swamps 175/146 or 160/30 injectors (what to go with)

Charles · Mar 6, 2013

mandkole said:
I get the faster empty time of larger nozzles.

The improved efficiency (as I think of fuel rate/HP) aspect is no comprende... if you were to watch a spray from a stock nozzle vs a 200,300,400% nozzle, from same injector, wouldnt you would see a definite difference in quality of atomization? How is tuning going to change the spray if you have a finite amount of IP (say 21K)? Are you saying that you'd need to tune higher/faster ICP ramps to keep the big nozz from pissing? I suspect you would, so why on a small injector setup is a big nozzle so desirable? The last thing I want is the exhaust hazing at idle...

With a bigger nozzle you have to keep the duration in check, else burn down the world. A small nozzle will mask a LOT of sh*t ass tuning. As well as a LOT of injector issues. When the injection rate can jump up quickly, then small changes become big effects.

With a larger nozzle you will need less pw for a given power. Or... put in terms that people don't normally talk about, but in a way my brain thinks about it... the pw to ICP ratio needs to be toned down. The RATIO... of icp to a given pulsewidth must be increased for a large nozzle to behave, and be crisp.

It's not that the bigger nozzle needs more icp.... it just needs more icp per ms of pw, or less pw per psi of icp. It moves the fuel much easier, so you need to use less duration to make things happen.

A 200+% nozzle can shoot a truck down the road sideways at 1.5ms of pulsewidth.

If idle hazing is simply unacceptable, then your priorities are not in line with high power output, and intake, exhaust and a chip might be best. Or just bone stock.

mandkole · Mar 6, 2013

Ok-- stronger, shorter shots.

Going back a couple years, didnt you used to run large injectors on stock nozzles, and if I recall, made a lot of power? I also recall you saying that you never had all that fuel available because you couldnt get it out in time.

This is all good-- Ive often considered a 100%er, but youre saying that 200% is better (but with haze).

Blowby · Mar 6, 2013

Haze can be tuned out of 400's, even at altitude. 200's should not be easier like Charles pointed out. I'll post a video if that helps prove the point.

Tom S · Mar 6, 2013

Blowby said:
Haze can be tuned out of 400's, even at altitude. 200's should not be easier like Charles pointed out. I'll post a video if that helps prove the point.

How tricky is that to get right as I have certainly see the trucks that do haze? I am at times tempted to try smaller injectors with nozzles but am not sure I would be happy in the end.

Blowby · Mar 6, 2013

Blowby said:
Haze can be tuned out of 400's, even at altitude. 200's should not be easier like Charles pointed out. I'll post a video if that helps prove the point.

Sorry for the extra word inserted above. "200's should be easier"

DocBar · Mar 6, 2013

Blowby said:
Sorry for the extra word inserted above. "200's should be easier"

Mike, please post all the videos you want to. I need some good, close up pics of your set up. LOL

Charles · Mar 7, 2013

I would rather have a smoother idle and a wisp of blue come by the cab every now and then rather than a little bit harsher idle with less haze.

I haven't put enough effort into it to try and get both. And I probably never will as a little idle smoke when the engine's been sitting just doesn't warrant my attention thus far.

I will say this.... running around at a fixed 20 degrees of timing the truck had less idle haze, and less off-boost smoke. So contrary to what I like... I may have to increase timing at low ICP to combat this. The cruising EGT was only 450 to 500 at 50mph on flat ground yesterday with the high timing. That has to be more fuel efficient, and I highly doubt 20 was "optimum" anyway.

I know the smoke was much worse this morning on cranking with my usual timing table back in place.

I will also say that right now I'm running 400/400's with a 15* OBS pump as a single, and a 38R/GT55 combo, and this truck LEAPS up on boost and blows tires off like nobody's business. Like... immediately upon stabbing the throttle the tires are spinning.

And that pump is only managing 2500 to 2600psi.

