Lets talk big injectors

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
initially i was planning on going 60% over injectors but after talking with a few well known shop owners, im really leaning toward something in the 100% or more range.

The problem is, i use this truck as a truck and hate haze. How are guys doing with the tuning on injectors that big? i know things have progress farther than they were a few years ago so here is what im after

injector that wont be too large that my small tune is over 600rwhp, still can tune in mpg there and wont be hazey/smokey.

for the next tunes up from there, i dont really care how the haze or smoke acts but the truck will be on that 600hp tune 90% of the time.

the reason im looking at such large injectors is how much better then work when i use them that 10% of the time. am i swaying myself too far from reality here? Truck made 800hp on 45% over lb7 injectors and s480 over modded stock. eventually id like to the 68 stg2r in place of the stock turbo and already have the s483 with tct wheel and race cover on the truck. im looking for the 4 digit power numbers :angel:
 

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
I am running 100 overs in my LLY with a Danville 72R and TCT483. I have never dynoed my lower tunes but tune 1 and 2 are super clean and I would guess they are both over 500hp. I don't tow heavy but the few times I was hooked to a trailer I had no issue with EGTs and actually tried to get it hot with no luck. All this is based on Mark's basic email tunes with very few changes and little to no logging. Since you seem to have unlimited access to live tuning I wouldn't hesitate to run a set of 100s.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,750
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Phoenix Az
I am running 100 overs in my LLY with a Danville 72R and TCT483. I have never dynoed my lower tunes but tune 1 and 2 are super clean and I would guess they are both over 500hp. I don't tow heavy but the few times I was hooked to a trailer I had no issue with EGTs and actually tried to get it hot with no luck. All this is based on Mark's basic email tunes with very few changes and little to no logging. Since you seem to have unlimited access to live tuning I wouldn't hesitate to run a set of 100s.

thanks Steve. any idea on mpg on your low tunes? i know, seems retarded when we are pushing for more power but i like to keep some decent mileage if possible
 

Harbin_22

Active member
Dec 4, 2010
3,858
7
38
Southern Indiana
I know it's not an LB7, but my truck has only gotten smokier Everytime I want bigger. My 40% were very clean, almost had to try to make smoke. Had two different 60% and both were definitely smokier when under boost than the 40% but cleanrs up pretty quick. I've had 100% and 120%. They were quite a bit smokier than the 60% and alot worst than the 40%. Towing my 4k boat with cruise control was a smokey mess in 6th gear and honestly had to "drive" the truck to keep it clean. Aggressive starts were going to put out alot of smoke and was rather embarrassing until the turbos were up and running. No I have 200% and they are a chore to keep clean normal driving. They aren't blacking the road out Everytime you touch the throttle but will leave a nice trail behind you lol.

My 60% with a healthy us made mid 900's on Danville's dyno and backed up the numbers on the track. I think LB7's flow more so that might be your best bet. I have never been in or around a truck with 100%+ that were actually clean running.
 

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
thanks Steve. any idea on mpg on your low tunes? i know, seems retarded when we are pushing for more power but i like to keep some decent mileage if possible

I usually drive the truck on tune 3 or 4 and haven;t really seen a huge drop in mileage. I am not "tracking" it but just based on how often I am at the fuel pump I don't think it has dropped off much from when I was running the 60 overs.

I know it's not an LB7, but my truck has only gotten smokier Everytime I want bigger. My 40% were very clean, almost had to try to make smoke. Had two different 60% and both were definitely smokier when under boost than the 40% but cleanrs up pretty quick. I've had 100% and 120%. They were quite a bit smokier than the 60% and alot worst than the 40%. Towing my 4k boat with cruise control was a smokey mess in 6th gear and honestly had to "drive" the truck to keep it clean. Aggressive starts were going to put out alot of smoke and was rather embarrassing until the turbos were up and running. No I have 200% and they are a chore to keep clean normal driving. They aren't blacking the road out Everytime you touch the throttle but will leave a nice trail behind you lol.

