7x10 vs. 5x12 - SAC @ 59LPM

[chrislib]

The 158(?!?) Denso 7x10`s in mine haze (at 158deg its no wonder), I found backing the timing off to about an 1/8 bump off the stock marks is cleanest. And I totally get the laydown feeling at higher boost #`s...if say I`m merging on the hiway they flat just do not pull as good as the PODS they replaced but around town they make good power and are relatively clean as long as I can keep it out of AFC control. Def stay away from Denso7x10`s I guess is my opinion...Wish I still had my o.e 6x9`s.

[RCCUMMINS89]

Update................

7x10s "have a tendency to haze, due to their larger sac volume" This is from my main builder. I was told that it is the most common injector to have hazing from his experience.

To be honest, the haze only bothers me when I'm up in the mountains and I can smell it all the time with the truck running.

[ellis93]

Is this the same guy that does the honing?

I refuse to believe it's because of the "sac volume",aren't the 5x12 sac too? Magical how the 5x12 "sac" nozzle does not haze from its larger sac volume.

[RCCUMMINS89]

Ellis........there is so much more to injector tips than sac or vco. Do you know how a SAC nozzle works? An enlarged sac volume leaves more fuel past the pintle/seat and therefore has more of an excess of non pressurized fuel after the injection event.

No, this is not the same guy.

[RCCUMMINS89]

You can be upset all you want about the 7 hole nozzle findings.

I have both found exactly what I already knew and have also learned some new things. What I have learned is actually how responsive they are. But what I already knew is just that...........what I already knew,

And that is 7 hole nozzles have a tendency to haze at an idle compared to other nozzles. What I have added above is the fact that it is more due to the design of the nozzle as opposed to the orifice count.

The loss on top end..........that is due to the hole count. The responsiveness down low, also due to the hole count.

[RCCUMMINS89]

aren't the 5x12 sac too? Magical how the 5x12 "sac" nozzle does not haze from its larger sac volume.

Who said that the 5x12 have an enlarged sac?

[ellis93]

Im not upset about anything ol buddy

I got the sac thought from the title.

I understand the fact of the smaller orifice multi hole injector losing steam upstairs,that's solely due to our pumps. The fact remains that they ARE a worthy injector for certain purposes,which contradicts some of your previous statements in previous treads.

Yes I have read what the voc and sac nozzles do and don't do from that injector tread smokem did on here,I can not say I understand all of it but some

Believe it or not the 7s I had,out of the box had no haze. It wasn't till I dicked up and pumped a butload of trashy fuel in my truck that I had problems.....also a change in climate (winter set in)

Bottom line.....thank you for trying to evaluate something new to you and attempting to change your opinion on something you where dead set against being a viable commodity.

[ellis93]

Just a thought.......do you think that pop psi would help or hurt their idle haze.

[RCCUMMINS89]

Really won't make much of a difference. I chose a slightly higher than normal pop pressure for this test already.


YES 7 HOLE INJECTORS HAVE THEIR PLACE. As all injectors do. I've never said anything against that.

HOWEVER, I fall victim to what looks like to most as a contradiction of advice that I give to people.

The reason for this is...........to properly match each and every set up for the customer one needs to take in an account of the hundred variables in a given set up.

What they tow or don't tow? what their tranny is, is it built? what stall? gear ratio? tire size? turbo? elevation? how much their truck weighs? Do they mind smoke? Haze? Fuel economy? What fuel pin? Where is their timing? How many miles on the truck? AFC tuning? Their want for proper tuning or just flop in and go? What are their long term goals?

Each and every one of the above questions can and will change the injector, turbo, on and on and on choice that best works for that person.



The reason you have 215 tips is because you chose those injectors and ask me if they would work.......I said yes.

For what you use on your truck, I would of recommended a 5x11 SAC style injector. They would of been cleaner than what you have, allowed you to use as much timing you have as without losing as much bottom end with going back to the 5 hole injectors and you would have gained even more mid to top end than you already gained.

[RCCUMMINS89]

Been upwards of mid 90s the last few days and they don't haze a lick.

A little bit of this haze might have something to do with my engine and most other 1st gens being such high mileage rigs.


I do have to be honest in the fact that I simply enjoy the way these injectors drive though. I can lug the dog crap out of this thing and it rolls on with no issues. I just have a hard time without the performance end.

[ellis93]

Now your getting to the part I loved about them,for pulling....you can't beat them. And really Eric,well.....for us mild guys, the roll out pretty good. I however have no experiences with them above 3k rpm

[ellis93]

[RCCUMMINS89]

LOL...........test is over, my big sticks are back in.

7x10s were sent off to be double checked.

[brandonmgreer]

these sound like an awesome injector for a lightly modified truck build for mileage... am i wrong? Pump tweaking, fuel pin, 2wd, 3.55, 5 speed, maybe an hx35 and 4" exhaust?

[RCCUMMINS89]

If you don't mind them hazing as bad as a set of competition injectors at an idle, they are pretty good.

I just recently put my 77 lpm sticks back in (just slightly larger than 5x16s) and they are cleaner at an idle.