The amount of smoke per get the *** down the road right now is astonishing. I can blow the tires off like nobody's business, and actually accelerate to the point where the tires are juuuuust starting to spin in each gear, then look back at about 60mph or so after just leaving from a stop and there will be nearly nothing in the way of smoke back behind me.

On a single OBS 15* pump and a 94mm first stage charger...

With attentive tuning a 400 can be a street dominator. Even so-so tuning like I'm dealing with right now. If you really sat down and nailed down a file, the results really should be awesome in terms of power per amount of smoke, response and temperatures.

mandkole · Mar 7, 2013

Keep Calm and get the *** down the road... got it

Using the 400/400s and the 15*, youre (very quickly) injecting fuel at approx. 13K (2600 x 5) through 4x nozzles. 13K seems like its pissing to me. Im not denying the truck running strong, but its not making sense as it seems like terrible spray. Perhaps its what it takes to make power, but with what I've long thought holds true, this is just not making sense. The spray doesnt matter?

Damn... (as he is thinking about 200s for 160s)

Blowby · Mar 7, 2013

mandkole said:
Ok-- stronger, shorter shots.

Going back a couple years, didnt you used to run large injectors on stock nozzles, and if I recall, made a lot of power? I also recall you saying that you never had all that fuel available because you couldnt get it out in time.

This is all good-- Ive often considered a 100%er, but youre saying that 200% is better (but with haze).

Fuel delivery (haze) is controllable, even with 400% nozzles.

YouTube Video

and one for DocBar

YouTube Video

lincolnlocker · Mar 7, 2013

mandkole said:
Keep Calm and get the *** down the road... got it

Using the 400/400s and the 15*, youre (very quickly) injecting fuel at approx. 13K (2600 x 5) through 4x nozzles. 13K seems like its pissing to me. Im not denying the truck running strong, but its not making sense as it seems like terrible spray. Perhaps its what it takes to make power, but with what I've long thought holds true, this is just not making sense. The spray doesnt matter?

Damn... (as he is thinking about 200s for 160s)

what everyone needs to remember is that charles has a ton of air and can run efficiently with the lower icp. the amount of air going in makes up for the lack of atomization. hence the instant tire fire with such low icp.

Charles, how well would it run with the same tuning without the low pressure turbo in the equation running only the 38r?

live life full throttle

mandkole · Mar 7, 2013

I got ya -- I was thinking the same thing regarding the available air, but the spray still seems to be very low quality. What keeps it from putting the fire out or going out the pipe?

Thanks guys--This is a good thread...

Charles · Mar 7, 2013

mandkole said:
Keep Calm and get the *** down the road... got it

Using the 400/400s and the 15*, youre (very quickly) injecting fuel at approx. 13K (2600 x 5) through 4x nozzles. 13K seems like its pissing to me. Im not denying the truck running strong, but its not making sense as it seems like terrible spray. Perhaps its what it takes to make power, but with what I've long thought holds true, this is just not making sense. The spray doesnt matter?

Damn... (as he is thinking about 200s for 160s)

I don't think the injection pressure is as much lower on the 400's, or as much higher on say a 100% nozzle as you might expect. Or.... based on what I'm driving right now, it must simply not matter.

Charles · Mar 7, 2013

lincolnlocker said:
what everyone needs to remember is that charles has a ton of air and can run efficiently with the lower icp. the amount of air going in makes up for the lack of atomization. hence the instant tire fire with such low icp.

Charles, how well would it run with the same tuning without the low pressure turbo in the equation running only the 38r?

live life full throttle

The 55 is probably making little if any boost when the tires start spinning. There is a definite pull change between that first stage boost gauge sitting on 10 vs 30, but the truck's already spinning down the road before the first stage really gets involved. And the 38R is totally non-intercooled, making things even worse still... yet it still pulls out hard.

On Edit:

The truck would probably run out well totally NA. It wouldn't make any power, but I think you could run around in traffic all day long and zip around just fine.

mandkole · Mar 7, 2013

I was thinking of a hybrid at 5:1. Even though the pressure would be the same behind the nozzle, it just seemed that the more you opened up the holes the more coarse the spray would be.