My 60% with a healthy us made mid 900's on Danville's dyno and backed up the numbers on the track. I think LB7's flow more so that might be your best bet. I have never been in or around a truck with 100%+ that were actually clean running.

I agree that the bigger sticks definitely take a bit more effort to keep clean on the big tunes but I haven't had any issues with smoke on my bottom 2 tunes. That being said on tune 4 and 5 the 60s would leave a little haze but the 100s will definitely leave a cloud if you aren't paying attention. LB7 injectors also seem to flow more than the newer models so maybe an 80 over LB7 would be closer to a 100 over LLY nozzle?
 

N2BRK

Well-known member
Dec 31, 2009
2,060
392
83
I have 40 overs and daily on my 575hp tune. Idle is good but she's dirty. Any time that I give her throttle, there's a puff. If I stab the pedal it gets cloudy out back in a hurry. I had family following me on the highway and commented about what's wrong with my truck that it keeps puffing smoke. It's not what I want, but it's a trade off for the performance. I try to plan my driving so as not to stuff it right in someone's face. With 100overs it would be worse; Towyouforfree has the same setup as me but with 100overs and his is much worse and even hazes at idle on a sunny day. I'd think long and hard about 100 overs, based on your post. I'd think a big assed pump and some 40 overs would be more streetable. I'm over 600 on a 2400us tune at 25,500psi with a stock engine and cp3 - so there's a ton left on the table for a guy with a stroker pump and supporting engine mods.
 

gmduramax

Shits broke
Jun 12, 2008
4,081
252
83
Nor cal
I think you'd be happy with 100 overs. You'll probably see haze at night when you're in a drivethru with cars behind you, driving I don't think you'd notice.
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
I know it's not an LB7, but my truck has only gotten smokier Everytime I want bigger. My 40% were very clean, almost had to try to make smoke. Had two different 60% and both were definitely smokier when under boost than the 40% but cleanrs up pretty quick. I've had 100% and 120%. They were quite a bit smokier than the 60% and alot worst than the 40%. Towing my 4k boat with cruise control was a smokey mess in 6th gear and honestly had to "drive" the truck to keep it clean. Aggressive starts were going to put out alot of smoke and was rather embarrassing until the turbos were up and running. No I have 200% and they are a chore to keep clean normal driving. They aren't blacking the road out Everytime you touch the throttle but will leave a nice trail behind you lol.

My 60% with a healthy us made mid 900's on Danville's dyno and backed up the numbers on the track. I think LB7's flow more so that might be your best bet. I have never been in or around a truck with 100%+ that were actually clean running.

I usually drive the truck on tune 3 or 4 and haven;t really seen a huge drop in mileage. I am not "tracking" it but just based on how often I am at the fuel pump I don't think it has dropped off much from when I was running the 60 overs.



I agree that the bigger sticks definitely take a bit more effort to keep clean on the big tunes but I haven't had any issues with smoke on my bottom 2 tunes. That being said on tune 4 and 5 the 60s would leave a little haze but the 100s will definitely leave a cloud if you aren't paying attention. LB7 injectors also seem to flow more than the newer models so maybe an 80 over LB7 would be closer to a 100 over LLY nozzle?

He has converted to a LLY top end guys.
 

Ne-max

I like turtles
Nov 15, 2011
3,361
64
48
Lincoln, Ne
With my set up we bumped up rail a little more to clean them up at idle. Many guys say go big so less pulse. But like you said. They seem more smokey compared to smaller sticks with higher pulse.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,750
5,920
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Phoenix Az
I know it's not an LB7, but my truck has only gotten smokier Everytime I want bigger. My 40% were very clean, almost had to try to make smoke. Had two different 60% and both were definitely smokier when under boost than the 40% but cleanrs up pretty quick. I've had 100% and 120%. They were quite a bit smokier than the 60% and alot worst than the 40%. Towing my 4k boat with cruise control was a smokey mess in 6th gear and honestly had to "drive" the truck to keep it clean. Aggressive starts were going to put out alot of smoke and was rather embarrassing until the turbos were up and running. No I have 200% and they are a chore to keep clean normal driving. They aren't blacking the road out Everytime you touch the throttle but will leave a nice trail behind you lol.

