of it comes down to injector design and spray pattern too, probably see more improvements if your injectors are poor design to start with and being further back gives more time for a horrible pencil jet type spray pattern to atomise with the incoming air charge, this was probably what was seen in the 90s… However most injectors nowadays are a much finer mist so atomise much better anyway so the likelihood of considerable gains is probably not what it once used to be. 

I never had any issues mapping ev6 green giants. Was a very common “go to” injector for most 4cyl stuff under 300bhp. Always lent themselves to good fuel control at low rpm too. And they are cheap! 
biggest issue I ever came across with these was fake copies! Only had it a few times but fake pico type injectors were everywhere ! Only buy injectors from trusted sources!! And ALWAYS get them flow tested prior to fitting. 
 

 

[Drakman]

Hi Colin,

Thank you very much for the information/comment.  I did once replace 4 hole injectors with 12 hole Ford Sierra injectors in a 4.7 litre Jeep and it seemed to improve the bottom end response, better atomisation i assumed.