160/100 vs 205/30 Injector Testing

[KCTurbos]

We did a little more 7.3 injector testing on Zac Bolen's truck... Results were a little surprising.

Truck is a 1999 F250 7.3 with irate t4 BASB turbo. 17 degree hpop. It is a dedicated tow rig that hauls heavy loads all over the country. Upwards of 30k lbs going up big grades in elevation.

He was running FF 160/100s, made good power, towed well, but struggled a little with egts while towing heavy and had an issue where it would run into icp/oil issues while towing really heavy at 3/4 throttle going up really long grades... we are pretty sure it was sucking the hpop oil reservoir dry. Very oil hungry injectors. Even on a 3.6ms tune ICP would drop to about 2700psi.

He decided to try some FF 205/30 hybrids injectors. Truck runs WAY cleaner, cooler, much easier to tow with, no more issues with sucking the oil reservoir dry. Very linear power band. EGTs are down 150-200 all across the board while towing and gained MPG. Holds a ROCK SOLID 3200icp at WOT. BUT... lost a little "oomph" down low under low throttle conditions, and top end power is down a little.

On the dyno the 205/30 brought on the power sooner, made more peak tq tq, ran cleaner, and made the same HP as the 160/100 up until 2500rpms where the power fell flat on the 205/30 and kept climbing with the 160/100... even though ICP was dropping like a rock with the 160/100s

So... why does it run so much cooler/cleaner and bring on the tq sooner? Smaller nozzles or hybrids? When we tested 180/30 vs 205/30, the 180/30 brought the power on sooner, not the hybrid. So I am going to say it is the smaller nozzle. Which makes sense because the smaller nozzle is known for better atomization and will spray the fuel farther into the stroke which increases tq.

Next on the list.... 238/80s... it will be interesting to see how they all compare.

Full Force Diesel Performance Inc.

 

[cjfarm111]

Interesting

 

[psduser1]

Nice numbers!
Makes me want to make the jump to a t4. Is that a sxe turbo, or the older style?
Never mind, just went over to the other thread, lol.

 

[cjfarm111]

Who’s tunes?

 

[Dan V]

Is there some sort of restrictor or diverter that limits how fast the LPOP can fill the HPOP reservoir?

 

[KCTurbos]

Who’s tunes?

SDK and ******** tunes

 

[KCTurbos]

Is there some sort of restrictor or diverter that limits how fast the LPOP can fill the HPOP reservoir?

That is a good question. I know they make a bigger reservoir for it that helps.

But overall these 205/30s are better in every way (minus the 20hp on the top end)

 

[jbolen323]

Is there some sort of restrictor or diverter that limits how fast the LPOP can fill the HPOP reservoir?

Not that I have found out, supposedly that is what the melling lpop is about. More volume / less pressure.

It has always been my theory if the riffraff spacer would aide in this issue.

 

[cjfarm111]

Yeah that extra oil might help? Maybe a set of 205/80’s would be a perfect size for overall performance

 

[KCTurbos]

Yeah that extra oil might help? Maybe a set of 205/80’s would be a perfect size for overall performance

I theorize the larger nozzle will bring the power on a little later and not run as cool... but we shall see.

 

[Garbage_Mechanic]

What an incredible concept! Back to back testing in real world environment backed up by back to back dyno runs. Keep it up man!
I can’t wait to see what my 160/30’s will do when I get it together!
It did 460 / 1000 on Swamps engine dyno when they broke it in. Much the same set up as this with a few effeceintcy mods such as ported heads.

 

[psduser1]

I theorize the larger nozzle will bring the power on a little later and not run as cool... but we shall see.

I think you will find the opposite to be true, with appropriate tuning tweaks, obviously.
And assuming you can maintain icp.

Look at the power curve from a stock injector compared to a 30% nozzle.
Assuming, like I said, there is big enough equiptment supporting it. Sounds like the turbo end is handled.

 

[superpsd]

Most see cooler Egts running a larger nozzle in real world environments. Also there is a difference in the manufacturing process for the 80% versus 100% nozzles. I can greatly vary how the power comes on/egts alone with only adjusting timing. The 20 hp loss couldn't also be the power taken to drive the hpop at higher discharge pressures.

 

[cjfarm111]

Good info. Can’t wait to see the results of the 238/80’s

 

[DZL JIM]

Most see cooler Egts running a larger nozzle in real world environments.

I disagree. For the majority of people anyway. You need extensive live tuning sessions to get the egt's under control with the 80% over nozzles and larger when towing, vs just going with a set of 30%. Seen by myself, dozens (hundreds?) of customers, and every tuning pro I have talked to about this.

In theory the larger nozzle is a great idea for controlling the temps when towing. But in the real word, when 95% of tunes purchased are just loaded to a chip and sent to the customer, it just isn't so.

 

[superpsd]

Tuning is the hard part. A smaller nozzle is more forgiving to so so tuning. I can reduce EGTs and power curve on my 7.3 by just adjusting timing and leaving all else in a tune alone. I still want to see tests done side by side apple for apple. Same truck same tuner same turbo same say 100% nozzles first on an 225cc A code then a 200cc hybrid. A larger nozzle works better on a hybrid then a A code that has been covered time and time again. The hybrid moves more fuel in X amount of time on the benches. This would indicate the hybrid will have a higher pressure at the nozzle. And there have been thread after thread of egt problems with larger A codes with larger nozzles where the owner swapped for hybrids and the egt problem was gone. Still no one has put a few combonations under a high speed camera to watch how the spray pattern actually looks under different pressures. That would be interesting.

 

[cjfarm111]

I always thought hybrids had lower injection pressures

 

[The Brad]

I always thought hybrids had lower injection pressures

You would think, but the fact that they move more fuel per time proves otherwise. I’m guessing it might have something to due with flow restriction on the oil side maybe.

 

[cjfarm111]

So what do most daily or tow tunes call for for icp at wot? 3,000?

 

[Zeb]

I always thought hybrids had lower injection pressures

If you look strictly at the intensifier/plunger ratio hybrids do have a lower nozzle pressure, but there are several things that factor in.

Fuel in time as The Brad mentioned.

You can only get the intensifier to move so fast so therefore you can only get the plunger to travel so fast. If you have too large a nozzle, pressure can actually drop at the nozzle because the orifice can unload fuel faster than the plunger can travel down to keep pressure on it. When that happens, actual nozzle pressure tanks, smoke and egt increase, and power starts to drop.
Properly sized, and up to a certain point, conventionals can have more nozzle pressure, and make a little more power per cc than a hybrid.
But, a hybrid can move a greater quantity of fuel per the same amount of plunger travel, so even tho it has a slightly lower (calculated) pressure, there is a more consistent pressure at the nozzle, and a greater quantity of fuel available in the same injection window, so therefore often a cleaner burn, less smoke and egt issues, and more power.