My 60% with a healthy us made mid 900's on Danville's dyno and backed up the numbers on the track. I think LB7's flow more so that might be your best bet. I have never been in or around a truck with 100%+ that were actually clean running.

Well my truck has a whole LLY top end so im working with LLY injectors and LLY ECM. thats why i get to run the 68 stg2r :D. right now there are stock sticks in her. do you think your smoke could have been cleaned up with more maf/fuel limiting down low? or was it starting to hinder spool up vs how it spooled on 60s or 40s?

I have 40 overs and daily on my 575hp tune. Idle is good but she's dirty. Any time that I give her throttle, there's a puff. If I stab the pedal it gets cloudy out back in a hurry. I had family following me on the highway and commented about what's wrong with my truck that it keeps puffing smoke. It's not what I want, but it's a trade off for the performance. I try to plan my driving so as not to stuff it right in someone's face. With 100overs it would be worse; Towyouforfree has the same setup as me but with 100overs and his is much worse and even hazes at idle on a sunny day. I'd think long and hard about 100 overs, based on your post. I'd think a big assed pump and some 40 overs would be more streetable. I'm over 600 on a 2400us tune at 25,500psi with a stock engine and cp3 - so there's a ton left on the table for a guy with a stroker pump and supporting engine mods.

my old 45s when i had an LB7 top end made 600hp on 2100uS and 25.5k rail pressure. what im looking at is how the lower pluse width from a big injector can net you more power than a smaller injector and big pulse width.

I think you'd be happy with 100 overs. You'll probably see haze at night when you're in a drivethru with cars behind you, driving I don't think you'd notice.

My 80s are great no haze but still enough fuel for 1k hp no issue and tuned really well

even that slight haze would bug me Anthony. if they couldnt clean up damn near all the way like my 45% overs did without making the truck a total racket from rail pressure, im gunna have to think about it. jake, what kind of pluse width were you running on that dyno run?

MUST be NICE RIGHT!? :rofl: :roflmao:

hey, chata!! its for the greater good! :roflmao:
 

Dozerboy

Well-known member
Jun 23, 2009
4,918
498
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TX of course
Pretty simple IMO. Decide what's the biggest PW you are willing to run on a max effort tune and make your goal of 1K hp. Pick the smallest injectors that will get you there.

I to have a goal of 900-1k hp at some point with good mileage and clean running. Tons of guys say do 100s it will be fine. Then you get a little more into the details and you see the bigger stick ain't for you. I'll probably do 60s or 80s knowing it will hardly ever see the max effort tune.

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Dozerboy

Well-known member
Jun 23, 2009
4,918
498
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TX of course
I swear McRat made 700 with stock lly injectors. Might of been running 3600us though...

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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
Pretty simple IMO. Decide what's the biggest PW you are willing to run on a max effort tune and make your goal of 1K hp. Pick the smallest injectors that will get you there.

I to have a goal of 900-1k hp at some point with good mileage and clean running. Tons of guys say do 100s it will be fine. Then you get a little more into the details and you see the bigger stick ain't for you. I'll probably do 60s or 80s knowing it will hardly ever see the max effort tune.

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id rather do it the other way around like i posted. pick an injector that will keep my power goal of 600 on a DD tune and not have a pulse width that cant be controlled cause its too low. otehr factors like haze and mpg play a part in this as well. the fuel that comes after that will then be more than enough to get me to 1k hp or more even on a small pulse width.

there seems to be a sweet spot in power in injectors from 1100uS to 2500uS max. beyond that you get deminishing returns when you dont have the air to clean it up