LLY: Just wondering info on injectors.

bunkerkid06

8327487855
Feb 26, 2013
31
0
0
33
Twentynine palms California
So I always see these post on injectors and nozzles... My question is, what do the nozzles do? Like if you were to buy injectors that are let's say 50 over, do you have to buy nozzles that are 50 over also or do they come with them? Or are the nozzles just to rebuild your stock injector to a 50 over? Little confused,
Cut me some slack though lol, I'm still learning about this wonderful world of duramax
 

DaJokr

Slum Lord Extraordinaire
Mar 7, 2013
450
0
16
Prince George, BC, Canada
I believe it's just the nozzles though the injector itself may need calibrating after replacing nozzles. I believe they just make the holes slightly bigger to let more fuel through in a shorter time.

Example. 1 small hole in the bottom of a beer can takes 60 seconds to empty can. Crack the can open though and it takes like 5 seconds.

Larger holes means smaller pulse width which means better injector life and/or....more powa!!
 

mtl_dmax

New member
Dec 7, 2010
114
0
0
Eastern Canada
So I always see these post on injectors and nozzles... My question is, what do the nozzles do? Like if you were to buy injectors that are let's say 50 over, do you have to buy nozzles that are 50 over also or do they come with them? Or are the nozzles just to rebuild your stock injector to a 50 over? Little confused,
Cut me some slack though lol, I'm still learning about this wonderful world of duramax


As mentioned above the idea is to make the fuel flow holes on the injector larger thereby when the injector is open for the same amount of time as a stock injector it will flow more fuel. The 50 over number doesn't mean much unless you can equate it to an actual flow rate vs stock injectors (thus you can adjust for the additional flow in your tuning). Also you'll want the injectors to be well matched (since the LLY can't adjust in the ECM for differences in flow rates from one injector to another). Given all this is why it's usually best to go with oversize injectors from a known company like Exergy (quality oversize injectors to come with flow sheets) instead of just grabbing whatever looks pretty off eBay.
 

bunkerkid06

8327487855
Feb 26, 2013
31
0
0
33
Twentynine palms California
Ok so let's say I have perfect flow rates which would be 0 correct? Or let's just say my flow rates are all the same on my stock injectors, and they flow nice, I could I get away with buying nozzles to bump my stock injectors to let's say a 50 over just with nozzles or is there more to it? I want to go quality, but at the same time cans afford to drop 3G on a set of injectors, I'm willing to take the time to learn how to do all this. Just won't have the funds to drop 3k into a set. So would I be able to get away with just buying nozzles that are oversized and rebuilding the stock injector with that nozzle or is that not how it works.
 

Dirtymaxx03

Active member
Aug 4, 2009
3,109
1
38
You certainly can just have your existing injectors (nozzles) modified. If they are in good shape you can send them to exergy and have them modified to your liking. They will punch out your nozzles and flow balance the injectors. Won't cost anywhere near $3k lol
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
All duramax engines compensate for differences in each cylinder, hence the reason you can look at "balance rates". Balance rates is the engine ecm checking the strength of each cylinder and adjusting fuel delivery to compensate for weaker/stronger cylinders.

The injector calibration code is something that can be installed in later engines LBZ and up IIRC. It is calibration code that each injector has on it for measuring the resistance in the coil pack only I believe. They measure a flow rate as well but I don't think so. Anywho each coil will have a slightly different resistance and the calibration code tells the ecm what each injector has for resistance. It is an emissions thing as the code won't affect the driveability but may burn a little less clean.

Now to your original question. Don't do Injectors..... Yet. Get your trans built. Stock injectors can make over 800 horsepower. Granted the pulse is huge and your chasing the piston up and down the hole but it can be done. The owner of this site did it.

Clear as mud?