Question for the quad and injector experts. Im about to pull the trigger on some injectors. Looking at the dfi 7x12, 7x13 and 7x14. Will be installing a 64/68/12sxe next month. From what iv read there seems to be something to detuning a larger injector with the v2 tuning and having a better power band then a smaller injector running at its limit. Question is what is the largest injector a vp can support and what is the point of diminishing return or has this even been tried yet? i used search function but can find no answers. I think i read somewhere that 7x14 was all a sovp could support but cant seem to find it again. Wondering if a injector that larger can be detuned enough to run cleanly and have a better power band?

7 x.013 should outflow a VP.

And the rest of the story is yes you can tune things out like never before thanks to Nick  and his creation of v2 tuning.

I only have 75hp injectors and 62/67/12 and it's plenty for women I date. I hardly even use wiretap I'm scared of it 

8 hours ago, Me78569 said:

7 x.013 should outflow a VP.

 

I disagree. lol

Gotta go with 6 hole?  or just bigger than 7 x .013?  figure 7 x .013's should get you to 650, which is about where I see "most" fall off.

Most fall of or give up. There are some 7 holes that run very very well in a vp application. Most give up as they do not want a laggy all around driver due to turbos needed.

Are larger injectors meant mainly for the power band in higher rpms (2400-3200)? 

What do yall mean when you say fall off or give up? As in power falls off or the vp gives up or the owner gives up? I myself am not looking for a extreme high hp im looking to have the widest range of tuneability possible I guess is what im trying to accomplish. My logic is to have a injector that can flow as much as the vp but while still being able to detune with my quad to be streetable and be able to grow with the rest of the truck.

how much power do you want?   That's what defines the injectors and what tuning range you have. 

 

do you want 400? 500? 600?

I would say im shooting for 500ish.

then I would go with 7 x .012's that will get you to 500 in the meat of your powerband then use wiretap up top to hold power up while it revs out.

Are larger injectors meant mainly for the power band in higher rpms (2400-3200)?

 

SAC or VCO? Or is that based on the intended use of the truck.

Edited December 15, 20177 yr by gipperkid

sac or vco , dunno   Once @Carbur8tr gets his injectors in I will have a better idea if I like SAC or not

Oh and the question if larger injectors are meant more for revving out to the higher rpm ranger? Meaning if I don't rev past 2400 is there reason to go larger than a 150.

injector size doesn't have anything to do with revving out.   the sizing of injectors I think about is trying to get canbus to be %100 at WOT at 2200 rpm.   then you can use wiretap above that to hold fueling as revs increase.  

 

Canbus fueling is much easier to control than wiretap.   Wiretap is very handy once things are moving.

I see. So injector size in a sense, with the quad, does not matter because the quad can control the fuel.

you still want to match your fuel to your air.  

 

As you move right on the graph rpms are climbing

 

Here's what the oem fueling command % looks like at WOT, note how it peaks at 2k ish then starts to fall off note also that it peaks at ~%80

 

 

Now here is the Quadzilla tuning, note the canbus curve can be taken down at low rpms ( smoke control) then peak at %100 duration.  Also note how wiretap can fill the fueling lul after 2200 rpm.  

 

 

 

 

so you want your injectors to be big enough to get the turbo at the top of the  map when rpms are at peak torque and throttle is %100, with boost high.  

 

clear as mud?

Lol, Yes clear as mud. I will eventually gain knowledge about the quad. With your guidance! Lol. I understand about matching injectors with turbos.

16 minutes ago, gipperkid said:

Lol, Yes clear as mud. I will eventually gain knowledge about the quad. With your guidance! Lol. I understand about matching injectors with turbos.

Basic interpretation: injector size still matters but way less now that we have control over fueling which was something never seen up until the quad. 

 

Great example would be @Me78569 running 7x.012s right now on a somewhat "stock" sized turbo with little to no change in performance and smoke output.  The performance part is where he has room to grow though seeing as though he is not using the full potential of what fuel he has available, nor does he need to for that matter. 

 

Edited December 15, 20177 yr by Carbur8tr

1 minute ago, Carbur8tr said:

Basic interpretation: injector size still matters but way less now that we have control over fueling which was something never seen up until the quad. 

 

Great example would be @Me78569 running 7x.012s right now on a somewhat "stock" sized turbo with little to no change in performance and smoke output.  The performance part is where he has room to grow though seeing as though he is not using the full potential of what fuel has has available, nor does he need to for that matter. 

 

To add to this. Injector size matters when looking for power. Larger size means faster rate of injection.

 

For 500hp nothing more than a 7x.010 is needed. The caveat there is you are at the top end of the duration scale to get it. A larger injector can support it more easily.

 

Sac vs. vco. Cost. That is it until you get into the larger nozzle sizes. They trade back and forth but vco starts to out perform sac. 

Ok, so like this. Using 100% of a 7x.010 to get that 500hp, or using (just guessing here) 70% of a 7x.012 to still get the same 500hp, but have more room to grow.