On Blowby's vids, its certainly smoke free but not sure Id call it a smooth idle (prolly smooth for the setup). Is that what you were talking about Charles?

thanks for the tour Blowby... wow

Charles · Mar 7, 2013

I added 4 degrees of timing at idle and the wisp of idle smoke after sitting still for a while wasn't visible. I'll have to drive around and see if it comes back later.

I added timing up to a MFD of like 30, so maybe this will increase fuel mileage too. Pulling it back out at that point seems to keep the engine happy as power comes up, as opposed to yesterday with the 20 degrees fixed timing all over where it felt rough as power came up, as you would expect.

I know my crusing EGT was down 1 to 200 degrees at higher timing yesterday, but the sound in the cab was obnoxious. Think 700hp, fuel only 12 valve...

lincolnlocker · Mar 7, 2013

Charles said:
The 55 is probably making little if any boost when the tires start spinning. There is a definite pull change between that first stage boost gauge sitting on 10 vs 30, but the truck's already spinning down the road before the first stage really gets involved. And the 38R is totally non-intercooled, making things even worse still... yet it still pulls out hard.

On Edit:

The truck would probably run out well totally NA. It wouldn't make any power, but I think you could run around in traffic all day long and zip around just fine.

ok... even at no boost it still should be feeding the 38r right or wrong? unless the comp wheel in the 55 is not spinning it has some flow into the 38r feeding it and allowing instant spool up? am i seeing this right or am i way off? or do you think that you can take the 55 off and run just the 38r in the stock configuration and it still be as responsive as it is now?

Charles · Mar 7, 2013

lincolnlocker said:
ok... even at no boost it still should be feeding the 38r right or wrong? unless the comp wheel in the 55 is not spinning it has some flow into the 38r feeding it and allowing instant spool up? am i seeing this right or am i way off? or do you think that you can take the 55 off and run just the 38r in the stock configuration and it still be as responsive as it is now?

The 55 isn't doing anything down low like that. It would probably be more responsive without the 55 down low. But the 55 comes in very quick, so I would quickly run out of gas from the 38R alone, especially with no cooler on the 38R.

As I said, the truck would probably run around well NA.

lincolnlocker · Mar 7, 2013

got ya, thank you sir!

Tom S · Mar 7, 2013

Just to generate some more good discussion I had just read this qoute from Dave on another site.

golfer said:
correct.

We've made 548rwhp with our 200/200%, FWIW...on a stock HPOP

so the nozzle can affect the power quite a bit, since it will carry (full) fueling much higher into the rpm...same tq at higher rpm = increase in hp

unless the truck has intentions of spinning more than 3000rpm...a 30% nozzle will have a nice compromise between peak power and low(no) smoke on the lower chip settings.

in our experience...80% & 100% nozzles are just a 'tweener' nozzle...too small to do much good (ie legit 'solid hp')...

so 90% of the injectors we build are either stock nozzle single shots (150s, 175s ~ 340/385rwhp respectively)

30% nozzled hybrids...425-450rwhp with excellent street manners and fuel economy

200% nozzled hybrids...450-650rwhp with stunningly good street manners (on the lower hp tunes)

as rpm increases, it takes an exponentially larger nozzle to really do more work (get more fuel out)...

ie...a "100%" nozzle doesn't really flow twice as fast as a stocker...not even close actually..but the lack of atomization is noticeable..especially for a "400-450hp" street truck.

stock nozzle- most fuel efficient 375+/-hp
30%- very fuel efficient 430+/- hp
200%- not bad on economy...up to 650-700rwhp max
400% nozzle- not so good on the fuel...but 1000+rwhp capable

I daily drive 400% nozzles...and have been for almost a year (did it to try to get 'daily' tunes as clean as possible)...lost about 2mpg but managed to get them nearly crystal clean..but they can still haze with 'good' tuning and wrong gear/too much pedal. Since the tuning is optimized (best *I* could do)...I'm dropping back to 200%'s.

just my take